From patchwork Wed May 19 23:54:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amey Narkhede X-Patchwork-Id: 1481326 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=KIgRdEc9; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4FlqWm0Wzmz9sWX for ; Thu, 20 May 2021 09:56:04 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229952AbhESX5W (ORCPT ); Wed, 19 May 2021 19:57:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229808AbhESX5V (ORCPT ); Wed, 19 May 2021 19:57:21 -0400 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47EDDC061574; Wed, 19 May 2021 16:56:00 -0700 (PDT) Received: by mail-pg1-x536.google.com with SMTP id t193so10597490pgb.4; Wed, 19 May 2021 16:56:00 -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=JID/D/KXtWMVZbJD63Qy/P1niv6pTy4RV0ayNkwMylI=; b=KIgRdEc9tBygnG0si+aZz6QPnCZLqGoi8r/tiKBxljEqXvl8h3I9TG19Midl7WkSsB GRHNI++c7Bp2cfFPwHF+eZn3mLy+3+oLAqQDnfOgtBTtmRC06PVP1VQGrncSG2J5Fzzo /kpLrO0Prgb021SKwGWygj0tt/2+IxqwKzFKAWghG2L3pVv9brDOCMkkeGosheGsepkT EeecSwvansL7np+p8Rjw5NOCmteSAIgNnGT7eQGHEOgcL4s8urgoIJgDBeAUilLpCH9N bm22ljDnSzpEe9liRgCoPKV0VmhpmP+L9fcM39KGeqO8Qshgtg3BRz4JicIEjA7aLrfW yQQQ== 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=JID/D/KXtWMVZbJD63Qy/P1niv6pTy4RV0ayNkwMylI=; b=Y26fUsEOO36BN6kO5Wzlt4HBcL1E+gyKHI5vF2izm2BLOGJlYsCIS9vyqb//v52+gp OpI/0dQw495J1brIdM4uJArx8J3SzAxkWOTqqFhy945lVM8uWl6CPW6DsO2NdcXGXzG8 vMejZHMZqbkL3hbVT9fILvxSg6ANR0rMPPj9dPbL5Ow7+UWluAS/a+DlOB9lavHEJSJh 5cv9eHob/WR4jdhddjPeWmF54Hawov8iZ85Jvp7wFEWdg2tKpkIrfhWJUKOthNVv4MlI O1zUTqT1+n8hA49Hu8z8UwemeKysQ2vBcHgbKpueyrl6b35UG9FjXq1SSkvInz30I8sE uueA== X-Gm-Message-State: AOAM530kqiWFtfQE5gO0g3lnQzPwVmRLwvEK+0f22lQ3pNCjokg5l6rr Dx9UssQ/xkmJNoCT1OP3Ly8= X-Google-Smtp-Source: ABdhPJwHNVfl28T31yW0FsTl7GDa+cG/GiO/x0XEtnesypMpVIAw0M0UfS62XDUKa+bwCzQSqpGdWg== X-Received: by 2002:a65:640c:: with SMTP id a12mr1667768pgv.229.1621468559857; Wed, 19 May 2021 16:55:59 -0700 (PDT) Received: from localhost.localdomain ([94.140.8.39]) by smtp.googlemail.com with ESMTPSA id z12sm397670pfk.45.2021.05.19.16.55.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 May 2021 16:55:59 -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, kw@linux.com, sdonthineni@nvidia.com Subject: [PATCH RESEND v2 6/7] PCI: Add support for a function level reset based on _RST method Date: Thu, 20 May 2021 05:24:25 +0530 Message-Id: <20210519235426.99728-7-ameynarkhede03@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210519235426.99728-1-ameynarkhede03@gmail.com> References: <20210519235426.99728-1-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 --- 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 664cf2d35..d39dba590 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[] = { { .reset_fn = &pci_dev_specific_reset, .name = "device_specific" }, + { .reset_fn = &pci_dev_acpi_reset, .name = "acpi" }, { .reset_fn = &pcie_reset_flr, .name = "flr" }, { .reset_fn = &pci_af_flr, .name = "af_flr" }, { .reset_fn = &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 9f8347799..b4a5d2146 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_FN_METHODS 5 +#define PCI_RESET_FN_METHODS 6 /* * The PCI interface treats multi-function devices as independent