@@ -989,7 +989,7 @@ static void octeon_pci_flr(struct octeon_device *oct)
pci_write_config_word(oct->pci_dev, PCI_COMMAND,
PCI_COMMAND_INTX_DISABLE);
- rc = __pci_reset_function_locked(oct->pci_dev);
+ rc = __pci_reset_function_locked(oct->pci_dev, PCI_RESET_ANY);
if (rc != 0)
dev_err(&oct->pci_dev->dev, "Error %d resetting PCI function %d\n",
@@ -4673,6 +4673,7 @@ static void pci_dev_restore(struct pci_dev *dev)
* __pci_reset_function_locked - reset a PCI device function while holding
* the @dev mutex lock.
* @dev: PCI device to reset
+ * @reset_type: reset mask to try
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
@@ -4688,9 +4689,9 @@ static void pci_dev_restore(struct pci_dev *dev)
* Returns 0 if the device function was successfully reset or negative if the
* device doesn't support resetting a single function.
*/
-int __pci_reset_function_locked(struct pci_dev *dev)
+int __pci_reset_function_locked(struct pci_dev *dev, u32 reset_type)
{
- int rc;
+ int rc = -EINVAL;
might_sleep();
@@ -4702,24 +4703,42 @@ int __pci_reset_function_locked(struct pci_dev *dev)
* other error, we're also finished: this indicates that further
* reset mechanisms might be broken on the device.
*/
- rc = pci_dev_specific_reset(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- if (pcie_has_flr(dev)) {
- rc = pcie_flr(dev);
+ if (reset_type & PCI_RESET_DEV_SPECIFIC) {
+ rc = pci_dev_specific_reset(dev, 0);
if (rc != -ENOTTY)
return rc;
}
- rc = pci_af_flr(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_pm_reset(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_dev_reset_slot_function(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- return pci_parent_bus_reset(dev, 0);
+
+ if (reset_type & PCI_RESET_FLR) {
+ if (pcie_has_flr(dev)) {
+ rc = pcie_flr(dev);
+ if (rc != -ENOTTY)
+ return rc;
+ }
+ rc = pci_af_flr(dev, 0);
+ if (rc != -ENOTTY)
+ return rc;
+ }
+
+ if (reset_type & PCI_RESET_PM) {
+ rc = pci_pm_reset(dev, 0);
+ if (rc != -ENOTTY)
+ return rc;
+ }
+
+ if (reset_type & PCI_RESET_SLOT) {
+ rc = pci_dev_reset_slot_function(dev, 0);
+ if (rc != -ENOTTY)
+ return rc;
+ }
+
+ if (reset_type & PCI_RESET_BUS) {
+ rc = pci_parent_bus_reset(dev, 0);
+ if (rc != -ENOTTY)
+ return rc;
+ }
+
+ return rc;
}
EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
@@ -4784,7 +4803,7 @@ int pci_reset_function(struct pci_dev *dev)
pci_dev_lock(dev);
pci_dev_save_and_disable(dev);
- rc = __pci_reset_function_locked(dev);
+ rc = __pci_reset_function_locked(dev, PCI_RESET_ANY);
pci_dev_restore(dev);
pci_dev_unlock(dev);
@@ -4819,7 +4838,7 @@ int pci_reset_function_locked(struct pci_dev *dev)
pci_dev_save_and_disable(dev);
- rc = __pci_reset_function_locked(dev);
+ rc = __pci_reset_function_locked(dev, PCI_RESET_ANY);
pci_dev_restore(dev);
@@ -4844,7 +4863,7 @@ int pci_try_reset_function(struct pci_dev *dev)
return -EAGAIN;
pci_dev_save_and_disable(dev);
- rc = __pci_reset_function_locked(dev);
+ rc = __pci_reset_function_locked(dev, PCI_RESET_ANY);
pci_dev_restore(dev);
pci_dev_unlock(dev);
@@ -105,7 +105,7 @@ static void pcistub_device_release(struct kref *kref)
/* Call the reset function which does not take lock as this
* is called from "unbind" which takes a device_lock mutex.
