From patchwork Tue Jun 29 16:00:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ameynarkhede03 X-Patchwork-Id: 12350363 X-Patchwork-Delegate: bhelgaas@google.com 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 4AD57C11F68 for ; Tue, 29 Jun 2021 16:03:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22AA661D88 for ; Tue, 29 Jun 2021 16:03:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233252AbhF2QFp (ORCPT ); Tue, 29 Jun 2021 12:05:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234174AbhF2QE5 (ORCPT ); Tue, 29 Jun 2021 12:04:57 -0400 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 859F3C061787; Tue, 29 Jun 2021 09:02:04 -0700 (PDT) Received: by mail-pf1-x42f.google.com with SMTP id x16so17517650pfa.13; Tue, 29 Jun 2021 09:02:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=CZSBgqj9QSjJVReWLwltrNpmZs8/2VpT4dw7D/o1wQY=; b=iCKfMF/AzzicNI0mEH63rxWvxLgW0vL/6ZYUMf5hmIqFkZC3MpZ32F/PtliC74IEK3 sJ8NSMAsA5oPJ7Ka0MNvfmO9heKlhbipAvq8OQlXWLPe/wk5JjKcf/wlL0It80rbv/SI JaZC/wHtRpMghb6hp9CdC+zvdvvY92eh6L84vQbBkSz6uAWIi6cQNfN8ZhQ9n/UDxv97 8vH6/bP3xFbtaDZgQEuW32Tnve/lEG/MT0lpbYvrYYOgIVPGPFmx5PvgZ5dEE+Sjm8Nc XmwpEqXDNhiQgJJR8OHHT6WoxXaIyJrRUDMD/WNmLT2VFGCu7fahb5Wz61sGiCPCfpVP tWYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CZSBgqj9QSjJVReWLwltrNpmZs8/2VpT4dw7D/o1wQY=; b=nG6yeZW3x58OerZsdMy1CNZ9TMaPGzwAWIdI5rrMF2OFvegI/MaRmdup/Lxbvzc9MN 1SmCU9Ays96F+WpK5wm5IZHbDzIfjwX0LhRu3xO+niUWWK+kJHaJm4/rRAcGC3+Y0J81 1TRoER1MwJ1MWuytVCDynUGFz8B0HLooVB7FF8EuXWCohQ7yiikwgO2C084gZ8NVqF/K T4FXD0jCrBB5k6Ne9/ckOmuQTGXbtfzMKgJ9tdyB6veUDzqs248RJ/nfmbzehCQAnZ+3 9QyDUmCMTfZ0QZR0DhEtZvm1xPthfWh+Lbk7Ar52FIbP715Vpp7oanIlYOvqwynrMuyV 5W1Q== X-Gm-Message-State: AOAM533/8MdNZOm+2AI+M+fhGCCf6HJCPen+TzzSTBRqUqnEsxoQ3Gxa hopwcLrPyWvvZcygKH3y/76h0e9IHZNb6Q== X-Google-Smtp-Source: ABdhPJwD4h2ZABpSKa7FBDw8oyttKODArdoitDxwFdT0B49ZD2CBT8dR5PLFiI/GI/3KHXlXJp9GDQ== X-Received: by 2002:aa7:9a5e:0:b029:305:5d37:7622 with SMTP id x30-20020aa79a5e0000b02903055d377622mr385115pfj.2.1624982524091; Tue, 29 Jun 2021 09:02:04 -0700 (PDT) Received: from localhost.localdomain ([103.200.106.119]) by smtp.googlemail.com with ESMTPSA id m14sm19166240pgu.84.2021.06.29.09.01.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Jun 2021 09:02:03 -0700 (PDT) From: Amey Narkhede To: Bjorn Helgaas Cc: alex.williamson@redhat.com, Raphael Norwitz , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, kw@linux.com, Shanker Donthineni , Sinan Kaya , Len Brown , "Rafael J . Wysocki" , Amey Narkhede Subject: [PATCH v8 2/8] PCI: Add new array for keeping track of ordering of reset methods Date: Tue, 29 Jun 2021 21:30:58 +0530 Message-Id: <20210629160104.2893-3-ameynarkhede03@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210629160104.2893-1-ameynarkhede03@gmail.com> References: <20210629160104.2893-1-ameynarkhede03@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Introduce a new array reset_methods in struct pci_dev to keep track of reset mechanisms supported by the device and their ordering. Also refactor probing and reset functions to take advantage of calling convention of reset functions. Co-developed-by: Alex Williamson Signed-off-by: Alex Williamson Signed-off-by: Amey Narkhede --- drivers/pci/pci.c | 97 ++++++++++++++++++++++++++------------------- drivers/pci/pci.h | 9 ++++- drivers/pci/probe.c | 5 +-- include/linux/pci.h | 7 ++++ 4 files changed, 74 insertions(+), 44 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 28f099a4f..1932c7ec4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -72,6 +72,14 @@ static void pci_dev_d3_sleep(struct pci_dev *dev) msleep(delay); } +int pci_reset_supported(struct pci_dev *dev) +{ + u8 null_reset_methods[PCI_NUM_RESET_METHODS] = { 0 }; + + return memcmp(null_reset_methods, + dev->reset_methods, sizeof(null_reset_methods)); +} + #ifdef CONFIG_PCI_DOMAINS int pci_domains_supported = 1; #endif @@ -5101,6 +5109,19 @@ static void pci_dev_restore(struct pci_dev *dev) err_handler->reset_done(dev); } +/* + * The ordering for functions in pci_reset_fn_methods is required for + * reset_methods byte array defined in struct pci_dev. + */ +const struct pci_reset_fn_method pci_reset_fn_methods[] = { + { }, + { &pci_dev_specific_reset, .name = "device_specific" }, + { &pcie_reset_flr, .name = "flr" }, + { &pci_af_flr, .name = "af_flr" }, + { &pci_pm_reset, .name = "pm" }, + { &pci_reset_bus_function, .name = "bus" }, +}; + /** * __pci_reset_function_locked - reset a PCI device function while holding * the @dev mutex lock. @@ -5123,65 +5144,61 @@ static void pci_dev_restore(struct pci_dev *dev) */ int __pci_reset_function_locked(struct pci_dev *dev) { - int rc; + int i, m, rc = -ENOTTY; might_sleep(); /* - * A reset method returns -ENOTTY if it doesn't support this device - * and we