From patchwork Mon Jan 11 22:51:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011829 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F756C433E6 for ; Tue, 12 Jan 2021 00:30:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8FFE22D5B for ; Tue, 12 Jan 2021 00:30:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729969AbhALAZ4 (ORCPT ); Mon, 11 Jan 2021 19:25:56 -0500 Received: from mga17.intel.com ([192.55.52.151]:11217 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390784AbhAKWwL (ORCPT ); Mon, 11 Jan 2021 17:52:11 -0500 IronPort-SDR: mteFqK2adw5DDWHEVDaTyTg25YPCoh/cHtydNs6Fi1okviNqW5WKVe1bdVGUOLuaQT3L6eckJ1 JjROMKiBgGtw== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726528" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726528" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:29 -0800 IronPort-SDR: uTBBEhhmSLxLFQjal18IP880OYmMe3m1/FkDWbicM7mn24Bg5Ws/jIhIbhdm17N83GifCnxLzF ABFNGsGA//qw== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352777928" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:28 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 01/16] docs: cxl: Add basic documentation Date: Mon, 11 Jan 2021 14:51:05 -0800 Message-Id: <20210111225121.820014-2-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This starts a new cxl directory because CXL is a new bus and it is expected that the documentation will grow large over time. Currently only memory devices are documented as they are all that's supported. Signed-off-by: Ben Widawsky --- Documentation/cxl/index.rst | 12 ++++++++++++ Documentation/cxl/memory-devices.rst | 15 +++++++++++++++ Documentation/index.rst | 1 + 3 files changed, 28 insertions(+) create mode 100644 Documentation/cxl/index.rst create mode 100644 Documentation/cxl/memory-devices.rst diff --git a/Documentation/cxl/index.rst b/Documentation/cxl/index.rst new file mode 100644 index 000000000000..036e49553542 --- /dev/null +++ b/Documentation/cxl/index.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================== +Compute Express Link +==================== + +.. toctree:: + :maxdepth: 1 + + memory-devices + +.. only:: subproject and html diff --git a/Documentation/cxl/memory-devices.rst b/Documentation/cxl/memory-devices.rst new file mode 100644 index 000000000000..aa4262280c67 --- /dev/null +++ b/Documentation/cxl/memory-devices.rst @@ -0,0 +1,15 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: + +=================================== +Compute Express Link Memory Devices +=================================== + +A Compute Express Link Memory Device is a CXL component that implements the +CXL.mem protocol. It contains some amount of volatile memory, persistent memory, +or both. + +Driver Infrastructure +===================== + +This sections covers the driver infrastructure for a CXL memory device. diff --git a/Documentation/index.rst b/Documentation/index.rst index 5888e8a7272f..7e5ab77264e9 100644 --- a/Documentation/index.rst +++ b/Documentation/index.rst @@ -137,6 +137,7 @@ needed). misc-devices/index scheduler/index mhi/index + cxl/index Architecture-agnostic documentation ----------------------------------- From patchwork Mon Jan 11 22:51:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011825 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7E0EC43381 for ; Tue, 12 Jan 2021 00:30:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9690B22D58 for ; Tue, 12 Jan 2021 00:30:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390784AbhALAZ5 (ORCPT ); Mon, 11 Jan 2021 19:25:57 -0500 Received: from mga17.intel.com ([192.55.52.151]:11219 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390790AbhAKWwN (ORCPT ); Mon, 11 Jan 2021 17:52:13 -0500 IronPort-SDR: wTw/r0bGTW4OjjrmJ6+ph5Mt71e/dUminedkXjYKYVApLggmaFRPxlOtwRQDxxLbSzcLj1rOy4 S66DgqcehrhA== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726529" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726529" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:30 -0800 IronPort-SDR: tHVUczitJ4wt2XrEAOkdexAIUVj31KmL8ogpd03o4wpDzyZAAbQzTGYPa6LPSc8mZ7VG6DvEwS LK8Qc66kTN/A== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352777933" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:29 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Vishal Verma , Ben Widawsky , Dan Williams , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 02/16] cxl/acpi: Add an acpi_cxl module for the CXL interconnect Date: Mon, 11 Jan 2021 14:51:06 -0800 Message-Id: <20210111225121.820014-3-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Vishal Verma Add an acpi_cxl module to coordinate the ACPI portions of the CXL (Compute eXpress Link) interconnect. This driver binds to ACPI0017 objects in the ACPI tree, and coordinates access to the resources provided by the ACPI CEDT (CXL Early Discovery Table). It also coordinates operations of the root port _OSC object to notify platform firmware that the OS has native support for the CXL capabilities of endpoints. Note: the actbl1.h changes are speculative. The expectation is that they will arrive through the ACPICA tree in due time. Cc: Ben Widawsky Cc: Dan Williams Signed-off-by: Vishal Verma Signed-off-by: Ben Widawsky --- drivers/Kconfig | 1 + drivers/Makefile | 1 + drivers/cxl/Kconfig | 36 ++++++++++++++++ drivers/cxl/Makefile | 5 +++ drivers/cxl/acpi.c | 97 +++++++++++++++++++++++++++++++++++++++++++ drivers/cxl/acpi.h | 15 +++++++ include/acpi/actbl1.h | 50 ++++++++++++++++++++++ 7 files changed, 205 insertions(+) create mode 100644 drivers/cxl/Kconfig create mode 100644 drivers/cxl/Makefile create mode 100644 drivers/cxl/acpi.c create mode 100644 drivers/cxl/acpi.h diff --git a/drivers/Kconfig b/drivers/Kconfig index dcecc9f6e33f..62c753a73651 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -6,6 +6,7 @@ menu "Device Drivers" source "drivers/amba/Kconfig" source "drivers/eisa/Kconfig" source "drivers/pci/Kconfig" +source "drivers/cxl/Kconfig" source "drivers/pcmcia/Kconfig" source "drivers/rapidio/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index fd11b9ac4cc3..678ea810410f 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -73,6 +73,7 @@ obj-$(CONFIG_NVM) += lightnvm/ obj-y += base/ block/ misc/ mfd/ nfc/ obj-$(CONFIG_LIBNVDIMM) += nvdimm/ obj-$(CONFIG_DAX) += dax/ +obj-$(CONFIG_CXL_BUS) += cxl/ obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/ obj-$(CONFIG_NUBUS) += nubus/ obj-y += macintosh/ diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig new file mode 100644 index 000000000000..68da926ba5b1 --- /dev/null +++ b/drivers/cxl/Kconfig @@ -0,0 +1,36 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig CXL_BUS + tristate "CXL (Compute Express Link) Devices Support" + help + CXL is a bus that is electrically compatible with PCI-E, but layers + three protocols on that signalling (CXL.io, CXL.cache, and CXL.mem). + The CXL.cache protocol allows devices to hold cachelines locally, the + CXL.mem protocol allows devices to be fully coherent memory targets, + the CXL.io protocol is equivalent to PCI-E. Say 'y' to enable support + for the configuration and management of devices supporting these + protocols. + +if CXL_BUS + +config CXL_BUS_PROVIDER + tristate + +config CXL_ACPI + tristate "CXL ACPI: Platform Support" + depends on ACPI + default CXL_BUS + select CXL_BUS_PROVIDER + help + Say 'y/m' to enable a driver (named "cxl_acpi.ko" when built + as a module) that will enable support for CXL.mem endpoint + devices. In general, CXL Platform Support is a prerequisite + for any CXL device driver that wants to claim ownership of a + component register space. By default platform firmware assumes + Linux is unaware of CXL capabilities and requires explicit + opt-in. This platform component also mediates resources + described by the CEDT (CXL Early Discovery Table). See + Chapter 9.14.1 CXL Early Discovery Table (CEDT) in the CXL 2.0 + specification. + + If unsure say 'm' +endif diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile new file mode 100644 index 000000000000..d38cd34a2582 --- /dev/null +++ b/drivers/cxl/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o + +ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL +cxl_acpi-y := acpi.o diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c new file mode 100644 index 000000000000..0f1ba9b3f1ed --- /dev/null +++ b/drivers/cxl/acpi.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "acpi.h" + +/* + * If/when CXL support is defined by other platform firmware the kernel + * will need a mechanism to select between the platform specific version + * of this routine, until then, hard-code ACPI assumptions + */ +int cxl_bus_acquire(struct pci_dev *pdev) +{ + struct acpi_device *adev; + struct pci_dev *root_port; + struct device *root; + + root_port = pcie_find_root_port(pdev); + if (!root_port) + return -ENXIO; + + root = root_port->dev.parent; + if (!root) + return -ENXIO; + + adev = ACPI_COMPANION(root); + if (!adev) + return -ENXIO; + + /* TODO: OSC enabling */ + + return 0; +} +EXPORT_SYMBOL_GPL(cxl_bus_acquire); + +static void acpi_cedt_put_table(void *table) +{ + acpi_put_table(table); +} + +static int cxl_acpi_probe(struct platform_device *pdev) +{ + struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); + struct cxl_acpi_desc *acpi_desc; + struct device *dev = &adev->dev; + struct acpi_table_header *tbl; + acpi_status status; + acpi_size sz; + int rc; + + status = acpi_get_table(ACPI_SIG_CEDT, 0, &tbl); + if (ACPI_FAILURE(status)) { + dev_err(dev, "failed to find CEDT at startup\n"); + return 0; + } + + rc = devm_add_action_or_reset(dev, acpi_cedt_put_table, tbl); + if (rc) + return rc; + + sz = tbl->length; + dev_info(dev, "found CEDT at startup: %lld bytes\n", sz); + + acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL); + if (!acpi_desc) + return -ENOMEM; + + dev_set_drvdata(&adev->dev, acpi_desc); + acpi_desc->dev = &adev->dev; + acpi_desc->acpi_header = *tbl; + + return 0; +} + +static const struct acpi_device_id cxl_acpi_ids[] = { + { "ACPI0017", 0 }, + { "", 0 }, +}; +MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids); + +static struct platform_driver cxl_acpi_driver = { + .probe = cxl_acpi_probe, + .driver = { + .name = KBUILD_MODNAME, + .acpi_match_table = cxl_acpi_ids, + }, +}; + +module_platform_driver(cxl_acpi_driver); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/cxl/acpi.h b/drivers/cxl/acpi.h new file mode 100644 index 000000000000..d638f8886ab7 --- /dev/null +++ b/drivers/cxl/acpi.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ + +#ifndef __CXL_ACPI_H__ +#define __CXL_ACPI_H__ +#include + +struct cxl_acpi_desc { + struct acpi_table_header acpi_header; + struct device *dev; +}; + +int cxl_bus_acquire(struct pci_dev *pci_dev); + +#endif /* __CXL_ACPI_H__ */ diff --git a/include/acpi/actbl1.h b/include/acpi/actbl1.h index 43549547ed3e..f3a0303984c8 100644 --- a/include/acpi/actbl1.h +++ b/include/acpi/actbl1.h @@ -28,6 +28,7 @@ #define ACPI_SIG_BERT "BERT" /* Boot Error Record Table */ #define ACPI_SIG_BGRT "BGRT" /* Boot Graphics Resource Table */ #define ACPI_SIG_BOOT "BOOT" /* Simple Boot Flag Table */ +#define ACPI_SIG_CEDT "CEDT" /* CXL Early Discovery Table */ #define ACPI_SIG_CPEP "CPEP" /* Corrected Platform Error Polling table */ #define ACPI_SIG_CSRT "CSRT" /* Core System Resource Table */ #define ACPI_SIG_DBG2 "DBG2" /* Debug Port table type 2 */ @@ -1624,6 +1625,55 @@ struct acpi_ibft_target { u16 reverse_chap_secret_offset; }; +/******************************************************************************* + * + * CEDT - CXL Early Discovery Table (ACPI 6.4) + * Version 1 + * + ******************************************************************************/ + +struct acpi_table_cedt { + struct acpi_table_header header; /* Common ACPI table header */ + u32 reserved; +}; + +/* Values for CEDT structure types */ + +enum acpi_cedt_type { + ACPI_CEDT_TYPE_HOST_BRIDGE = 0, /* CHBS - CXL Host Bridge Structure */ +}; + +struct acpi_cedt_structure { + u8 type; + u8 reserved; + u16 length; +}; + +/* + * CEDT Structures, correspond to Type in struct acpi_cedt_structure + */ + +/* 0: CXL Host Bridge Structure */ + +struct acpi_cedt_chbs { + struct acpi_cedt_structure header; + u32 uid; + u32 version; + u32 reserved1; + u64 base; + u64 length; +}; + +/* Values for version field above */ + +#define ACPI_CEDT_CHBS_VERSION_CXL11 (0) +#define ACPI_CEDT_CHBS_VERSION_CXL20 (1) + +/* Values for length field above */ + +#define ACPI_CEDT_CHBS_LENGTH_CXL11 (0x2000) +#define ACPI_CEDT_CHBS_LENGTH_CXL20 (0x10000) + /* Reset to default packing */ #pragma pack() From patchwork Mon Jan 11 22:51:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011827 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28E04C433E9 for ; Tue, 12 Jan 2021 00:30:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06BCA22D6E for ; Tue, 12 Jan 2021 00:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391789AbhALAZ5 (ORCPT ); Mon, 11 Jan 2021 19:25:57 -0500 Received: from mga17.intel.com ([192.55.52.151]:11211 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390792AbhAKWwZ (ORCPT ); Mon, 11 Jan 2021 17:52:25 -0500 IronPort-SDR: 2k4tSKq5JUQImTdMjWHRWo0M6kWXHXFz0eUZ5VRFnCfTG3OTEPQRqwntpfyvvw1pfVoA+1xdud TTq3lfoA9owQ== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726530" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726530" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:31 -0800 IronPort-SDR: t7Ycay7vGglJDba2P/49q7vxpm3h/0RQiQLIx/PukJxhRCp9sZWhmZKhnUkqhcj0k3roLNBI5k a4ZP9PKevETg== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352777938" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:30 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Vishal Verma , Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 03/16] cxl/acpi: add OSC support Date: Mon, 11 Jan 2021 14:51:07 -0800 Message-Id: <20210111225121.820014-4-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Vishal Verma Add support to advertise OS capabilities, and request OS control for CXL features using the ACPI _OSC mechanism. Advertise support for all possible CXL features, and attempt to request control for all possible features. Based on a patch by Sean Kelley. Signed-off-by: Vishal Verma Signed-off-by: Ben Widawsky --- Documentation/cxl/memory-devices.rst | 15 ++ drivers/cxl/acpi.c | 260 ++++++++++++++++++++++++++- drivers/cxl/acpi.h | 20 +++ 3 files changed, 292 insertions(+), 3 deletions(-) diff --git a/Documentation/cxl/memory-devices.rst b/Documentation/cxl/memory-devices.rst index aa4262280c67..6ce88f9d5f4f 100644 --- a/Documentation/cxl/memory-devices.rst +++ b/Documentation/cxl/memory-devices.rst @@ -13,3 +13,18 @@ Driver Infrastructure ===================== This sections covers the driver infrastructure for a CXL memory device. + +ACPI CXL +-------- + +.. kernel-doc:: drivers/cxl/acpi.c + :doc: cxl acpi + +.. kernel-doc:: drivers/cxl/acpi.c + :internal: + +External Interfaces +=================== + +.. kernel-doc:: drivers/cxl/acpi.c + :export: diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 0f1ba9b3f1ed..af9c0dfdee20 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -11,7 +11,258 @@ #include #include "acpi.h" -/* +/** + * DOC: cxl acpi + * + * ACPI _OSC setup: The exported function cxl_bus_acquire() sets up ACPI + * Operating System Capabilities (_OSC) for the CXL bus. It declares support + * for all CXL capabilities, and attempts to request control for all possible + * capabilities. The resulting support and control sets are saved in global + * variables cxl_osc_support_set and cxl_osc_control_set. The internal + * functions cxl_osc_declare_support(), and cxl_osc_request_control() can be + * used to update the support and control sets in accordance with the ACPI + * rules for _OSC evaluation - most importantly, capabilities already granted + * should not be rescinded by either the OS or firmware. + */ + +static u32 cxl_osc_support_set; +static u32 cxl_osc_control_set; +static DEFINE_MUTEX(acpi_desc_lock); + +struct pci_osc_bit_struct { + u32 bit; + char *desc; +}; + +static struct pci_osc_bit_struct