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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-03 23:58:05 +00:00
Merge branch 'pci/reset' into next
* pci/reset: vfio-pci: Use pci "try" reset interface PCI: Add pci_try_reset_function(), pci_try_reset_slot(), pci_try_reset_bus()
This commit is contained in:
Bjorn Helgaas
commit
6e2d98dc1a
3 changed files with 167 additions and 20 deletions
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@ -3250,6 +3250,18 @@ static void pci_dev_lock(struct pci_dev *dev)
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device_lock(&dev->dev);
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}
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/* Return 1 on successful lock, 0 on contention */
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static int pci_dev_trylock(struct pci_dev *dev)
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{
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if (pci_cfg_access_trylock(dev)) {
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if (device_trylock(&dev->dev))
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return 1;
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pci_cfg_access_unlock(dev);
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}
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return 0;
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}
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static void pci_dev_unlock(struct pci_dev *dev)
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{
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device_unlock(&dev->dev);
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@ -3393,6 +3405,34 @@ int pci_reset_function(struct pci_dev *dev)
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}
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EXPORT_SYMBOL_GPL(pci_reset_function);
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/**
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* pci_try_reset_function - quiesce and reset a PCI device function
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* @dev: PCI device to reset
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*
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* Same as above, except return -EAGAIN if unable to lock device.
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*/
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int pci_try_reset_function(struct pci_dev *dev)
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{
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int rc;
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rc = pci_dev_reset(dev, 1);
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if (rc)
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return rc;
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pci_dev_save_and_disable(dev);
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if (pci_dev_trylock(dev)) {
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rc = __pci_dev_reset(dev, 0);
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pci_dev_unlock(dev);
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} else
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rc = -EAGAIN;
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pci_dev_restore(dev);
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return rc;
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}
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EXPORT_SYMBOL_GPL(pci_try_reset_function);
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/* Lock devices from the top of the tree down */
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static void pci_bus_lock(struct pci_bus *bus)
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{
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@ -3417,6 +3457,32 @@ static void pci_bus_unlock(struct pci_bus *bus)
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}
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}
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/* Return 1 on successful lock, 0 on contention */
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static int pci_bus_trylock(struct pci_bus *bus)
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{
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struct pci_dev *dev;
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list_for_each_entry(dev, &bus->devices, bus_list) {
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if (!pci_dev_trylock(dev))
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goto unlock;
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if (dev->subordinate) {
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if (!pci_bus_trylock(dev->subordinate)) {
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pci_dev_unlock(dev);
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goto unlock;
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}
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}
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}
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return 1;
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unlock:
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list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
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if (dev->subordinate)
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pci_bus_unlock(dev->subordinate);
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pci_dev_unlock(dev);
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}
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return 0;
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}
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/* Lock devices from the top of the tree down */
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static void pci_slot_lock(struct pci_slot *slot)
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{
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@ -3445,6 +3511,37 @@ static void pci_slot_unlock(struct pci_slot *slot)
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}
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}
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/* Return 1 on successful lock, 0 on contention */
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static int pci_slot_trylock(struct pci_slot *slot)
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{
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struct pci_dev *dev;
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list_for_each_entry(dev, &slot->bus->devices, bus_list) {
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if (!dev->slot || dev->slot != slot)
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continue;
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if (!pci_dev_trylock(dev))
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goto unlock;
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if (dev->subordinate) {
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if (!pci_bus_trylock(dev->subordinate)) {
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pci_dev_unlock(dev);
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goto unlock;
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}
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}
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}
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return 1;
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unlock:
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list_for_each_entry_continue_reverse(dev,
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&slot->bus->devices, bus_list) {
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if (!dev->slot || dev->slot != slot)
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continue;
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if (dev->subordinate)
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pci_bus_unlock(dev->subordinate);
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pci_dev_unlock(dev);
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}
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return 0;
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}
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/* Save and disable devices from the top of the tree down */
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static void pci_bus_save_and_disable(struct pci_bus *bus)
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{
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@ -3568,6 +3665,35 @@ int pci_reset_slot(struct pci_slot *slot)
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}
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EXPORT_SYMBOL_GPL(pci_reset_slot);
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/**
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* pci_try_reset_slot - Try to reset a PCI slot
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* @slot: PCI slot to reset
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*
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* Same as above except return -EAGAIN if the slot cannot be locked
