xen/events: Always allocate legacy interrupts on PV guests

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>

diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
index be1d07d59ee9784c7b3dd12a2150a009c7c742ba..1bd9510de1b9ced64b1947f2734ddbf4c8ce4f5d 100644 (file)
--- 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 bbb251b14746cb7005d1be35d50fdfb453464870..8b9bf54105b3e12dc41829194981bac6c95ef3fc 100644 (file)
--- 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 849500e4e14d14af7dd29fe7737d77d62f87a36d..524c22146429d7c87acc8682976031c2f8a727d6 100644 (file)
--- 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>
 #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);