cxl_osc_support_bit[] = { + { CXL_OSC_PORT_REG_ACCESS_SUPPORT, "CXLPortRegAccess" }, + { CXL_OSC_PORT_DEV_REG_ACCESS_SUPPORT, "CXLPortDevRegAccess" }, + { CXL_OSC_PER_SUPPORT, "CXLProtocolErrorReporting" }, + { CXL_OSC_NATIVE_HP_SUPPORT, "CXLNativeHotPlug" }, +}; + +static struct pci_osc_bit_struct cxl_osc_control_bit[] = { + { CXL_OSC_MEM_ERROR_CONTROL, "CXLMemErrorReporting" }, +}; + +static u8 cxl_osc_uuid_str[] = "68F2D50B-C469-4d8A-BD3D-941A103FD3FC"; + +static void decode_osc_bits(struct device *dev, char *msg, u32 word, + struct pci_osc_bit_struct *table, int size) +{ + char buf[80]; + int i, len = 0; + struct pci_osc_bit_struct *entry; + + buf[0] = '\0'; + for (i = 0, entry = table; i < size; i++, entry++) + if (word & entry->bit) + len += scnprintf(buf + len, sizeof(buf) - len, "%s%s", + len ? " " : "", entry->desc); + + dev_info(dev, "_OSC: %s [%s]\n", msg, buf); +} + +static void decode_cxl_osc_support(struct device *dev, char *msg, u32 word) +{ + decode_osc_bits(dev, msg, word, cxl_osc_support_bit, + ARRAY_SIZE(cxl_osc_support_bit)); +} + +static void decode_cxl_osc_control(struct device *dev, char *msg, u32 word) +{ + decode_osc_bits(dev, msg, word, cxl_osc_control_bit, + ARRAY_SIZE(cxl_osc_control_bit)); +} + +static acpi_status acpi_cap_run_osc(acpi_handle handle, const u32 *capbuf, + u8 *uuid_str, u32 *retval) +{ + struct acpi_osc_context context = { + .uuid_str = uuid_str, + .rev = 1, + .cap.length = 20, + .cap.pointer = (void *)capbuf, + }; + acpi_status status; + + status = acpi_run_osc(handle, &context); + if (ACPI_SUCCESS(status)) { + /* pointer + offset to DWORD 5 */ + *retval = *((u32 *)(context.ret.pointer + 16)); + kfree(context.ret.pointer); + } + return status; +} + +static acpi_status cxl_query_osc(acpi_handle handle, u32 support, u32 *control) +{ + struct acpi_pci_root *root; + acpi_status status; + u32 result, capbuf[5]; + + root = acpi_pci_find_root(handle); + if (!root) + return -ENXIO; + + support &= CXL_OSC_SUPPORT_VALID_MASK; + support |= cxl_osc_support_set; + + capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE; + capbuf[PCI_OSC_SUPPORT_DWORD] = root->osc_support_set; + capbuf[PCI_OSC_CONTROL_DWORD] = root->osc_control_set; + capbuf[CXL_OSC_SUPPORT_DWORD] = support; + if (control) { + *control &= CXL_OSC_CONTROL_VALID_MASK; + capbuf[CXL_OSC_CONTROL_DWORD] = *control | cxl_osc_control_set; + } else { + /* Run _OSC query only with existing controls. */ + capbuf[CXL_OSC_CONTROL_DWORD] = cxl_osc_control_set; + } + + status = acpi_cap_run_osc(handle, capbuf, cxl_osc_uuid_str, &result); + if (ACPI_SUCCESS(status)) { + cxl_osc_support_set = support; + if (control) + *control = result; + } + return status; +} + +/** + * cxl_osc_declare_support - Declare support for CXL root _OSC features. + * @handle: ACPI device handle for the PCI root bridge (or PCIe Root Complex). + * @flags: The _OSC bits to declare support for. + * + * The PCI specific DWORDS are obtained from the pci root port device, and + * used as-is. The resulting CXL support set is saved in cxl_osc_support_set. + * Any future calls to this are forced to be strictly incremental from the + * existing cxl_osc_support_set. + */ +static acpi_status cxl_osc_declare_support(acpi_handle handle, u32 flags) +{ + acpi_status status; + + mutex_lock(&acpi_desc_lock); + status = cxl_query_osc(handle, flags, NULL); + mutex_unlock(&acpi_desc_lock); + return status; +} + +/** + * cxl_osc_request_control - Request control of CXL root _OSC features. + * @adev: ACPI device for the PCI root bridge (or PCIe Root Complex). + * @mask: Mask of _OSC bits to request control of, place to store control mask. + * @req: Mask of _OSC bits the control of is essential to the caller. + * + * The PCI specific DWORDS are obtained from the pci root port device, and + * used as-is. The resulting CXL control set is saved in cxl_osc_control_set. + * Any future calls to this are forced to be strictly incremental from the + * existing cxl_osc_control_set. + */ +static acpi_status cxl_osc_request_control(struct acpi_device *adev, u32 *mask, + u32 req) +{ + acpi_handle handle = adev->handle; + struct device *dev = &adev->dev; + struct acpi_pci_root *root; + acpi_status status = AE_OK; + u32 ctrl, capbuf[5]; + + if (!mask) + return AE_BAD_PARAMETER; + + ctrl = *mask & CXL_OSC_MEM_ERROR_CONTROL; + if ((ctrl & req) != req) + return AE_TYPE; + + root = acpi_pci_find_root(handle); + if (!root) + return -ENXIO; + + mutex_lock(&acpi_desc_lock); + + *mask = ctrl | cxl_osc_control_set; + /* No need to evaluate _OSC if the control was already granted. */ + if ((cxl_osc_control_set & ctrl) == ctrl) + goto out; + + /* Need to check the available controls bits before requesting them. */ + while (*mask) { + status = cxl_query_osc(handle, cxl_osc_support_set, mask); + if (ACPI_FAILURE(status)) + goto out; + if (ctrl == *mask) + break; + decode_cxl_osc_control(dev, "platform does not support", + ctrl & ~(*mask)); + ctrl = *mask; + } + + if ((ctrl & req) != req) { + decode_cxl_osc_control(dev, + "not requesting control; platform does not support", + req & ~(ctrl)); + status = AE_SUPPORT; + goto out; + } + + capbuf[OSC_QUERY_DWORD] = 0; + capbuf[PCI_OSC_SUPPORT_DWORD] = root->osc_support_set; + capbuf[PCI_OSC_CONTROL_DWORD] = root->osc_control_set; + capbuf[CXL_OSC_SUPPORT_DWORD] = cxl_osc_support_set; + capbuf[CXL_OSC_CONTROL_DWORD] = ctrl; + status = acpi_cap_run_osc(handle, capbuf, cxl_osc_uuid_str, mask); + if (ACPI_SUCCESS(status)) + cxl_osc_control_set = *mask; +out: + mutex_unlock(&acpi_desc_lock); + return status; +} + +static int cxl_negotiate_osc(struct acpi_device *adev) +{ + u32 cxl_support, cxl_control, requested; + acpi_handle handle = adev->handle; + struct device *dev = &adev->dev; + acpi_status status; + + /* Declare support for everything */ + cxl_support = CXL_OSC_SUPPORT_VALID_MASK; + decode_cxl_osc_support(dev, "OS supports", cxl_support); + status = cxl_osc_declare_support(handle, cxl_support); + if (ACPI_FAILURE(status)) { + dev_info(dev, "CXL_OSC failed (%s)\n", + acpi_format_exception(status)); + return -ENXIO; + } + + /* Request control for everything */ + cxl_control = CXL_OSC_CONTROL_VALID_MASK; + requested = cxl_control; + status = cxl_osc_request_control(adev, &cxl_control, + CXL_OSC_MEM_ERROR_CONTROL); + if (ACPI_SUCCESS(status)) { + decode_cxl_osc_control(dev, "OS now controls", cxl_control); + } else { + decode_cxl_osc_control(dev, "OS requested", requested); + decode_cxl_osc_control(dev, "platform willing to grant", + cxl_control); + dev_info(dev, "_OSC failed (%s)\n", + acpi_format_exception(status)); + } + return 0; +} + +/** + * cxl_bus_acquire - Perform platform-specific bus operations + * @pdev: pci_dev associated with the CXL device + * + * This performs bus-specific operations such as ACPI _OSC to ensure that + * the bus is 'prepared'. Since the CXL definition of _OSC depends on the + * existing PCI _OSC DWORDS in 'Arg3', pull those in from the pci root port + * device, and merge those into the new CXL-augmented _OSC calls. + * * If/when CXL support is defined by other platform firmware the kernel * will need a mechanism to select between the platform specific version * of this routine, until then, hard-code ACPI assumptions @@ -21,6 +272,7 @@ int cxl_bus_acquire(struct pci_dev *pdev) struct acpi_device *adev; struct pci_dev *root_port; struct device *root; + int rc; root_port = pcie_find_root_port(pdev); if (!root_port) @@ -34,9 +286,11 @@ int cxl_bus_acquire(struct pci_dev *pdev) if (!adev) return -ENXIO; - /* TODO: OSC enabling */ + rc = cxl_negotiate_osc(adev); + if (rc) + dev_err(&pdev->dev, "Failed to negotiate OSC\n"); - return 0; + return rc; } EXPORT_SYMBOL_GPL(cxl_bus_acquire); diff --git a/drivers/cxl/acpi.h b/drivers/cxl/acpi.h index d638f8886ab7..6ef154021745 100644 --- a/drivers/cxl/acpi.h +++ b/drivers/cxl/acpi.h @@ -12,4 +12,24 @@ struct cxl_acpi_desc { int cxl_bus_acquire(struct pci_dev *pci_dev); +/* Indexes into _OSC Capabilities Buffer */ +#define PCI_OSC_SUPPORT_DWORD 1 /* DWORD 2 */ +#define PCI_OSC_CONTROL_DWORD 2 /* DWORD 3 */ +#define CXL_OSC_SUPPORT_DWORD 3 /* DWORD 4 */ +#define CXL_OSC_CONTROL_DWORD 4 /* DWORD 5 */ + +/* CXL Host Bridge _OSC: Capabilities DWORD 4: Support Field */ +#define CXL_OSC_PORT_REG_ACCESS_SUPPORT 0x00000001 +#define CXL_OSC_PORT_DEV_REG_ACCESS_SUPPORT 0x00000002 +#define CXL_OSC_PER_SUPPORT 0x00000004 +#define CXL_OSC_NATIVE_HP_SUPPORT 0x00000008 +#define CXL_OSC_SUPPORT_VALID_MASK (CXL_OSC_PORT_REG_ACCESS_SUPPORT | \ + CXL_OSC_PORT_DEV_REG_ACCESS_SUPPORT | \ + CXL_OSC_PER_SUPPORT | \ + CXL_OSC_NATIVE_HP_SUPPORT) + +/* CXL Host Bridge _OSC: Capabilities DWORD 5: Control Field */ +#define CXL_OSC_MEM_ERROR_CONTROL 0x00000001 +#define CXL_OSC_CONTROL_VALID_MASK (CXL_OSC_MEM_ERROR_CONTROL) + #endif /* __CXL_ACPI_H__ */ From patchwork Mon Jan 11 22:51:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011823 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68C5BC433E6 for ; Tue, 12 Jan 2021 00:30:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BA2622D57 for ; Tue, 12 Jan 2021 00:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391791AbhALAZ5 (ORCPT ); Mon, 11 Jan 2021 19:25:57 -0500 Received: from mga17.intel.com ([192.55.52.151]:11217 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390793AbhAKWw1 (ORCPT ); Mon, 11 Jan 2021 17:52:27 -0500 IronPort-SDR: e0/zu56RER4gpscXReukuRm81pUWAyYGrDSWkKxUjfYoz05P33ziRei0eJrlhNPCKIvlHoXp1+ MAW2BMZ8DgDw== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726531" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726531" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:32 -0800 IronPort-SDR: u/pYsBqHZwkELUf0+YDhzxQQE1UBrsmog5L/HjntD/YKgNifUJOGVbPmfJ3h4XdDiO/R7juq7M KCyjPH0M+53A== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352777942" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:31 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Dan Williams , Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 04/16] cxl/mem: Introduce a driver for CXL-2.0-Type-3 endpoints Date: Mon, 11 Jan 2021 14:51:08 -0800 Message-Id: <20210111225121.820014-5-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Dan Williams The CXL.mem protocol allows a device to act as a provider of "System RAM" and/or "Persistent Memory" that is fully coherent as if the memory was attached to the typical CPU memory controller. With the CXL-2.0 specification a PCI endpoint can implement a "Type-3" device interface and give the operating system control over "Host Managed Device Memory". See section 2.3 Type 3 CXL Device. The memory range exported by the device may optionally be described by the platform firmware memory map, or by infrastructure like LIBNVDIMM to provision persistent memory capacity from one, or more, CXL.mem devices. A pre-requisite for Linux-managed memory-capacity provisioning is this cxl_mem driver that can speak the mailbox protocol defined in section 8.2.8.4 Mailbox Registers. For now just land the driver boiler-plate and fill it in with functionality in subsequent commits. Link: https://www.computeexpresslink.org/download-the-specification Signed-off-by: Dan Williams Signed-off-by: Ben Widawsky --- Documentation/cxl/memory-devices.rst | 9 ++++ drivers/cxl/Kconfig | 22 +++++++++ drivers/cxl/Makefile | 2 + drivers/cxl/mem.c | 69 ++++++++++++++++++++++++++++ drivers/cxl/pci.h | 20 ++++++++ 5 files changed, 122 insertions(+) create mode 100644 drivers/cxl/mem.c create mode 100644 drivers/cxl/pci.h diff --git a/Documentation/cxl/memory-devices.rst b/Documentation/cxl/memory-devices.rst index 6ce88f9d5f4f..134c9b6b4ff4 100644 --- a/Documentation/cxl/memory-devices.rst +++ b/Documentation/cxl/memory-devices.rst @@ -23,6 +23,15 @@ ACPI CXL .. kernel-doc:: drivers/cxl/acpi.c :internal: +CXL Memory Device +----------------- + +.. kernel-doc:: drivers/cxl/mem.c + :doc: cxl mem + +.. kernel-doc:: drivers/cxl/mem.c + :internal: + External Interfaces =================== diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 68da926ba5b1..0ac5080cd6e0 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -33,4 +33,26 @@ config CXL_ACPI specification. If unsure say 'm' + +config CXL_MEM + tristate "CXL.mem: Endpoint Support" + depends on PCI && CXL_BUS_PROVIDER + default CXL_BUS_PROVIDER + help + The CXL.mem protocol allows a device to act as a provider of + "System RAM" and/or "Persistent Memory" that is fully coherent + as if the memory was attached to the typical CPU memory + controller. + + Say 'y/m' to enable a driver (named "cxl_mem.ko" when built as + a module) that will attach to CXL.mem devices for + configuration, provisioning, and health monitoring. This + driver is required for dynamic provisioning of CXL.mem + attached memory which is a pre-requisite for persistent memory + support. Typically volatile memory is mapped by platform + firmware and included in the platform memory map, but in some + cases the OS is responsible for mapping that memory. See + Chapter 2.3 Type 3 CXL Device in the CXL 2.0 specification. + + If unsure say 'm'. endif diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index d38cd34a2582..97fdffb00f2d 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -1,5 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o +obj-$(CONFIG_CXL_MEM) += cxl_mem.o ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL cxl_acpi-y := acpi.o +cxl_mem-y := mem.o diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c new file mode 100644 index 000000000000..005404888942 --- /dev/null +++ b/drivers/cxl/mem.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +#include +#include +#include +#include "acpi.h" +#include "pci.h" + +static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec) +{ + int pos; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DVSEC); + if (!pos) + return 0; + + while (pos) { + u16 vendor, id; + + pci_read_config_word(pdev, pos + PCI_DVSEC_VENDOR_ID_OFFSET, + &vendor); + pci_read_config_word(pdev, pos + PCI_DVSEC_ID_OFFSET, &id); + if (vendor == PCI_DVSEC_VENDOR_ID_CXL && dvsec == id) + return pos; + + pos = pci_find_next_ext_capability(pdev, pos, + PCI_EXT_CAP_ID_DVSEC); + } + + return 0; +} + +static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct device *dev = &pdev->dev; + int rc, regloc; + + rc = cxl_bus_acquire(pdev); + if (rc != 0) { + dev_err(dev, "failed to acquire interface\n"); + return rc; + } + + regloc = cxl_mem_dvsec(pdev, PCI_DVSEC_ID_CXL_REGLOC); + if (!regloc) { + dev_err(dev, "register location dvsec not found\n"); + return -ENXIO; + } + + return 0; +} + +static const struct pci_device_id cxl_mem_pci_tbl[] = { + /* PCI class code for CXL.mem Type-3 Devices */ + { PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, + PCI_CLASS_MEMORY_CXL, 0xffffff, 0 }, + { /* terminate list */ }, +}; +MODULE_DEVICE_TABLE(pci, cxl_mem_pci_tbl); + +static struct pci_driver cxl_mem_driver = { + .name = KBUILD_MODNAME, + .id_table = cxl_mem_pci_tbl, + .probe = cxl_mem_probe, +}; + +MODULE_LICENSE("GPL v2"); +module_pci_driver(cxl_mem_driver); +MODULE_IMPORT_NS(CXL); diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h new file mode 100644 index 000000000000..a8a9935fa90b --- /dev/null +++ b/drivers/cxl/pci.