From patchwork Wed Jun 16 00:20:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alison Schofield X-Patchwork-Id: 12323415 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=ham 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 01E94C48BE5 for ; Wed, 16 Jun 2021 00:24:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D67886109E for ; Wed, 16 Jun 2021 00:24:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231725AbhFPA1A (ORCPT ); Tue, 15 Jun 2021 20:27:00 -0400 Received: from mga03.intel.com ([134.134.136.65]:14098 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231617AbhFPA07 (ORCPT ); Tue, 15 Jun 2021 20:26:59 -0400 IronPort-SDR: PHHp/uaotySIAnY/IlzG3oWPpKTdZzc00YSr8NKIWiZr7IijQIYSIyYOXH0T2nndKPjJc0MyFw d2Tde+RVzh9g== X-IronPort-AV: E=McAfee;i="6200,9189,10016"; a="206127848" X-IronPort-AV: E=Sophos;i="5.83,276,1616482800"; d="scan'208";a="206127848" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2021 17:24:53 -0700 IronPort-SDR: ABp0BcE4Y1Oohh52DpbwdVeMQyfffX9TC1jLS2/naX0YKbMcMS4ghMbi9TtbWPWgciDPFZaAdU wGNi3gMj7lOw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,276,1616482800"; d="scan'208";a="639822561" Received: from alison-desk.jf.intel.com (HELO alison-desk) ([10.54.74.53]) by fmsmga005.fm.intel.com with ESMTP; 15 Jun 2021 17:24:53 -0700 From: Alison Schofield To: Ben Widawsky , Dan Williams , Ira Weiny , Alison Schofield , Vishal Verma Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Linux ACPI Subject: [PATCH v2 1/2] cxl/acpi: Add the Host Bridge base address to CXL port objects Date: Tue, 15 Jun 2021 17:20:38 -0700 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org The base address for the Host Bridge port component registers is located in the CXL Host Bridge Structure (CHBS) of the ACPI CXL Early Discovery Table (CEDT). Retrieve the CHBS for each Host Bridge (ACPI0016 device) and include that base address in the port object. Co-developed-by: Vishal Verma Signed-off-by: Vishal Verma Signed-off-by: Alison Schofield --- drivers/cxl/acpi.c | 105 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 99 insertions(+), 6 deletions(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index be357eea552c..b6d9cd45428c 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -8,6 +8,61 @@ #include #include "cxl.h" +static struct acpi_table_header *cedt_table; + +static struct acpi_cedt_chbs *cxl_acpi_match_chbs(struct device *dev, u32 uid) +{ + struct acpi_cedt_chbs *chbs, *chbs_match = NULL; + acpi_size len, cur = 0; + void *cedt_base; + int rc = 0; + + len = cedt_table->length - sizeof(*cedt_table); + cedt_base = cedt_table + 1; + + while (cur < len) { + struct acpi_cedt_header *c = cedt_base + cur; + + if (c->type != ACPI_CEDT_TYPE_CHBS) { + cur += c->length; + continue; + } + + chbs = cedt_base + cur; + + if (chbs->header.length < sizeof(*chbs)) { + dev_err(dev, "Invalid CHBS header length: %u\n", + chbs->header.length); + rc = -EINVAL; + break; + } + + if (chbs->uid == uid && !chbs_match) { + chbs_match = chbs; + cur += c->length; + continue; + } + + if (chbs->uid == uid && chbs_match) { + dev_err(dev, "Duplicate CHBS UIDs %u\n", uid); + rc = -EINVAL; + break; + } + cur += c->length; + } + if (!chbs_match) + rc = -EINVAL; + if (rc) + return ERR_PTR(rc); + + return chbs_match; +} + +static resource_size_t get_chbcr(struct acpi_cedt_chbs *chbs) +{ + return IS_ERR(chbs) ? CXL_RESOURCE_NONE : chbs->base; +} + struct cxl_walk_context { struct device *dev; struct pci_bus *root; @@ -50,6 +105,21 @@ static int match_add_root_ports(struct pci_dev *pdev, void *data) return 0; } +static struct cxl_dport *find_dport_by_dev(struct cxl_port *port, struct device *dev) +{ + struct cxl_dport *dport; + + device_lock(&port->dev); + list_for_each_entry(dport, &port->dports, list) + if (dport->dport == dev) { + device_unlock(&port->dev); + return dport; + } + + device_unlock(&port->dev); + return NULL; +} + static struct acpi_device *to_cxl_host_bridge(struct device *dev) { struct acpi_device *adev = to_acpi_device(dev); @@ -71,6 +141,7 @@ static int add_host_bridge_uport(struct device *match, void *arg) struct acpi_pci_root *pci_root; struct cxl_walk_context ctx; struct cxl_decoder *cxld; + struct cxl_dport *dport; struct cxl_port *port; if (!bridge) @@ -80,8 +151,15 @@ static int add_host_bridge_uport(struct device *match, void *arg) if (!pci_root) return -ENXIO; - /* TODO: fold in CEDT.CHBS retrieval */ - port = devm_cxl_add_port(host, match, CXL_RESOURCE_NONE, root_port); + dport = find_dport_by_dev(root_port, match); + if (!dport) { + dev_dbg(host, "host bridge expected and not found\n"); + return -ENODEV; + } + + port = devm_cxl_add_port(host, match, dport->component_reg_phys, + root_port); + if (IS_ERR(port)) return PTR_ERR(port); dev_dbg(host, "%s: add: %s\n", dev_name(match), dev_name(&port->dev)); @@ -120,6 +198,7 @@ static int add_host_bridge_dport(struct device *match, void *arg) int rc; acpi_status status; unsigned long long uid; + struct acpi_cedt_chbs *chbs; struct cxl_port *root_port = arg; struct device *host = root_port->dev.parent; struct acpi_device *bridge = to_cxl_host_bridge(match); @@ -135,7 +214,12 @@ static int add_host_bridge_dport(struct device *match, void *arg) return -ENODEV; } - rc = cxl_add_dport(root_port, match, uid, CXL_RESOURCE_NONE); + chbs = cxl_acpi_match_chbs(host, uid); + if (IS_ERR(chbs)) + dev_dbg(host, "No CHBS found for Host Bridge: %s\n", + dev_name(match)); + + rc = cxl_add_dport(root_port, match, uid, get_chbcr(chbs)); if (rc) { dev_err(host, "failed to add downstream port: %s\n", dev_name(match)); @@ -148,6 +232,7 @@ static int add_host_bridge_dport(struct device *match, void *arg) static int cxl_acpi_probe(struct platform_device *pdev) { int rc; + acpi_status status; struct cxl_port *root_port; struct device *host = &pdev->dev; struct acpi_device *adev = ACPI_COMPANION(host); @@ -157,17 +242,25 @@ static int cxl_acpi_probe(struct platform_device *pdev) return PTR_ERR(root_port); dev_dbg(host, "add: %s\n", dev_name(&root_port->dev)); + status = acpi_get_table(ACPI_SIG_CEDT, 0, &cedt_table); + if (ACPI_FAILURE(status)) + return -ENXIO; + rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, add_host_bridge_dport); if (rc) - return rc; + goto out; /* * Root level scanned with host-bridge as dports, now scan host-bridges * for their role as CXL uports to their CXL-capable PCIe Root Ports. */ - return bus_for_each_dev(adev->dev.bus, NULL, root_port, - add_host_bridge_uport); + rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, + add_host_bridge_uport); + +out: + acpi_put_table(cedt_table); + return rc; } static const struct acpi_device_id cxl_acpi_ids[] = {