From patchwork Sat May 29 19:25:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ameynarkhede03 X-Patchwork-Id: 12288023 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=-15.7 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,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 C7A87C47090 for ; Sat, 29 May 2021 19:25:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A552D610FC for ; Sat, 29 May 2021 19:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229864AbhE2T1T (ORCPT ); Sat, 29 May 2021 15:27:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229851AbhE2T1S (ORCPT ); Sat, 29 May 2021 15:27:18 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3501AC061574; Sat, 29 May 2021 12:25:42 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id v12so3207089plo.10; Sat, 29 May 2021 12:25:42 -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=29N2RGXp6yuyHENFWANA6iVksXjLMoovSI9EBMet6jE=; b=OATYX1Xznn/Z8EYaEU56WkkSxAY2+siL83yezmAu5YOi1Luh0lKcEESEuQmNpgLqWc s/fyfB+cFA1mHYdHcnux7ocACgzl6BJbesnwvMamMWAlvSc6OJIYVQzkZbBET9B8Wbg0 2t2zV472BodEl3XAqchojeL3mYs5RDE+naiufHLSBeekO/BW45ysgq3jkF1cjcJIFLoH x2KcCXhWLHRF6vdC9dLdsiX0ElRwyQ32M1uB6YBd79XL/WSUl4d95wHggAcMaLlHCPYu N+hcZkV70o7A9nI2aa1V3bpMNg8boWwPXPkULa0AmmFzcBPyMcvZzmsKy3OhmHEX484L hlKQ== 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=29N2RGXp6yuyHENFWANA6iVksXjLMoovSI9EBMet6jE=; b=bLpsI/FMk/v61YL1gI0YpPgz2t5wQoi4cXYlUbk6qSolY/m6O1inj2jLQaSbY+1VIx ECckfHLJVUxQt6AJfp2/0nkjAAo8P2FL06gSiu2/3gO+3W9v6lO3i7wYB+kp2kVru9pY KlHM0jdQHbL/i8KW1Y+vYdEezFZVHr4QueUa4mfum8E1kyUvL6xT4VZRKbLnGgQoEzBp c2ppftWjELc7CQWSgyu89fTZg+16WdApH2k8AQml9c9IOYiyYq/iBgNLvTdPmHCTsQv7 kTohG8P4d3m/JfwRpWUm5mwpsm6Dc8eHlsHGffvAKTAvmxZB+JEHh+7lH1YPjege3KO2 UB8w== X-Gm-Message-State: AOAM5304WfawbCS6s8oXcdUv3NTp2alyP3VSeWTCqzB7Pz7jPm/AMjX0 l6Oifz0CxUOBJWti0wR2OF0= X-Google-Smtp-Source: ABdhPJxM1PFXpBMFFB4CBIcZZoJfPFo3nFjsFVPS8z2T7dCO+KRMJmWaB/038tStp89+2I8XS4ILfQ== X-Received: by 2002:a17:902:d507:b029:f2:c88c:5b45 with SMTP id b7-20020a170902d507b02900f2c88c5b45mr13849798plg.66.1622316341718; Sat, 29 May 2021 12:25:41 -0700 (PDT) Received: from localhost.localdomain ([103.248.31.172]) by smtp.googlemail.com with ESMTPSA id ge5sm7286754pjb.45.2021.05.29.12.25.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 May 2021 12:25:41 -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 , Amey Narkhede Subject: [PATCH v5 2/7] PCI: Add new array for keeping track of ordering of reset methods Date: Sun, 30 May 2021 00:55:22 +0530 Message-Id: <20210529192527.2708-3-ameynarkhede03@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210529192527.2708-1-ameynarkhede03@gmail.com> References: <20210529192527.2708-1-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. Reviewed-by: Alex Williamson Reviewed-by: Raphael Norwitz Co-developed-by: Alex Williamson Signed-off-by: Alex Williamson Signed-off-by: Amey Narkhede Tested-by: Shanker Donthineni --- drivers/pci/pci.c | 107 ++++++++++++++++++++++++++------------------ drivers/pci/pci.h | 8 +++- drivers/pci/probe.c | 5 +-- include/linux/pci.h | 7 +++ 4 files changed, 80 insertions(+), 47 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 3bf36924c..67a2605d4 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); } +bool pci_reset_supported(struct pci_dev *dev) +{ + u8 null_reset_methods[PCI_RESET_METHODS_NUM] = { 0 }; + + return memcmp(null_reset_methods, + dev->reset_methods, PCI_RESET_METHODS_NUM); +} + #ifdef CONFIG_PCI_DOMAINS int pci_domains_supported = 1; #endif @@ -5107,6 +5115,19 @@ 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. @@ -5129,65 +5150,65 @@ static void pci_dev_restore(struct pci_dev *dev) */ int __pci_reset_function_locked(struct pci_dev *dev) { - int rc; + int i, rc = -ENOTTY; + u8 prio; might_sleep(); - /* - * 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. - */ - 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 (prio = PCI_RESET_METHODS_NUM; prio; prio--) { + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { + if (dev->reset_methods[i] == prio) { + /* + * 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. + */ + rc = pci_reset_fn_methods[i].reset_fn(dev, 0); + if (rc != -ENOTTY) + return rc; + break; + } + } + if (i == PCI_RESET_METHODS_NUM) + break; + } + return rc; } 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, rc; + u8 prio = PCI_RESET_METHODS_NUM; + u8 reset_methods[PCI_RESET_METHODS_NUM] = { 0 }; - might_sleep(); + BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_RESET_METHODS_NUM); - 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; + might_sleep(); - return pci_reset_bus_function(dev, 1); + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { + rc = pci_reset_fn_methods[i].reset_fn(dev, 1); + if (!rc) + reset_methods[i] = prio--; + 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..13ec6bd6f 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -33,7 +33,7 @@ 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); +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 +606,12 @@ 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 3a62d09b8..8cf532681 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2404,9 +2404,8 @@ 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 20b90c205..0955246f8 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -49,6 +49,8 @@ PCI_STATUS_SIG_TARGET_ABORT | \ PCI_STATUS_PARITY) +#define PCI_RESET_METHODS_NUM 5 + /* * The PCI interface treats multi-function devices as independent * devices. The slot/function address of each device is encoded @@ -505,6 +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_RESET_METHODS_NUM]; /* Reset methods ordered by priority */ }; static inline struct pci_dev *pci_physfn(struct pci_dev *dev) @@ -1227,6 +1233,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, void pcie_print_link_status(struct pci_dev *dev); int pcie_reset_flr(struct pci_dev *dev, int probe); int pcie_flr(struct pci_dev *dev); +bool pci_reset_supported(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); int pci_reset_function_locked(struct pci_dev *dev);