From patchwork Sat May 29 19:25:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ameynarkhede03 X-Patchwork-Id: 12288027 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 7E827C47093 for ; Sat, 29 May 2021 19:25:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59C8D6113E for ; Sat, 29 May 2021 19:25:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229928AbhE2T12 (ORCPT ); Sat, 29 May 2021 15:27:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229905AbhE2T10 (ORCPT ); Sat, 29 May 2021 15:27:26 -0400 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 851D4C061574; Sat, 29 May 2021 12:25:48 -0700 (PDT) Received: by mail-pf1-x42e.google.com with SMTP id p39so5852074pfw.8; Sat, 29 May 2021 12:25:48 -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=9MvIdKhfq+0Mdk+szDC0tPoyoxwUROEYUAQaW6Hav6U=; b=hwN4ZdnjqDq5XpqauPc1yVGso8hRDB5GFuQuIng3qX4nIdWH71G/9tGKPYD6LZ5omu 7AWbZUEE8szBScckodxmrcjbKz9O8UOHTBfyveJwSvkPGwMcUdFUVbEEnRc4YlbQvj28 rhz+1yaC3VJmpIzaEVQe2+LaNzj7polJ4c+nE8Wmv2Kdunpht2gXK9UA0QFbnYRxz0cN ABSvZXITZMGo+DgLQBPnJq/zuTFowyYpWh6TTV7+z8wzPgpwKcz7QhaOykVCMfkhePco U4sV1WvNce/xvFRyIUuUgelPNxegso0kStdr/MeRQs73VSyq20iFWgxNR/+Oo67IsdSF KIAQ== 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=9MvIdKhfq+0Mdk+szDC0tPoyoxwUROEYUAQaW6Hav6U=; b=CSM+nz0HTDRYZNXLJvLR+qOur5x6uaDjEn8U8Cu/7zb6m0EvYqDxBAf/wamGMSz65/ JvsSTffU+R47v+KFLpvlybS/OtRuRwVsnvYEw3RJ3nyfo4497kZAqMbvrSiRD7C57l5p ZVICy+sAlV6dufRrXsMhDGKB6gNPTqdDrpeV7B7Yq2oHgLUQGD3gIlU6WDN1y/Gmg+dL 1wn7NGSiP12lFnBvSz+Y9FiGnUJMzX/EkgggAwruRvG5I+hIFpbExF4dgP1+g4J767Jd WcJyK4FQKuzaepmQfXWjChUAdvchpA2uDALVCQoRa9XIFOZFD26qu3OezpU9Shk6dxzg MuMQ== X-Gm-Message-State: AOAM530IUjj2pxPD1fF36nmzOTV5k6kLNE6F4Mh64yU3q6RPvRNeq6dq 1p477fgxDiYjN3WHX7TUY8o= X-Google-Smtp-Source: ABdhPJyU22Er6YJCWflyaqNxjxaU6VtBu4ZlxRf/dj7qptIoAL7+HL+sw91s/Kxd3xDWYEkH90uxuw== X-Received: by 2002:a62:860b:0:b029:28e:d45b:4d2e with SMTP id x11-20020a62860b0000b029028ed45b4d2emr9928353pfd.70.1622316348062; Sat, 29 May 2021 12:25:48 -0700 (PDT) Received: from localhost.localdomain ([103.248.31.172]) by smtp.googlemail.com with ESMTPSA id ge5sm7286754pjb.45.2021.05.29.12.25.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 May 2021 12:25:47 -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 4/7] PCI/sysfs: Allow userspace to query and set device reset mechanism Date: Sun, 30 May 2021 00:55:24 +0530 Message-Id: <20210529192527.2708-5-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 Add reset_method sysfs attribute to enable user to query and set user preferred device reset methods and their ordering. 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 --- Documentation/ABI/testing/sysfs-bus-pci | 16 ++++ drivers/pci/pci-sysfs.c | 105 ++++++++++++++++++++++++ 2 files changed, 121 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index ef00fada2..cf6dbbb3c 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -121,6 +121,22 @@ Description: child buses, and re-discover devices removed earlier from this part of the device tree. +What: /sys/bus/pci/devices/.../reset_method +Date: March 2021 +Contact: Amey Narkhede +Description: + Some devices allow an individual function to be reset + without affecting other functions in the same slot. + For devices that have this support, a file named reset_method + will be present in sysfs. Reading this file will give names + of the device supported reset methods and