linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Amey Narkhede <ameynarkhede03@gmail.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: alex.williamson@redhat.com,
	Raphael Norwitz <raphael.norwitz@nutanix.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	kw@linux.com, Shanker Donthineni <sdonthineni@nvidia.com>,
	Sinan Kaya <okaya@kernel.org>
Subject: [PATCH v5 5/7] PCI: Add support for a function level reset based on _RST method
Date: Sun, 30 May 2021 00:55:25 +0530	[thread overview]
Message-ID: <20210529192527.2708-6-ameynarkhede03@gmail.com> (raw)
In-Reply-To: <20210529192527.2708-1-ameynarkhede03@gmail.com>

From: Shanker Donthineni <sdonthineni@nvidia.com>

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(). To consider
_RST method, move pci_init_reset_methods() to end of pci_device_add()
and craete two sysfs entries reset & reset_methond from
pci_create_sysfs_dev_files()

The default priority of the acpi reset is set to below device-specific
and above hardware resets.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
---
 drivers/pci/pci-sysfs.c | 23 ++++++++++++++++++++---
 drivers/pci/pci.c       | 30 ++++++++++++++++++++++++++++++
 drivers/pci/probe.c     |  2 +-
 include/linux/pci.h     |  2 +-
 4 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 04b3d6565..b332d7923 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1482,12 +1482,30 @@ static const struct attribute_group pci_dev_reset_attr_group = {
 	.is_visible = pci_dev_reset_attr_is_visible,
 };
 
+const struct attribute_group *pci_dev_reset_groups[] = {
+	&pci_dev_reset_attr_group,
+	&pci_dev_reset_method_attr_group,
+	NULL,
+};
+
 int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
 {
+	int retval;
+
 	if (!sysfs_initialized)
 		return -EACCES;
 
-	return pci_create_resource_files(pdev);
+	retval = pci_create_resource_files(pdev);
+	if (retval)
+		return retval;
+
+	retval = device_add_groups(&pdev->dev, pci_dev_reset_groups);
+	if (retval) {
+		pci_remove_resource_files(pdev);
+		return retval;
+	}
+
+	return 0;
 }
 
 /**
@@ -1501,6 +1519,7 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 	if (!sysfs_initialized)
 		return;
 
+	device_remove_groups(&pdev->dev, pci_dev_reset_groups);
 	pci_remove_resource_files(pdev);
 }
 
@@ -1594,8 +1613,6 @@ const struct attribute_group *pci_dev_groups[] = {
 	&pci_dev_group,
 	&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,
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index bbed852d9..4a7019d0b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5115,6 +5115,35 @@ 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
@@ -5122,6 +5151,7 @@ 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 90fd4f61f..eeab791a0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2404,7 +2404,6 @@ 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);
 }
 
 /*
@@ -2495,6 +2494,7 @@ 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 6e9bc4f9c..a7f063da2 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
-- 
2.31.1


  parent reply	other threads:[~2021-05-29 19:25 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-29 19:25 [PATCH v5 0/7] Expose and manage PCI device reset Amey Narkhede
2021-05-29 19:25 ` [PATCH v5 1/7] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
2021-05-29 19:25 ` [PATCH v5 2/7] PCI: Add new array for keeping track of ordering of " Amey Narkhede
2021-06-02 21:37   ` Shanker R Donthineni
2021-06-05 20:55   ` Bjorn Helgaas
2021-05-29 19:25 ` [PATCH v5 3/7] PCI: Remove reset_fn field from pci_dev Amey Narkhede
2021-06-02 22:16   ` Shanker R Donthineni
2021-06-05 20:57   ` Bjorn Helgaas
2021-05-29 19:25 ` [PATCH v5 4/7] PCI/sysfs: Allow userspace to query and set device reset mechanism Amey Narkhede
2021-06-02 22:17   ` Shanker R Donthineni
2021-06-06 12:58   ` Krzysztof Wilczyński
2021-06-06 14:27     ` Shanker R Donthineni
2021-05-29 19:25 ` Amey Narkhede [this message]
2021-06-05 20:53   ` [PATCH v5 5/7] PCI: Add support for a function level reset based on _RST method Bjorn Helgaas
2021-06-06  0:04     ` Shanker R Donthineni
2021-06-06  5:00     ` Shanker R Donthineni
2021-06-09 12:51     ` Shanker R Donthineni
2021-05-29 19:25 ` [PATCH v5 6/7] PCI: Enable NO_BUS_RESET quirk for Nvidia GPUs Amey Narkhede
2021-05-29 19:25 ` [PATCH v5 7/7] PCI: Change the type of probe argument in reset functions Amey Narkhede
2021-06-02 22:15   ` Shanker R Donthineni

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210529192527.2708-6-ameynarkhede03@gmail.com \
    --to=ameynarkhede03@gmail.com \
    --cc=alex.williamson@redhat.com \
    --cc=bhelgaas@google.com \
    --cc=kw@linux.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=okaya@kernel.org \
    --cc=raphael.norwitz@nutanix.com \
    --cc=sdonthineni@nvidia.com \
    --subject='Re: [PATCH v5 5/7] PCI: Add support for a function level reset based on _RST method' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).