[PATCH 4.6 066/100] xen/x86: actually allocate legacy interrupts on PV guests

Greg Kroah-Hartman
2016-05-30T21:11:17Z

From: Stefano Stabellini <sstabellini@kernel.org>

commit 702f926067d2a4b28c10a3c41a1172dd62d9e735 upstream.

b4ff8389ed14 is incomplete: relies on nr_legacy_irqs() to get the number
of legacy interrupts when actually nr_legacy_irqs() returns 0 after
probe_8259A(). Use NR_IRQS_LEGACY instead.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/pci/xen.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -491,8 +491,11 @@ int __init pci_xen_initial_domain(void)
#endif
__acpi_register_gsi = acpi_register_gsi_xen;
__acpi_unregister_gsi = NULL;
- /* Pre-allocate legacy irqs */
- for (irq = 0; irq < nr_legacy_irqs(); irq++) {
+ /*
+ * Pre-allocate the legacy IRQs. Use NR_LEGACY_IRQS here
+ * because we don't have a PIC and thus nr_legacy_irqs() is zero.
+ */
+ for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
int trigger, polarity;

if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)