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +#ifndef __CXL_PCI_H__ +#define __CXL_PCI_H__ + +#define PCI_CLASS_MEMORY_CXL 0x050210 + +/* + * See section 8.1 Configuration Space Registers in the CXL 2.0 + * Specification + */ +#define PCI_EXT_CAP_ID_DVSEC 0x23 +#define PCI_DVSEC_VENDOR_ID_CXL 0x1E98 +#define PCI_DVSEC_VENDOR_ID_OFFSET 0x4 +#define PCI_DVSEC_ID_CXL 0x0 +#define PCI_DVSEC_ID_OFFSET 0x8 + +#define PCI_DVSEC_ID_CXL_REGLOC 0x8 + +#endif /* __CXL_PCI_H__ */ From patchwork Mon Jan 11 22:51:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011821 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE54EC433E9 for ; Tue, 12 Jan 2021 00:30:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97AB722D57 for ; Tue, 12 Jan 2021 00:30:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404061AbhALAZ5 (ORCPT ); Mon, 11 Jan 2021 19:25:57 -0500 Received: from mga17.intel.com ([192.55.52.151]:11219 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390796AbhAKWw3 (ORCPT ); Mon, 11 Jan 2021 17:52:29 -0500 IronPort-SDR: BjR76enYkkHdtGGwFZaQ4yN4+1syhBEBPIs08xAsqPSl66DtLvH2C9+VjdSUG4AHpRhzdM7Is1 zOhhqoCfS53w== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726532" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726532" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:33 -0800 IronPort-SDR: 9351Mj+WafLgjPBvo2EvKHmaYSIsASxmgJjb73e6Hi3G7GoZFAqNqInru2qYbqX0FnJ33JJ4kt Ywz8KGpHyvng== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352777983" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:32 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 05/16] cxl/mem: Map memory device registers Date: Mon, 11 Jan 2021 14:51:09 -0800 Message-Id: <20210111225121.820014-6-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org All the necessary bits are initialized in order to find and map the register space for CXL Memory Devices. This is accomplished by using the Register Locator DVSEC (CXL 2.0 - 8.1.9.1) to determine which PCI BAR to use, and how much of an offset from that BAR should be added. If the memory device registers are found and mapped a new internal data structure tracking device state is allocated. Signed-off-by: Ben Widawsky --- drivers/cxl/cxl.h | 17 ++++++++ drivers/cxl/mem.c | 100 +++++++++++++++++++++++++++++++++++++++++++++- drivers/cxl/pci.h | 14 +++++++ 3 files changed, 130 insertions(+), 1 deletion(-) create mode 100644 drivers/cxl/cxl.h diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h new file mode 100644 index 000000000000..d81d0ba4617c --- /dev/null +++ b/drivers/cxl/cxl.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright(c) 2020 Intel Corporation. */ + +#ifndef __CXL_H__ +#define __CXL_H__ + +/** + * struct cxl_mem - A CXL memory device + * @pdev: The PCI device associated with this CXL device. + * @regs: IO mappings to the device's MMIO + */ +struct cxl_mem { + struct pci_dev *pdev; + void __iomem *regs; +}; + +#endif diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 005404888942..8301db34d2ff 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -5,6 +5,58 @@ #include #include "acpi.h" #include "pci.h" +#include "cxl.h" + +/** + * cxl_mem_create() - Create a new &struct cxl_mem. + * @pdev: The pci device associated with the new &struct cxl_mem. + * @reg_lo: Lower 32b of the register locator + * @reg_hi: Upper 32b of the register locator. + * + * Return: The new &struct cxl_mem on success, NULL on failure. + * + * Map the BAR for a CXL memory device. This BAR has the memory device's + * registers for the device as specified in CXL specification. + */ +static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, + u32 reg_hi) +{ + struct device *dev = &pdev->dev; + struct cxl_mem *cxlm; + void __iomem *regs; + u64 offset; + u8 bar; + int rc; + + offset = ((u64)reg_hi << 32) | (reg_lo & CXL_REGLOC_ADDR_MASK); + bar = (reg_lo >> CXL_REGLOC_BIR_SHIFT) & CXL_REGLOC_BIR_MASK; + + /* Basic sanity check that BAR is big enough */ + if (pci_resource_len(pdev, bar) < offset) { + dev_err(dev, "BAR%d: %pr: too small (offset: %#llx)\n", bar, + &pdev->resource[bar], (unsigned long long)offset); + return NULL; + } + + rc = pcim_iomap_regions(pdev, BIT(bar), pci_name(pdev)); + if (rc != 0) { + dev_err(dev, "failed to map registers\n"); + return NULL; + } + + cxlm = devm_kzalloc(&pdev->dev, sizeof(*cxlm), GFP_KERNEL); + if (!cxlm) { + dev_err(dev, "No memory available\n"); + return NULL; + } + + regs = pcim_iomap_table(pdev)[bar]; + cxlm->pdev = pdev; + cxlm->regs = regs + offset; + + dev_dbg(dev, "Mapped CXL Memory Device resource\n"); + return cxlm; +} static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec) { @@ -33,7 +85,8 @@ static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec) static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct device *dev = &pdev->dev; - int rc, regloc; + struct cxl_mem *cxlm; + int rc, regloc, i; rc = cxl_bus_acquire(pdev); if (rc != 0) { @@ -41,15 +94,59 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) return rc; } + rc = pcim_enable_device(pdev); + if (rc) + return rc; + regloc = cxl_mem_dvsec(pdev, PCI_DVSEC_ID_CXL_REGLOC); if (!regloc) { dev_err(dev, "register location dvsec not found\n"); return -ENXIO; } + regloc += 0xc; /* Skip DVSEC + reserved fields */ + + rc = -ENXIO; + for (i = regloc; i < regloc + 0x24; i += 8) { + u32 reg_lo, reg_hi; + u8 reg_type; + + /* "register low and high" contain other bits */ + pci_read_config_dword(pdev, i, ®_lo); + pci_read_config_dword(pdev, i + 4, ®_hi); + + reg_type = + (reg_lo >> CXL_REGLOC_RBI_SHIFT) & CXL_REGLOC_RBI_MASK; + + if (reg_type == CXL_REGLOC_RBI_MEMDEV) { + rc = 0; + cxlm = cxl_mem_create(pdev, reg_lo, reg_hi); + if (!cxlm) + rc = -ENODEV; + break; + } + } + + if (rc) + return rc; + pci_set_drvdata(pdev, cxlm); return 0; } +static void cxl_mem_remove(struct pci_dev *pdev) +{ + struct cxl_mem *cxlm; + + cxlm = pci_get_drvdata(pdev); + if (!cxlm) + return; + + kfree(cxlm); + + pcim_iounmap_regions(pdev, ~0); + pci_set_drvdata(pdev, NULL); +} + static const struct pci_device_id cxl_mem_pci_tbl[] = { /* PCI class code for CXL.mem Type-3 Devices */ { PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, @@ -62,6 +159,7 @@ static struct pci_driver cxl_mem_driver = { .name = KBUILD_MODNAME, .id_table = cxl_mem_pci_tbl, .probe = cxl_mem_probe, + .remove = cxl_mem_remove, }; MODULE_LICENSE("GPL v2"); diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h index a8a9935fa90b..df222edb6ac3 100644 --- a/drivers/cxl/pci.h +++ b/drivers/cxl/pci.h @@ -17,4 +17,18 @@ #define PCI_DVSEC_ID_CXL_REGLOC 0x8 +/* BAR Indicator Register (BIR) */ +#define CXL_REGLOC_BIR_SHIFT 0 +#define CXL_REGLOC_BIR_MASK 0x7 + +/* Register Block Identifier (RBI) */ +#define CXL_REGLOC_RBI_SHIFT 8 +#define CXL_REGLOC_RBI_MASK 0xff +#define CXL_REGLOC_RBI_EMPTY 0 +#define CXL_REGLOC_RBI_COMPONENT 1 +#define CXL_REGLOC_RBI_VIRT 2 +#define CXL_REGLOC_RBI_MEMDEV 3 + +#define CXL_REGLOC_ADDR_MASK 0xffff0000 + #endif /* __CXL_PCI_H__ */ From patchwork Mon Jan 11 22:51:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011819 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F2F0C433E0 for ; Tue, 12 Jan 2021 00:30:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19CF122D0A for ; Tue, 12 Jan 2021 00:30:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404075AbhALAZ5 (ORCPT ); Mon, 11 Jan 2021 19:25:57 -0500 Received: from mga17.intel.com ([192.55.52.151]:11211 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390804AbhAKWwk (ORCPT ); Mon, 11 Jan 2021 17:52:40 -0500 IronPort-SDR: 6dBqPs9zPdn4eRVCo7vq0vJf2L5GQn43ZfIss8X2QIsEW0VHmuK68plP/yru5Zd9X68k5lKQwH Gqs6RFKXtF7Q== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726536" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726536" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:34 -0800 IronPort-SDR: nxN9PiqNZhBYr+TAkbrH8jBsAS6wSvfIF//l+WLJV472SHjJR2/XfqZ3nvoXR5XIeHwO3Dh8vN lmM8FaWOBqzQ== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352777989" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:33 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 06/16] cxl/mem: Find device capabilities Date: Mon, 11 Jan 2021 14:51:10 -0800 Message-Id: <20210111225121.820014-7-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org CXL devices contain an array of capabilities that describe the interactions software can have with the device or firmware running on the device. A CXL compliant device must implement the device status and the mailbox capability. A CXL compliant memory device must implement the memory device capability. Each of the capabilities can [will] provide an offset within the MMIO region for interacting with the CXL device. For more details see 8.2.8 of the CXL 2.0 specification. Link: Link: https://www.computeexpresslink.org/download-the-specification Signed-off-by: Ben Widawsky --- drivers/cxl/cxl.h | 82 ++++++++++++++++++++++++++++++++++++++- drivers/cxl/mem.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 178 insertions(+), 1 deletion(-) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index d81d0ba4617c..a77286d04ce4 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -4,6 +4,38 @@ #ifndef __CXL_H__ #define __CXL_H__ +#include +#include +#include + +#define CXL_SET_FIELD(value, field) \ + ({ \ + WARN_ON(!FIELD_FIT(field##_MASK, value)); \ + FIELD_PREP(field##_MASK, value); \ + }) + +#define CXL_GET_FIELD(word, field) FIELD_GET(field##_MASK, word) + +/* Device (CXL 2.0 - 8.2.8.3) */ +#define CXLDEV_CAP_ARRAY_REG 0x0 +#define CXLDEV_CAP_ARRAY_CAP_ID 0 +#define CXLDEV_CAP_ARRAY_ID(x) ((x) & (0xffff)) +#define CXLDEV_CAP_ARRAY_COUNT(x) (((x) >> 32) & 0xffff) + +#define CXL_CAP_CAP_ID_DEVICE_STATUS 0x1 +#define CXL_CAP_CAP_ID_PRIMARY_MAILBOX 0x2 +#define CXL_CAP_CAP_ID_SECONDARY_MAILBOX 0x3 +#define CXL_CAP_CAP_ID_MEMDEV 0x4000 + +/* Mailbox (CXL 2.0 - 8.2.8.4) */ +#define CXLDEV_MB_CAPS_OFFSET 0x00 +#define CXLDEV_MB_CAP_PAYLOAD_SIZE_MASK GENMASK(4, 0) +#define CXLDEV_MB_CAP_PAYLOAD_SIZE_SHIFT 0 +#define CXLDEV_MB_CTRL_OFFSET 0x04 +#define CXLDEV_MB_CMD_OFFSET 0x08 +#define CXLDEV_MB_STATUS_OFFSET 0x10 +#define CXLDEV_MB_BG_CMD_STATUS_OFFSET 0x18 + /** * struct cxl_mem - A CXL memory device * @pdev: The PCI device associated with this CXL device. @@ -12,6 +44,54 @@ struct cxl_mem { struct pci_dev *pdev; void __iomem *regs; + + /* Cap 0001h - CXL_CAP_CAP_ID_DEVICE_STATUS */ + struct { + void __iomem *regs; + } status; + + /* Cap 0002h - CXL_CAP_CAP_ID_PRIMARY_MAILBOX */ + struct { + void __iomem *regs; + size_t payload_size; + } mbox; + + /* Cap 4000h - CXL_CAP_CAP_ID_MEMDEV */ + struct { + void __iomem *regs; + } mem; }; -#endif +#define cxl_reg(type) \ + static inline void cxl_write_##type##_reg32(struct cxl_mem *cxlm, \ + u32 reg, u32 value) \ + { \ + void __iomem *reg_addr = cxlm->type.regs; \ + writel(value, reg_addr + reg); \ + } \ + static inline void cxl_write_##type##_reg64(struct cxl_mem *cxlm, \ + u32 reg, u64 value) \ + { \ + void __iomem *reg_addr = cxlm->type.regs; \ + writeq(value, reg_addr + reg); \ + } \ + static inline u32 cxl_read_##type##_reg32(struct cxl_mem *cxlm, \ + u32 reg) \ + { \ + void __iomem *reg_addr = cxlm->type.regs; \ + return readl(reg_addr + reg); \ + } \ + static inline u64 cxl_read_##type##_reg64(struct cxl_mem *cxlm, \ + u32 reg) \ + { \ + void __iomem *reg_addr = cxlm->type.regs; \ + return readq(reg_addr + reg); \ + } + +cxl_reg(status); +cxl_reg(mbox); + +#define cxl_payload_regs(cxlm) \ + ((void __iomem *)(cxlm)->mbox.regs + CXLDEV_MB_PAYLOAD_OFFSET) + +#endif /* __CXL_H__ */ diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 8301db34d2ff..8da9f4a861ea 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -7,6 +7,91 @@ #include "pci.h" #include "cxl.h" +/** + * cxl_mem_setup_regs() - Setup necessary MMIO. + * @cxlm: The CXL memory device to communicate with. + * + * Return: 0 if all necessary registers mapped. + * + * A memory device is required by spec to implement a certain set of MMIO + * regions. The purpose of this function is to enumerate and map those + * registers. + * + * XXX: Register accessors need the mappings set up by this function, so + * any reads or writes must be read(b|w|l|q) or write(b|w|l|q) + */ +static int cxl_mem_setup_regs(struct cxl_mem *cxlm) +{ + u64 cap_array; + int cap; + + /* + */ + cap_array = readq(cxlm->regs + CXLDEV_CAP_ARRAY_REG); + if (CXLDEV_CAP_ARRAY_ID(cap_array) != CXLDEV_CAP_ARRAY_CAP_ID) + return -ENODEV; + + for (cap = 1; cap <= CXLDEV_CAP_ARRAY_COUNT(cap_array); cap++) { + void __iomem *register_block; + u32 offset; + u16 cap_id; + + cap_id = readl(cxlm->regs + cap * 0x10) & 0xffff; + offset = readl(cxlm->regs + cap * 0x10 + 0x4); + register_block = cxlm->regs + offset; + + switch (cap_id) { + case CXL_CAP_CAP_ID_DEVICE_STATUS: + dev_dbg(&cxlm->pdev->dev, + "found Status capability (0x%x)\n", offset); + cxlm->status.regs = register_block; + break; + case CXL_CAP_CAP_ID_PRIMARY_MAILBOX: + dev_dbg(&cxlm->pdev->dev, + "found Mailbox capability (0x%x)\n", offset); + cxlm->mbox.regs = register_block; + break; + case CXL_CAP_CAP_ID_SECONDARY_MAILBOX: + dev_dbg(&cxlm->pdev->dev, + "found Secondary Mailbox capability (0x%x)\n", + offset); + break; + case CXL_CAP_CAP_ID_MEMDEV: + dev_dbg(&cxlm->pdev->dev, + "found Memory Device capability (0x%x)\n", + offset); + cxlm->mem.regs = register_block; + break; + default: + dev_warn(&cxlm->pdev->dev, + "Unknown cap ID: %d (0x%x)\n", cap_id, offset); + break; + } + } + + if (!cxlm->status.regs || !cxlm->mbox.regs || !cxlm->mem.regs) + return -ENXIO; + + return 0; +} + +static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm) +{ + const int cap = cxl_read_mbox_reg32(cxlm, CXLDEV_MB_CAPS_OFFSET); + + cxlm->mbox.payload_size = + 1 << CXL_GET_FIELD(cap, CXLDEV_MB_CAP_PAYLOAD_SIZE); + + /* 8.2.8.4.3 */ + if (cxlm->mbox.payload_size < 256) + return -ENXIO; + + dev_dbg(&cxlm->pdev->dev, "Mailbox payload sized %zu", + cxlm->mbox.payload_size); + + return 0; +} + /** * cxl_mem_create() - Create a new &struct cxl_mem. * @pdev: The pci device associated with the new &struct cxl_mem. @@ -129,8 +214,20 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (rc) return rc; + rc = cxl_mem_setup_regs(cxlm); + if (rc) + goto err; + + rc = cxl_mem_setup_mailbox(cxlm); + if (rc) + goto err; + pci_set_drvdata(pdev, cxlm); return 0; + +err: + kfree(cxlm); + return rc; } static void cxl_mem_remove(struct pci_dev *pdev) From patchwork Mon Jan 11 22:51:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011817 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0294FC433E0 for ; Tue, 12 Jan 2021 00:30:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9E5E22D0A for ; 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11 Jan 2021 14:51:34 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 07/16] cxl/mem: Implement polled mode mailbox Date: Mon, 11 Jan 2021 14:51:11 -0800 Message-Id: <20210111225121.820014-8-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Provide enough functionality to utilize the mailbox of a memory device. The mailbox is used to interact with the firmware running on the memory device. The CXL specification defines separate capabilities for the mailbox and the memory device. While we can confirm the mailbox is ready, in order to actually interact with the memory device, you must also confirm the device's firmware is ready. Create a function to handle sending a command, optionally with a payload, to the memory device, polling on a result, and then optionally copying out the payload. The algorithm for doing this comes straight out of the CXL 2.0 specification. Primary mailboxes are capable of generating an interrupt when submitting a command in the background. That implementation is saved for a later time. Secondary mailboxes aren't implemented at this time. The flow is proven with one implemented command, "identify". Because the class code has already told the driver this is a memory device and the identify command is mandatory, it's safe to assume for sane devices that everything here will work. Signed-off-by: Ben Widawsky --- drivers/cxl/cxl.h | 43 +++++++ drivers/cxl/mem.