If we've detected that the PCI device is removed, do not attempt to
access the device's config space.
On a config read, if the device is not present, the value returned will be
set to all 1's. This is the same as what hardware would normally return
when accessing a removed device, but we do not need to repeatedly test
hardware's completion capabilities if software can take a short-cut.
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
---
include/linux/pci.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 865d3ec..1b62f7a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -932,28 +932,46 @@ struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops);
static inline int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
{
+ if (unlikely(dev->is_removed)) {
+ *val = ~0;
+ return -ENODEV;
+ }
return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
}
static inline int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
{
+ if (unlikely(dev->is_removed)) {
+ *val = ~0;
+ return -ENODEV;
+ }
return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
}
static inline int pci_read_config_dword(const struct pci_dev *dev, int where,
u32 *val)
{
+ if (unlikely(dev->is_removed)) {
+ *val = ~0;
+ return -ENODEV;
+ }
return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
}
static inline int pci_write_config_byte(const struct pci_dev *dev, int where, u8 val)
{
+ if (unlikely(dev->is_removed))
+ return -ENODEV;
return pci_bus_write_config_byte(dev->bus, dev->devfn, where, val);
}
static inline int pci_write_config_word(const struct pci_dev *dev, int where, u16 val)
{
+ if (unlikely(dev->is_removed))
+ return -ENODEV;
return pci_bus_write_config_word(dev->bus, dev->devfn, where, val);
}
static inline int pci_write_config_dword(const struct pci_dev *dev, int where,
u32 val)
{
+ if (unlikely(dev->is_removed))
+ return -ENODEV;
return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val);
}
--
2.7.2
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
