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>

diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
index 53c15dec7af6aa09faee9b1851782f9244365e56..6a9851ea6a6011d6a7cb151ef55d58fd903d8363 100644 (file)
--- a/arch/arm/include/asm/irq.h
+++ b/arch/arm/include/asm/irq.h
@@ -35,6 +35,11 @@ extern void (*handle_arch_irq)(struct pt_regs *);
 extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
 #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 96093ae369a5613938962b4970decda66c19d342..cdc3d3360764cb830fb11cab2d4bd5fff9c1e4cc 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>
 #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);