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*/
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int pci_try_reset_slot(struct pci_slot *slot)
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{
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int rc;
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rc = pci_slot_reset(slot, 1);
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if (rc)
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return rc;
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pci_slot_save_and_disable(slot);
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if (pci_slot_trylock(slot)) {
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might_sleep();
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rc = pci_reset_hotplug_slot(slot->hotplug, 0);
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pci_slot_unlock(slot);
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} else
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rc = -EAGAIN;
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pci_slot_restore(slot);
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return rc;
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}
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EXPORT_SYMBOL_GPL(pci_try_reset_slot);
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static int pci_bus_reset(struct pci_bus *bus, int probe)
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{
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if (!bus->self)
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@ -3626,6 +3752,35 @@ int pci_reset_bus(struct pci_bus *bus)
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}
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EXPORT_SYMBOL_GPL(pci_reset_bus);
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/**
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* pci_try_reset_bus - Try to reset a PCI bus
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* @bus: top level PCI bus to reset
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*
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* Same as above except return -EAGAIN if the bus cannot be locked
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*/
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int pci_try_reset_bus(struct pci_bus *bus)
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{
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int rc;
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rc = pci_bus_reset(bus, 1);
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if (rc)
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return rc;
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pci_bus_save_and_disable(bus);
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if (pci_bus_trylock(bus)) {
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might_sleep();
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pci_reset_bridge_secondary_bus(bus->self);
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pci_bus_unlock(bus);
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} else
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rc = -EAGAIN;
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pci_bus_restore(bus);
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return rc;
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}
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EXPORT_SYMBOL_GPL(pci_try_reset_bus);
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/**
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* pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
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* @dev: PCI device to query
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@ -139,25 +139,14 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
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pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
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/*
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* Careful, device_lock may already be held. This is the case if
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* a driver unbind is blocked. Try to get the locks ourselves to
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* prevent a deadlock.
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* Try to reset the device. The success of this is dependent on
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* being able to lock the device, which is not always possible.
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*/
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if (vdev->reset_works) {
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bool reset_done = false;
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if (pci_cfg_access_trylock(pdev)) {
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if (device_trylock(&pdev->dev)) {
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__pci_reset_function_locked(pdev);
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reset_done = true;
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device_unlock(&pdev->dev);
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}
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pci_cfg_access_unlock(pdev);
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}
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if (!reset_done)
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pr_warn("%s: Unable to acquire locks for reset of %s\n",
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__func__, dev_name(&pdev->dev));
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int ret = pci_try_reset_function(pdev);
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if (ret)
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pr_warn("%s: Failed to reset device %s (%d)\n",
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__func__, dev_name(&pdev->dev), ret);
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}
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pci_restore_state(pdev);
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@ -514,7 +503,7 @@ static long vfio_pci_ioctl(void *device_data,
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} else if (cmd == VFIO_DEVICE_RESET) {
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return vdev->reset_works ?
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pci_reset_function(vdev->pdev) : -EINVAL;
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pci_try_reset_function(vdev->pdev) : -EINVAL;
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} else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
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struct vfio_pci_hot_reset_info hdr;
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@ -684,8 +673,8 @@ static long vfio_pci_ioctl(void *device_data,
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&info, slot);
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if (!ret)
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/* User has access, do the reset */
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ret = slot ? pci_reset_slot(vdev->pdev->slot) :
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pci_reset_bus(vdev->pdev->bus);
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ret = slot ? pci_try_reset_slot(vdev->pdev->slot) :
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pci_try_reset_bus(vdev->pdev->bus);
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hot_reset_release:
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for (i--; i >= 0; i--)
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@ -949,10 +949,13 @@ int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
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int __pci_reset_function(struct pci_dev *dev);
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int __pci_reset_function_locked(struct pci_dev *dev);
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int pci_reset_function(struct pci_dev *dev);
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int pci_try_reset_function(struct pci_dev *dev);
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int pci_probe_reset_slot(struct pci_slot *slot);
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int pci_reset_slot(struct pci_slot *slot);
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int pci_try_reset_slot(struct pci_slot *slot);
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int pci_probe_reset_bus(struct pci_bus *bus);
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int pci_reset_bus(struct pci_bus *bus);
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int pci_try_reset_bus(struct pci_bus *bus);
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void pci_reset_bridge_secondary_bus(struct pci_dev *dev);
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void pci_update_resource(struct pci_dev *dev, int resno);
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int __must_check pci_assign_resource(struct pci_dev *dev, int i);
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