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Merge branch 'pci/reset'

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- Warn about doing a Secondary Bus Reset without holding the device lock
  (Dan Williams)

- Lock bridge in addition to downstream hierarchy before doing a Secondary
  Bus Reset (Dan Williams)

* pci/reset:
  PCI: Add missing bridge lock to pci_bus_lock()
  PCI: Warn on missing cfg_access_lock during secondary bus reset
This commit is contained in:
Bjorn Helgaas 2024-07-19 10:10:23 -05:00
commit 62281339e3
1 changed files with 24 additions and 14 deletions
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38
drivers/pci/pci.c
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@ -4954,6 +4954,9 @@ void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
{
lock_map_assert_held(&dev->cfg_access_lock);
if (!dev->block_cfg_access)
pci_warn_once(dev, "unlocked secondary bus reset via: %pS\n",
__builtin_return_address(0));
pcibios_reset_secondary_bus(dev);
return pci_bridge_wait_for_secondary_bus(dev, "bus reset");
@ -5512,10 +5515,12 @@ static void pci_bus_lock(struct pci_bus *bus)
{
struct pci_dev *dev;
pci_dev_lock(bus->self);
list_for_each_entry(dev, &bus->devices, bus_list) {
pci_dev_lock(dev);
if (dev->subordinate)
pci_bus_lock(dev->subordinate);
else
pci_dev_lock(dev);
}
}
@ -5527,8 +5532,10 @@ static void pci_bus_unlock(struct pci_bus *bus)
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
else
pci_dev_unlock(dev);
}
pci_dev_unlock(bus->self);
}
/* Return 1 on successful lock, 0 on contention */
@ -5536,15 +5543,15 @@ static int pci_bus_trylock(struct pci_bus *bus)
{
struct pci_dev *dev;
if (!pci_dev_trylock(bus->self))
return 0;
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);
if (!pci_bus_trylock(dev->subordinate))
goto unlock;
}
}
} else if (!pci_dev_trylock(dev))
goto unlock;
}
return 1;
@ -5552,8 +5559,10 @@ unlock:
list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) {
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
else
pci_dev_unlock(dev);
}
pci_dev_unlock(bus->self);
return 0;
}
@ -5585,9 +5594,10 @@ static void pci_slot_lock(struct pci_slot *slot)
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);
else
pci_dev_lock(dev);
}
}
@ -5613,14 +5623,13 @@ static int pci_slot_trylock(struct pci_slot *slot)
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;
}
}
} else if (!pci_dev_trylock(dev))
goto unlock;
}
return 1;
@ -5631,7 +5640,8 @@ unlock:
continue;
if (dev->subordinate)
pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
else
pci_dev_unlock(dev);
}
return 0;
}