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 <[email protected]>
---
changes since v2:
- fix typo in the commit text
changes since v2:
- rebase patch on top of https://lore.kernel.org/linux-pci/[email protected]/
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 664cf2d358d6..510f9224a3b0 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" },
{ .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 4764e031a44b..d4becd6ffb52 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 9f8347799634..b4a5d2146542 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
--
2.17.1
On Wed, 28 Apr 2021 19:49:06 -0500
Shanker Donthineni <[email protected]> wrote:
> 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 <[email protected]>
> ---
> changes since v2:
> - fix typo in the commit text
> changes since v2:
> - rebase patch on top of https://lore.kernel.org/linux-pci/[email protected]/
>
> 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 664cf2d358d6..510f9224a3b0 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" },
Would it make sense to name this "acpi_rst" after the method name?
Otherwise "_reset" is a bit redundant to the sysfs attribute, we could
simply name it "acpi" to indicate an ACPI based reset. Thanks,
Alex
> { .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 4764e031a44b..d4becd6ffb52 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 9f8347799634..b4a5d2146542 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
Hi Alex,
On 4/30/21 1:39 PM, Alex Williamson wrote:
> External email: Use caution opening links or attachments
>
>
> On Wed, 28 Apr 2021 19:49:06 -0500
> Shanker Donthineni <[email protected]> wrote:
>
>> 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 <[email protected]>
>> ---
>> changes since v2:
>> - fix typo in the commit text
>> changes since v2:
>> - rebase patch on top of https://lore.kernel.org/linux-pci/[email protected]/
>>
>> 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 664cf2d358d6..510f9224a3b0 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" },
> Would it make sense to name this "acpi_rst" after the method name?
> Otherwise "_reset" is a bit redundant to the sysfs attribute, we could
> simply name it "acpi" to indicate an ACPI based reset. Thanks,
>
Thanks, I will change to "{ .reset_fn = &pci_dev_acpi_reset, .name = "acpi" }"