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 355 insertions(+) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index a77286d04ce4..ca3fa496e21c 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -32,9 +32,40 @@ #define CXLDEV_MB_CAP_PAYLOAD_SIZE_MASK GENMASK(4, 0) #define CXLDEV_MB_CAP_PAYLOAD_SIZE_SHIFT 0 #define CXLDEV_MB_CTRL_OFFSET 0x04 +#define CXLDEV_MB_CTRL_DOORBELL BIT(0) #define CXLDEV_MB_CMD_OFFSET 0x08 +#define CXLDEV_MB_CMD_COMMAND_OPCODE_SHIFT 0 +#define CXLDEV_MB_CMD_COMMAND_OPCODE_MASK GENMASK(15, 0) +#define CXLDEV_MB_CMD_PAYLOAD_LENGTH_SHIFT 16 +#define CXLDEV_MB_CMD_PAYLOAD_LENGTH_MASK GENMASK(36, 16) #define CXLDEV_MB_STATUS_OFFSET 0x10 +#define CXLDEV_MB_STATUS_RET_CODE_SHIFT 32 +#define CXLDEV_MB_STATUS_RET_CODE_MASK GENMASK(47, 32) #define CXLDEV_MB_BG_CMD_STATUS_OFFSET 0x18 +#define CXLDEV_MB_PAYLOAD_OFFSET 0x20 + +/* Memory Device (CXL 2.0 - 8.2.8.5.1.1) */ +#define CXLMDEV_STATUS_OFFSET 0x0 +#define CXLMDEV_DEV_FATAL BIT(0) +#define CXLMDEV_FW_HALT BIT(1) +#define CXLMDEV_STATUS_MEDIA_STATUS_SHIFT 2 +#define CXLMDEV_STATUS_MEDIA_STATUS_MASK GENMASK(3, 2) +#define CXLMDEV_MS_NOT_READY 0 +#define CXLMDEV_MS_READY 1 +#define CXLMDEV_MS_ERROR 2 +#define CXLMDEV_MS_DISABLED 3 +#define CXLMDEV_READY(status) \ + (CXL_GET_FIELD(status, CXLMDEV_STATUS_MEDIA_STATUS) == CXLMDEV_MS_READY) +#define CXLMDEV_MBOX_IF_READY BIT(4) +#define CXLMDEV_RESET_NEEDED_SHIFT 5 +#define CXLMDEV_RESET_NEEDED_MASK GENMASK(7, 5) +#define CXLMDEV_RESET_NEEDED_NOT 0 +#define CXLMDEV_RESET_NEEDED_COLD 1 +#define CXLMDEV_RESET_NEEDED_WARM 2 +#define CXLMDEV_RESET_NEEDED_HOT 3 +#define CXLMDEV_RESET_NEEDED_CXL 4 +#define CXLMDEV_RESET_NEEDED(status) \ + (CXL_GET_FIELD(status, CXLMDEV_RESET_NEEDED) != CXLMDEV_RESET_NEEDED_NOT) /** * struct cxl_mem - A CXL memory device @@ -45,6 +76,16 @@ struct cxl_mem { struct pci_dev *pdev; void __iomem *regs; + struct { + struct range range; + } pmem; + + struct { + struct range range; + } ram; + + char firmware_version[0x10]; + /* Cap 0001h - CXL_CAP_CAP_ID_DEVICE_STATUS */ struct { void __iomem *regs; @@ -52,6 +93,7 @@ struct cxl_mem { /* Cap 0002h - CXL_CAP_CAP_ID_PRIMARY_MAILBOX */ struct { + struct mutex mutex; /* Protects device mailbox and firmware */ void __iomem *regs; size_t payload_size; } mbox; @@ -90,6 +132,7 @@ struct cxl_mem { cxl_reg(status); cxl_reg(mbox); +cxl_reg(mem); #define cxl_payload_regs(cxlm) \ ((void __iomem *)(cxlm)->mbox.regs + CXLDEV_MB_PAYLOAD_OFFSET) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 8da9f4a861ea..e9ba97bbd7b9 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +#include #include #include #include @@ -7,6 +8,248 @@ #include "pci.h" #include "cxl.h" +#define cxl_doorbell_busy(cxlm) \ + (cxl_read_mbox_reg32(cxlm, CXLDEV_MB_CTRL_OFFSET) & \ + CXLDEV_MB_CTRL_DOORBELL) + +#define CXL_MAILBOX_TIMEOUT_US 2000 + +enum opcode { + CXL_MBOX_OP_IDENTIFY = 0x4000, + CXL_MBOX_OP_MAX = 0x10000 +}; + +/** + * struct mbox_cmd - A command to be submitted to hardware. + * @opcode: (input) The command set and command submitted to hardware. + * @payload: (input/output) Pointer to the input and output payload. + * Payload can be NULL if the caller wants to populate the payload + * registers themselves (potentially avoiding a copy). + * @size_in: (input) Number of bytes to load from @payload. + * @size_out: + * - (input) Number of bytes allocated to load into @payload. + * - (output) Number of bytes loaded into @payload. + * @return_code: (output) Error code returned from hardware. + * + * This is the primary mechanism used to send commands to the hardware. + * All the fields except @payload correspond exactly to the fields described in + * Command Register section of the CXL 2.0 spec (8.2.8.4.5). @payload + * corresponds to the Command Payload Registers (8.2.8.4.8). + */ +struct mbox_cmd { + u16 opcode; + void *payload; + size_t size_in; + size_t size_out; + u16 return_code; +}; + +static int cxl_mem_wait_for_doorbell(struct cxl_mem *cxlm) +{ + const int timeout = msecs_to_jiffies(CXL_MAILBOX_TIMEOUT_US); + const unsigned long start = jiffies; + unsigned long end = start; + + while (cxl_doorbell_busy(cxlm)) { + end = jiffies; + + if (time_after(end, start + timeout)) { + /* Check again in case preempted before timeout test */ + if (!cxl_doorbell_busy(cxlm)) + break; + return -ETIMEDOUT; + } + cpu_relax(); + } + + dev_dbg(&cxlm->pdev->dev, "Doorbell wait took %dms", + jiffies_to_msecs(end) - jiffies_to_msecs(start)); + return 0; +} + +static void cxl_mem_mbox_timeout(struct cxl_mem *cxlm, + struct mbox_cmd *mbox_cmd) +{ + dev_warn(&cxlm->pdev->dev, "Mailbox command timed out\n"); + dev_info(&cxlm->pdev->dev, + "\topcode: 0x%04x\n" + "\tpayload size: %zub\n", + mbox_cmd->opcode, mbox_cmd->size_in); + print_hex_dump_debug("Payload ", DUMP_PREFIX_OFFSET, 16, 1, + mbox_cmd->payload, mbox_cmd->size_in, true); + + /* Here's a good place to figure out if a device reset is needed */ +} + +/** + * cxl_mem_mbox_send_cmd() - Send a mailbox command to a memory device. + * @cxlm: The CXL memory device to communicate with. + * @mbox_cmd: Command to send to the memory device. + * + * Context: Any context. Expects mbox_lock to be held. + * Return: -ETIMEDOUT if timeout occurred waiting for completion. 0 on success. + * Caller should check the return code in @mbox_cmd to make sure it + * succeeded. + * + * This is a generic form of the CXL mailbox send command, thus the only I/O + * operations used are cxl_read_mbox_reg(). Memory devices, and perhaps other + * types of CXL devices may have further information available upon error + * conditions. + * + * FIXME: As stated above, references to &struct cxl_mem should be changed to a + * more generic cxl structure when needed. + */ +static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, + struct mbox_cmd *mbox_cmd) +{ + u64 cmd_reg, status_reg; + size_t out_len; + int rc; + + lockdep_assert_held(&cxlm->mbox.mutex); + + /* + * Here are the steps from 8.2.8.4 of the CXL 2.0 spec. + * 1. Caller reads MB Control Register to verify doorbell is clear + * 2. Caller writes Command Register + * 3. Caller writes Command Payload Registers if input payload is non-empty + * 4. Caller writes MB Control Register to set doorbell + * 5. Caller either polls for doorbell to be clear or waits for interrupt if configured + * 6. Caller reads MB Status Register to fetch Return code + * 7. If command successful, Caller reads Command Register to get Payload Length + * 8. If output payload is non-empty, host reads Command Payload Registers + */ + + /* #1 */ + WARN_ON(cxl_doorbell_busy(cxlm)); + + cmd_reg = CXL_SET_FIELD(mbox_cmd->opcode, CXLDEV_MB_CMD_COMMAND_OPCODE); + if (mbox_cmd->size_in) { + cmd_reg |= CXL_SET_FIELD(mbox_cmd->size_in, + CXLDEV_MB_CMD_PAYLOAD_LENGTH); + if (mbox_cmd->payload) + memcpy_toio(cxl_payload_regs(cxlm), mbox_cmd->payload, + mbox_cmd->size_in); + } + + /* #2, #3 */ + cxl_write_mbox_reg64(cxlm, CXLDEV_MB_CMD_OFFSET, cmd_reg); + + /* #4 */ + dev_dbg(&cxlm->pdev->dev, "Sending command\n"); + cxl_write_mbox_reg32(cxlm, CXLDEV_MB_CTRL_OFFSET, + CXLDEV_MB_CTRL_DOORBELL); + + /* #5 */ + rc = cxl_mem_wait_for_doorbell(cxlm); + if (rc == -ETIMEDOUT) { + cxl_mem_mbox_timeout(cxlm, mbox_cmd); + return rc; + } + + /* #6 */ + status_reg = cxl_read_mbox_reg64(cxlm, CXLDEV_MB_STATUS_OFFSET); + mbox_cmd->return_code = + CXL_GET_FIELD(status_reg, CXLDEV_MB_STATUS_RET_CODE); + + if (mbox_cmd->return_code != 0) { + dev_dbg(&cxlm->pdev->dev, "Mailbox operation had an error\n"); + return 0; + } + + /* #7 */ + cmd_reg = cxl_read_mbox_reg64(cxlm, CXLDEV_MB_CMD_OFFSET); + out_len = CXL_GET_FIELD(cmd_reg, CXLDEV_MB_CMD_PAYLOAD_LENGTH); + mbox_cmd->size_out = out_len; + + /* #8 */ + if (out_len && mbox_cmd->payload) + memcpy_fromio(mbox_cmd->payload, cxl_payload_regs(cxlm), + mbox_cmd->size_out); + + return 0; +} + +/** + * cxl_mem_mbox_get() - Acquire exclusive access to the mailbox. + * @cxlm: The memory device to gain access to. + * + * Context: Any context. Takes the mbox_lock. + * Return: 0 if exclusive access was acquired. + */ +static int cxl_mem_mbox_get(struct cxl_mem *cxlm) +{ + u64 md_status; + int rc = -EBUSY; + + mutex_lock_io(&cxlm->mbox.mutex); + + /* + * XXX: There is some amount of ambiguity in the 2.0 version of the spec + * around the mailbox interface ready (8.2.8.5.1.1). The purpose of the + * bit is to allow firmware running on the device to notify us that it's + * ready to receive commands. It is unclear if the bit needs to be read + * every time one tries to use the mailbox, ie. the firmware can switch + * it on and off as needed. Second, there is no defined timeout for + * mailbox ready, like there is for the doorbell interface. + * + * As such, we make the following assumptions: + * 1. The firmware might toggle the Mailbox Interface Ready bit, and so + * we check it for every command. + * 2. If the doorbell is clear, the firmware should have first set the + * Mailbox Interface Ready bit. Therefore, waiting for the doorbell + * to be ready is a sufficient amount of time. + */ + rc = cxl_mem_wait_for_doorbell(cxlm); + if (rc) { + dev_warn(&cxlm->pdev->dev, "Mailbox interface not ready\n"); + goto out; + } + + md_status = cxl_read_mem_reg64(cxlm, CXLMDEV_STATUS_OFFSET); + if (md_status & CXLMDEV_MBOX_IF_READY && CXLMDEV_READY(md_status)) { + /* + * Hardware shouldn't allow a ready status but also have failure + * bits set. Spit out an error, this should be a bug report + */ + if (md_status & CXLMDEV_DEV_FATAL) { + dev_err(&cxlm->pdev->dev, + "CXL device reporting ready and fatal\n"); + rc = -EFAULT; + goto out; + } + if (md_status & CXLMDEV_FW_HALT) { + dev_err(&cxlm->pdev->dev, + "CXL device reporting ready and halted\n"); + rc = -EFAULT; + goto out; + } + if (CXLMDEV_RESET_NEEDED(md_status)) { + dev_err(&cxlm->pdev->dev, + "CXL device reporting ready and reset needed\n"); + rc = -EFAULT; + goto out; + } + + return 0; + } + +out: + mutex_unlock(&cxlm->mbox.mutex); + return rc; +} + +/** + * cxl_mem_mbox_put() - Release exclusive access to the mailbox. + * @cxlm: The CXL memory device to communicate with. + * + * Context: Any context. Expects mbox_lock to be held. + */ +static void cxl_mem_mbox_put(struct cxl_mem *cxlm) +{ + mutex_unlock(&cxlm->mbox.mutex); +} + /** * cxl_mem_setup_regs() - Setup necessary MMIO. * @cxlm: The CXL memory device to communicate with. @@ -135,6 +378,8 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, return NULL; } + mutex_init(&cxlm->mbox.mutex); + regs = pcim_iomap_table(pdev)[bar]; cxlm->pdev = pdev; cxlm->regs = regs + offset; @@ -167,6 +412,69 @@ static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec) return 0; } +/** + * cxl_mem_identify() - Send the IDENTIFY command to the device. + * @cxlm: The device to identify. + * + * Return: 0 if identify was executed successfully. + * + * This will dispatch the identify command to the device and on success populate + * structures to be exported to sysfs. + */ +static int cxl_mem_identify(struct cxl_mem *cxlm) +{ + struct cxl_mbox_identify { + char fw_revision[0x10]; + __le64 total_capacity; + __le64 volatile_capacity; + __le64 persistent_capacity; + __le64 partition_align; + __le16 info_event_log_size; + __le16 warning_event_log_size; + __le16 failure_event_log_size; + __le16 fatal_event_log_size; + __le32 lsa_size; + u8 poison_list_max_mer[3]; + __le16 inject_poison_limit; + u8 poison_caps; + u8 qos_telemetry_caps; + } __packed id; + struct mbox_cmd mbox_cmd; + int rc; + + /* Retrieve initial device memory map */ + rc = cxl_mem_mbox_get(cxlm); + if (rc) + return rc; + + mbox_cmd = (struct mbox_cmd){ + .opcode = CXL_MBOX_OP_IDENTIFY, + .payload = &id, + .size_in = 0, + }; + rc = cxl_mem_mbox_send_cmd(cxlm, &mbox_cmd); + cxl_mem_mbox_put(cxlm); + if (rc) + return rc; + + if (mbox_cmd.size_out != sizeof(id)) + return -ENXIO; + + /* + * TODO: enumerate DPA map, as 'ram' and 'pmem' do not alias. + * For now, only the capacity is exported in sysfs + */ + cxlm->ram.range.start = 0; + cxlm->ram.range.end = le64_to_cpu(id.volatile_capacity) - 1; + + cxlm->pmem.range.start = 0; + cxlm->pmem.range.end = le64_to_cpu(id.persistent_capacity) - 1; + + memcpy(cxlm->firmware_version, id.fw_revision, sizeof(id.fw_revision)); + + return rc; +} + static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct device *dev = &pdev->dev; @@ -222,6 +530,10 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (rc) goto err; + rc = cxl_mem_identify(cxlm); + if (rc) + goto err; + pci_set_drvdata(pdev, cxlm); return 0; From patchwork Mon Jan 11 22:51:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011815 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A12B3C433E0 for ; Tue, 12 Jan 2021 00:29:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6ED4B22CF7 for ; Tue, 12 Jan 2021 00:29:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404158AbhALAZ6 (ORCPT ); Mon, 11 Jan 2021 19:25:58 -0500 Received: from mga17.intel.com ([192.55.52.151]:11219 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390807AbhAKWwo (ORCPT ); Mon, 11 Jan 2021 17:52:44 -0500 IronPort-SDR: odXNIWqpMg/f93HnaGveDgjvaOHEeW9S1DHRclXVPefeFY15S+SONS3olHYupvbSNLK/+cwh09 VtxSp24ky0hg== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726539" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726539" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:36 -0800 IronPort-SDR: /XnJbypgTtA/OHwTvcIzfDy9OI6Sz8SJBgfra2OjG39V8QmYP7mCrfC8tL1T6HTbcDCTyXc7/n srXuqTI3BKmw== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778000" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:35 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Dan Williams , Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 08/16] cxl/mem: Register CXL memX devices Date: Mon, 11 Jan 2021 14:51:12 -0800 Message-Id: <20210111225121.820014-9-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Dan Williams Create the /sys/bus/cxl hierarchy to enumerate memory devices (per-endpoint control devices), memory address space devices (platform address ranges with interleaving, performance, and persistence attributes), and memory regions (active provisioned memory from an address space device that is in use as System RAM or delegated to libnvdimm as Persistent Memory regions). For now, only the per-endpoint control devices are registered on the 'cxl' bus. Signed-off-by: Dan Williams Signed-off-by: Ben Widawsky --- Documentation/ABI/testing/sysfs-bus-cxl | 26 +++ Documentation/cxl/memory-devices.rst | 3 + drivers/base/core.c | 14 ++ drivers/cxl/Makefile | 2 + drivers/cxl/bus.c | 54 +++++ drivers/cxl/bus.h | 8 + drivers/cxl/cxl.h | 3 + drivers/cxl/mem.c | 282 +++++++++++++++++++++++- include/linux/device.h | 1 + 9 files changed, 392 insertions(+), 1 deletion(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-cxl create mode 100644 drivers/cxl/bus.c create mode 100644 drivers/cxl/bus.h diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl new file mode 100644 index 000000000000..fe7b87eba988 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -0,0 +1,26 @@ +What: /sys/bus/cxl/devices/memX/firmware_version +Date: December, 2020 +KernelVersion: v5.12 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) "FW Revision" string as reported by the Identify + Memory Device Output Payload in the CXL-2.0 + specification. + +What: /sys/bus/cxl/devices/memX/ram/size +Date: December, 2020 +KernelVersion: v5.12 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) "Volatile Only Capacity" as reported by the + Identify Memory Device Output Payload in the CXL-2.0 + specification. + +What: /sys/bus/cxl/devices/memX/pmem/size +Date: December, 2020 +KernelVersion: v5.12 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) "Persistent Only Capacity" as reported by the + Identify Memory Device Output Payload in the CXL-2.0 + specification. diff --git a/Documentation/cxl/memory-devices.rst b/Documentation/cxl/memory-devices.rst index 134c9b6b4ff4..5f723c25382b 100644 --- a/Documentation/cxl/memory-devices.rst +++ b/Documentation/cxl/memory-devices.rst @@ -37,3 +37,6 @@ External Interfaces .. kernel-doc:: drivers/cxl/acpi.c :export: + +.. kernel-doc:: drivers/cxl/bus.c + :export: diff --git a/drivers/base/core.c b/drivers/base/core.c index 25e08e5f40bd..33432a4cbe23 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3179,6 +3179,20 @@ struct device *get_device(struct device *dev) } EXPORT_SYMBOL_GPL(get_device); +/** + * get_live_device() - increment reference count for device iff !dead + * @dev: device. + * + * Forward the call to get_device() if the device is still alive. If + * this is called with the device_lock() held then the device is + * guaranteed to not die until the device_lock() is dropped. + */ +struct device *get_live_device(struct device *dev) +{ + return dev && !dev->p->dead ? get_device(dev) : NULL; +} +EXPORT_SYMBOL_GPL(get_live_device); + /** * put_device - decrement reference count. * @dev: device in question. diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index 97fdffb00f2d..f9baaeb94bda 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -1,7 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_CXL_BUS_PROVIDER) += cxl_bus.o obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o obj-$(CONFIG_CXL_MEM) += cxl_mem.o ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL +cxl_bus-y := bus.o cxl_acpi-y := acpi.o cxl_mem-y := mem.o diff --git a/drivers/cxl/bus.c b/drivers/cxl/bus.c new file mode 100644 index 000000000000..91fe765bea94 --- /dev/null +++ b/drivers/cxl/bus.