From: Shanker Donthineni <sdonthineni@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Sinan Kaya <okaya@xxxxxxxxxx>
---
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
