[PATCH] PCI: Fix pcibios_update_irq misuse of irq number
From: bhelgaas@google.com (Bjorn Helgaas)
Date: 2015-02-02 15:58:12
Also in:
linux-pci, lkml
On Wed, Jan 28, 2015 at 8:51 AM, Marc Zyngier [off-list ref] wrote:
pcibios_update_irq writes an irq number into the config space of a given PCI device, but ignores the fact that this number is a virtual interrupt number, which might be a very different value from what the underlying hardware is using. The obvious fix is to fetch the HW interrupt number from the corresponding irq_data structure. This is slightly complicated by the fact that this interrupt might be services by a stacked domain. This has been tested on KVM with kvmtool. Reported-by: Lorenzo Pieralisi <redacted> Tested-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <redacted>
Jiang, are you OK with this patch as-is now, since it isn't used on x86? Marc, Lorenzo, I assume this actually fixes a bug. Can we get any more details about what happens when you hit the bug, and how you reproduced it (what platform, driver, etc.)? Bjorn
quoted hunk ↗ jump to hunk
--- drivers/pci/setup-irq.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)diff --git a/drivers/pci/setup-irq.c b/drivers/pci/setup-irq.c index 4e2d595..828cbc9 100644 --- a/drivers/pci/setup-irq.c +++ b/drivers/pci/setup-irq.c@@ -15,11 +15,19 @@ #include <linux/errno.h> #include <linux/ioport.h> #include <linux/cache.h> +#include <linux/irq.h> void __weak pcibios_update_irq(struct pci_dev *dev, int irq) { - dev_dbg(&dev->dev, "assigning IRQ %02d\n", irq); - pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq); + struct irq_data *d; + + d = irq_get_irq_data(irq); +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY + while (d->parent_data) + d = d->parent_data; +#endif + dev_dbg(&dev->dev, "assigning IRQ %02ld\n", d->hwirq); + pci_write_config_byte(dev, PCI_INTERRUPT_LINE, d->hwirq); } static void pdev_fixup_irq(struct pci_dev *dev, --2.1.4