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +#include +#include +#include "bus.h" + +static struct bus_type cxl_bus_type = { + .name = "cxl", +}; + +static void cxl_unregister(void *dev) +{ + device_unregister(dev); +} + +/** + * cxl_register() - Register a device on the CXL bus. + * @dev: The device to register onto the CXL bus. + * + * A CXL device driver must call this in order to have the device be a part of + * the CXL bus. All endpoint device drivers should utilize this function. + * + * Return: 0 on success. + */ +int cxl_register(struct device *dev) +{ + int rc; + + if (!dev->parent || !dev->parent->driver) + return -EINVAL; + + dev->bus = &cxl_bus_type; + rc = device_add(dev); + if (rc) + put_device(dev); + else + rc = devm_add_action_or_reset(dev->parent, cxl_unregister, dev); + return rc; +} +EXPORT_SYMBOL_GPL(cxl_register); + +static __init int cxl_bus_init(void) +{ + return bus_register(&cxl_bus_type); +} + +static void cxl_bus_exit(void) +{ + bus_unregister(&cxl_bus_type); +} + +module_init(cxl_bus_init); +module_exit(cxl_bus_exit); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/cxl/bus.h b/drivers/cxl/bus.h new file mode 100644 index 000000000000..5fc75ebd3650 --- /dev/null +++ b/drivers/cxl/bus.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +#ifndef __CXL_BUS_H__ +#define __CXL_BUS_H__ + +int cxl_register(struct device *dev); + +#endif /* __CXL_BUS_H__ */ diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index ca3fa496e21c..537ac4d8e6bd 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -3,6 +3,7 @@ #ifndef __CXL_H__ #define __CXL_H__ +#include #include #include @@ -67,6 +68,7 @@ #define CXLMDEV_RESET_NEEDED(status) \ (CXL_GET_FIELD(status, CXLMDEV_RESET_NEEDED) != CXLMDEV_RESET_NEEDED_NOT) +struct cxl_memdev; /** * struct cxl_mem - A CXL memory device * @pdev: The PCI device associated with this CXL device. @@ -75,6 +77,7 @@ struct cxl_mem { struct pci_dev *pdev; void __iomem *regs; + struct cxl_memdev *cxlmd; struct { struct range range; diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index e9ba97bbd7b9..da2bf941fe92 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -2,11 +2,37 @@ /* Copyright(c) 2020 Intel Corporation. All rights reserved. */ #include #include +#include +#include +#include #include #include #include "acpi.h" #include "pci.h" #include "cxl.h" +#include "bus.h" + +/** + * DOC: cxl mem + * + * This implements a CXL memory device ("type-3") as it is defined by the + * Compute Express Link specification. + * + * The driver has several responsibilities, mainly: + * - Create the memX device and register on the CXL bus. + * - Enumerate device's register interface and map them. + * - Probe the device attributes to establish sysfs interface. + * - Provide an IOCTL interface to userspace to communicate with the device for + * things like firmware update. + * - Support management of interleave sets. + * - Handle and manage error conditions. + */ + +/* + * An entire PCI topology full of devices should be enough for any + * config + */ +#define CXL_MEM_MAX_DEVS 65536 #define cxl_doorbell_busy(cxlm) \ (cxl_read_mbox_reg32(cxlm, CXLDEV_MB_CTRL_OFFSET) & \ @@ -44,6 +70,18 @@ struct mbox_cmd { u16 return_code; }; +struct cxl_memdev { + struct device dev; + struct cxl_mem *cxlm; + int id; +}; + +static int cxl_mem_major; +static struct cdev cxl_mem_cdev; +static DEFINE_IDR(cxl_mem_idr); +/* protect cxl_mem_idr allocations */ +static DEFINE_MUTEX(cxl_memdev_lock); + static int cxl_mem_wait_for_doorbell(struct cxl_mem *cxlm) { const int timeout = msecs_to_jiffies(CXL_MAILBOX_TIMEOUT_US); @@ -250,6 +288,55 @@ static void cxl_mem_mbox_put(struct cxl_mem *cxlm) mutex_unlock(&cxlm->mbox.mutex); } +static int cxl_mem_open(struct inode *inode, struct file *file) +{ + long minor = iminor(inode); + struct cxl_memdev *cxlmd; + struct device *dev; + int rc = -ENXIO; + + mutex_lock(&cxl_memdev_lock); + cxlmd = idr_find(&cxl_mem_idr, minor); + if (!cxlmd) + goto out; + + dev = get_live_device(&cxlmd->dev); + if (!dev) + goto out; + + rc = 0; + dev_dbg(dev, "Opened %pD\n", file); + + file->private_data = cxlmd; + +out: + mutex_unlock(&cxl_memdev_lock); + return rc; +} + +static int cxl_mem_release(struct inode *inode, struct file *file) +{ + struct cxl_memdev *cxlmd = file->private_data; + + put_device(&cxlmd->dev); + + return 0; +} + +static long cxl_mem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return -ENOTTY; +} + +static const struct file_operations cxl_mem_fops = { + .owner = THIS_MODULE, + .open = cxl_mem_open, + .release = cxl_mem_release, + .unlocked_ioctl = cxl_mem_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .llseek = noop_llseek, +}; + /** * cxl_mem_setup_regs() - Setup necessary MMIO. * @cxlm: The CXL memory device to communicate with. @@ -412,6 +499,157 @@ static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec) return 0; } +static struct cxl_memdev *to_cxl_memdev(struct device *dev) +{ + return container_of(dev, struct cxl_memdev, dev); +} + +static void cxl_memdev_release(struct device *dev) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + + mutex_lock(&cxl_memdev_lock); + idr_remove(&cxl_mem_idr, cxlmd->id); + mutex_unlock(&cxl_memdev_lock); + + kfree(cxlmd); +} + +static char *cxl_memdev_devnode(struct device *dev, umode_t *mode, kuid_t *uid, + kgid_t *gid) +{ + return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev)); +} + +static ssize_t firmware_version_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + + return sprintf(buf, "%.16s\n", cxlm->firmware_version); +} +static DEVICE_ATTR_RO(firmware_version); + +static ssize_t payload_max_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + + return sprintf(buf, "%zu\n", cxlm->mbox.payload_size); +} +static DEVICE_ATTR_RO(payload_max); + +static ssize_t ram_size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + unsigned long long len = range_len(&cxlm->ram.range); + + return sprintf(buf, "%#llx\n", len); +} + +static struct device_attribute dev_attr_ram_size = + __ATTR(size, 0444, ram_size_show, NULL); + +static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + unsigned long long len = range_len(&cxlm->pmem.range); + + return sprintf(buf, "%#llx\n", len); +} + +static struct device_attribute dev_attr_pmem_size = + __ATTR(size, 0444, pmem_size_show, NULL); + +static struct attribute *cxl_memdev_attributes[] = { + &dev_attr_firmware_version.attr, + &dev_attr_payload_max.attr, + NULL, +}; + +static struct attribute *cxl_memdev_pmem_attributes[] = { + &dev_attr_pmem_size.attr, + NULL, +}; + +static struct attribute *cxl_memdev_ram_attributes[] = { + &dev_attr_ram_size.attr, + NULL, +}; + +static struct attribute_group cxl_memdev_attribute_group = { + .attrs = cxl_memdev_attributes, +}; + +static struct attribute_group cxl_memdev_ram_attribute_group = { + .name = "ram", + .attrs = cxl_memdev_ram_attributes, +}; + +static struct attribute_group cxl_memdev_pmem_attribute_group = { + .name = "pmem", + .attrs = cxl_memdev_pmem_attributes, +}; + +static const struct attribute_group *cxl_memdev_attribute_groups[] = { + &cxl_memdev_attribute_group, + &cxl_memdev_ram_attribute_group, + &cxl_memdev_pmem_attribute_group, + NULL, +}; + +static const struct device_type cxl_memdev_type = { + .name = "cxl_memdev", + .release = cxl_memdev_release, + .devnode = cxl_memdev_devnode, + .groups = cxl_memdev_attribute_groups, +}; + +static int cxl_mem_add_memdev(struct cxl_mem *cxlm) +{ + struct pci_dev *pdev = cxlm->pdev; + struct cxl_memdev *cxlmd; + struct device *dev; + int rc; + + cxlmd = kzalloc(sizeof(*cxlmd), GFP_KERNEL); + if (!cxlmd) + return -ENOMEM; + + cxlmd->cxlm = cxlm; + + mutex_lock(&cxl_memdev_lock); + rc = idr_alloc(&cxl_mem_idr, cxlmd, 0, CXL_MEM_MAX_DEVS, GFP_KERNEL); + mutex_unlock(&cxl_memdev_lock); + if (rc < 0) { + kfree(cxlmd); + return rc; + } + + cxlmd->id = rc; + + dev = &cxlmd->dev; + + /* sync with racing open */ + mutex_lock(&cxl_memdev_lock); + device_initialize(dev); + dev->parent = &pdev->dev; + dev->devt = MKDEV(cxl_mem_major, cxlmd->id); + dev->type = &cxl_memdev_type; + dev_set_name(dev, "mem%d", cxlmd->id); + + rc = cxl_register(dev); + mutex_unlock(&cxl_memdev_lock); + + return rc; +} + /** * cxl_mem_identify() - Send the IDENTIFY command to the device. * @cxlm: The device to identify. @@ -534,6 +772,10 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (rc) goto err; + rc = cxl_mem_add_memdev(cxlm); + if (rc) + goto err; + pci_set_drvdata(pdev, cxlm); return 0; @@ -571,6 +813,44 @@ static struct pci_driver cxl_mem_driver = { .remove = cxl_mem_remove, }; +static __init int cxl_mem_init(void) +{ + int rc; + dev_t devt; + + rc = alloc_chrdev_region(&devt, 0, CXL_MEM_MAX_DEVS, "cxl"); + if (rc) + return rc; + + cxl_mem_major = MAJOR(devt); + + cdev_init(&cxl_mem_cdev, &cxl_mem_fops); + rc = cdev_add(&cxl_mem_cdev, MKDEV(cxl_mem_major, 0), CXL_MEM_MAX_DEVS); + if (rc) + goto err_cdev; + + rc = pci_register_driver(&cxl_mem_driver); + if (rc) + goto err_driver; + + return 0; + +err_driver: + cdev_del(&cxl_mem_cdev); +err_cdev: + unregister_chrdev_region(MKDEV(cxl_mem_major, 0), CXL_MEM_MAX_DEVS); + + return rc; +} + +static __exit void cxl_mem_exit(void) +{ + pci_unregister_driver(&cxl_mem_driver); + cdev_del(&cxl_mem_cdev); + unregister_chrdev_region(MKDEV(cxl_mem_major, 0), CXL_MEM_MAX_DEVS); +} + MODULE_LICENSE("GPL v2"); -module_pci_driver(cxl_mem_driver); +module_init(cxl_mem_init); +module_exit(cxl_mem_exit); MODULE_IMPORT_NS(CXL); diff --git a/include/linux/device.h b/include/linux/device.h index 89bb8b84173e..8659deee8ae6 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -895,6 +895,7 @@ extern int (*platform_notify_remove)(struct device *dev); * */ struct device *get_device(struct device *dev); +struct device *get_live_device(struct device *dev); void put_device(struct device *dev); bool kill_device(struct device *dev); From patchwork Mon Jan 11 22:51:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011813 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70DE6C433E9 for ; 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d="scan'208";a="352778012" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:36 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 09/16] cxl/mem: Add basic IOCTL interface Date: Mon, 11 Jan 2021 14:51:13 -0800 Message-Id: <20210111225121.820014-10-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add a straightforward IOCTL that provides a mechanism for userspace to query the supported memory device commands. CXL commands as they appear to userspace are described as part of the UAPI kerneldoc. The command list returned via this IOCTL will contain the full set of commands that the driver supports, however, some of those commands may not be available for use by userspace. Memory device commands are specified in 8.2.9 of the CXL 2.0 specification. They are submitted through a mailbox mechanism specified in 8.2.8.4. Signed-off-by: Ben Widawsky --- .clang-format | 1 + Documentation/cxl/memory-devices.rst | 9 + .../userspace-api/ioctl/ioctl-number.rst | 1 + drivers/cxl/mem.c | 156 ++++++++++++++++++ include/uapi/linux/cxl_mem.h | 117 +++++++++++++ 5 files changed, 284 insertions(+) create mode 100644 include/uapi/linux/cxl_mem.h diff --git a/.clang-format b/.clang-format index 10dc5a9a61b3..3f11c8901b43 100644 --- a/.clang-format +++ b/.clang-format @@ -109,6 +109,7 @@ ForEachMacros: - 'css_for_each_child' - 'css_for_each_descendant_post' - 'css_for_each_descendant_pre' + - 'cxl_for_each_cmd' - 'device_for_each_child_node' - 'dma_fence_chain_for_each' - 'do_for_each_ftrace_op' diff --git a/Documentation/cxl/memory-devices.rst b/Documentation/cxl/memory-devices.rst index 5f723c25382b..ec54674b3822 100644 --- a/Documentation/cxl/memory-devices.rst +++ b/Documentation/cxl/memory-devices.rst @@ -32,6 +32,15 @@ CXL Memory Device .. kernel-doc:: drivers/cxl/mem.c :internal: +CXL IOCTL Interface +------------------- + +.. kernel-doc:: include/uapi/linux/cxl_mem.h + :doc: UAPI + +.. kernel-doc:: include/uapi/linux/cxl_mem.h + :internal: + External Interfaces =================== diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index a4c75a28c839..6eb8e634664d 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -352,6 +352,7 @@ Code Seq# Include File Comments 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 0xCD 01 linux/reiserfs_fs.h +0xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 0xCF 02 fs/cifs/ioctl.c 0xDB 00-0F drivers/char/mwave/mwavepub.h 0xDD 00-3F ZFCP device driver see drivers/s390/scsi/ diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index da2bf941fe92..d4eb3f5b9469 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -7,6 +7,7 @@ #include #include #include +#include #include "acpi.h" #include "pci.h" #include "cxl.h" @@ -41,6 +42,7 @@ #define CXL_MAILBOX_TIMEOUT_US 2000 enum opcode { + CXL_MBOX_OP_INVALID = 0x0000, CXL_MBOX_OP_IDENTIFY = 0x4000, CXL_MBOX_OP_MAX = 0x10000 }; @@ -82,6 +84,90 @@ static DEFINE_IDR(cxl_mem_idr); /* protect cxl_mem_idr allocations */ static DEFINE_MUTEX(cxl_memdev_lock); +#define CXL_CMD(_id, _flags, sin, sout, f) \ + [CXL_MEM_COMMAND_ID_##_id] = { \ + { \ + .id = CXL_MEM_COMMAND_ID_##_id, \ + .flags = CXL_MEM_COMMAND_FLAG_##_flags, \ + .size_in = sin, \ + .size_out = sout, \ + }, \ + .flags = CXL_CMD_INTERNAL_FLAG_##f, \ + .opcode = CXL_MBOX_OP_##_id, \ + } + +/** + * struct cxl_mem_command - Driver representation of a memory device command + * @info: Command information as it exists for the UAPI + * @opcode: The actual bits used for the mailbox protocol + * @flags: Set of flags reflecting the state of the command. + * + * * %CXL_CMD_INTERNAL_FLAG_HIDDEN: Command is hidden from userspace. This + * would typically be used for deprecated commands. + * * %CXL_CMD_FLAG_MANDATORY: Hardware must support this command. This flag is + * only used internally by the driver for sanity checking. + * + * The cxl_mem_command is the driver's internal representation of commands that + * are supported by the driver. Some of these commands may not be supported by + * the hardware. The driver will use @info to validate the fields passed in by + * the user then submit the @opcode to the hardware. + * + * See struct cxl_command_info. + */ +struct cxl_mem_command { + const struct cxl_command_info info; + enum opcode opcode; + u32 flags; +#define CXL_CMD_INTERNAL_FLAG_NONE 0 +#define CXL_CMD_INTERNAL_FLAG_HIDDEN BIT(0) +#define CXL_CMD_INTERNAL_FLAG_MANDATORY BIT(1) +}; + +/* + * This table defines the supported mailbox commands for the driver. This table + * is made up of a UAPI structure. Non-negative values as parameters in the + * table will be validated against the user's input. For example, if size_in is + * 0, and the user passed in 1, it is an error. + */ +static struct cxl_mem_command mem_commands[] = { + CXL_CMD(INVALID, KERNEL, 0, 0, HIDDEN), + CXL_CMD(IDENTIFY, NONE, 0, 0x43, MANDATORY), +}; + +#define cxl_for_each_cmd(cmd) \ + for ((cmd) = &mem_commands[0]; \ + ((cmd) - mem_commands) < ARRAY_SIZE(mem_commands); (cmd)++) + +static inline int cxl_cmd_index(const struct cxl_mem_command *c) +{ + if (unlikely(c >= mem_commands && + c < (mem_commands + sizeof(mem_commands)))) { + struct cxl_mem_command *p; + + cxl_for_each_cmd(p) + if (p->opcode == c->opcode && + p->flags == c->flags) + return p - mem_commands; + } else { + return c - mem_commands; + } + + WARN_ON_ONCE(1); + return 0; +} + +static inline struct cxl_mem_command *cxl_mem_find_command(u16 opcode) +{ + struct cxl_mem_command *c; + + cxl_for_each_cmd(c) { + if (c->opcode == opcode) + return c; + } + + return NULL; +} + static int cxl_mem_wait_for_doorbell(struct cxl_mem *cxlm) { const int timeout = msecs_to_jiffies(CXL_MAILBOX_TIMEOUT_US); @@ -140,6 +226,7 @@ static void cxl_mem_mbox_timeout(struct cxl_mem *cxlm, static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, struct mbox_cmd *mbox_cmd) { + const struct cxl_mem_command *cmd; u64 cmd_reg, status_reg; size_t out_len; int rc; @@ -158,6 +245,13 @@ static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, * 8. If output payload is non-empty, host reads Command Payload Registers */ + cmd = cxl_mem_find_command(mbox_cmd->opcode); + if (!cmd) { + dev_info(&cxlm->pdev->dev, + "Unknown opcode 0x%04x being sent to hardware\n", + mbox_cmd->opcode); + } + /* #1 */ WARN_ON(cxl_doorbell_busy(cxlm)); @@ -200,6 +294,20 @@ static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, out_len = CXL_GET_FIELD(cmd_reg, CXLDEV_MB_CMD_PAYLOAD_LENGTH); mbox_cmd->size_out = out_len; + /* + * If the command had a fixed size output, but the hardware did + * something unexpected, just print an error and move on. It would be + * worth sending a bug report. + */ + if (cmd && cmd->info.size_out >= 0 && + mbox_cmd->size_out != cmd->info.size_out) { + bool too_big = mbox_cmd->size_out > cmd->info.size_out; + + dev_err(&cxlm->pdev->dev, + "payload was %s than driver expectations\n", + too_big ? "larger" : "smaller"); + } + /* #8 */ if (out_len && mbox_cmd->payload) memcpy_fromio(mbox_cmd->payload, cxl_payload_regs(cxlm), @@ -323,8 +431,56 @@ static int cxl_mem_release(struct inode *inode, struct file *file) return 0; } +static int cxl_mem_count_commands(void) +{ + struct cxl_mem_command *c; + int n = 0; + + cxl_for_each_cmd(c) { + if (c->flags & CXL_CMD_INTERNAL_FLAG_HIDDEN) + continue; + n++; + } + + return n; +} + static long cxl_mem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { + struct cxl_memdev *cxlmd = file->private_data; + struct device *dev = &cxlmd->dev; + + if (cmd == CXL_MEM_QUERY_COMMANDS) { + struct cxl_mem_query_commands __user *q = (void __user *)arg; + struct cxl_mem_command *cmd; + u32 n_commands; + int j = 0; + + dev_dbg(dev, "Query IOCTL\n"); + + if (get_user(n_commands, (u32 __user *)arg)) + return -EFAULT; + + /* returns the total number if 0 elements are requested. */ + if (n_commands == 0) + return put_user(cxl_mem_count_commands(), + (u32 __user *)arg); + + /* otherwise, return max(n_commands, total commands) */ + cxl_for_each_cmd(cmd) { + const struct cxl_command_info *info = &cmd->info; + + if (cmd->flags & CXL_CMD_INTERNAL_FLAG_HIDDEN) + continue; + + if (copy_to_user(&q->commands[j++], info, sizeof(*info))) + return -EFAULT; + + if (j == n_commands) + break; + } + } + return -ENOTTY; } diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h new file mode 100644 index 000000000000..847f825bbe18 --- /dev/null +++ b/include/uapi/linux/cxl_mem.h @@ -0,0 +1,117 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * CXL IOCTLs for Memory Devices + */ + +#ifndef _UAPI_CXL_MEM_H_ +#define _UAPI_CXL_MEM_H_ + +#if defined(__cplusplus) +extern "C" { +#endif + +/** + * DOC: UAPI + * + * CXL memory devices expose UAPI to have a standard user interface. + * Userspace can refer to these structure definitions and UAPI formats + * to communicate to driver. The commands themselves are somewhat obfuscated + * with macro magic. They have the form CXL_MEM_COMMAND_ID_. + * + * For example "CXL_MEM_COMMAND_ID_INVALID" + * + * Not all of all commands that the driver supports are always available for use + * by userspace. Userspace must check the results from the QUERY command in + * order to determine the live set of commands. + */ + +#define CXL_MEM_QUERY_COMMANDS _IOR(0xCE, 1, struct cxl_mem_query_commands) + +#undef CMDS +#define CMDS \ + C(INVALID, "Invalid Command"), \ + C(IDENTIFY, "Identify Command"), \ + C(MAX, "Last command") +#undef C +#define C(a, b) CXL_MEM_COMMAND_ID_##a + +enum { CMDS }; + +/** + * struct cxl_command_info - Command information returned from a query. + * @id: ID number for the command. + * @flags: Flags that specify command behavior. + * + * * %CXL_MEM_COMMAND_FLAG_KERNEL: This command is reserved for exclusive + * kernel use. + * * %CXL_MEM_COMMAND_FLAG_MUTEX: This command may require coordination with + * the kernel in order to complete successfully. + * + * @size_in: Expected input size, or -1 if variable length. + * @size_out: Expected output size, or -1 if variable length. + * + * Represents a single command that is supported by both the driver and the + * hardware. The is returned as part of an array from the query ioctl. The + * following would be a command named "foobar" that takes a variable length + * input and returns 0 bytes of output. + * + * - @id = 10 + * - @flags = CXL_MEM_COMMAND_FLAG_MUTEX + * - @size_in = -1 + * - @size_out = 0 + * + * See struct cxl_mem_query_commands. + */ +struct cxl_command_info { + __u32 id; + + __u32 flags; +#define CXL_MEM_COMMAND_FLAG_NONE 0 +#define CXL_MEM_COMMAND_FLAG_KERNEL BIT(0) +#define CXL_MEM_COMMAND_FLAG_MUTEX BIT(1) + + __s32 size_in; + __s32 size_out; +}; + +/** + * struct cxl_mem_query_commands - Query supported commands. + * @n_commands: In/out parameter. When @n_commands is > 0, the driver will + * return min(num_support_commands, n_commands). When @n_commands + * is 0, driver will return the number of total supported commands. + * @rsvd: Reserved for future use. + * @commands: Output array of supported commands. This array must be allocated + * by userspace to be at least min(num_support_commands, @n_commands) + * + * Allow userspace to query the available commands supported by both the driver, + * and the hardware. Commands that aren't supported by either the driver, or the + * hardware are not returned in the query. + * + * Examples: + * + * - { .n_commands = 0 } // Get number of supported commands + * - { .n_commands = 15, .commands = buf } // Return first 15 (or less) + * supported commands + * + * See struct cxl_command_info. + */ +struct cxl_mem_query_commands { + /* + * Input: Number of commands to return (space allocated by user) + * Output: Number of commands supported by the driver/hardware + * + * If n_commands is 0, kernel will only return number of commands and + * not try to populate commands[], thus allowing userspace to know how + * much space to allocate + */ + __u32 n_commands; + __u32 rsvd; + + struct cxl_command_info __user commands[]; /* out: supported commands */ +}; + +#if defined(__cplusplus) +} +#endif + +#endif From patchwork Mon Jan 11 22:51:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011811 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FCCFC43381 for ; Tue, 12 Jan 2021 00:29:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD19522CB8 for ; Tue, 12 Jan 2021 00:29:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404206AbhALAZ6 (ORCPT ); Mon, 11 Jan 2021 19:25:58 -0500 Received: from mga17.intel.com ([192.55.52.151]:11217 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390810AbhAKWw6 (ORCPT ); Mon, 11 Jan 2021 17:52:58 -0500 IronPort-SDR: hEaZWTcPoZmMeWIp7GqKmB7N1TR0Qgx4x+IdHzhofd2FRAEuUjKTVI/jGOhsjNxj1yL7CcOblb 9iRa9o2lr6NQ== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726545" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726545" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:39 -0800 IronPort-SDR: QJNbhPeeZybgP0fOpn6snQDzRclcrCcv34peKBzxrBaTfGFJsBTyCh5BIBJuFFuejwqqiiwOFu 2jjYxL2uw9QQ== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778026" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:37 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 10/16] cxl/mem: Add send command Date: Mon, 11 Jan 2021 14:51:14 -0800 Message-Id: <20210111225121.820014-11-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The send command allows userspace to issue mailbox commands directly to the hardware. The driver will verify basic properties of the command and possible inspect the input (or output) payload to determine whether or not the command is allowed (or might taint the kernel). The list of allowed commands and their properties can be determined by using the QUERY IOCTL for CXL memory devices. Signed-off-by: Ben Widawsky --- drivers/cxl/mem.c | 204 ++++++++++++++++++++++++++++++++++- include/uapi/linux/cxl_mem.h | 39 +++++++ 2 files changed, 239 insertions(+), 4 deletions(-) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index d4eb3f5b9469..f979788b4d9f 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -84,6 +84,13 @@ static DEFINE_IDR(cxl_mem_idr); /* protect cxl_mem_idr allocations */ static DEFINE_MUTEX(cxl_memdev_lock); +#undef C +#define C(a, b) { b } +static struct { + const char *name; +} command_names[] = { CMDS }; +#undef C + #define CXL_CMD(_id, _flags, sin, sout, f) \ [CXL_MEM_COMMAND_ID_##_id] = { \ { \ @@ -319,16 +326,25 @@ static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, /** * cxl_mem_mbox_get() - Acquire exclusive access to the mailbox. * @cxlm: The memory device to gain access to. + * @interruptible: Allow interrupting mutex acquisition. * * Context: Any context. Takes the mbox_lock. * Return: 0 if exclusive access was acquired. */ -static int cxl_mem_mbox_get(struct cxl_mem *cxlm) +static int cxl_mem_mbox_get(struct cxl_mem *cxlm, bool interruptible) { u64 md_status; - int rc = -EBUSY; + int rc; + + if (interruptible) { + rc = mutex_lock_interruptible(&cxlm->mbox.mutex); + if (rc) + return rc; + } else { + mutex_lock_io(&cxlm->mbox.mutex); + } - mutex_lock_io(&cxlm->mbox.mutex); + rc = -EBUSY; /* * XXX: There is some amount of ambiguity in the 2.0 version of the spec @@ -443,6 +459,155 @@ static int cxl_mem_count_commands(void) } return n; +}; + +/** + * handle_mailbox_cmd_from_user() - Dispatch a mailbox command. + * @cxlmd: The CXL memory device to communicate with. + * @cmd: The validated command. + * @in_payload: Pointer to userspace's input payload. + * @out_payload: Pointer to userspace's output payload. + * @u: The command submitted by userspace. Has output fields. + * + * Return: + * * %0 - Mailbox transaction succeeded. + * * %-EFAULT - Something happened with copy_to/from_user. + * * %-EINTR - Mailbox acquisition interrupted. + * * %-E2BIG - Output payload would overrun buffer. + * + * Creates the appropriate mailbox command on behalf of a userspace request. + * Return value, size, and output payload are all copied out to @u. The + * parameters for the command must be validated before calling this function. + * + * A 0 return code indicates the command executed successfully, not that it was + * itself successful. IOW, the retval should always be checked if wanting to + * determine the actual result. + */ +static int handle_mailbox_cmd_from_user(struct cxl_memdev *cxlmd, + const struct cxl_mem_command *cmd, + u64 in_payload, + u64 out_payload, + struct cxl_send_command __user *u) +{ + struct mbox_cmd mbox_cmd = { + .opcode = cmd->opcode, + .size_in = cmd->info.size_in, + .payload = NULL, /* Copied by copy_to|from_user() */ + }; + int rc; + + if (cmd->info.size_in) { + /* + * Directly copy the userspace payload into the hardware. UAPI + * states that the buffer must already be little endian. + */ + if (copy_from_user((__force void *)cxl_payload_regs(cxlmd->cxlm), + u64_to_user_ptr(in_payload), + cmd->info.size_in)) { + cxl_mem_mbox_put(cxlmd->cxlm); + return -EFAULT; + } + } + + rc = cxl_mem_mbox_get(cxlmd->cxlm, true); + if (rc) + return rc; + + dev_dbg(&cxlmd->dev, + "Submitting %s command for user\n" + "\topcode: %x\n" + "\tsize: %ub\n", + command_names[cmd->info.id].name, mbox_cmd.opcode, + cmd->info.size_in); + + rc = cxl_mem_mbox_send_cmd(cxlmd->cxlm, &mbox_cmd); + cxl_mem_mbox_put(cxlmd->cxlm); + if (rc) + return rc; + + if (mbox_cmd.size_out > cmd->info.size_out) + return -E2BIG; + + rc = put_user(mbox_cmd.return_code, &u->retval); + if (rc) + return rc; + + rc = put_user(mbox_cmd.size_out, &u->size_out); + if (rc) + return rc; + + if (mbox_cmd.size_out) + if (copy_to_user(u64_to_user_ptr(out_payload), + (__force void *)cxl_payload_regs(cxlmd->cxlm), + mbox_cmd.size_out)) + return -EFAULT; + + return 0; +} + +/** + * cxl_validate_cmd_from_user() - Check fields for CXL_MEM_SEND_COMMAND. + * @cxlm: &struct cxl_mem device whose mailbox will be used. + * @send_cmd: &struct cxl_send_command copied in from userspace. + * @out_cmd: Sanitized and populated &struct cxl_mem_command. + * + * Return: + * * %0 - @out_cmd is ready to send. + * * %-ENOTTY - Invalid command specified. + * * %-EINVAL - Reserved fields or invalid values were used. + * * %-EPERM - Attempted to use a protected command. + * * %-ENOMEM - Input or output buffer wasn't sized properly. + * + * The result of this command is a fully validated command in @out_cmd that is + * safe to send to the hardware. + * + * See handle_mailbox_cmd_from_user() + */ +static int cxl_validate_cmd_from_user(struct cxl_mem *cxlm, + const struct cxl_send_command *send_cmd, + struct cxl_mem_command *out_cmd) +{ + const struct cxl_command_info *info; + struct cxl_mem_command *c; + + if (send_cmd->id == 0 || send_cmd->id >= CXL_MEM_COMMAND_ID_MAX) + return -ENOTTY; + + /* + * The user can never specify an input payload larger than our hardware + * supports, but output can be arbitrarily large, we simply write out as + * much data as the hardware provides. + */ + if (send_cmd->size_in > cxlm->mbox.payload_size) + return -EINVAL; + + if (send_cmd->flags & CXL_MEM_COMMAND_FLAG_MASK) + return -EINVAL; + + if (send_cmd->rsvd) + return -EINVAL; + + /* Convert user's command into the internal representation */ + c = &mem_commands[send_cmd->id]; + info = &c->info; + + if (info->flags & CXL_MEM_COMMAND_FLAG_KERNEL) + return -EPERM; + + /* Check the input buffer is the expected size */ + if (info->size_in >= 0 && info->size_in != send_cmd->size_in) + return -ENOMEM; + + /* Check the output buffer is at least large enough */ + if (info->size_out >= 0 && send_cmd->size_out < info->size_out) + return -ENOMEM; + + /* Setting a few const fields here... */ + memcpy(out_cmd, c, sizeof(*c)); + *(s32 *)&out_cmd->info.size_in = send_cmd->size_in; + *(s32 *)&out_cmd->info.size_out = send_cmd->size_out; + + return 0; } static long cxl_mem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) @@ -479,6 +644,37 @@ static long cxl_mem_ioctl(struct file *file, unsigned int cmd, unsigned long arg if (j == n_commands) break; } + + return 0; + } else if (cmd == CXL_MEM_SEND_COMMAND) { + struct cxl_send_command send, __user *u = (void __user *)arg; + struct cxl_mem_command c; + int rc; + + dev_dbg(dev, "Send IOCTL\n"); + + if (copy_from_user(&send, u, sizeof(send))) + return -EFAULT; + + rc = device_lock_interruptible(dev); + if (rc) + return rc; + + if (!get_live_device(dev)) { + device_unlock(dev); + return -ENXIO; + } + + rc = cxl_validate_cmd_from_user(cxlmd->cxlm, &send, &c); + if (!rc) + rc = handle_mailbox_cmd_from_user(cxlmd, &c, + send.in_payload, + send.out_payload, u); + + put_device(dev); + device_unlock(dev); + + return rc; } return -ENOTTY; @@ -837,7 +1033,7 @@ static int cxl_mem_identify(struct cxl_mem *cxlm) int rc; /* Retrieve initial device memory map */ - rc = cxl_mem_mbox_get(cxlm); + rc = cxl_mem_mbox_get(cxlm, false); if (rc) return rc; diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h index 847f825bbe18..cb4e2bee5228 100644 --- a/include/uapi/linux/cxl_mem.h +++ b/include/uapi/linux/cxl_mem.h @@ -26,6 +26,7 @@ extern "C" { */ #define CXL_MEM_QUERY_COMMANDS _IOR(0xCE, 1, struct cxl_mem_query_commands) +#define CXL_MEM_SEND_COMMAND _IOWR(0xCE, 2, struct cxl_send_command) #undef CMDS #define CMDS \ @@ -69,6 +70,7 @@ struct cxl_command_info { #define CXL_MEM_COMMAND_FLAG_NONE 0 #define CXL_MEM_COMMAND_FLAG_KERNEL BIT(0) #define CXL_MEM_COMMAND_FLAG_MUTEX BIT(1) +#define CXL_MEM_COMMAND_FLAG_MASK GENMASK(31, 2) __s32 size_in; __s32 size_out; @@ -110,6 +112,43 @@ struct cxl_mem_query_commands { struct cxl_command_info __user commands[]; /* out: supported commands */ }; +/** + * struct cxl_send_command - Send a command to a memory device. + * @id: The command to send to the memory device. This must be one of the + * commands returned by the query command. + * @flags: Flags for the command (input). + * @rsvd: Must be zero. + * @retval: Return value from the memory device (output). + * @size_in: Size of the payload to provide to the device (input). + * @size_out: Size of the payload received from the device (input/output). This + * field is filled in by userspace to let the driver know how much + * space was allocated for output. It is populated by the driver to + * let userspace know how large the output