From patchwork Mon Apr 19 16:54:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12212317 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 8B0CAC433ED for ; Mon, 19 Apr 2021 16:56:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D9DA611C9 for ; Mon, 19 Apr 2021 16:56:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232598AbhDSQ4a (ORCPT ); Mon, 19 Apr 2021 12:56:30 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2882 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230127AbhDSQ4a (ORCPT ); Mon, 19 Apr 2021 12:56:30 -0400 Received: from fraeml713-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FPCVf1Q1pz6yhH2; Tue, 20 Apr 2021 00:50:34 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml713-chm.china.huawei.com (10.206.15.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 18:55:58 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 17:55:57 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v3 1/4] PCI: Add vendor ID for the PCI SIG Date: Tue, 20 Apr 2021 00:54:48 +0800 Message-ID: <20210419165451.2176200-2-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> References: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml750-chm.china.huawei.com (10.201.108.200) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org This ID is used in DOE headers to identify protocols that are defined within the PCI Express Base Specification. Specified in Table 7-x2 of the Data Object Exchange ECN (approved 12 March 2020) available from https://members.pcisig.com/wg/PCI-SIG/document/14143 Signed-off-by: Jonathan Cameron --- v3: Add a reference to the patch description. include/linux/pci_ids.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index a76ccb697bef..2c0459c23331 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -149,6 +149,7 @@ #define PCI_CLASS_OTHERS 0xff /* Vendors and devices. Sort key: vendor first, device next. */ +#define PCI_VENDOR_ID_PCI_SIG 0x0001 #define PCI_VENDOR_ID_LOONGSON 0x0014 From patchwork Mon Apr 19 16:54:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12212319 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 B83B7C433B4 for ; Mon, 19 Apr 2021 16:56:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 910AF61157 for ; Mon, 19 Apr 2021 16:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231674AbhDSQ5J (ORCPT ); Mon, 19 Apr 2021 12:57:09 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2883 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230127AbhDSQ5E (ORCPT ); Mon, 19 Apr 2021 12:57:04 -0400 Received: from fraeml715-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FPCPn3PbXz6xj25; Tue, 20 Apr 2021 00:46:21 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml715-chm.china.huawei.com (10.206.15.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 18:56:29 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 17:56:28 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v3 2/4] PCI/doe: Add Data Object Exchange support Date: Tue, 20 Apr 2021 00:54:49 +0800 Message-ID: <20210419165451.2176200-3-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> References: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml750-chm.china.huawei.com (10.201.108.200) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Introduced in a PCI ECN [1], DOE provides a config space based mailbox with standard protocol discovery. Each mailbox is accessed through a DOE Extended Capability. A device may have 1 or more DOE mailboxes, each of which is allowed to support any number of protocols (some DOE protocol specifications apply additional restrictions). A given protocol may be supported on more than one DOE mailbox on a given function. If a driver wishes to access any number of DOE instances / protocols it makes a single call to pcie_doe_register_all() which will find available DOEs, create the required infrastructure and cache the protocols they support. pcie_doe_find() can then retrieve a pointer to an appropriate DOE instance. A synchronous interface is provided in pcie_doe_exchange_sync() to perform a single query / response exchange. Testing conducted against QEMU using: https://lore.kernel.org/qemu-devel/1612900760-7361-1-git-send-email-cbrowy@avery-design.com/ + fix for interrupt flag mentioned in that thread and a whole load of hacks to exercise error paths etc. [1] https://members.pcisig.com/wg/PCI-SIG/document/14143 Data Object Exchange (DOE) - Approved 12 March 2020 Signed-off-by: Jonathan Cameron --- Thanks to Bjorn Helgaas for reviewing v2. Changes since v2: * Move files and rename so as not to make them PCIe specific. * Rename pretty much everything from pcie* to pci*. * Editorial changes in patch description. * Rename pcie_doe_sync() to pci_doe_exchange_sync() to add a verb. Note that I'm not happy with this naming, but have not come up with anything better. Suggestions welcome! * Various white space, punctuation and similar changes as suggested by Bjorn. * Consistent reporting of return values in kernel-doc. * Use bitfields for Boolean elements of struct pci_doe. * Change some labels so we don't have both a local variable and label abort. * Add missing EXPORT_SYMBOL_GPL(pci_doe_exchange_sync) to allow use from modules. * Consistenty use sizeof(u32) for DW size. Thanks to Dan Williams for reviewing v1. Note code has changed a lot, so I may well have missed stuff in this log Changes since v1: Major stuff: * Rework the registration of DOE. DOE instances are added to a list in the struct pci_dev. A single call to pcie_doe_register_all() finds all DOEs present on a device and caches which protocols they support. The lifetime of these can then all be managed alongside the struct pci_dev avoiding need for reference counting etc whilst allowing a driver not to care if different protocols are using the same DOE instance, or different ones. The driver issues a call to pcie_doe_find() to get a pointer to the first appropriate DOE. Note, a side effect of minimizing impact of this on struct pci_dev is that we can't build DOE support as a module. * Instead of serializing on a mutex, move to a more complex state machine based scheme in which the DOE config space registers are only