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authorBoris Ostrovsky <boris.ostrovsky@oracle.com>2015-11-20 11:25:04 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-09 14:34:43 -0500
commita8adab1a510bbb18be8cf2e35276dc933db814cc (patch)
treead8fd610363b02bfe7ccaed94ce4e4823fda1808
parentb2cb7afbb1693195b3171e85b10c0aa42ff37990 (diff)
downloadlwn-a8adab1a510bbb18be8cf2e35276dc933db814cc.tar.gz
lwn-a8adab1a510bbb18be8cf2e35276dc933db814cc.zip
xen/events: Always allocate legacy interrupts on PV guests
commit b4ff8389ed14b849354b59ce9b360bdefcdbf99c upstream. After commit 8c058b0b9c34 ("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> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/arm/include/asm/irq.h5
-rw-r--r--arch/arm64/include/asm/irq.h5
-rw-r--r--drivers/xen/events/events_base.c5
3 files changed, 13 insertions, 2 deletions
diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
index be1d07d59ee9..1bd9510de1b9 100644
--- a/arch/arm/include/asm/irq.h
+++ b/arch/arm/include/asm/irq.h
@@ -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
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index bbb251b14746..8b9bf54105b3 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -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
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 6cd5e65c4aff..fb236239972f 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -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>
#include <xen/page.h>
#endif
@@ -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);