payload actually was. + * @in_payload: Pointer to memory for payload input (little endian order). + * @out_payload: Pointer to memory for payload output (little endian order). + * + * Mechanism for userspace to send a command to the hardware for processing. The + * driver will do basic validation on the command sizes, but the payload input + * and output are not introspected. Userspace is required to allocate large + * enough buffers for max(size_in, size_out). + */ +struct cxl_send_command { + __u32 id; + __u32 flags; + __u32 rsvd; + __u32 retval; + + struct { + __s32 size_in; + __u64 in_payload; + }; + + struct { + __s32 size_out; + __u64 out_payload; + }; +}; + #if defined(__cplusplus) } #endif From patchwork Mon Jan 11 22:51:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011807 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5CF1C433E9 for ; Tue, 12 Jan 2021 00:29:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8F2222CB8 for ; Tue, 12 Jan 2021 00:29:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405552AbhALAZ7 (ORCPT ); Mon, 11 Jan 2021 19:25:59 -0500 Received: from mga17.intel.com ([192.55.52.151]:11211 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390821AbhAKWxL (ORCPT ); Mon, 11 Jan 2021 17:53:11 -0500 IronPort-SDR: jDrJFoLEuLLHxXwvZfazOgwmyefzrHLSVjIYPrjj1BYWXqr2H1XCSxElJZRrt7AeCS9hAlYC1d I6MOX+mwLU0g== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726549" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726549" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:41 -0800 IronPort-SDR: ZxpCVApPOpk0948rEmPyzjcAQIfRJ4RpvKSw9tMLqqgCHH8ZLE8YbvsQijFc5W547cymkbrvI1 vXGRFrgpg1ig== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778039" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:40 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 11/16] taint: add taint for unfettered hardware access Date: Mon, 11 Jan 2021 14:51:16 -0800 Message-Id: <20210111225121.820014-13-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Make notes about why we use this. Signed-off-by: Ben Widawsky --- Documentation/admin-guide/sysctl/kernel.rst | 1 + Documentation/admin-guide/tainted-kernels.rst | 6 +++++- include/linux/kernel.h | 3 ++- kernel/panic.c | 1 + 4 files changed, 9 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 1d56a6b73a4e..3e1eada53504 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -1352,6 +1352,7 @@ ORed together. The letters are seen in "Tainted" line of Oops reports. 32768 `(K)` kernel has been live patched 65536 `(X)` Auxiliary taint, defined and used by for distros 131072 `(T)` The kernel was built with the struct randomization plugin +262144 `(H)` The kernel has allowed vendor shenanigans ====== ===== ============================================================== See :doc:`/admin-guide/tainted-kernels` for more information. diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst index ceeed7b0798d..ee2913316344 100644 --- a/Documentation/admin-guide/tainted-kernels.rst +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -74,7 +74,7 @@ a particular type of taint. It's best to leave that to the aforementioned script, but if you need something quick you can use this shell command to check which bits are set:: - $ for i in $(seq 18); do echo $(($i-1)) $(($(cat /proc/sys/kernel/tainted)>>($i-1)&1));done + $ for i in $(seq 19); do echo $(($i-1)) $(($(cat /proc/sys/kernel/tainted)>>($i-1)&1));done Table for decoding tainted state ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -100,6 +100,7 @@ Bit Log Number Reason that got the kernel tainted 15 _/K 32768 kernel has been live patched 16 _/X 65536 auxiliary taint, defined for and used by distros 17 _/T 131072 kernel was built with the struct randomization plugin + 18 _/H 262144 kernel has allowed vendor shenanigans === === ====== ======================================================== Note: The character ``_`` is representing a blank in this table to make reading @@ -175,3 +176,6 @@ More detailed explanation for tainting produce extremely unusual kernel structure layouts (even performance pathological ones), which is important to know when debugging. Set at build time. + + 18) ``H`` Kernel has allowed direct access to hardware and can no longer make + any guarantees about the stability of the device or driver. diff --git a/include/linux/kernel.h b/include/linux/kernel.h index f7902d8c1048..bc95486f817e 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -443,7 +443,8 @@ extern enum system_states { #define TAINT_LIVEPATCH 15 #define TAINT_AUX 16 #define TAINT_RANDSTRUCT 17 -#define TAINT_FLAGS_COUNT 18 +#define TAINT_RAW_PASSTHROUGH 18 +#define TAINT_FLAGS_COUNT 19 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) struct taint_flag { diff --git a/kernel/panic.c b/kernel/panic.c index 332736a72a58..dff22bd80eaf 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -386,6 +386,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, [ TAINT_AUX ] = { 'X', ' ', true }, [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, + [ TAINT_RAW_PASSTHROUGH ] = { 'H', ' ', true }, }; /** From patchwork Mon Jan 11 22:51:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011805 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F19DC433DB for ; Tue, 12 Jan 2021 00:29:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C10922CB8 for ; Tue, 12 Jan 2021 00:29:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405554AbhALAZ7 (ORCPT ); Mon, 11 Jan 2021 19:25:59 -0500 Received: from mga17.intel.com ([192.55.52.151]:11217 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390823AbhAKWxO (ORCPT ); Mon, 11 Jan 2021 17:53:14 -0500 IronPort-SDR: QQd7VrHP79wBsjMC4iLPmK6PKq/00uP+dr7RMyoP9/3krLnl/so28w067ZxZPUrADjOXXtde/4 Zj6RFejUXYVw== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726551" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726551" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:42 -0800 IronPort-SDR: 9vT7xNVlp66s3vmTTHdPG0OuUd7Rp2ye6lDOGC1tN90knAjPBYCiE2JllOTYjWw9EddnHmgeKP +1IhX0SVjdNw== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778043" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:41 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 12/16] cxl/mem: Add a "RAW" send command Date: Mon, 11 Jan 2021 14:51:17 -0800 Message-Id: <20210111225121.820014-14-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The CXL memory device send interface will have a number of supported commands. The raw command is not such a command. Raw commands allow userspace to send a specified opcode to the underlying hardware and bypass all driver checks on the command. This is useful for a couple of usecases, mainly: 1. Undocumented vendor specific hardware commands 2. Prototyping new hardware commands not yet supported by the driver While this all sounds very powerful it comes with a couple of caveats: 1. Bug reports using raw commands will not get the same level of attention as bug reports using supported commands (via taint). 2. Supported commands will be rejected by the RAW command. Signed-off-by: Ben Widawsky --- drivers/cxl/mem.c | 27 +++++++++++++++++++++++++++ include/uapi/linux/cxl_mem.h | 12 +++++++++++- 2 files changed, 38 insertions(+), 1 deletion(-) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index f979788b4d9f..a824cfd4342a 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -43,6 +43,7 @@ enum opcode { CXL_MBOX_OP_INVALID = 0x0000, +#define CXL_MBOX_OP_RAW CXL_MBOX_OP_INVALID CXL_MBOX_OP_IDENTIFY = 0x4000, CXL_MBOX_OP_MAX = 0x10000 }; @@ -139,6 +140,7 @@ struct cxl_mem_command { static struct cxl_mem_command mem_commands[] = { CXL_CMD(INVALID, KERNEL, 0, 0, HIDDEN), CXL_CMD(IDENTIFY, NONE, 0, 0x43, MANDATORY), + CXL_CMD(RAW, NONE, ~0, ~0, MANDATORY), }; #define cxl_for_each_cmd(cmd) \ @@ -520,6 +522,9 @@ static int handle_mailbox_cmd_from_user(struct cxl_memdev *cxlmd, command_names[cmd->info.id].name, mbox_cmd.opcode, cmd->info.size_in); + if (cmd->info.id == CXL_MEM_COMMAND_ID_RAW) + add_taint(TAINT_RAW_PASSTHROUGH, LOCKDEP_STILL_OK); + rc = cxl_mem_mbox_send_cmd(cxlmd->cxlm, &mbox_cmd); cxl_mem_mbox_put(cxlmd->cxlm); if (rc) @@ -581,6 +586,28 @@ static int cxl_validate_cmd_from_user(struct cxl_mem *cxlm, if (send_cmd->size_in > cxlm->mbox.payload_size) return -EINVAL; + /* Checks are bypassed for raw commands but along comes the taint! */ + if (send_cmd->id == CXL_MEM_COMMAND_ID_RAW) { + const struct cxl_mem_command temp = { + { + .id = CXL_MEM_COMMAND_ID_RAW, + .flags = CXL_MEM_COMMAND_FLAG_NONE, + .size_in = send_cmd->size_in, + .size_out = send_cmd->size_out, + }, + .flags = 0, + .opcode = send_cmd->raw.opcode + }; + + if (send_cmd->raw.rsvd) + return -EINVAL; + + if (cxl_mem_find_command(send_cmd->raw.opcode)) + return -EPERM; + + return PTR_ERR_OR_ZERO(memcpy(out_cmd, &temp, sizeof(temp))); + } + if (send_cmd->flags & CXL_MEM_COMMAND_FLAG_MASK) return -EINVAL; diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h index cb4e2bee5228..50acd6cc14d4 100644 --- a/include/uapi/linux/cxl_mem.h +++ b/include/uapi/linux/cxl_mem.h @@ -32,6 +32,7 @@ extern "C" { #define CMDS \ C(INVALID, "Invalid Command"), \ C(IDENTIFY, "Identify Command"), \ + C(RAW, "Raw device command"), \ C(MAX, "Last command") #undef C #define C(a, b) CXL_MEM_COMMAND_ID_##a @@ -117,6 +118,9 @@ struct cxl_mem_query_commands { * @id: The command to send to the memory device. This must be one of the * commands returned by the query command. * @flags: Flags for the command (input). + * @raw: Special fields for raw commands + * @raw.opcode: Opcode passed to hardware when using the RAW command. + * @raw.rsvd: Must be zero. * @rsvd: Must be zero. * @retval: Return value from the memory device (output). * @size_in: Size of the payload to provide to the device (input). @@ -135,7 +139,13 @@ struct cxl_mem_query_commands { struct cxl_send_command { __u32 id; __u32 flags; - __u32 rsvd; + union { + struct { + __u16 opcode; + __u16 rsvd; + } raw; + __u32 rsvd; + }; __u32 retval; struct { From patchwork Mon Jan 11 22:51:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011803 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01CD1C433E6 for ; Tue, 12 Jan 2021 00:29:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBFAC22CB8 for ; Tue, 12 Jan 2021 00:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390804AbhALAZ7 (ORCPT ); Mon, 11 Jan 2021 19:25:59 -0500 Received: from mga17.intel.com ([192.55.52.151]:11219 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390824AbhAKWxP (ORCPT ); Mon, 11 Jan 2021 17:53:15 -0500 IronPort-SDR: 6a4yepCyN/+PCgnpnrjbcTUOPxWJAW4CQxt88wDh/5AfknTCW+cyYJ/p2Z4cS6BGl84eoNZlNG QJQPHe13RqoQ== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726554" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726554" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:43 -0800 IronPort-SDR: VJOTcjm/dpby0S70mG4OmSZIUeCRFhAMGMF18ZGz7HHVUBRiBvVhxbqNaKGjQatvF/YNEP9HAp Ap62qn3RKaSg== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778047" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:42 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 13/16] cxl/mem: Create concept of enabled commands Date: Mon, 11 Jan 2021 14:51:18 -0800 Message-Id: <20210111225121.820014-15-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org CXL devices must implement the Device Command Interface (described in 8.2.9 of the CXL 2.0 spec). While the driver already maintains a list of commands it supports, there is still a need to be able to distinguish between commands that the driver knows about from commands that may not be supported by the hardware. No such commands currently are defined in the driver. The implementation leaves the statically defined table of commands and supplements it with a bitmap to determine commands that are enabled. --- There are multiple approaches that can be taken, but this is nice for a few reasons. Here are some of the other solutions: Create a per instance table with only the supported commands. 1. Having a fixed command id -> command mapping is much easier to manage for development and debugging. 2. Dealing with dynamic memory allocation for the table adds unnecessary complexity. 3. Most tables for device types are likely to be quite similar. 4. Makes it difficult to implement helper macros like cxl_for_each_cmd() If the per instance table did preserve ids, #1 above can be addressed. However, as "enable" is currently the only mutable state for the commands, it would yield a lot of overhead for not much gain. Additionally, the other issues remain. If "enable" remains the only mutable state, I believe this to be the best solution. Once the number of mutable elements in a command grows, it probably makes sense to move to per device instance state with a fixed command ID mapping. Signed-off-by: Ben Widawsky --- drivers/cxl/cxl.h | 4 ++++ drivers/cxl/mem.c | 38 +++++++++++++++++++++++++++++++++++++- 2 files changed, 41 insertions(+), 1 deletion(-) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 537ac4d8e6bd..963ba30cb200 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -17,6 +17,9 @@ #define CXL_GET_FIELD(word, field) FIELD_GET(field##_MASK, word) +/* XXX: Arbitrary max */ +#define CXL_MAX_COMMANDS 32 + /* Device (CXL 2.0 - 8.2.8.3) */ #define CXLDEV_CAP_ARRAY_REG 0x0 #define CXLDEV_CAP_ARRAY_CAP_ID 0 @@ -88,6 +91,7 @@ struct cxl_mem { } ram; char firmware_version[0x10]; + DECLARE_BITMAP(enabled_cmds, CXL_MAX_COMMANDS); /* Cap 0001h - CXL_CAP_CAP_ID_DEVICE_STATUS */ struct { diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index a824cfd4342a..20b26fa2c466 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -114,6 +114,8 @@ static struct { * would typically be used for deprecated commands. * * %CXL_CMD_FLAG_MANDATORY: Hardware must support this command. This flag is * only used internally by the driver for sanity checking. + * * %CXL_CMD_INTERNAL_FLAG_PSEUDO: This is a pseudo command which doesn't have + * a direct mapping to hardware. They are implicitly always enabled. * * The cxl_mem_command is the driver's internal representation of commands that * are supported by the driver. Some of these commands may not be supported by @@ -129,6 +131,7 @@ struct cxl_mem_command { #define CXL_CMD_INTERNAL_FLAG_NONE 0 #define CXL_CMD_INTERNAL_FLAG_HIDDEN BIT(0) #define CXL_CMD_INTERNAL_FLAG_MANDATORY BIT(1) +#define CXL_CMD_INTERNAL_FLAG_PSEUDO BIT(2) }; /* @@ -140,7 +143,7 @@ struct cxl_mem_command { static struct cxl_mem_command mem_commands[] = { CXL_CMD(INVALID, KERNEL, 0, 0, HIDDEN), CXL_CMD(IDENTIFY, NONE, 0, 0x43, MANDATORY), - CXL_CMD(RAW, NONE, ~0, ~0, MANDATORY), + CXL_CMD(RAW, NONE, ~0, ~0, PSEUDO), }; #define cxl_for_each_cmd(cmd) \ @@ -618,6 +621,10 @@ static int cxl_validate_cmd_from_user(struct cxl_mem *cxlm, c = &mem_commands[send_cmd->id]; info = &c->info; + /* Check that the command is enabled for hardware */ + if (!test_bit(cxl_cmd_index(c), cxlm->enabled_cmds)) + return -ENOTTY; + if (info->flags & CXL_MEM_COMMAND_FLAG_KERNEL) return -EPERM; @@ -1029,6 +1036,31 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) return rc; } +/** + * cxl_mem_enumerate_cmds() - Enumerate commands for a device. + * @cxlm: The device. + * + * Returns 0 if enumerate completed successfully. + * + * CXL devices have optional support for certain commands. This function will + * determine the set of supported commands for the hardware and update the + * enabled_cmds bitmap in the @cxlm. + */ +static int cxl_mem_enumerate_cmds(struct cxl_mem *cxlm) +{ + struct cxl_mem_command *c; + + /* All commands are considered enabled for now (except INVALID). */ + cxl_for_each_cmd(c) { + if (c->flags & CXL_CMD_INTERNAL_FLAG_HIDDEN) + continue; + + set_bit(cxl_cmd_index(c), cxlm->enabled_cmds); + } + + return 0; +} + /** * cxl_mem_identify() - Send the IDENTIFY command to the device. * @cxlm: The device to identify. @@ -1147,6 +1179,10 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (rc) goto err; + rc = cxl_mem_enumerate_cmds(cxlm); + if (rc) + return rc; + rc = cxl_mem_identify(cxlm); if (rc) goto err; From patchwork Mon Jan 11 22:51:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011801 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01043C433DB for ; Tue, 12 Jan 2021 00:29:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD5D222CB8 for ; Tue, 12 Jan 2021 00:29:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390809AbhALAZ7 (ORCPT ); Mon, 11 Jan 2021 19:25:59 -0500 Received: from mga17.intel.com ([192.55.52.151]:11211 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390825AbhAKWx1 (ORCPT ); Mon, 11 Jan 2021 17:53:27 -0500 IronPort-SDR: WyHNVoQhwmY/wkGNKbpDLtBdQtQ5rwc1/rMSlstlXb/vaT2lIj07Kz7RVRC1k7E+2KmmgR6dav E1LR34ful8VA== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726555" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726555" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:44 -0800 IronPort-SDR: UNV0kNKA2Yu0Mz7uxhJI+QFRisZUciKHG/jg1FpI9MIamIbJ0R2i1ITAVatW9+3F8XJe1Tnh4A /TInKVZ32U0g== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778054" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:43 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 14/16] cxl/mem: Use CEL for enabling commands Date: Mon, 11 Jan 2021 14:51:19 -0800 Message-Id: <20210111225121.820014-16-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The Command Effects Log (CEL) is specified in the CXL 2.0 specification. The CEL is one of two types of logs, the other being vendor specific. They are distinguished in hardware/spec via UUID. The CEL is immediately useful for 2 things: 1. Determine which optional commands are supported by the CXL device. 