From patchwork Wed Dec 9 00:24:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12188013 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=-16.7 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 898A8C2BBD5 for ; Wed, 9 Dec 2020 00:28:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 655C5239D1 for ; Wed, 9 Dec 2020 00:28:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731902AbgLIAZo (ORCPT ); Tue, 8 Dec 2020 19:25:44 -0500 Received: from mga09.intel.com ([134.134.136.24]:16959 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731895AbgLIAZk (ORCPT ); Tue, 8 Dec 2020 19:25:40 -0500 IronPort-SDR: xqstFyOh9XnrSMrWsaPSllib0xOOuG5GEg+Qgv2xJW1PZESqweqYgu9RUcTjbE4tjCzYG8lQLV S1LKQSQakfqA== X-IronPort-AV: E=McAfee;i="6000,8403,9829"; a="174142079" X-IronPort-AV: E=Sophos;i="5.78,404,1599548400"; d="scan'208";a="174142079" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2020 16:24:25 -0800 IronPort-SDR: o9X7rNHop8rYuOfdHxs7jvL1rDq5M0TL0NxbGKoSTMUo5QZbMhIZkib7UKEC9EvXCHsrE6HPUE efixVCUY107g== X-IronPort-AV: E=Sophos;i="5.78,404,1599548400"; d="scan'208";a="407838487" Received: from mlubyani-mobl2.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.137.9]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2020 16:24:24 -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 Subject: [RFC PATCH v2 06/14] cxl/mem: Find device capabilities Date: Tue, 8 Dec 2020 16:24:10 -0800 Message-Id: <20201209002418.1976362-7-ben.widawsky@intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201209002418.1976362-1-ben.widawsky@intel.com> References: <20201209002418.1976362-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org CXL devices contain an array of capabilities that describe the interactions software can interact 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. Signed-off-by: Ben Widawsky --- drivers/cxl/cxl.h | 92 ++++++++++++++++++++++++++++++++++++++++++++++- drivers/cxl/mem.c | 74 +++++++++++++++++++++++++++++++++++++- 2 files changed, 164 insertions(+), 2 deletions(-) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index d81d0ba4617c..91bb40f73ddc 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 */ +#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(5, 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 +44,64 @@ 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); + +static inline u32 __cxl_read_reg32(struct cxl_mem *cxlm, u32 reg) +{ + void __iomem *reg_addr = cxlm->regs; + + return readl(reg_addr + reg); +} + +static inline u64 __cxl_read_reg64(struct cxl_mem *cxlm, u32 reg) +{ + void __iomem *reg_addr = cxlm->regs; + + return readq(reg_addr + reg); +} +#endif /* __CXL_H__ */ diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 06113d306cd2..8ea830ffdbba 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -7,6 +7,75 @@ #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. + */ +static int cxl_mem_setup_regs(struct cxl_mem *cxlm) +{ + u64 cap_array; + int cap; + + /* + * Register accessors need the mappings set up by this function, so the + * raw versions of the mmio accessors must be used instead. + */ + cap_array = __cxl_read_reg64(cxlm, 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 = __cxl_read_reg32(cxlm, cap * 0x10) & 0xffff; + offset = __cxl_read_reg32(cxlm, 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; + cxlm->mbox.payload_size = + CXL_GET_FIELD(cap, CXLDEV_MB_CAP_PAYLOAD_SIZE); + 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_err(&cxlm->pdev->dev, "Unknown cap ID: %d (0x%x)\n", + cap_id, offset); + return -ENXIO; + } + } + + if (!cxlm->status.regs || !cxlm->mbox.regs || !cxlm->mem.regs) + return -ENXIO; + + return 0; +} + /** * cxl_mem_create() - Create a new &struct cxl_mem. * @pdev: The pci device associated with the new &struct cxl_mem. @@ -126,7 +195,10 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) } } - return rc; + if (rc) + return rc; + + return cxl_mem_setup_regs(cxlm); } static const struct pci_device_id cxl_mem_pci_tbl[] = {