[IA64] assign_irq_vector() should not panic

Current assign_irq_vector() will panic if interrupt vectors is running
out. But I think how to handle the case of lack of interrupt vectors
should be handled by the caller of this function. For example, some
PCI devices can raise the interrupt signal via both MSI and I/O
APIC. So even if the driver for these device fails to allocate a
vector for MSI, the driver still has a chance to use I/O APIC based
interrupt. But currently there is no chance for these driver to use
I/O APIC based interrupt because kernel will panic when
assign_irq_vector() fails to allocate interrupt vector.

The following patch changes assign_irq_vector() for ia64 to return
-ENOSPC on error instead of panic (as i386 and x86_64 versions do).

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 2 insertions, 13 deletions

diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index 4fe60c7a2e90..6c4d59fd0364 100644
--- a/arch/ia64/kernel/irq_ia64.c
+++ b/arch/ia64/kernel/irq_ia64.c
@@ -63,30 +63,19 @@ EXPORT_SYMBOL(isa_irq_to_vector_map);
 static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_NUM_DEVICE_VECTORS)];
 
 int
-assign_irq_vector_nopanic (int irq)
+assign_irq_vector (int irq)
 {
 	int pos, vector;
  again:
 	pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
 	vector = IA64_FIRST_DEVICE_VECTOR + pos;
 	if (vector > IA64_LAST_DEVICE_VECTOR)
-		return -1;
+		return -ENOSPC;
 	if (test_and_set_bit(pos, ia64_vector_mask))
 		goto again;
 	return vector;
 }
 
-int
-assign_irq_vector (int irq)
-{
-	int vector = assign_irq_vector_nopanic(irq);
-
-	if (vector < 0)
-		panic("assign_irq_vector: out of interrupt vectors!");
-
-	return vector;
-}
-
 void
 free_irq_vector (int vector)
 {