accessed from a single delayed work item. The state machine uses two states for normal operation, IDLE and WAITING. Two states also exist for ABORT to indicate if it was called in response to error, or at startup. Interrupts result in mod_delayed_work() to force an immediate check on the status register. Message queuing is implemented with a list of tasks and kicking the state machine work item as needed. * Decide, inside the core DOE code, whether to poll based on if the MSI/MSIX interrupts are enabled and the DOE instance advertises an interrupt. * Define a struct pcie_doe_exchange to encapsulate header info with payloads etc. Specific fields used for VID and protocol + lengths so the DOE header can be constructed inside the DOE functions rather than relying on callers to do that. * Don't hide away devm_ stuff in calls that don't make it obvious. Minor stuff: * pcie_doe_init() and pcie_doe_register separation to cover the bits that can fail in register() and the bits that can't in init() * Many typos * Rename cap_offset field to cap * Use new PCI_VENDOR_ID_PCI_SIG define to avoid open coding the value * Add defines for timeouts etc. * Missing EXPORT_SYMBOL_GPL() added to allow DOE access from modules. drivers/pci/Kconfig | 8 + drivers/pci/Makefile | 1 + drivers/pci/doe.c | 601 ++++++++++++++++++++++++++++++++++ include/linux/pci-doe.h | 85 +++++ include/linux/pci.h | 3 + include/uapi/linux/pci_regs.h | 29 +- 6 files changed, 726 insertions(+), 1 deletion(-) diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 0c473d75e625..6dd48a1ad2a4 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -190,6 +190,14 @@ config PCI_HYPERV The PCI device frontend driver allows the kernel to import arbitrary PCI devices from a PCI backend to support PCI driver domains. +config PCI_DOE + bool + help + This enables library support for the PCI Data Object Exchange + capability. DOE provides a simple mailbox in PCI config space that is + used by a number of different protocols. + DOE is defined in the Data Object Exchange ECN to PCI 5.0. + choice prompt "PCI Express hierarchy optimization setting" default PCIE_BUS_DEFAULT diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index d62c4ac4ae1b..1b61c1a1c232 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_PCI_STUB) += pci-stub.o obj-$(CONFIG_PCI_PF_STUB) += pci-pf-stub.o obj-$(CONFIG_PCI_ECAM) += ecam.o obj-$(CONFIG_PCI_P2PDMA) += p2pdma.o +obj-$(CONFIG_PCI_DOE) += doe.o obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o # Endpoint library must be initialized before its users diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c new file mode 100644 index 000000000000..fce16c78ff45 --- /dev/null +++ b/drivers/pci/doe.c @@ -0,0 +1,601 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Data Object Exchange ECN + * https://members.pcisig.com/wg/PCI-SIG/document/14143 + * + * Copyright (C) 2021 Huawei + * Jonathan Cameron + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define PCI_DOE_PROTOCOL_DISCOVERY 0 + +#define PCI_DOE_BUSY_MAX_RETRIES 16 +#define PCI_DOE_POLL_INTERVAL (HZ / 128) + +/* Timeout of 1 second from 6.xx.1 (Operation), ECN - Data Object Exchange */ +#define PCI_DOE_TIMEOUT HZ + +static irqreturn_t pci_doe_irq(int irq, void *data) +{ + struct pci_doe *doe = data; + struct pci_dev *pdev = doe->pdev; + u32 val; + + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_INT_STATUS, val)) { + pci_write_config_dword(pdev, doe->cap + PCI_DOE_STATUS, val); + mod_delayed_work(system_wq, &doe->statemachine, 0); + return IRQ_HANDLED; + } + /* Leave the error case to be handled outside IRQ */ + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) { + mod_delayed_work(system_wq, &doe->statemachine, 0); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +/* + * Only call when safe to directly access the DOE, either because no tasks yet + * queued, or called from doe_statemachine_work() which has exclusive access to + * the DOE config space. + */ +static void pci_doe_abort_start(struct pci_doe *doe) +{ + struct pci_dev *pdev = doe->pdev; + + pci_write_config_dword(pdev, doe->cap + PCI_DOE_CTRL, + PCI_DOE_CTRL_ABORT); + + doe->timeout_jiffies = jiffies + HZ; + schedule_delayed_work(&doe->statemachine, HZ); +} + +static int pci_doe_send_req(struct pci_doe *doe, struct pci_doe_exchange *ex) +{ + struct pci_dev *pdev = doe->pdev; + u32 val; + int i; + + /* + * Check the DOE busy bit is not set. If it is set, this could indicate + * someone other than Linux (e.g. firmware) is using the mailbox. Note + * it is expected that firmware and OS will negotiate access rights via + * an, as yet to be defined method. + */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_BUSY, val)) + return -EBUSY; + + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) + return -EIO; + + /* Write DOE Header */ + val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, ex->vid) | + FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, ex->protocol); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_WRITE, val); + /* Length is 2 DW of header + length of payload in DW */ + pci_write_config_dword(pdev, doe->cap + PCI_DOE_WRITE, + FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, + 2 + ex->request_pl_sz / sizeof(u32))); + for (i = 0; i < ex->request_pl_sz / sizeof(u32); i++) + pci_write_config_dword(pdev, doe->cap + PCI_DOE_WRITE, + ex->request_pl[i]); + + pci_write_config_dword(pdev, doe->cap + PCI_DOE_CTRL, PCI_DOE_CTRL_GO); + /* Request is sent - now wait for poll or IRQ */ + return 0; +} + +static int pci_doe_recv_resp(struct pci_doe *doe, struct pci_doe_exchange *ex) +{ + struct pci_dev *pdev = doe->pdev; + size_t length; + u32 val; + int i; + + /* Read the first two dwords to get the length and protocol */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, &val); + if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != ex->vid) || + (FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != ex->protocol)) { + pci_err(pdev, + "Expected [VID, Protocol] = [%x, %x], got [%x, %x]\n", + ex->vid, ex->protocol, + FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val), + FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val)); + return -EIO; + } + + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, &val); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + + length = FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, val); + if (length > SZ_1M) + return -EIO; + + /* Read the rest of the response payload */ + for (i = 0; i < min(length, ex->response_pl_sz / sizeof(u32)); i++) { + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, + &ex->response_pl[i]); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + } + + /* Flush excess length */ + for (; i < length; i++) { + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, &val); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + } + /* Final error check to pick up on any since Data Object Ready */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) + return -EIO; + + return min(length, ex->response_pl_sz / sizeof(u32)) * sizeof(u32); +} + +static void pci_doe_task_complete(void *private) +{ + complete(private); +} + +/** + * struct pci_doe_task - description of a query / response task. + * @h: Head to add it to the list of outstanding tasks. + * @ex: The details of the task to be done. + * @rv: Return value. Length of received response or error. + * @cb: Callback for completion of task. + * @private: Private data passed to callback on completion. + */ +struct pci_doe_task { + struct list_head h; + struct pci_doe_exchange *ex; + int rv; + void (*cb)(void *private); + void *private; +}; + +/** + * pci_doe_exchange_sync() - Send a request, then wait for and receive response. + * @doe: DOE mailbox state structure. + * @ex: Description of the buffers and Vendor ID + type used in this + * request/response pair, + * + * Excess data will be discarded. + * + * RETURNS: payload in bytes on success, < 0 on error. + */ +int pci_doe_exchange_sync(struct pci_doe *doe, struct pci_doe_exchange *ex) +{ + struct pci_doe_task task; + DECLARE_COMPLETION_ONSTACK(c); + int only_task; + + /* DOE requests must be a whole number of DW */ + if (ex->request_pl_sz % sizeof(u32)) + return -EINVAL; + + task.ex = ex; + task.cb = pci_doe_task_complete; + task.private = &c; + + mutex_lock(&doe->tasks_lock); + if (doe->dead) { + mutex_unlock(&doe->tasks_lock); + return -EIO; + } + only_task = list_empty(&doe->tasks); + list_add_tail(&task.h, &doe->tasks); + if (only_task) + schedule_delayed_work(&doe->statemachine, 0); + mutex_unlock(&doe->tasks_lock); + wait_for_completion(&c); + + return task.rv; +} +EXPORT_SYMBOL_GPL(pci_doe_exchange_sync); + +static void doe_statemachine_work(struct work_struct *work) +{ + struct delayed_work *w = to_delayed_work(work); + struct pci_doe *doe = container_of(w, struct pci_doe, statemachine); + struct pci_dev *pdev = doe->pdev; + struct pci_doe_task *task; + bool abort; + u32 val; + int rc; + + mutex_lock(&doe->tasks_lock); + task = list_first_entry_or_null(&doe->tasks, struct pci_doe_task, h); + abort = doe->abort; + doe->abort = false; + mutex_unlock(&doe->tasks_lock); + + if (abort) { + /* + * Currently only used during init - care needed if we want to + * generally expose pci_doe_abort() as it would impact queries + * in flight. + */ + WARN_ON(task); + doe->state = DOE_WAIT_ABORT; + pci_doe_abort_start(doe); + return; + } + + switch (doe->state) { + case DOE_IDLE: + if (task == NULL) + return; + + /* Nothing currently in flight so queue a task */ + rc = pci_doe_send_req(doe, task->ex); + /* + * The specification does not provide any guidance on how long + * some other entity could keep the DOE busy, so try for 1 + * second then fail. Busy handling is best effort only, because + * there is no way of avoiding racing against another user of + * the DOE. + */ + if (rc == -EBUSY) { + doe->busy_retries++; + if (doe->busy_retries == PCI_DOE_BUSY_MAX_RETRIES) { + /* Long enough, fail this request */ + doe->busy_retries = 0; + goto err_busy; + } + schedule_delayed_work(w, HZ / PCI_DOE_BUSY_MAX_RETRIES); + return; + } + if (rc) + goto err_abort; + doe->busy_retries = 0; + + doe->state = DOE_WAIT_RESP; + doe->timeout_jiffies = jiffies + HZ; + /* Now poll or wait for IRQ with timeout */ + if (doe->irq > 0) + schedule_delayed_work(w, PCI_DOE_TIMEOUT); + else + schedule_delayed_work(w, PCI_DOE_POLL_INTERVAL); + return; + + case DOE_WAIT_RESP: + /* Not possible to get here with NULL task */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) { + rc = -EIO; + goto err_abort; + } + + if (!FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val)) { + /* If not yet at timeout reschedule otherwise abort */ + if (time_after(jiffies, doe->timeout_jiffies)) { + rc = -ETIMEDOUT; + goto err_abort; + } + schedule_delayed_work(w, PCI_DOE_POLL_INTERVAL); + return; + } + + rc = pci_doe_recv_resp(doe, task->ex); + if (rc < 0) + goto err_abort; + + doe->state = DOE_IDLE; + + mutex_lock(&doe->tasks_lock); + list_del(&task->h); + if (!list_empty(&doe->tasks)) + schedule_delayed_work(w, 0); + mutex_unlock(&doe->tasks_lock); + + /* Set the return value to the length of received payload */ + task->rv = rc; + task->cb(task->private); + return; + + case DOE_WAIT_ABORT: + case DOE_WAIT_ABORT_ON_ERR: + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + + if (!FIELD_GET(PCI_DOE_STATUS_ERROR, val) && + !FIELD_GET(PCI_DOE_STATUS_BUSY, val)) { + /* Back to normal state - carry on */ + mutex_lock(&doe->tasks_lock); + if (!list_empty(&doe->tasks)) + schedule_delayed_work(w, 0); + mutex_unlock(&doe->tasks_lock); + + /* + * For deliberately triggered abort, someone is + * waiting. + */ + if (doe->state == DOE_WAIT_ABORT) + complete(&doe->abort_c); + doe->state = DOE_IDLE; + + return; + } + if (time_after(jiffies, doe->timeout_jiffies)) { + struct pci_doe_task *t, *n; + + /* We are dead - abort all queued tasks */ + pci_err(pdev, "DOE ABORT timed out\n"); + mutex_lock(&doe->tasks_lock); + doe->dead = true; + list_for_each_entry_safe(t, n, &doe->tasks, h) { + t->rv = -EIO; + t->cb(t->private); + list_del(&t->h); + } + + mutex_unlock(&doe->tasks_lock); + if (doe->state == DOE_WAIT_ABORT) + complete(&doe->abort_c); + } + return; + } + +err_abort: + pci_doe_abort_start(doe); + doe->state = DOE_WAIT_ABORT_ON_ERR; +err_busy: + mutex_lock(&doe->tasks_lock); + list_del(&task->h); + mutex_unlock(&doe->tasks_lock); + + task->rv = rc; + task->cb(task->private); + /* + * If we got here via err_busy, and the queue isn't empty then we need + * to go again. + */ + if (doe->state == DOE_IDLE) { + mutex_lock(&doe->tasks_lock); + if (!list_empty(&doe->tasks)) + schedule_delayed_work(w, 0); + mutex_unlock(&doe->tasks_lock); + } +} + +static int pci_doe_discovery(struct pci_doe *doe, u8 *index, u16 *vid, + u8 *protocol) +{ + u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX, *index); + u32 response_pl; + struct pci_doe_exchange ex = { + .vid = PCI_VENDOR_ID_PCI_SIG, + .protocol = PCI_DOE_PROTOCOL_DISCOVERY, + .request_pl = &request_pl, + .request_pl_sz = sizeof(request_pl), + .response_pl = &response_pl, + .response_pl_sz = sizeof(response_pl), + }; + int ret; + + ret = pci_doe_exchange_sync(doe, &ex); + if (ret < 0) + return ret; + + if (ret != sizeof(response_pl)) + return -EIO; + + *vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl); + *protocol = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL, response_pl); + *index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX, response_pl); + + return 0; +} + +static int pci_doe_cache_protocols(struct pci_doe *doe) +{ + u8 index = 0; + int rc; + + /* Discovery protocol must always be supported and must report itself */ + doe->num_prots = 1; + doe->prots = kzalloc(sizeof(*doe->prots) * doe->num_prots, GFP_KERNEL); + if (doe->prots == NULL) + return -ENOMEM; + + do { + struct pci_doe_prot *prot, *prot_new; + + prot = &doe->prots[doe->num_prots - 1]; + rc = pci_doe_discovery(doe, &index, &prot->vid, &prot->type); + if (rc) + goto err_free_prots; + + if (index) { + prot_new = krealloc(doe->prots, + sizeof(*doe->prots) * doe->num_prots, + GFP_KERNEL); + if (prot_new == NULL) { + rc = -ENOMEM; + goto err_free_prots; + } + doe->prots = prot_new; + doe->num_prots++; + } + } while (index); + + return 0; + +err_free_prots: + kfree(doe->prots); + return rc; +} + +static void pci_doe_init(struct pci_doe *doe, struct pci_dev *pdev, int doe_offset) +{ + mutex_init(&doe->tasks_lock); + init_completion(&doe->abort_c); + doe->cap = doe_offset; + doe->pdev = pdev; + INIT_LIST_HEAD(&doe->tasks); + INIT_DELAYED_WORK(&doe->statemachine, doe_statemachine_work); +} + +static int pci_doe_abort(struct pci_doe *doe) +{ + reinit_completion(&doe->abort_c); + mutex_lock(&doe->tasks_lock); + doe->abort = true; + mutex_unlock(&doe->tasks_lock); + schedule_delayed_work(&doe->statemachine, 0); + wait_for_completion(&doe->abort_c); + + if (doe->dead) + return -EIO; + + return 0; +} + +static int pci_doe_register(struct pci_doe *doe) +{ + struct pci_dev *pdev = doe->pdev; + bool poll = !pci_dev_msi_enabled(pdev); + int rc, irq; + u32 val; + + pci_read_config_dword(pdev, doe->cap + PCI_DOE_CAP, &val); + + if (!poll && FIELD_GET(PCI_DOE_CAP_INT, val)) { + irq = pci_irq_vector(pdev, FIELD_GET(PCI_DOE_CAP_IRQ, val)); + if (irq < 0) + return irq; + + rc = request_irq(irq, pci_doe_irq, 0, "DOE", doe); + if (rc) + return rc; + + doe->irq = irq; + pci_write_config_dword(pdev, doe->cap + PCI_DOE_CTRL, + FIELD_PREP(PCI_DOE_CTRL_INT_EN, 1)); + } + + /* Reset the mailbox by issuing an abort */ + rc = pci_doe_abort(doe); + if (rc) + goto err_free_irqs; + + return 0; + +err_free_irqs: + if (doe->irq > 0) + free_irq(doe->irq, doe); + + return rc; +} + +static void pci_doe_unregister(struct pci_doe *doe) +{ + if (doe->irq > 0) + free_irq(doe->irq, doe); +} + +void pci_doe_unregister_all(struct pci_dev *pdev) +{ + struct pci_doe *doe, *next; + + list_for_each_entry_safe(doe, next, &pdev->doe_list, h) { + /* First halt the state machine */ + cancel_delayed_work_sync(&doe->statemachine); + kfree(doe->prots); + pci_doe_unregister(doe); + kfree(doe); + } +} +EXPORT_SYMBOL_GPL(pci_doe_unregister_all); + +/** + * pci_doe_register_all() - Find and register all DOE mailboxes. + * @pdev: PCI device whose DOE mailboxes we are finding. + * + * Will locate any DOE mailboxes present on the device and cache the protocols + * so that pci_doe_find() can be used to retrieve a suitable DOE instance. + * + * DOE mailboxes are available until pci_doe_unregister_all() is called. + * + * RETURNS: 0 on success, < 0 on error. + */ +int pci_doe_register_all(struct pci_dev *pdev) +{ + struct pci_doe *doe; + int pos = 0; + int rc; + + INIT_LIST_HEAD(&pdev->doe_list); + + /* Walk the DOE extended capabilities and add to per pci_dev list */ + while (true) { + pos = pci_find_next_ext_capability(pdev, pos, + PCI_EXT_CAP_ID_DOE); + if (!pos) + return 0; + + doe = kzalloc(sizeof(*doe), GFP_KERNEL); + if (!doe) { + rc = -ENOMEM; + goto err_free_does; + } + + pci_doe_init(doe, pdev, pos); + rc = pci_doe_register(doe); + if (rc) { + kfree(doe); + goto err_free_does; + } + + rc = pci_doe_cache_protocols(doe); + if (rc) { + pci_doe_unregister(doe); + kfree(doe); + goto err_free_does; + } + + list_add(&doe->h, &pdev->doe_list); + } + +err_free_does: + pci_doe_unregister_all(pdev); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_doe_register_all); + +/** + * pci_doe_find() - Find the first DOE instance that supports a given protocol. + * @pdev: Device on which to find the DOE instance. + * @vid: Vendor ID. + * @type: Specific protocol for this vendor. + * + * RETURNS: Pointer to DOE instance on success, NULL on no suitable instance + * available. + */ +struct pci_doe *pci_doe_find(struct pci_dev *pdev, u16 vid, u8 type) +{ + struct pci_doe *doe; + int i; + + list_for_each_entry(doe, &pdev->doe_list, h) { + for (i = 0; i < doe->num_prots; i++) + if ((doe->prots[i].vid == vid) && + (doe->prots[i].type == type)) + return doe; + } + + return NULL; +} +EXPORT_SYMBOL_GPL(pci_doe_find); diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h new file mode 100644 index 000000000000..0307ed17d3ab --- /dev/null +++ b/include/linux/pci-doe.