*/
- __pci_reset_function_locked(dev);
+ __pci_reset_function_locked(dev, PCI_RESET_ANY);
if (pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state))
dev_info(&dev->dev, "Could not reload PCI state\n");
else
@@ -283,7 +283,7 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
* (so it's ready for the next domain)
*/
device_lock_assert(&dev->dev);
- __pci_reset_function_locked(dev);
+ __pci_reset_function_locked(dev, PCI_RESET_ANY);
dev_data = pci_get_drvdata(dev);
ret = pci_load_saved_state(dev, dev_data->pci_saved_state);
@@ -417,7 +417,7 @@ static int pcistub_init_device(struct pci_dev *dev)
dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
else {
dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n");
- __pci_reset_function_locked(dev);
+ __pci_reset_function_locked(dev, PCI_RESET_ANY);
pci_restore_state(dev);
}
/* Now disable the device (this also ensures some private device
@@ -849,6 +849,60 @@ enum {
PCI_SCAN_ALL_PCIE_DEVS = 0x00000040, /* Scan all, not just dev 0 */
};
+/*
+ * A common theme here is that the driver wants some degree of
+ * control of the type of reset used, vfio specifically wants to specify a
+ * bus or slot reset while hfi1 just wants to specify that the link is
+ * reset and doesn't care if it's a bus or slot reset that accomplishes
+ * that. The right "unified" interface is one that takes a parameter
+ * allowing the caller to specify the scope or type of reset
+ * with aliases so drivers can ignore the hotplug interface if they wish
+ * for special cases.
+ *
+ * PCI_RESET_ANY tries all reset type one by one until device is successfully
+ * reset. Under normal circumstances, most drivers are expected to use
+ * PCI_RESET_ANY as they don't usually care about the type of reset as long
+ * as device is reset.
+ *
+ * PCI_RESET_FUNC is useful when you want to reset one particular PCI device
+ * but you don't want to impact other devices or cause a temporary service
+ * outage.
+ *
+ * PCI_RESET_LINK can be used to cause a link retraining. This operation will
+ * cause service outage for the PCI bus if there are other devices on the same
+ * bus. PCI_RESET_LINK determines if a platform supports hotplug or not and
+ * suppresses hotplug interrupts during secondary bus reset.
+ *
+ * PCI_RESET_DEV_SPECIFIC can be used to reset a device by help from the
+ * device driver. Not all device drivers support this option.
+ *
+ * PCI_RESET_FLR can be used to issue a Function Level Reset to a device. This
+ * option will fail if FLR is not supported.
+ *
+ * PCI_RESET_PM can be used to reset the device via D3->D0 and D0->D3 sleep
+ * transition. This assumes that device supports PM based reset.
+ *
+ * PCI_RESET_SLOT forces a slot/hotplug reset. This will not work on platforms
+ * without hotplug capability and assumes hotplug capability from a platform
+ * This option should only be used for advanced use-cases.
+ * Not recommended for scalability. Please refer to PCI_RESET_LINK.
+ *
+ * PCI_RESET_BUS performs a secondary bus reset on the link and causes a link
+ * recovery. Using this option directly and bypassing hotplug driver may
+ * cause a deadlock if platform supports hotplug. Please refer to
+ * PCI_RESET_LINK above.
+ */
+#define PCI_RESET_DEV_SPECIFIC (1 << 0)
+#define PCI_RESET_FLR (1 << 1)
+#define PCI_RESET_PM (1 << 2)
+#define PCI_RESET_SLOT (1 << 3)
+#define PCI_RESET_BUS (1 << 4)
+
+#define PCI_RESET_ANY (~0)
+#define PCI_RESET_FUNC (PCI_RESET_DEV_SPECIFIC | \
+ PCI_RESET_FLR | PCI_RESET_PM)
+#define PCI_RESET_LINK (PCI_RESET_SLOT | PCI_RESET_BUS)
+
/* These external functions are only available when PCI support is enabled */
#ifdef CONFIG_PCI
@@ -1111,7 +1165,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
void pcie_print_link_status(struct pci_dev *dev);
bool pcie_has_flr(struct pci_dev *dev);
int pcie_flr(struct pci_dev *dev);
-int __pci_reset_function_locked(struct pci_dev *dev);
+int __pci_reset_function_locked(struct pci_dev *dev, u32 reset_type);
int pci_reset_function(struct pci_dev *dev);
int pci_reset_function_locked(struct pci_dev *dev);
int pci_try_reset_function(struct pci_dev *dev);
We need a contract between the reset API users and the PCI core about the types of reset that a user needs vs. what PCI core can do internally. If a platform supports hotplug, we need to do hotplug reset as an example. Expose the reset types to the drivers and try different reset types based on the new reset_type parameter. Most users are expected to use PCI_RESET_ANY, PCI_RESET_FUNC or PCI_RESET_LINK parameters. Link: https://www.spinics.net/lists/linux-pci/msg75828.html Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sinan Kaya <okaya@kernel.org> --- .../net/ethernet/cavium/liquidio/lio_main.c | 2 +- drivers/pci/pci.c | 59 ++++++++++++------- drivers/xen/xen-pciback/pci_stub.c | 6 +- include/linux/pci.h | 56 +++++++++++++++++- 4 files changed, 98 insertions(+), 25 deletions(-)