should try the next method. + * A reset method returns -ENOTTY if it doesn't support this device and + * we should try the next method. * - * If it returns 0 (success), we're finished. If it returns any - * other error, we're also finished: this indicates that further - * reset mechanisms might be broken on the device. + * If it returns 0 (success), we're finished. If it returns any other + * error, we're also finished: this indicates that further reset + * mechanisms might be broken on the device. */ - rc = pci_dev_specific_reset(dev, 0); - if (rc != -ENOTTY) - return rc; - rc = pcie_reset_flr(dev, 0); - if (rc != -ENOTTY) - return rc; - rc = pci_af_flr(dev, 0); - if (rc != -ENOTTY) - return rc; - rc = pci_pm_reset(dev, 0); - if (rc != -ENOTTY) - return rc; - return pci_reset_bus_function(dev, 0); + for (i = 0; i < PCI_NUM_RESET_METHODS && (m = dev->reset_methods[i]); i++) { + rc = pci_reset_fn_methods[m].reset_fn(dev, 0); + if (!rc) + return 0; + if (rc != -ENOTTY) + return rc; + } + + return -ENOTTY; } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); /** - * pci_probe_reset_function - check whether the device can be safely reset - * @dev: PCI device to reset + * pci_init_reset_methods - check whether device can be safely reset + * and store supported reset mechanisms. + * @dev: PCI device to check for reset mechanisms * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive - * to PCI config space in order to use this function. + * to reads and writes to its PCI config space in order to use this function. * - * Returns 0 if the device function can be reset or negative if the - * device doesn't support resetting a single function. + * Stores reset mechanisms supported by device in reset_methods byte array + * which is a member of struct pci_dev. */ -int pci_probe_reset_function(struct pci_dev *dev) +void pci_init_reset_methods(struct pci_dev *dev) { - int rc; + int i, n, rc; + u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 }; - might_sleep(); + n = 0; - rc = pci_dev_specific_reset(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pcie_reset_flr(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pci_af_flr(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pci_pm_reset(dev, 1); - if (rc != -ENOTTY) - return rc; + BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_NUM_RESET_METHODS); - return pci_reset_bus_function(dev, 1); + might_sleep(); + + for (i = 1; i < PCI_NUM_RESET_METHODS; i++) { + rc = pci_reset_fn_methods[i].reset_fn(dev, 1); + if (!rc) + reset_methods[n++] = i; + else if (rc != -ENOTTY) + break; + } + memcpy(dev->reset_methods, reset_methods, sizeof(reset_methods)); } /** diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 37c913bbc..db1ad94e7 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -33,7 +33,8 @@ enum pci_mmap_api { int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai, enum pci_mmap_api mmap_api); -int pci_probe_reset_function(struct pci_dev *dev); +int pci_reset_supported(struct pci_dev *dev); +void pci_init_reset_methods(struct pci_dev *dev); int pci_bridge_secondary_bus_reset(struct pci_dev *dev); int pci_bus_error_reset(struct pci_dev *dev); @@ -606,6 +607,12 @@ struct pci_dev_reset_methods { int (*reset)(struct pci_dev *dev, int probe); }; +struct pci_reset_fn_method { + int (*reset_fn)(struct pci_dev *pdev, int probe); + char *name; +}; + +extern const struct pci_reset_fn_method pci_reset_fn_methods[]; #ifdef CONFIG_PCI_QUIRKS int pci_dev_specific_reset(struct pci_dev *dev, int probe); #else diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 862d91615..7355769f8 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2406,9 +2406,8 @@ static void pci_init_capabilities(struct pci_dev *dev) pci_rcec_init(dev); /* Root Complex Event Collector */ pcie_report_downtraining(dev); - - if (pci_probe_reset_function(dev) == 0) - dev->reset_fn = 1; + pci_init_reset_methods(dev); + dev->reset_fn = pci_reset_supported(dev); } /* diff --git a/include/linux/pci.h b/include/linux/pci.h index 74f42a2cd..bce3d3e52 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -49,6 +49,9 @@ PCI_STATUS_SIG_TARGET_ABORT | \ PCI_STATUS_PARITY) +/* Number of reset methods used in pci_reset_fn_methods array in pci.c */ +#define PCI_NUM_RESET_METHODS 6 + /* * The PCI interface treats multi-function devices as independent * devices. The slot/function address of each device is encoded @@ -504,6 +507,10 @@ struct pci_dev { char *driver_override; /* Driver name to force a match */ unsigned long priv_flags; /* Private flags for the PCI driver */ + /* + * See pci_reset_fn_methods array in pci.c for ordering. + */ + u8 reset_methods[PCI_NUM_RESET_METHODS]; /* Reset methods ordered by priority */ }; static inline struct pci_dev *pci_physfn(struct pci_dev *dev)