From patchwork Fri Apr 9 19:23:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ameynarkhede03 X-Patchwork-Id: 12194971 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 5E6F4C433ED for ; Fri, 9 Apr 2021 19:25:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B2476115B for ; Fri, 9 Apr 2021 19:25:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235039AbhDITZW (ORCPT ); Fri, 9 Apr 2021 15:25:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235010AbhDITZU (ORCPT ); Fri, 9 Apr 2021 15:25:20 -0400 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 375DAC061762; Fri, 9 Apr 2021 12:25:07 -0700 (PDT) Received: by mail-wm1-x334.google.com with SMTP id e34so1514596wmp.0; Fri, 09 Apr 2021 12:25:07 -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=HuduY+gK1o4V1a+1CvxRCByt7bwGjlQdRi4ZrjqyKHg=; b=Kyury6jjAyZVAoHpkT5QObVmYjPHwd/ywXHpVMmm9K5ZEA1sosl+Y4CxWjUa8Jrmnj nCLEC+GfCTH9PbwDXmrshXwDMklZP0xqbS+anYkq6S221Udb1NhQ1ibgIxxUF5kHs8UZ 3HBhvhQJgkHsQHVmyxKDojkNIz6kA7fea54stNPRfzkEWLZ3hUxJ2Raagu7CTpy9SxjP lwYSpp0VHqPesGGkiIB5Jk+A/haGsGwLmd8WoyDIpAEE8+HuaKAKEgLnQvstyJi0fNt7 cfpW+I5qKri3QOnH9Yt8nm2okzSL1XmPGcgn4VUQcCqAkJ1eYmrBJQMuiCJCHl0GEWYQ t1tQ== 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=HuduY+gK1o4V1a+1CvxRCByt7bwGjlQdRi4ZrjqyKHg=; b=O6S2/Ms2Bu1MeN/UAl0JhoYjdPjbkGqNjK5PVVDyZ1jCjSVFihuNyMaO4muDDSvRXv /Sl3LimMvN6OCfHH+yJGn7wb1RmIvngeFNaSAV8RKd3pL+oxBLcFWKpOgL/K3K8MdB9p peswQPpx+gIhVqazxpNiV6t0K5Z7omuzRRtGGHZ8x5G9nB0H/UdqmPJP65Vysi0IaTbH y99HeKwkKqMLmUuMR94sgxTyca4m+PUYSdmbxUWIAKQ9y5h5zA3MMZkVuGL+23NT5c3o 4TOTvmzGXr8h2INhE3d+sEWGRuQsuLuQA9viTHmtec/hJYFHD6hTrc37Awq/+wkyuN81 jfAQ== X-Gm-Message-State: AOAM530ZzzYdEmKs/XUxG7h+ySZ83nu+gFSTXKfE4TVLEZDunDgIzUut ul7mS/dtiE1zY/gg8x7j7V4= X-Google-Smtp-Source: ABdhPJy4gTxH+rpOvgxPY5ie7XzhkRC2Wqk+YqhnZeLAbscLk3BUFbzO024ZTVs8G2da82nd6NcIkA== X-Received: by 2002:a7b:c8da:: with SMTP id f26mr9430934wml.91.1617996305984; Fri, 09 Apr 2021 12:25:05 -0700 (PDT) Received: from localhost.localdomain ([103.248.31.176]) by smtp.googlemail.com with ESMTPSA id j6sm6618573wru.18.2021.04.09.12.25.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Apr 2021 12:25:05 -0700 (PDT) From: Amey Narkhede To: Bjorn Helgaas Cc: alex.williamson@redhat.com, raphael.norwitz@nutanix.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Amey Narkhede Subject: [PATCH v2 3/5] PCI: Add new array for keeping track of ordering of reset methods Date: Sat, 10 Apr 2021 00:53:22 +0530 Message-Id: <20210409192324.30080-4-ameynarkhede03@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210409192324.30080-1-ameynarkhede03@gmail.com> References: <20210409192324.30080-1-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 --- drivers/pci/pci.c | 107 ++++++++++++++++++++++++++------------------ drivers/pci/pci.h | 10 ++++- drivers/pci/probe.c | 5 +-- include/linux/pci.h | 7 +++ 4 files changed, 82 insertions(+), 47 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b998d6ad3..ca46a55c7 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_FN_METHODS] = { 0 }; + + return memcmp(null_reset_methods, + dev->reset_methods, PCI_RESET_FN_METHODS); +} + #ifdef CONFIG_PCI_DOMAINS int pci_domains_supported = 1; #endif @@ -5068,6 +5076,19 @@ 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[] = { + { .reset_fn = &pci_dev_specific_reset, .name = "device_specific" }, + { .reset_fn = &pcie_reset_flr, .name = "flr" }, + { .reset_fn = &pci_af_flr, .name = "af_flr" }, + { .reset_fn = &pci_pm_reset, .name = "pm" }, + { .reset_fn = &pci_reset_bus_function, .name = "bus" }, +}; + /** * __pci_reset_function_locked - reset a PCI device function while holding * the @dev mutex lock. @@ -5090,65 +5111,65 @@ 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_FN_METHODS; prio; prio--) { + for (i = 0; i < PCI_RESET_FN_METHODS; 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_FN_METHODS) + 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_FN_METHODS; + u8 reset_methods[PCI_RESET_FN_METHODS] = { 0 }; - might_sleep(); + BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_RESET_FN_METHODS); - 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_FN_METHODS; 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 ef7c46613..61d09e4dd 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -39,7 +39,7 @@ 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); @@ -612,6 +612,14 @@ struct pci_dev_reset_methods { int (*reset)(struct pci_dev *dev, int probe); }; +typedef int (*pci_reset_fn_t)(struct pci_dev *, int); + +struct pci_reset_fn_method { + pci_reset_fn_t reset_fn; + 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 953f15abc..c5cfdd239 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2403,9 +2403,8 @@ 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 8d20e51ab..5c5925ecf 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_FN_METHODS 5 + /* * The PCI interface treats multi-function devices as independent * devices. The slot/function address of each device is encoded @@ -506,6 +508,10 @@ 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_FN_METHODS]; /* Array for storing ordering of reset methods */ }; static inline struct pci_dev *pci_physfn(struct pci_dev *dev) @@ -1219,6 +1225,7 @@ 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);