2. Enumerate any vendor specific commands The CEL can be used by the driver to determine which commands are available in the hardware (though it isn't, yet). That set of commands might itself be a subset of commands which are available to be used via CXL_MEM_SEND_COMMAND IOCTL. Prior to this, all commands that the driver exposed were explicitly enabled. After this, only those commands that are found in the CEL are enabled. Signed-off-by: Ben Widawsky --- drivers/cxl/mem.c | 178 +++++++++++++++++++++++++++++++++-- include/uapi/linux/cxl_mem.h | 1 + 2 files changed, 172 insertions(+), 7 deletions(-) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 20b26fa2c466..6dfc8ff0aefb 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -44,8 +44,10 @@ enum opcode { CXL_MBOX_OP_INVALID = 0x0000, #define CXL_MBOX_OP_RAW CXL_MBOX_OP_INVALID - CXL_MBOX_OP_IDENTIFY = 0x4000, - CXL_MBOX_OP_MAX = 0x10000 + CXL_MBOX_OP_GET_SUPPORTED_LOGS = 0x0400, + CXL_MBOX_OP_GET_LOG = 0x0401, + CXL_MBOX_OP_IDENTIFY = 0x4000, + CXL_MBOX_OP_MAX = 0x10000 }; /** @@ -104,6 +106,16 @@ static struct { .opcode = CXL_MBOX_OP_##_id, \ } +enum { + CEL_UUID, + DEBUG_UUID +}; + +static const uuid_t log_uuid[] = { + UUID_INIT(0xda9c0b5, 0xbf41, 0x4b78, 0x8f, 0x79, 0x96, 0xb1, 0x62, 0x3b, 0x3f, 0x17), + UUID_INIT(0xe1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19, 0x40, 0x3d, 0x86) +}; + /** * struct cxl_mem_command - Driver representation of a memory device command * @info: Command information as it exists for the UAPI @@ -144,6 +156,7 @@ static struct cxl_mem_command mem_commands[] = { CXL_CMD(INVALID, KERNEL, 0, 0, HIDDEN), CXL_CMD(IDENTIFY, NONE, 0, 0x43, MANDATORY), CXL_CMD(RAW, NONE, ~0, ~0, PSEUDO), + CXL_CMD(GET_SUPPORTED_LOGS, NONE, 0, ~0, MANDATORY), }; #define cxl_for_each_cmd(cmd) \ @@ -1036,6 +1049,103 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) return rc; } +struct cxl_mbox_get_supported_logs { + __le16 entries; + u8 rsvd[6]; + struct gsl_entry { + uuid_t uuid; + __le32 size; + } __packed entry[2]; +} __packed; +struct cxl_mbox_get_log { + uuid_t uuid; + __le32 offset; + __le32 length; +} __packed; + +static int cxl_xfer_log(struct cxl_mem *cxlm, uuid_t *uuid, u32 size, + u8 *out) +{ + u32 remaining = size; + u32 offset = 0; + + while (remaining) { + u32 xfer_size = min_t(u32, remaining, cxlm->mbox.payload_size); + struct mbox_cmd mbox_cmd; + int rc; + struct cxl_mbox_get_log log = { + .uuid = *uuid, + .offset = cpu_to_le32(offset), + .length = cpu_to_le32(xfer_size) + }; + + memcpy_toio(cxl_payload_regs(cxlm), &log, sizeof(log)); + mbox_cmd = (struct mbox_cmd) { + .opcode = CXL_MBOX_OP_GET_LOG, + .payload = NULL, + .size_in = sizeof(log), + }; + + rc = cxl_mem_mbox_send_cmd(cxlm, &mbox_cmd); + if (rc) + return rc; + + WARN_ON(mbox_cmd.size_out != xfer_size); + + memcpy_fromio(out, cxl_payload_regs(cxlm), mbox_cmd.size_out); + out += xfer_size; + remaining -= xfer_size; + offset += xfer_size; + } + + return 0; +} + +static void cxl_enable_cmd(struct cxl_mem *cxlm, + const struct cxl_mem_command *cmd) +{ + if (test_and_set_bit(cxl_cmd_index(cmd), cxlm->enabled_cmds)) + dev_warn(&cxlm->pdev->dev, "Command enabled twice\n"); + + dev_info(&cxlm->pdev->dev, "%s enabled", + command_names[cxl_cmd_index(cmd)].name); +} + +/** + * cxl_walk_cel() - Walk through the Command Effects Log. + * @cxlm: Device. + * @size: Length of the Command Effects Log. + * @cel: CEL + * + * Iterate over each entry in the CEL and determine if the driver supports the + * command. If so, the command is enabled for the device and can be used later. + */ +static void cxl_walk_cel(struct cxl_mem *cxlm, size_t size, u8 *cel) +{ + struct cel_entry { + __le16 opcode; + __le16 effect; + } *cel_entry; + const int cel_entries = size / sizeof(*cel_entry); + int i; + + cel_entry = (struct cel_entry *)cel; + + for (i = 0; i < cel_entries; i++) { + const struct cel_entry *ce = &cel_entry[i]; + const struct cxl_mem_command *cmd = + cxl_mem_find_command(le16_to_cpu(ce->opcode)); + + if (!cmd) { + dev_dbg(&cxlm->pdev->dev, "Unsupported opcode 0x%04x", + le16_to_cpu(ce->opcode)); + continue; + } + + cxl_enable_cmd(cxlm, cmd); + } +} + /** * cxl_mem_enumerate_cmds() - Enumerate commands for a device. * @cxlm: The device. @@ -1048,17 +1158,71 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) */ static int cxl_mem_enumerate_cmds(struct cxl_mem *cxlm) { - struct cxl_mem_command *c; + struct cxl_mbox_get_supported_logs gsl; + const struct cxl_mem_command *c; + struct mbox_cmd mbox_cmd; + int i, rc; - /* All commands are considered enabled for now (except INVALID). */ + /* Pseudo commands are always enabled */ cxl_for_each_cmd(c) { - if (c->flags & CXL_CMD_INTERNAL_FLAG_HIDDEN) + if (c->flags & CXL_CMD_INTERNAL_FLAG_PSEUDO) + cxl_enable_cmd(cxlm, c); + } + + rc = cxl_mem_mbox_get(cxlm, false); + if (rc) + return rc; + + mbox_cmd = (struct mbox_cmd){ + .opcode = CXL_MBOX_OP_GET_SUPPORTED_LOGS, + .payload = &gsl, + .size_in = 0, + }; + rc = cxl_mem_mbox_send_cmd(cxlm, &mbox_cmd); + if (rc) + goto out; + + for (i = 0; i < le16_to_cpu(gsl.entries); i++) { + u32 size = le32_to_cpu(gsl.entry[i].size); + uuid_t uuid = gsl.entry[i].uuid; + u8 *log; + + dev_dbg(&cxlm->pdev->dev, "Found LOG type %pU of size %d", + &uuid, size); + + if (!uuid_equal(&uuid, &log_uuid[CEL_UUID])) continue; - set_bit(cxl_cmd_index(c), cxlm->enabled_cmds); + /* + * It's a hardware bug if the log size is less than the input + * payload size because there are many mandatory commands. + */ + if (sizeof(struct cxl_mbox_get_log) > size) { + dev_err(&cxlm->pdev->dev, + "CEL log size reported was too small (%d)", + size); + rc = -ENOMEM; + goto out; + } + + log = kvmalloc(size, GFP_KERNEL); + if (!log) { + rc = -ENOMEM; + goto out; + } + + rc = cxl_xfer_log(cxlm, &uuid, size, log); + if (rc) + goto out; + + cxl_walk_cel(cxlm, size, log); + + kvfree(log); } - return 0; +out: + cxl_mem_mbox_put(cxlm); + return rc; } /** diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h index 50acd6cc14d4..b504412d1db7 100644 --- a/include/uapi/linux/cxl_mem.h +++ b/include/uapi/linux/cxl_mem.h @@ -33,6 +33,7 @@ extern "C" { C(INVALID, "Invalid Command"), \ C(IDENTIFY, "Identify Command"), \ C(RAW, "Raw device command"), \ + C(GET_SUPPORTED_LOGS, "Get Supported Logs"), \ C(MAX, "Last command") #undef C #define C(a, b) CXL_MEM_COMMAND_ID_##a From patchwork Mon Jan 11 22:51:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011799 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99B5BC4332B for ; Tue, 12 Jan 2021 00:29:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F55122CB8 for ; Tue, 12 Jan 2021 00:29:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390821AbhALAZ7 (ORCPT ); Mon, 11 Jan 2021 19:25:59 -0500 Received: from mga17.intel.com ([192.55.52.151]:11217 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390826AbhAKWx3 (ORCPT ); Mon, 11 Jan 2021 17:53:29 -0500 IronPort-SDR: CL/0oszWglIRsDqEGsIPoaeaKJ43aAQb+1GdSkkpb2SKkWsKU/261xzEioTCUuyiUa9XAcJuWy lI7l7okkY1Fw== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726556" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726556" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:45 -0800 IronPort-SDR: 6pJ6EpmEYXLhnzNPZesqE1yNHmYCjD1gD8greVg39HvwW3032McTQ7gljJ5lxij43bU7VKyAD0 tYiCyHLYh3MQ== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778058" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:44 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , Dan Williams , Vishal Verma , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 15/16] cxl/mem: Add limited Get Log command (0401h) Date: Mon, 11 Jan 2021 14:51:20 -0800 Message-Id: <20210111225121.820014-17-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The Get Log command returns the actual log entries that are advertised via the Get Supported Logs command (0400h). CXL device logs are selected by UUID which is part of the CXL spec. Because the driver tries to sanitize what is sent to hardware, there becomes a need to restrict the types of logs which can be accessed by userspace. For example, the vendor specific log might only be consumable by proprietary, or offline applications, and therefore a good candidate for userspace. The current driver infrastructure does allow basic validation for all commands, but doesn't inspect any of the payload data. Along with Get Log support comes new infrastructure to add a hook for payload validation. This infrastructure is used to filter out the CEL UUID, which the userspace driver doesn't have business knowing, and taints on invalid UUIDs being sent to hardware. Signed-off-by: Ben Widawsky --- drivers/cxl/mem.c | 42 +++++++++++++++++++++++++++++++++++- include/uapi/linux/cxl_mem.h | 1 + 2 files changed, 42 insertions(+), 1 deletion(-) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 6dfc8ff0aefb..593db737e7a4 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -94,7 +94,7 @@ static struct { } command_names[] = { CMDS }; #undef C -#define CXL_CMD(_id, _flags, sin, sout, f) \ +#define CXL_CMD_VALIDATE(_id, _flags, sin, sout, f, v) \ [CXL_MEM_COMMAND_ID_##_id] = { \ { \ .id = CXL_MEM_COMMAND_ID_##_id, \ @@ -104,8 +104,12 @@ static struct { }, \ .flags = CXL_CMD_INTERNAL_FLAG_##f, \ .opcode = CXL_MBOX_OP_##_id, \ + .validate_payload = v, \ } +#define CXL_CMD(_id, _flags, sin, sout, f) \ + CXL_CMD_VALIDATE(_id, _flags, sin, sout, f, NULL) + enum { CEL_UUID, DEBUG_UUID @@ -116,6 +120,8 @@ static const uuid_t log_uuid[] = { UUID_INIT(0xe1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19, 0x40, 0x3d, 0x86) }; +static int validate_log_uuid(void __user *payload, size_t size); + /** * struct cxl_mem_command - Driver representation of a memory device command * @info: Command information as it exists for the UAPI @@ -129,6 +135,10 @@ static const uuid_t log_uuid[] = { * * %CXL_CMD_INTERNAL_FLAG_PSEUDO: This is a pseudo command which doesn't have * a direct mapping to hardware. They are implicitly always enabled. * + * @validate_payload: A function called after the command is validated but + * before it's sent to the hardware. The primary purpose is to validate, or + * fixup the actual payload. + * * The cxl_mem_command is the driver's internal representation of commands that * are supported by the driver. Some of these commands may not be supported by * the hardware. The driver will use @info to validate the fields passed in by @@ -144,6 +154,8 @@ struct cxl_mem_command { #define CXL_CMD_INTERNAL_FLAG_HIDDEN BIT(0) #define CXL_CMD_INTERNAL_FLAG_MANDATORY BIT(1) #define CXL_CMD_INTERNAL_FLAG_PSEUDO BIT(2) + + int (*validate_payload)(void __user *payload, size_t size); }; /* @@ -157,6 +169,8 @@ static struct cxl_mem_command mem_commands[] = { CXL_CMD(IDENTIFY, NONE, 0, 0x43, MANDATORY), CXL_CMD(RAW, NONE, ~0, ~0, PSEUDO), CXL_CMD(GET_SUPPORTED_LOGS, NONE, 0, ~0, MANDATORY), + CXL_CMD_VALIDATE(GET_LOG, MUTEX, 0x18, ~0, MANDATORY, + validate_log_uuid), }; #define cxl_for_each_cmd(cmd) \ @@ -515,6 +529,15 @@ static int handle_mailbox_cmd_from_user(struct cxl_memdev *cxlmd, int rc; if (cmd->info.size_in) { + if (cmd->validate_payload) { + rc = cmd->validate_payload(u64_to_user_ptr(in_payload), + cmd->info.size_in); + if (rc) { + cxl_mem_mbox_put(cxlmd->cxlm); + return -EFAULT; + } + } + /* * Directly copy the userspace payload into the hardware. UAPI * states that the buffer must already be little endian. @@ -1063,6 +1086,23 @@ struct cxl_mbox_get_log { __le32 length; } __packed; +static int validate_log_uuid(void __user *input, size_t size) +{ + struct cxl_mbox_get_log __user *get_log = input; + uuid_t payload_uuid; + + if (copy_from_user(&payload_uuid, &get_log->uuid, sizeof(uuid_t))) + return -EFAULT; + + /* All commands taint except debug vendor log */ + if (uuid_equal(&payload_uuid, &log_uuid[DEBUG_UUID])) + return 0; + + add_taint(TAINT_RAW_PASSTHROUGH, LOCKDEP_STILL_OK); + + return 0; +} + static int cxl_xfer_log(struct cxl_mem *cxlm, uuid_t *uuid, u32 size, u8 *out) { diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h index b504412d1db7..4c4a12c7a4d5 100644 --- a/include/uapi/linux/cxl_mem.h +++ b/include/uapi/linux/cxl_mem.h @@ -34,6 +34,7 @@ extern "C" { C(IDENTIFY, "Identify Command"), \ C(RAW, "Raw device command"), \ C(GET_SUPPORTED_LOGS, "Get Supported Logs"), \ + C(GET_LOG, "Get Log"), \ C(MAX, "Last command") #undef C #define C(a, b) CXL_MEM_COMMAND_ID_##a From patchwork Mon Jan 11 22:51:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12011797 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67014C433E0 for ; Tue, 12 Jan 2021 00:29:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DDC922CB8 for ; Tue, 12 Jan 2021 00:29:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390825AbhALAZ7 (ORCPT ); Mon, 11 Jan 2021 19:25:59 -0500 Received: from mga17.intel.com ([192.55.52.151]:11219 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390833AbhAKWxb (ORCPT ); Mon, 11 Jan 2021 17:53:31 -0500 IronPort-SDR: NXatNrkbPfB+G2j1/cHYUgOmHtpTPnA9gKo3FkYL9RqxYtzwUZrcta2tH3krndsge+NmTxaoqv LOLNBGgWMfSw== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="157726558" X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="157726558" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:46 -0800 IronPort-SDR: VdJ05s1NChzHk7duOIerNMDumd6j1VR5FhcSlVVNOvy50xDDnztFRh35l+lpp5z3CnuayyejMB 7y40Iq17FxrQ== X-IronPort-AV: E=Sophos;i="5.79,339,1602572400"; d="scan'208";a="352778062" Received: from yyang31-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.142.71]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2021 14:51:45 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , Dan Williams , Vishal Verma , Ira Weiny , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "linux-acpi@vger.kernel.org, Ira Weiny" , "Kelley, Sean V" , Rafael Wysocki , Bjorn Helgaas , Jonathan Cameron , Jon Masters , Chris Browy , Randy Dunlap , Christoph Hellwig , daniel.lll@alibaba-inc.com Subject: [RFC PATCH v3 16/16] MAINTAINERS: Add maintainers of the CXL driver Date: Mon, 11 Jan 2021 14:51:21 -0800 Message-Id: <20210111225121.820014-18-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com> References: <20210111225121.820014-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Cc: Dan Williams Cc: Vishal Verma Cc: Ira Weiny Signed-off-by: Ben Widawsky --- MAINTAINERS | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 6eff4f720c72..70c7ec4b2921 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4459,6 +4459,16 @@ F: fs/configfs/ F: include/linux/configfs.h F: samples/configfs/ +COMPUTE EXPRESS LINK (CXL) +M: Vishal Verma +M: Ira Weiny +M: Ben Widawsky +M: Dan Williams +L: linux-cxl@vger.kernel.org +S: Maintained +F: drivers/cxl/ +F: include/uapi/linux/cxl_mem.h + CONSOLE SUBSYSTEM M: Greg Kroah-Hartman S: Supported