xen/events: Always allocate legacy interrupts on PV guests

After commit 8c058b0b9c ("x86/irq: Probe for PIC presence before
allocating descs for legacy IRQs") early_irq_init() will no longer
preallocate descriptors for legacy interrupts if PIC does not
exist, which is the case for Xen PV guests.

Therefore we may need to allocate those descriptors ourselves.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This commit is contained in:
Boris Ostrovsky 2015-11-20 11:25:04 -05:00 committed by David Vrabel
parent 9c17d96500
commit b4ff8389ed
3 changed files with 13 additions and 2 deletions

View File

@ -40,6 +40,11 @@ extern void arch_trigger_all_cpu_backtrace(bool);
#define arch_trigger_all_cpu_backtrace(x) arch_trigger_all_cpu_backtrace(x)
#endif
static inline int nr_legacy_irqs(void)
{
return NR_IRQS_LEGACY;
}
#endif
#endif

View File

@ -21,4 +21,9 @@ static inline void acpi_irq_init(void)
}
#define acpi_irq_init acpi_irq_init
static inline int nr_legacy_irqs(void)
{
return 0;
}
#endif

View File

@ -39,6 +39,7 @@
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/io_apic.h>
#include <asm/i8259.h>
#include <asm/xen/pci.h>
#endif
#include <asm/sync_bitops.h>
@ -420,7 +421,7 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
return xen_allocate_irq_dynamic();
/* Legacy IRQ descriptors are already allocated by the arch. */
if (gsi < NR_IRQS_LEGACY)
if (gsi < nr_legacy_irqs())
irq = gsi;
else
irq = irq_alloc_desc_at(gsi, -1);
@ -446,7 +447,7 @@ static void xen_free_irq(unsigned irq)
kfree(info);
/* Legacy IRQ descriptors are managed by the arch. */
if (irq < NR_IRQS_LEGACY)
if (irq < nr_legacy_irqs())
return;
irq_free_desc(irq);