Hi Bjorn,
I've marked this as RFC as I guess there might be a better way to do
this, but I'm not sure how. I would appreciate your thoughts on this.
Thanks
Phil
---
pdev_fixup_irq() performs interrupt swizzling on all PCI devices,
no matter that the device may be on a completely unrelated PCI
Host controller.
When you have multiple PCI Host controllers, pdev_fixup_irq() can
clobber the dev->irq of devices it should not be changing.
This has been seen when performing suspend/resume on boards with
two R-Car PCIe Host controllers, resulting in a NULL ptr access
in __pci_restore_msi_state. This happens because dev->irq has been
overwritten with 0, and irq_get_msi_desc(dev->irq) returns NULL.
This patch introduces a new function, pci_fixup_irqs_local(), that
performs the same operation as pdev_fixup_irq(), but only changes
the dev->irq of device on the same domain.
Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
---
drivers/pci/setup-irq.c | 25 ++++++++++++++++++++++---
include/linux/pci.h | 3 +++
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/setup-irq.c b/drivers/pci/setup-irq.c
index 95c225b..90ea8fa 100644
--- a/drivers/pci/setup-irq.c
+++ b/drivers/pci/setup-irq.c
@@ -22,7 +22,8 @@ void __weak pcibios_update_irq(struct pci_dev *dev, int irq)
pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}
-static void pdev_fixup_irq(struct pci_dev *dev,
+static void pdev_fixup_irq(int domain_nr,
+ struct pci_dev *dev,
u8 (*swizzle)(struct pci_dev *, u8 *),
int (*map_irq)(const struct pci_dev *, u8, u8))
{
@@ -48,8 +49,15 @@ static void pdev_fixup_irq(struct pci_dev *dev,
if (irq == -1)
irq = 0;
}
- dev->irq = irq;
+ /* Since pci_fixup_irqs() can be called more than once due to multiple
+ * host controllers, and we scan all PCI devices, not just those
+ * attached to this controller, make sure we don't clobber dev->irq
+ * that has nothing to do with this domain.
+ */
+ if (domain_nr >= 0 && dev->bus->domain_nr != domain_nr)
+ return;
+ dev->irq = irq;
dev_dbg(&dev->dev, "fixup irq: got %d\n", dev->irq);
/* Always tell the device, so the driver knows what is
@@ -63,6 +71,17 @@ void pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, u8 *),
struct pci_dev *dev = NULL;
for_each_pci_dev(dev)
- pdev_fixup_irq(dev, swizzle, map_irq);
+ pdev_fixup_irq(-1, dev, swizzle, map_irq);
}
EXPORT_SYMBOL_GPL(pci_fixup_irqs);
+
+void pci_fixup_irqs_local(struct pci_bus *bus,
+ u8 (*swizzle)(struct pci_dev *, u8 *),
+ int (*map_irq)(const struct pci_dev *, u8, u8))
+{
+ struct pci_dev *dev = NULL;
+
+ for_each_pci_dev(dev)
+ pdev_fixup_irq(bus->domain_nr, dev, swizzle, map_irq);
+}
+EXPORT_SYMBOL_GPL(pci_fixup_irqs_local);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8badb66..37a97df 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1134,6 +1134,9 @@ void pdev_enable_device(struct pci_dev *);
int pci_enable_resources(struct pci_dev *, int mask);
void pci_fixup_irqs(u8 (*)(struct pci_dev *, u8 *),
int (*)(const struct pci_dev *, u8, u8));
+void pci_fixup_irqs_local(struct pci_bus *,
+ u8 (*)(struct pci_dev *, u8 *),
+ int (*)(const struct pci_dev *, u8, u8));
#define HAVE_PCI_REQ_REGIONS 2
int __must_check pci_request_regions(struct pci_dev *, const char *);
int __must_check pci_request_regions_exclusive(struct pci_dev *, const char *);
--
2.5.0
--
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