their ordering. + Writing the name or comma separated list of names of any of + the device supported reset methods to this file will set the + reset methods and their ordering to be used when resetting + the device. Writing empty string to this file will disable + ability to reset the device and writing "default" will return + to the original value. + What: /sys/bus/pci/devices/.../reset Date: July 2009 Contact: Michael S. Tsirkin diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 316f70c3e..04b3d6565 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1334,6 +1334,110 @@ static const struct attribute_group pci_dev_rom_attr_group = { .is_bin_visible = pci_dev_rom_attr_is_visible, }; +static ssize_t reset_method_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + ssize_t len = 0; + int i, prio; + + for (prio = PCI_RESET_METHODS_NUM; prio; prio--) { + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { + if (prio == pdev->reset_methods[i]) { + len += sysfs_emit_at(buf, len, "%s%s", + len ? "," : "", + pci_reset_fn_methods[i].name); + break; + } + } + + if (i == PCI_RESET_METHODS_NUM) + break; + } + + return len; +} + +static ssize_t reset_method_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + u8 reset_methods[PCI_RESET_METHODS_NUM]; + struct pci_dev *pdev = to_pci_dev(dev); + u8 prio = PCI_RESET_METHODS_NUM; + char *name; + int i; + + /* + * Initialize reset_method such that 0xff indicates + * supported but not currently enabled reset methods + * as we only use priority values which are within + * the range of PCI_RESET_FN_METHODS array size + */ + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) + reset_methods[i] = pdev->reset_methods[i] ? 0xff : 0; + + if (sysfs_streq(buf, "")) { + pci_warn(pdev, "All device reset methods disabled by user"); + goto set_reset_methods; + } + + if (sysfs_streq(buf, "default")) { + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) + reset_methods[i] = reset_methods[i] ? prio-- : 0; + goto set_reset_methods; + } + + while ((name = strsep((char **)&buf, ",")) != NULL) { + if (sysfs_streq(name, "")) + continue; + + name = strim(name); + + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { + if (reset_methods[i] && + sysfs_streq(name, pci_reset_fn_methods[i].name)) { + reset_methods[i] = prio--; + break; + } + } + if (i == PCI_RESET_METHODS_NUM) + return -EINVAL; + } + + if (reset_methods[0] && + reset_methods[0] != PCI_RESET_METHODS_NUM) + pci_warn(pdev, "Device specific reset disabled/de-prioritized by user"); + +set_reset_methods: + memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods)); + return count; +} + +static DEVICE_ATTR_RW(reset_method); + +static struct attribute *pci_dev_reset_method_attrs[] = { + &dev_attr_reset_method.attr, + NULL, +}; + +static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); + + if (!pci_reset_supported(pdev)) + return 0; + + return a->mode; +} + +static const struct attribute_group pci_dev_reset_method_attr_group = { + .attrs = pci_dev_reset_method_attrs, + .is_visible = pci_dev_reset_method_attr_is_visible, +}; + static ssize_t reset_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -1491,6 +1595,7 @@ const struct attribute_group *pci_dev_groups[] = { &pci_dev_config_attr_group, &pci_dev_rom_attr_group, &pci_dev_reset_attr_group, + &pci_dev_reset_method_attr_group, &pci_dev_vpd_attr_group, #ifdef CONFIG_DMI &pci_dev_smbios_attr_group,