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path: root/drivers/pci/pci.c
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Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c155
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1cbd590cf1d1..8386367814ee 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3250,6 +3250,18 @@ static void pci_dev_lock(struct pci_dev *dev)
device_lock(&dev->dev);
}
+/* Return 1 on successful lock, 0 on contention */
+static int pci_dev_trylock(struct pci_dev *dev)
+{
+ if (pci_cfg_access_trylock(dev)) {
+ if (device_trylock(&dev->dev))
+ return 1;
+ pci_cfg_access_unlock(dev);
+ }
+
+ return 0;
+}
+
static void pci_dev_unlock(struct pci_dev *dev)
{
device_unlock(&dev->dev);
@@ -3393,6 +3405,34 @@ int pci_reset_function(struct pci_dev *dev)
}
EXPORT_SYMBOL_GPL(pci_reset_function);
+/**
+ * pci_try_reset_function - quiesce and reset a PCI device function
+ * @dev: PCI device to reset
+ *
+ * Same as above, except return -EAGAIN if unable to lock device.
+ */
+int pci_try_reset_function(struct pci_dev *dev)
+{
+ int rc;
+
+ rc = pci_dev_reset(dev, 1);
+ if (rc)
+ return rc;
+
+ pci_dev_save_and_disable(dev);
+
+ if (pci_dev_trylock(dev)) {
+ rc = __pci_dev_reset(dev, 0);
+ pci_dev_unlock(dev);
+ } else
+ rc = -EAGAIN;
+
+ pci_dev_restore(dev);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(pci_try_reset_function);
+
/* Lock devices from the top of the tree down */
static void pci_bus_lock(struct pci_bus *bus)
{
@@ -3417,6 +3457,32 @@ static void pci_bus_unlock(struct pci_bus *bus)
}
}
+/* Return 1 on successful lock, 0 on contention */
+static int pci_bus_trylock(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ if (!pci_dev_trylock(dev))
+ goto unlock;
+ if (dev->subordinate) {
+ if (!pci_bus_trylock(dev->subordinate)) {
+ pci_dev_unlock(dev);
+ goto unlock;
+ }
+ }
+ }
+ return 1;
+
+unlock:
+ list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
+ if (dev->subordinate)
+ pci_bus_unlock(dev->subordinate);
+ pci_dev_unlock(dev);
+ }
+ return 0;
+}
+
/* Lock devices from the top of the tree down */
static void pci_slot_lock(struct pci_slot *slot)
{
@@ -3445,6 +3511,37 @@ static void pci_slot_unlock(struct pci_slot *slot)
}
}
+/* Return 1 on successful lock, 0 on contention */
+static int pci_slot_trylock(struct pci_slot *slot)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &slot->bus->devices, bus_list) {
+ if (!dev->slot || dev->slot != slot)
+ continue;
+ if (!pci_dev_trylock(dev))
+ goto unlock;
+ if (dev->subordinate) {
+ if (!pci_bus_trylock(dev->subordinate)) {
+ pci_dev_unlock(dev);
+ goto unlock;
+ }
+ }
+ }
+ return 1;
+
+unlock:
+ list_for_each_entry_continue_reverse(dev,
+ &slot->bus->devices, bus_list) {
+ if (!dev->slot || dev->slot != slot)
+ continue;
+ if (dev->subordinate)
+ pci_bus_unlock(dev->subordinate);
+ pci_dev_unlock(dev);
+ }
+ return 0;
+}
+
/* Save and disable devices from the top of the tree down */
static void pci_bus_save_and_disable(struct pci_bus *bus)
{
@@ -3568,6 +3665,35 @@ int pci_reset_slot(struct pci_slot *slot)
}
EXPORT_SYMBOL_GPL(pci_reset_slot);
+/**
+ * pci_try_reset_slot - Try to reset a PCI slot
+ * @slot: PCI slot to reset
+ *
+ * Same as above except return -EAGAIN if the slot cannot be locked
+ */
+int pci_try_reset_slot(struct pci_slot *slot)
+{
+ int rc;
+
+ rc = pci_slot_reset(slot, 1);
+ if (rc)
+ return rc;
+
+ pci_slot_save_and_disable(slot);
+
+ if (pci_slot_trylock(slot)) {
+ might_sleep();
+ rc = pci_reset_hotplug_slot(slot->hotplug, 0);
+ pci_slot_unlock(slot);
+ } else
+ rc = -EAGAIN;
+
+ pci_slot_restore(slot);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(pci_try_reset_slot);
+
static int pci_bus_reset(struct pci_bus *bus, int probe)
{
if (!bus->self)
@@ -3627,6 +3753,35 @@ int pci_reset_bus(struct pci_bus *bus)
EXPORT_SYMBOL_GPL(pci_reset_bus);
/**
+ * pci_try_reset_bus - Try to reset a PCI bus
+ * @bus: top level PCI bus to reset
+ *
+ * Same as above except return -EAGAIN if the bus cannot be locked
+ */
+int pci_try_reset_bus(struct pci_bus *bus)
+{
+ int rc;
+
+ rc = pci_bus_reset(bus, 1);
+ if (rc)
+ return rc;
+
+ pci_bus_save_and_disable(bus);
+
+ if (pci_bus_trylock(bus)) {
+ might_sleep();
+ pci_reset_bridge_secondary_bus(bus->self);
+ pci_bus_unlock(bus);
+ } else
+ rc = -EAGAIN;
+
+ pci_bus_restore(bus);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(pci_try_reset_bus);
+
+/**
* pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
* @dev: PCI device to query
*