From patchwork Fri May 28 14:07:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amey Narkhede X-Patchwork-Id: 1485245 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=M+rVx+dk; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Fs63d5C06z9sX1 for ; Sat, 29 May 2021 00:08:29 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236602AbhE1OJ7 (ORCPT ); Fri, 28 May 2021 10:09:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236589AbhE1OJz (ORCPT ); Fri, 28 May 2021 10:09:55 -0400 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0699C06138B; Fri, 28 May 2021 07:08:20 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id z4so1671626plg.8; Fri, 28 May 2021 07:08:20 -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=+kjX7vYmWzq1R7BiwbLx/rhOeELktigh7hpXVvkPMNY=; b=M+rVx+dkVP1vUeMpsr3lOGvUkiEkAWDTmytwA/1aSCM0Gq6G11rlHFqFl2xY2zUyvW uvY/s0AMgQ0v7hjE7YTbri3uq67NUEq0aI3FaPKC2OLhKJyO/QBbZ989Bs4B4qcTtzA1 fpOzEJSga93LcFdQ/o/TT7nq+FoiH45Rn9sKwiazDm5SXHQzcpiRCHOCrPC6olbAAq/W 0b9DY5ybDyvJubogGHvCbxOAoBkEx3m3X6bT0+57OGciviiHpHdsuzFcWABGkYq/Kg8H l93bNEgXSwl0L6ukAvNj0Rxyr9got9wxRNbe0xyN9cXgXgeHIY92mFSSQEiR3wfuS3mk Mykw== 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=+kjX7vYmWzq1R7BiwbLx/rhOeELktigh7hpXVvkPMNY=; b=Cr+NG2FzHIKFzTeXhHXS/+im0cMn02OHytvngP61ERTcIQN1mjMhllVYzw9KG3Sqaz QbnjctnUvFHHOIPQ7BilddNP2KdBNP3H3DDWo3GXS4WmfjSoroSxbfIMuJ6sr4JRerUe I+SaLkQ4K6/NBw13ggRENS7FWwk1hx5SVLkNYs7KBaET+gYbhSMV+KV3Z3s4wcSXHonS fonWjMpD/8tMwVCUqEMoa9vPwIPWYSx7UXHHNfezv7I7cS1nsriAvFkYyL0AbYfI6+GT HzVSwYYxu9/0kjF2JQLY12oVxe9V2PjdjUJGDkRoCA/BtUdfXH4JZVK8L1KL7s0G+AF8 iFEw== X-Gm-Message-State: AOAM533mJe/Nm7oBLJkGaIn2T1uwAJzteOeIenVHceFm0KoJdxioVC7k Vl1OSpS1uCv+JqcZ2O4FMtA= X-Google-Smtp-Source: ABdhPJxIyWOF5cMnlxq8QgYXZ4P0pfmCenTjjdt7mBHHcpLlPW5B8J1uJ6OwsgDHd/HQpWfTlJUd7Q== X-Received: by 2002:a17:90a:e391:: with SMTP id b17mr4546463pjz.75.1622210900254; Fri, 28 May 2021 07:08:20 -0700 (PDT) Received: from localhost.localdomain ([103.248.31.164]) by smtp.googlemail.com with ESMTPSA id j3sm4607841pfe.98.2021.05.28.07.08.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 May 2021 07:08:20 -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 Subject: [PATCH v4 5/7] PCI: Add support for a function level reset based on _RST method Date: Fri, 28 May 2021 19:37:53 +0530 Message-Id: <20210528140755.7044-6-ameynarkhede03@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210528140755.7044-1-ameynarkhede03@gmail.com> References: <20210528140755.7044-1-ameynarkhede03@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Shanker Donthineni The _RST is a standard method specified in the ACPI specification. It provides a function level reset when it is described in the acpi_device context associated with PCI-device. Implement a new reset function pci_dev_acpi_reset() for probing RST method and execute if it is defined in the firmware. The ACPI binding information is available only after calling device_add(), so move pci_init_reset_methods() to end of the pci_device_add(). The default priority of the acpi reset is set to below device-specific and above hardware resets. Signed-off-by: Shanker Donthineni Reviewed-by: Sinan Kaya --- drivers/pci/pci.c | 30 ++++++++++++++++++++++++++++++ drivers/pci/probe.c | 2 +- include/linux/pci.h | 2 +- 3 files changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index fad209c5f..1d859b100 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5076,6 +5076,35 @@ static void pci_dev_restore(struct pci_dev *dev) err_handler->reset_done(dev); } +/** + * pci_dev_acpi_reset - do a function level reset using _RST method + * @dev: device to reset + * @probe: check if _RST method is included in the acpi_device context. + */ +static int pci_dev_acpi_reset(struct pci_dev *dev, int probe) +{ +#ifdef CONFIG_ACPI + acpi_handle handle = ACPI_HANDLE(&dev->dev); + + /* Return -ENOTTY if _RST method is not included in the dev context */ + if (!handle || !acpi_has_method(handle, "_RST")) + return -ENOTTY; + + /* Return 0 for probe phase indicating that we can reset this device */ + if (probe) + return 0; + + /* Invoke _RST() method to perform a function level reset */ + if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) { + pci_warn(dev, "Failed to reset the device\n"); + return -EINVAL; + } + return 0; +#else + return -ENOTTY; +#endif +} + /* * The ordering for functions in pci_reset_fn_methods * is required for reset_methods byte array defined @@ -5083,6 +5112,7 @@ static void pci_dev_restore(struct pci_dev *dev) */ const struct pci_reset_fn_method pci_reset_fn_methods[] = { { &pci_dev_specific_reset, .name = "device_specific" }, + { &pci_dev_acpi_reset, .name = "acpi" }, { &pcie_reset_flr, .name = "flr" }, { &pci_af_flr, .name = "af_flr" }, { &pci_pm_reset, .name = "pm" }, diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 4764e031a..d4becd6ff 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2403,7 +2403,6 @@ static void pci_init_capabilities(struct pci_dev *dev) pci_rcec_init(dev); /* Root Complex Event Collector */ pcie_report_downtraining(dev); - pci_init_reset_methods(dev); } /* @@ -2494,6 +2493,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) dev->match_driver = false; ret = device_add(&dev->dev); WARN_ON(ret < 0); + pci_init_reset_methods(dev); } struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn) diff --git a/include/linux/pci.h b/include/linux/pci.h index e9603d638..9bec3c616 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -49,7 +49,7 @@ PCI_STATUS_SIG_TARGET_ABORT | \ PCI_STATUS_PARITY) -#define PCI_RESET_METHODS_NUM 5 +#define PCI_RESET_METHODS_NUM 6 /* * The PCI interface treats multi-function devices as independent