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Data Object Exchange was added to the PCI spec as an ECN to 5.0. + * + * Copyright (C) 2021 Huawei + * Jonathan Cameron + */ + +#include +#include +#include + +#ifndef LINUX_PCI_DOE_H +#define LINUX_PCI_DOE_H + +struct pci_doe_prot { + u16 vid; + u8 type; +}; + +struct workqueue_struct; + +enum pci_doe_state { + DOE_IDLE, + DOE_WAIT_RESP, + DOE_WAIT_ABORT, + DOE_WAIT_ABORT_ON_ERR, +}; + +struct pci_doe_exchange { + u16 vid; + u8 protocol; + u32 *request_pl; + size_t request_pl_sz; + u32 *response_pl; + size_t response_pl_sz; +}; + +/** + * struct pci_doe - State to support use of DOE mailbox + * @cap: Config space offset to base of DOE capability. + * @pdev: PCI device that hosts this DOE. + * @abort_c: Completion used for initial abort handling. + * @irq: Interrupt used for signaling DOE ready or abort. + * @prots: Cache of identifiers for protocols supported. + * @num_prots: Size of prots cache. + * @h: Used for DOE instance lifetime management. + * @wq: Workqueue used to handle state machine and polling / timeouts. + * @tasks: List of task in flight + pending. + * @tasks_lock: Protect the tasks list. + * @statemachine: Work item for the DOE state machine. + * @state: Current state of this DOE. + * @timeout_jiffies: 1 second after GO set. + * @busy_retries: Count of retry attempts. + * @abort: Request a manual abort (e.g. on init). + * @dead: Used to mark a DOE for which an ABORT has timed out. Further messages + * will immediately be aborted with error. + */ +struct pci_doe { + int cap; + struct pci_dev *pdev; + struct completion abort_c; + int irq; + struct pci_doe_prot *prots; + int num_prots; + struct list_head h; + + struct workqueue_struct *wq; + struct list_head tasks; + struct mutex tasks_lock; + struct delayed_work statemachine; + enum pci_doe_state state; + unsigned long timeout_jiffies; + unsigned int busy_retries; + unsigned int abort:1; + unsigned int dead:1; +}; + +int pci_doe_register_all(struct pci_dev *pdev); +void pci_doe_unregister_all(struct pci_dev *pdev); +struct pci_doe *pci_doe_find(struct pci_dev *pdev, u16 vid, u8 type); + +int pci_doe_exchange_sync(struct pci_doe *doe, struct pci_doe_exchange *ex); + +#endif diff --git a/include/linux/pci.h b/include/linux/pci.h index 86c799c97b77..ac7a18826096 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -332,6 +332,9 @@ struct pci_dev { #ifdef CONFIG_PCIEPORTBUS struct rcec_ea *rcec_ea; /* RCEC cached endpoint association */ struct pci_dev *rcec; /* Associated RCEC device */ +#endif +#ifdef CONFIG_PCI_DOE + struct list_head doe_list; /* Data Object Exchange mailboxes */ #endif u8 pcie_cap; /* PCIe capability offset */ u8 msi_cap; /* MSI capability offset */ diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index e709ae8235e7..b97df1d8bd19 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -730,7 +730,8 @@ #define PCI_EXT_CAP_ID_DVSEC 0x23 /* Designated Vendor-Specific */ #define PCI_EXT_CAP_ID_DLF 0x25 /* Data Link Feature */ #define PCI_EXT_CAP_ID_PL_16GT 0x26 /* Physical Layer 16.0 GT/s */ -#define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_PL_16GT +#define PCI_EXT_CAP_ID_DOE 0x2E /* Data Object Exchange */ +#define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_DOE #define PCI_EXT_CAP_DSN_SIZEOF 12 #define PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF 40 @@ -1092,4 +1093,30 @@ #define PCI_PL_16GT_LE_CTRL_USP_TX_PRESET_MASK 0x000000F0 #define PCI_PL_16GT_LE_CTRL_USP_TX_PRESET_SHIFT 4 +/* Data Object Exchange */ +#define PCI_DOE_CAP 0x04 /* DOE Capabilities Register */ +#define PCI_DOE_CAP_INT 0x00000001 /* Interrupt Support */ +#define PCI_DOE_CAP_IRQ 0x00000ffe /* Interrupt Message Number */ +#define PCI_DOE_CTRL 0x08 /* DOE Control Register */ +#define PCI_DOE_CTRL_ABORT 0x00000001 /* DOE Abort */ +#define PCI_DOE_CTRL_INT_EN 0x00000002 /* DOE Interrupt Enable */ +#define PCI_DOE_CTRL_GO 0x80000000 /* DOE Go */ +#define PCI_DOE_STATUS 0x0c /* DOE Status Register */ +#define PCI_DOE_STATUS_BUSY 0x00000001 /* DOE Busy */ +#define PCI_DOE_STATUS_INT_STATUS 0x00000002 /* DOE Interrupt Status */ +#define PCI_DOE_STATUS_ERROR 0x00000004 /* DOE Error */ +#define PCI_DOE_STATUS_DATA_OBJECT_READY 0x80000000 /* Data Object Ready */ +#define PCI_DOE_WRITE 0x10 /* DOE Write Data Mailbox Register */ +#define PCI_DOE_READ 0x14 /* DOE Read Data Mailbox Register */ + +/* DOE Data Object - note not actually registers */ +#define PCI_DOE_DATA_OBJECT_HEADER_1_VID 0x0000ffff +#define PCI_DOE_DATA_OBJECT_HEADER_1_TYPE 0x00ff0000 +#define PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH 0x0003ffff + +#define PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX 0x000000ff +#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID 0x0000ffff +#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL 0x00ff0000 +#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX 0xff000000 + #endif /* LINUX_PCI_REGS_H */ From patchwork Mon Apr 19 16:54:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12212321 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 C14BBC433ED for ; Mon, 19 Apr 2021 16:57:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CDDE61166 for ; Mon, 19 Apr 2021 16:57:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232598AbhDSQ5b (ORCPT ); Mon, 19 Apr 2021 12:57:31 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2884 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230127AbhDSQ5b (ORCPT ); Mon, 19 Apr 2021 12:57:31 -0400 Received: from fraeml710-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FPCWq1k9lz6yh5q; Tue, 20 Apr 2021 00:51:35 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml710-chm.china.huawei.com (10.206.15.59) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 18:56:59 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 17:56:59 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v3 3/4] cxl/mem: Add CDAT table reading from DOE Date: Tue, 20 Apr 2021 00:54:50 +0800 Message-ID: <20210419165451.2176200-4-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> References: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml750-chm.china.huawei.com (10.201.108.200) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org This patch provides a sysfs binary attribute to allow dumping of the whole table. Binary dumping is modeled on /sys/firmware/ACPI/tables/ The ability to dump this table will be very useful for emulation of real devices once they become available as