diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d48d9febc241..12fccc24925c 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3460,6 +3460,215 @@ int pci_reset_function(struct pci_dev *dev) } EXPORT_SYMBOL_GPL(pci_reset_function); +/* Lock devices from the top of the tree down */ +static void pci_bus_lock(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_lock(dev); + if (dev->subordinate) + pci_bus_lock(dev->subordinate); + } +} + +/* Unlock devices from the bottom of the tree up */ +static void pci_bus_unlock(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } +} + +/* Lock devices from the top of the tree down */ +static void pci_slot_lock(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; + pci_dev_lock(dev); + if (dev->subordinate) + pci_bus_lock(dev->subordinate); + } +} + +/* Unlock devices from the bottom of the tree up */ +static void pci_slot_unlock(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 (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } +} + +/* Save and disable devices from the top of the tree down */ +static void pci_bus_save_and_disable(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_save_and_disable(dev); + if (dev->subordinate) + pci_bus_save_and_disable(dev->subordinate); + } +} + +/* + * Restore devices from top of the tree down - parent bridges need to be + * restored before we can get to subordinate devices. + */ +static void pci_bus_restore(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_restore(dev); + if (dev->subordinate) + pci_bus_restore(dev->subordinate); + } +} + +/* Save and disable devices from the top of the tree down */ +static void pci_slot_save_and_disable(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; + pci_dev_save_and_disable(dev); + if (dev->subordinate) + pci_bus_save_and_disable(dev->subordinate); + } +} + +/* + * Restore devices from top of the tree down - parent bridges need to be + * restored before we can get to subordinate devices. + */ +static void pci_slot_restore(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; + pci_dev_restore(dev); + if (dev->subordinate) + pci_bus_restore(dev->subordinate); + } +} + +static int pci_slot_reset(struct pci_slot *slot, int probe) +{ + int rc; + + if (!slot) + return -ENOTTY; + + if (!probe) + pci_slot_lock(slot); + + might_sleep(); + + rc = pci_reset_hotplug_slot(slot->hotplug, probe); + + if (!probe) + pci_slot_unlock(slot); + + return rc; +} + +/** + * pci_reset_slot - reset a PCI slot + * @slot: PCI slot to reset + * + * A PCI bus may host multiple slots, each slot may support a reset mechanism + * independent of other slots. For instance, some slots may support slot power + * control. In the case of a 1:1 bus to slot architecture, this function may + * wrap the bus reset to avoid spurious slot related events such as hotplug. + * Generally a slot reset should be attempted before a bus reset. All of the + * function of the slot and any subordinate buses behind the slot are reset + * through this function. PCI config space of all devices in the slot and + * behind the slot is saved before and restored after reset. + * + * Return 0 on success, non-zero on error. + */ +int pci_reset_slot(struct pci_slot *slot) +{ + int rc; + + rc = pci_slot_reset(slot, 1); + if (rc) + return rc; + + pci_slot_save_and_disable(slot); + + rc = pci_slot_reset(slot, 0); + + pci_slot_restore(slot); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_slot); + +static int pci_bus_reset(struct pci_bus *bus, int probe) +{ + if (!bus->self) + return -ENOTTY; + + if (probe) + return 0; + + pci_bus_lock(bus); + + might_sleep(); + + pci_reset_bridge_secondary_bus(bus->self); + + pci_bus_unlock(bus); + + return 0; +} + +/** + * pci_reset_bus - reset a PCI bus + * @bus: top level PCI bus to reset + * + * Do a bus reset on the given bus and any subordinate buses, saving + * and restoring state of all devices. + * + * Return 0 on success, non-zero on error. + */ +int pci_reset_bus(struct pci_bus *bus) +{ + int rc; + + rc = pci_bus_reset(bus, 1); + if (rc) + return rc; + + pci_bus_save_and_disable(bus); + + rc = pci_bus_reset(bus, 0); + + pci_bus_restore(bus); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_bus); + /** * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count * @dev: PCI device to query |