From patchwork Fri Jul 9 12:38:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ameynarkhede03 X-Patchwork-Id: 12367287 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=-16.0 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 34053C07E9B for ; Fri, 9 Jul 2021 12:38:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1EFB6613B0 for ; Fri, 9 Jul 2021 12:38:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231544AbhGIMlj (ORCPT ); Fri, 9 Jul 2021 08:41:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231556AbhGIMli (ORCPT ); Fri, 9 Jul 2021 08:41:38 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B5E9C0613DD; Fri, 9 Jul 2021 05:38:55 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id y4so8584182pfi.9; Fri, 09 Jul 2021 05:38:55 -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=+SeOboOLlz+xap97sxOppn3yBL6kAtfgBYzXOsGvd0s=; b=gt4efscUHLLjbgAltWGtdyB8zUfh21GTWeznXmW4oC8/mZSeSkrPp8X5mWEB3aTdcw B8mLQWU+Zr53YzFIsyZ2SXeKn6Mq9RxZmNWeo3tLsSwOOojOS5R2p5ha2tbz9mGixwJW S/q1mWy62lDMB0+7SsvQGLwkv/iA8gTBR0+tfCG/chV0JEErQIsXG5OXma5JjP246el5 3dhZr0UbbOS05h5n0iv70FdD8MwStBarVJaHCwJKDdi/b0MuxNrsIv8onZJFQmBAZZpc IiOCmmBXbzQ//9FGcNWCE/oPOLVbNQU2xqwaibn3k91sm2VfGXtBD2YBq5UDkaZWoNzk WftA== 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=+SeOboOLlz+xap97sxOppn3yBL6kAtfgBYzXOsGvd0s=; b=rrFjGkAFFS10gWc33S8ix0WmPRudwUn9ZgTVuL503QKafG4C+ia2e3mNKiPIGjIqGs 1r0YKSvKUZ8WXhSSi1MEWM/XyL+VHxKrF4qs+hf+ZU+e8a579Du5w7nryF3BHqfuqcCJ mYz10p60PRSgEqk8QzdQ+N1fUHi5tJjBdvX+oVOh6ydKZXzGQoFASZYWg/ZF2dN4d1nw 2wrgzzUzRlCjkwpA/momqvVK+k6UX9Vy9GMpqVD1r5YneNz4+fnrOPgbFcHNNyYMqPx5 FyMkbX4YtOqtbVXAYvqRemePANUK5RhvAQ+pntYH6DQrXPtFD261w8C5rccKecRHhBs2 X2Bg== X-Gm-Message-State: AOAM532/wZZMAV8hD87Re0HDb8/26MsvPFw2SLwOj7GBhzERo98ll/1k B+slTcsL6MTP9faPVJihXxo= X-Google-Smtp-Source: ABdhPJyEYZ+kJJwlNpY9xiVgxjiBUoNTFK7j5g/DsNXpVq2oB6thtj9jEe75llsK35UzoJa8qEzgKQ== X-Received: by 2002:a63:6bc5:: with SMTP id g188mr38265726pgc.186.1625834334933; Fri, 09 Jul 2021 05:38:54 -0700 (PDT) Received: from localhost.localdomain ([152.57.176.46]) by smtp.googlemail.com with ESMTPSA id j6sm5592402pji.23.2021.07.09.05.38.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Jul 2021 05:38:54 -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 v10 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism Date: Fri, 9 Jul 2021 18:08:09 +0530 Message-Id: <20210709123813.8700-5-ameynarkhede03@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210709123813.8700-1-ameynarkhede03@gmail.com> References: <20210709123813.8700-1-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. Co-developed-by: Alex Williamson Signed-off-by: Alex Williamson Signed-off-by: Amey Narkhede --- Documentation/ABI/testing/sysfs-bus-pci | 19 +++++ drivers/pci/pci-sysfs.c | 103 ++++++++++++++++++++++++ 2 files changed, 122 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index ef00fada2..43f4e33c7 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -121,6 +121,25 @@ 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. Initially reading + this file will give names of the device supported reset + methods and their ordering. After write, this file will + give names and ordering of currently enabled reset methods. + 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..8a740e211 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1334,6 +1334,108 @@ 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, idx; + + for (i = 0; i < PCI_NUM_RESET_METHODS; i++) { + idx = pdev->reset_methods[i]; + if (!idx) + break; + + len += sysfs_emit_at(buf, len, "%s%s", len ? "," : "", + pci_reset_fn_methods[idx].name); + } + + if (len) + len += sysfs_emit_at(buf, len, "\n"); + + return len; +} + +static ssize_t reset_method_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pci_dev *pdev = to_pci_dev(dev); + int n = 0; + char *name, *options = NULL; + u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 }; + + if (count >= (PAGE_SIZE - 1)) + return -EINVAL; + + if (sysfs_streq(buf, "")) { + pci_warn(pdev, "All device reset methods disabled by user"); + goto set_reset_methods; + } + + if (sysfs_streq(buf, "default")) { + pci_init_reset_methods(pdev); + return count; + } + + options = kstrndup(buf, count, GFP_KERNEL); + if (!options) + return -ENOMEM; + + while ((name = strsep(&options, ",")) != NULL) { + int i; + + if (sysfs_streq(name, "")) + continue; + + name = strim(name); + + for (i = 1; i < PCI_NUM_RESET_METHODS; i++) { + if (sysfs_streq(name, pci_reset_fn_methods[i].name) && + !pci_reset_fn_methods[i].reset_fn(pdev, 1)) { + reset_methods[n++] = i; + break; + } + } + + if (i == PCI_NUM_RESET_METHODS) { + kfree(options); + return -EINVAL; + } + } + + if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1) + pci_warn(pdev, "Device specific reset disabled/de-prioritized by user"); + +set_reset_methods: + memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods)); + kfree(options); + 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 +1593,7 @@ 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,