QEMU CXL type 3 device emulation will be able to load this file in. Open questions: * No support here for table updates via the binary attribute. You get whatever was there when it was first cached.. Worth including these from the start, or leave that complexity for later? We could read directly from the DOE every time, but need to check we get a coherent table. Let's figure this out once we are making 'real' use of the table. * What is maximum size of the SSLBIS entry - I haven't quite managed to figure that out and this is the record with largest size. We could support dynamic allocation of the record size, but it would add complexity that seems unnecessary. It would not be compliant with the specification for a type 3 memory device to report this record anyway so I'm not that worried about this for now. It will become relevant once we have support for reading CDAT from CXL switches. * cdat.h is formatted in a similar style to pci_regs.h on basis that it may well be helpful to share this header with userspace tools. * Move the generic parts of this out to driver/cxl/cdat.c or leave that until we have other CXL drivers wishing to use this? Signed-off-by: Jonathan Cameron --- Changes since v2: * Naming changes to match those in the patch introducing DOE support. * Consistent use of lowercase hexadecimal values. Thanks to Dan Williams for review Changes since v1: * static creation of the binary attribute * moved the debug print to separate patch to make it easy to drop later. * select PCIE_DOE * Changes due to interface changes in previous patch. drivers/cxl/Kconfig | 1 + drivers/cxl/cdat.h | 78 +++++++++++++++++++ drivers/cxl/cxl.h | 13 ++++ drivers/cxl/mem.c | 177 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 269 insertions(+) diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 97dc4d751651..26cad9fa29f7 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -15,6 +15,7 @@ if CXL_BUS config CXL_MEM tristate "CXL.mem: Memory Devices" + select PCI_DOE help The CXL.mem protocol allows a device to act as a provider of "System RAM" and/or "Persistent Memory" that is fully coherent diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h new file mode 100644 index 000000000000..da9c147cbdfa --- /dev/null +++ b/drivers/cxl/cdat.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Coherent Device Attribute table (CDAT) + * + * Specification available from UEFI.org + * + * Whilst CDAT is defined as a single table, the access via DOE maiboxes is + * done one entry at a time, where the first entry is the header. + */ + +#define CXL_DOE_TABLE_ACCESS_REQ_CODE 0x000000ff +#define CXL_DOE_TABLE_ACCESS_REQ_CODE_READ 0 +#define CXL_DOE_TABLE_ACCESS_TABLE_TYPE 0x0000ff00 +#define CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA 0 +#define CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE 0xffff0000 + +/* + * CDAT entries are little endian and are read from PCI config space which + * is also little endian. + * As such, on a big endian system these will have been reversed. + * This prevents us from making easy use of packed structures. + * Style form pci_regs.h + */ + +#define CDAT_HEADER_LENGTH_DW 3 +#define CDAT_HEADER_DW0_LENGTH 0xffffffff +#define CDAT_HEADER_DW1_REVISION 0x000000ff +#define CDAT_HEADER_DW1_CHECKSUM 0x0000ff00 +#define CDAT_HEADER_DW2_SEQUENCE 0xffffffff + +/* All structures have a common first DW */ +#define CDAT_STRUCTURE_DW0_TYPE 0x000000ff +#define CDAT_STRUCTURE_DW0_TYPE_DSMAS 0 +#define CDAT_STRUCTURE_DW0_TYPE_DSLBIS 1 +#define CDAT_STRUCTURE_DW0_TYPE_DSMSCIS 2 +#define CDAT_STRUCTURE_DW0_TYPE_DSIS 3 +#define CDAT_STRUCTURE_DW0_TYPE_DSEMTS 4 +#define CDAT_STRUCTURE_DW0_TYPE_SSLBIS 5 + +#define CDAT_STRUCTURE_DW0_LENGTH 0xffff0000 + +/* Device Scoped Memory Affinity Structure */ +#define CDAT_DSMAS_DW1_DSMAD_HANDLE 0x000000ff +#define CDAT_DSMAS_DW1_FLAGS 0x0000ff00 +#define CDAT_DSMAS_DPA_OFFSET(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSMAS_DPA_LEN(entry) ((u64)((entry)[5]) << 32 | (entry)[4]) + +/* Device Scoped Latency and Bandwidth Information Structure */ +#define CDAT_DSLBIS_DW1_HANDLE 0x000000ff +#define CDAT_DSLBIS_DW1_FLAGS 0x0000ff00 +#define CDAT_DSLBIS_DW1_DATA_TYPE 0x00ff0000 +#define CDAT_DSLBIS_BASE_UNIT(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSLBIS_DW4_ENTRY_0 0x0000ffff +#define CDAT_DSLBIS_DW4_ENTRY_1 0xffff0000 +#define CDAT_DSLBIS_DW5_ENTRY_2 0x0000ffff + +/* Device Scoped Memory Side Cache Information Structure */ +#define CDAT_DSMSCIS_DW1_HANDLE 0x000000ff +#define CDAT_DSMSCIS_MEMORY_SIDE_CACHE_SIZE(entry) \ + ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSMSCIS_DW4_MEMORY_SIDE_CACHE_ATTRS 0xffffffff + +/* Device Scoped Initiator Structure */ +#define CDAT_DSIS_DW1_FLAGS 0x000000ff +#define CDAT_DSIS_DW1_HANDLE 0x0000ff00 + +/* Device Scoped EFI Memory Type Structure */ +#define CDAT_DSEMTS_DW1_HANDLE 0x000000ff +#define CDAT_DSEMTS_DW1_EFI_MEMORY_TYPE_ATTR 0x0000ff00 +#define CDAT_DSEMTS_DPA_OFFSET(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSEMTS_DPA_LENGTH(entry) ((u64)((entry)[5]) << 32 | (entry)[4]) + +/* Switch Scoped Latency and Bandwidth Information Structure */ +#define CDAT_SSLBIS_DW1_DATA_TYPE 0x000000ff +#define CDAT_SSLBIS_BASE_UNIT(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_SSLBIS_ENTRY_PORT_X(entry, i) ((entry)[4 + (i) * 2] & 0x0000ffff) +#define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) +#define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 6f14838c2d25..eba3f7e7d997 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -7,6 +7,7 @@ #include #include #include +#include /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */ #define CXLDEV_CAP_ARRAY_OFFSET 0x0 @@ -57,10 +58,21 @@ (FIELD_GET(CXLMDEV_RESET_NEEDED_MASK, status) != \ CXLMDEV_RESET_NEEDED_NOT) +#define CXL_DOE_PROTOCOL_COMPLIANCE 0 +#define CXL_DOE_PROTOCOL_TABLE_ACCESS 2 + +/* Common to request and response */ +#define CXL_DOE_TABLE_ACCESS_3_CODE GENMASK(7, 0) +#define CXL_DOE_TABLE_ACCESS_3_CODE_READ 0 +#define CXL_DOE_TABLE_ACCESS_3_TYPE GENMASK(15, 8) +#define CXL_DOE_TABLE_ACCESS_3_TYPE_CDAT 0 +#define CXL_DOE_TABLE_ACCESS_3_ENTRY_HANDLE GENMASK(31, 