Some devices are broken and use a requester ID other than their
physical devfn. Add a byte, using an existing gap in the pci_dev
structure, to store an alternate "alias" devfn. A bit in the
dev_flags tells us when this is valid. We then add the alias as
one more step in the pci_for_each_dma_alias() iterator.
Signed-off-by: Alex Williamson <alex.william...@redhat.com>
---
drivers/pci/search.c | 11 +++++++++++
include/linux/pci.h | 3 +++
2 files changed, 14 insertions(+)
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 5601cdb..2c19f3f 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -37,6 +37,17 @@ int pci_for_each_dma_alias(struct pci_dev *pdev,
if (ret)
return ret;
+ /*
+ * If the device is broken and uses an alias requester ID for
+ * DMA, iterate over that too.
+ */
+ if (unlikely(pdev->dev_flags & PCI_DEV_FLAGS_DMA_ALIAS_DEVFN)) {
+ ret = fn(pdev, PCI_DEVID(pdev->bus->number,
+ pdev->dma_alias_devfn), data);
+ if (ret)
+ return ret;
+ }
+
for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
struct pci_dev *tmp;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 545903d..9d4035c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -171,6 +171,8 @@ enum pci_dev_flags {
PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) (1 << 2),
/* Flag for quirk use to store if quirk-specific ACS is enabled */
PCI_DEV_FLAGS_ACS_ENABLED_QUIRK = (__force pci_dev_flags_t) (1 << 3),
+ /* Flag to indicate the device uses dma_alias_devfn */
+ PCI_DEV_FLAGS_DMA_ALIAS_DEVFN = (__force pci_dev_flags_t) (1 << 4),
};
enum pci_irq_reroute_variant {
@@ -268,6 +270,7 @@ struct pci_dev {
u8 rom_base_reg; /* which config register controls the
ROM */
u8 pin; /* which interrupt pin this device uses
*/
u16 pcie_flags_reg; /* cached PCIe Capabilities Register */
+ u8 dma_alias_devfn;/* devfn of DMA alias, if any */
struct pci_driver *driver; /* which driver has allocated this
device */
u64 dma_mask; /* Mask of the bits of bus address this
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
