From patchwork Thu Jun 17 18:21:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alison Schofield X-Patchwork-Id: 12329167 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,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 C5F6EC49361 for ; Thu, 17 Jun 2021 18:26:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A96D1613AA for ; Thu, 17 Jun 2021 18:26:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233126AbhFQS2q (ORCPT ); Thu, 17 Jun 2021 14:28:46 -0400 Received: from mga03.intel.com ([134.134.136.65]:54628 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232184AbhFQS2N (ORCPT ); Thu, 17 Jun 2021 14:28:13 -0400 IronPort-SDR: 857oeECqapaDIDe1BVmWt+3cvf4OO84jkl802HaKpPsLzVVNcnsbJCTyWWt3RMaARp/WnzxTil ZoAab6PjNwPQ== X-IronPort-AV: E=McAfee;i="6200,9189,10018"; a="206465036" X-IronPort-AV: E=Sophos;i="5.83,281,1616482800"; d="scan'208";a="206465036" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jun 2021 11:25:59 -0700 IronPort-SDR: fi0r6L2RTlNatMzHASyCwqad/HxLJKCUzCP71SWys0JYsaS6qSbMXc6GwJhrNLzIBXXQMJcNEw SkJcFvst1AZQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,281,1616482800"; d="scan'208";a="555282555" Received: from alison-desk.jf.intel.com (HELO alison-desk) ([10.54.74.53]) by fmsmga001.fm.intel.com with ESMTP; 17 Jun 2021 11:25:58 -0700 From: Alison Schofield To: Ben Widawsky , Dan Williams , Ira Weiny , Alison Schofield , Vishal Verma , Jonathan Cameron Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH v4 1/2] cxl/acpi: Add the Host Bridge base address to CXL port objects Date: Thu, 17 Jun 2021 11:21:37 -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-acpi@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 Reviewed-by: Jonathan Cameron Reviewed-by: Ben Widawsky --- drivers/cxl/acpi.c | 98 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 93 insertions(+), 5 deletions(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 8a723f7f3f73..852b5c270464 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -8,6 +8,58 @@ #include #include "cxl.h" +static struct acpi_table_header *acpi_cedt; + +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_subtable; + + len = acpi_cedt->length - sizeof(*acpi_cedt); + cedt_subtable = acpi_cedt + 1; + + while (cur < len) { + struct acpi_cedt_header *c = cedt_subtable + cur; + + if (c->type != ACPI_CEDT_TYPE_CHBS) { + cur += c->length; + continue; + } + + chbs = cedt_subtable + cur; + + if (dev_WARN_ONCE(dev, chbs->header.length < sizeof(*chbs), + "CHBS entry skipped: invalid length:%u\n", + chbs->header.length)) { + cur += c->length; + continue; + } + + if (chbs->uid != uid) { + cur += c->length; + continue; + } + + if (dev_WARN_ONCE(dev, chbs_match, + "CHBS entry skipped: duplicate UID:%u\n", + uid)) { + cur += c->length; + continue; + } + + chbs_match = chbs; + cur += c->length; + } + + return chbs_match ? chbs_match : ERR_PTR(-ENODEV); +} + +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 +102,21 @@ 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 +138,7 @@ 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 +148,14 @@ 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 +194,7 @@ 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 +210,12 @@ 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)); @@ -172,6 +252,7 @@ static int add_root_nvdimm_bridge(struct device *match, void *data) 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); @@ -181,10 +262,14 @@ 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, &acpi_cedt); + 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 @@ -193,11 +278,14 @@ static int cxl_acpi_probe(struct platform_device *pdev) rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, add_host_bridge_uport); if (rc) - return rc; + goto out; if (IS_ENABLED(CONFIG_CXL_PMEM)) rc = device_for_each_child(&root_port->dev, root_port, add_root_nvdimm_bridge); + +out: + acpi_put_table(acpi_cedt); if (rc < 0) return rc; return 0;