16) + struct cxl_memdev; /** * struct cxl_mem - A CXL memory device * @pdev: The PCI device associated with this CXL device. + * @table_doe: Data exchange object mailbox used to read tables. * @regs: IO mappings to the device's MMIO * @status_regs: CXL 2.0 8.2.8.3 Device Status Registers * @mbox_regs: CXL 2.0 8.2.8.4 Mailbox Registers @@ -75,6 +87,7 @@ struct cxl_memdev; */ struct cxl_mem { struct pci_dev *pdev; + struct pci_doe *table_doe; void __iomem *regs; struct cxl_memdev *cxlmd; diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 244cb7d89678..32354d443f2e 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -12,6 +12,7 @@ #include #include "pci.h" #include "cxl.h" +#include "cdat.h" /** * DOC: cxl mem @@ -99,6 +100,8 @@ struct mbox_cmd { * @ops_active: active user of @cxlm in ops handlers * @ops_dead: completion when all @cxlm ops users have exited * @id: id number of this memdev instance. + * @cdat_table: cache of CDAT table + * @cdat_length: length of cached CDAT table */ struct cxl_memdev { struct device dev; @@ -107,6 +110,8 @@ struct cxl_memdev { struct percpu_ref ops_active; struct completion ops_dead; int id; + void *cdat_table; + size_t cdat_length; }; static int cxl_mem_major; @@ -968,6 +973,85 @@ static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm) return 0; } +#define CDAT_DOE_REQ(entry_handle) \ + (FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \ + CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \ + FIELD_PREP(CXL_DOE_TABLE_ACCESS_TABLE_TYPE, \ + CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA) | \ + FIELD_PREP(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, (entry_handle))) + +static ssize_t cdat_get_length(struct pci_doe *doe) +{ + u32 cdat_request_pl = CDAT_DOE_REQ(0); + u32 cdat_response_pl[32]; + struct pci_doe_exchange ex = { + .vid = PCI_DVSEC_VENDOR_ID_CXL, + .protocol = CXL_DOE_PROTOCOL_TABLE_ACCESS, + .request_pl = &cdat_request_pl, + .request_pl_sz = sizeof(cdat_request_pl), + .response_pl = cdat_response_pl, + .response_pl_sz = sizeof(cdat_response_pl), + }; + + ssize_t rc; + + rc = pci_doe_exchange_sync(doe, &ex); + if (rc < 0) + return rc; + if (rc < 1) + return -EIO; + + return cdat_response_pl[1]; +} + +static int cdat_to_buffer(struct pci_doe *doe, u32 *buffer, size_t length) +{ + int entry_handle = 0; + int rc; + + do { + u32 cdat_request_pl = CDAT_DOE_REQ(entry_handle); + u32 cdat_response_pl[32]; + struct pci_doe_exchange ex = { + .vid = PCI_DVSEC_VENDOR_ID_CXL, + .protocol = CXL_DOE_PROTOCOL_TABLE_ACCESS, + .request_pl = &cdat_request_pl, + .request_pl_sz = sizeof(cdat_request_pl), + .response_pl = cdat_response_pl, + .response_pl_sz = sizeof(cdat_response_pl), + }; + size_t entry_dw; + u32 *entry; + + rc = pci_doe_exchange_sync(doe, &ex); + if (rc < 0) + return rc; + + entry = cdat_response_pl + 1; + entry_dw = rc / sizeof(u32); + /* Skip Header */ + entry_dw -= 1; + entry_dw = min(length / 4, entry_dw); + memcpy(buffer, entry, entry_dw * sizeof(u32)); + length -= entry_dw * sizeof(u32); + buffer += entry_dw; + entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, cdat_response_pl[0]); + + } while (entry_handle != 0xFFFF); + + return 0; +} + +static void cxl_mem_free_irq_vectors(void *data) +{ + pci_free_irq_vectors(data); +} + +static void cxl_mem_doe_unregister_all(void *data) +{ + pci_doe_unregister_all(data); +} + static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi) { @@ -975,6 +1059,7 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, struct cxl_mem *cxlm; void __iomem *regs; u64 offset; + int irqs; u8 bar; int rc; @@ -1013,6 +1098,44 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, return NULL; } + /* + * An implementation of a cxl type3 device may support an unknown + * number of interrupts. Assume that number is not that large and + * request them all. + */ + irqs = pci_msix_vec_count(pdev); + rc = pci_alloc_irq_vectors(pdev, irqs, irqs, PCI_IRQ_MSIX); + if (rc != irqs) { + /* No interrupt available - carry on */ + dev_dbg(dev, "No interrupts available for DOE\n"); + } else { + /* + * Enabling bus mastering could be done within the DOE + * initialization, but as it potentially has other impacts + * keep it within the driver. + */ + pci_set_master(pdev); + rc = devm_add_action_or_reset(dev, cxl_mem_free_irq_vectors, + pdev); + if (rc) + return NULL; + } + + /* + * Find a DOE mailbox that supports CDAT. + * Supporting other DOE protocols will require more complexity. + */ + rc = pci_doe_register_all(pdev); + if (rc < 0) + return NULL; + + rc = devm_add_action_or_reset(dev, cxl_mem_doe_unregister_all, pdev); + if (rc) + return NULL; + + cxlm->table_doe = pci_doe_find(pdev, PCI_DVSEC_VENDOR_ID_CXL, + CXL_DOE_PROTOCOL_TABLE_ACCESS); + dev_dbg(dev, "Mapped CXL Memory Device resource\n"); return cxlm; } @@ -1103,6 +1226,31 @@ static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr, return sprintf(buf, "%#llx\n", len); } +static ssize_t CDAT_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, char *buf, + loff_t offset, size_t count) +{ + struct device *dev = kobj_to_dev(kobj); + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + + return memory_read_from_buffer(buf, count, &offset, cxlmd->cdat_table, + cxlmd->cdat_length); +} + +static BIN_ATTR_RO(CDAT, 0); + +static umode_t cxl_memdev_bin_attr_is_visible(struct kobject *kobj, + struct bin_attribute *attr, int i) +{ + struct device *dev = kobj_to_dev(kobj); + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + + if ((attr == &bin_attr_CDAT) && cxlmd->cdat_table) + return 0400; + + return 0; +} + static struct device_attribute dev_attr_pmem_size = __ATTR(size, 0444, pmem_size_show, NULL); @@ -1112,6 +1260,11 @@ static struct attribute *cxl_memdev_attributes[] = { NULL, }; +static struct bin_attribute *cxl_memdev_bin_attributes[] = { + &bin_attr_CDAT, + NULL, +}; + static struct attribute *cxl_memdev_pmem_attributes[] = { &dev_attr_pmem_size.attr, NULL, @@ -1124,6 +1277,8 @@ static struct attribute *cxl_memdev_ram_attributes[] = { static struct attribute_group cxl_memdev_attribute_group = { .attrs = cxl_memdev_attributes, + .bin_attrs = cxl_memdev_bin_attributes, + .is_bin_visible = cxl_memdev_bin_attr_is_visible, }; static struct attribute_group cxl_memdev_ram_attribute_group = { @@ -1170,6 +1325,25 @@ static void cxlmdev_ops_active_release(struct percpu_ref *ref) complete(&cxlmd->ops_dead); } +static int cxl_cache_cdat_table(struct cxl_memdev *cxlmd) +{ + struct cxl_mem *cxlm = cxlmd->cxlm; + struct device *dev = &cxlmd->dev; + ssize_t cdat_length; + + if (cxlm->table_doe == NULL) + return 0; + + cdat_length = cdat_get_length(cxlm->table_doe); + if (cdat_length < 0) + return cdat_length; + + cxlmd->cdat_length = cdat_length; + cxlmd->cdat_table = devm_kzalloc(dev->parent, cdat_length, GFP_KERNEL); + + return cdat_to_buffer(cxlm->table_doe, cxlmd->cdat_table, cxlmd->cdat_length); +} + static int cxl_mem_add_memdev(struct cxl_mem *cxlm) { struct pci_dev *pdev = cxlm->pdev; @@ -1208,6 +1382,9 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) cdev = &cxlmd->cdev; cdev_init(cdev, &cxl_memdev_fops); + rc = cxl_cache_cdat_table(cxlmd); + if (rc) + goto err_add; rc = cdev_device_add(cdev, dev); if (rc) From patchwork Mon Apr 19 16:54:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12212323 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 B6E93C433ED for ; Mon, 19 Apr 2021 16:57:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9495661166 for ; Mon, 19 Apr 2021 16:57:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239432AbhDSQ6B (ORCPT ); Mon, 19 Apr 2021 12:58:01 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2885 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231674AbhDSQ6B (ORCPT ); Mon, 19 Apr 2021 12:58:01 -0400 Received: from fraeml712-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FPCV30fR9z68Bs6; Tue, 20 Apr 2021 00:50:03 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml712-chm.china.huawei.com (10.206.15.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 18:57:30 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Apr 2021 17:57:29 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v3 4/4] cxl/mem: Add a debug parser for CDAT commands Date: Tue, 20 Apr 2021 00:54:51 +0800 Message-ID: <20210419165451.2176200-5-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> References: <20210419165451.2176200-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml750-chm.china.huawei.com (10.201.108.200) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Logs a pretty printed version of the CDAT table entries at driver load. I find this helpful for development, so including as an extra patch that I would suggest is never merged. Signed-off-by: Jonathan Cameron --- v3: renames to match changes in doe function naming. drivers/cxl/mem.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 32354d443f2e..b357dba9048b 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -1042,6 +1042,104 @@ static int cdat_to_buffer(struct pci_doe *doe, u32 *buffer, size_t length) return 0; } +static int cdat_dump(struct pci_doe *doe) +{ + struct pci_dev *dev = doe->pdev; + int entry_handle = 0; + int rc; + + if (doe == NULL) + return 0; + + dev = doe->pdev; + do { + /* Table access is available */ + u32 cdat_request_pl = CDAT_DOE_REQ(entry_handle); + u32 cdat_response_pl[32]; + struct pci_doe_exchange ex = { + .vid = PCI_DVSEC_VENDOR_ID_CXL, + .protocol = CXL_DOE_PROTOCOL_TABLE_ACCESS, + .request_pl = &cdat_request_pl, + .request_pl_sz = sizeof(cdat_request_pl), + .response_pl = cdat_response_pl, + .response_pl_sz = sizeof(cdat_response_pl), + }; + u32 *entry; + + rc = pci_doe_exchange_sync(doe, &ex); + if (rc < 0) + return rc; + + /* Skip past table response header */ + entry = cdat_response_pl + 1; + if (entry_handle == 0) { + pci_info(dev, + "CDAT Header (Length=%u, Revision=%u, Checksum=0x%x, Sequence=%u\n", + entry[0], + FIELD_GET(CDAT_HEADER_DW1_REVISION, entry[1]), + FIELD_GET(CDAT_HEADER_DW1_CHECKSUM, entry[1]), + entry[2]); + } else { + u8 entry_type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, entry[0]); + + switch (entry_type) { + case CDAT_STRUCTURE_DW0_TYPE_DSMAS: + pci_info(dev, + "CDAT DSMAS (handle=%u flags=0x%x, dpa(0x%llx 0x%llx)\n", + FIELD_GET(CDAT_DSMAS_DW1_DSMAD_HANDLE, entry[1]), + FIELD_GET(CDAT_DSMAS_DW1_FLAGS, entry[1]), + CDAT_DSMAS_DPA_OFFSET(entry), + CDAT_DSMAS_DPA_LEN(entry)); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSLBIS: + pci_info(dev, + "CDAT DSLBIS (handle=%u flags=0x%x, ent_base=0x%llx, entry[%u %u %u])\n", + FIELD_GET(CDAT_DSLBIS_DW1_HANDLE, entry[1]), + FIELD_GET(CDAT_DSLBIS_DW1_FLAGS, entry[1]), + CDAT_DSLBIS_BASE_UNIT(entry), + FIELD_GET(CDAT_DSLBIS_DW4_ENTRY_0, entry[4]), + FIELD_GET(CDAT_DSLBIS_DW4_ENTRY_1, entry[4]), + FIELD_GET(CDAT_DSLBIS_DW5_ENTRY_2, entry[5])); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSMSCIS: + pci_info(dev, + "CDAT DSMSCIS (handle=%u sc_size=0x%llx attrs=0x%x)\n", + FIELD_GET(CDAT_DSMSCIS_DW1_HANDLE, entry[1]), + CDAT_DSMSCIS_MEMORY_SIDE_CACHE_SIZE(entry), + FIELD_GET(CDAT_DSMSCIS_DW4_MEMORY_SIDE_CACHE_ATTRS, + entry[4])); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSIS: + pci_info(dev, + "CDAT DSIS (handle=%u flags=0x%x)\n", + FIELD_GET(CDAT_DSIS_DW1_HANDLE, entry[1]), + FIELD_GET(CDAT_DSIS_DW1_FLAGS, entry[1])); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSEMTS: + pci_info(dev, + "CDAT DSEMTS (handle=%u EFI=0x%x dpa(0x%llx 0x%llx)\n", + FIELD_GET(CDAT_DSEMTS_DW1_HANDLE, entry[1]), + FIELD_GET(CDAT_DSEMTS_DW1_EFI_MEMORY_TYPE_ATTR, + entry[1]), + CDAT_DSEMTS_DPA_OFFSET(entry), + CDAT_DSEMTS_DPA_LENGTH(entry)); + break; + case CDAT_STRUCTURE_DW0_TYPE_SSLBIS: + pci_info(dev, + "CDAT SSLBIS (type%u ent_base=%llu...)\n", + FIELD_GET(CDAT_SSLBIS_DW1_DATA_TYPE, + entry[1]), + CDAT_SSLBIS_BASE_UNIT(entry)); + break; + } + } + entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, + cdat_response_pl[0]); + } while (entry_handle != 0xFFFF); + + return 0; +} + static void cxl_mem_free_irq_vectors(void *data) { pci_free_irq_vectors(data); @@ -1136,6 +1234,10 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, cxlm->table_doe = pci_doe_find(pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS); + rc = cdat_dump(cxlm->table_doe); + if (rc) + return NULL; + dev_dbg(dev, "Mapped CXL Memory Device resource\n"); return cxlm; }