powerpc: Remove all usages of NO_IRQ

NO_IRQ has been == 0 on powerpc for just over ten years (since commit
0ebfff1491ef ("[POWERPC] Add new interrupt mapping core and change
platforms to use it")). It's also 0 on most other arches.

Although it's fairly harmless, every now and then it causes confusion
when a driver is built on powerpc and another arch which doesn't define
NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least
some of which are to work around that problem.

So we'd like to remove it. This is fairly trivial in the arch code, we
just convert:

    if (irq == NO_IRQ)	to	if (!irq)
    if (irq != NO_IRQ)	to	if (irq)
    irq = NO_IRQ;	to	irq = 0;
    return NO_IRQ;	to	return 0;

And a few other odd cases as well.

At least for now we keep the #define NO_IRQ, because there is driver
code that uses NO_IRQ and the fixes to remove those will go via other
trees.

Note we also change some occurrences in PPC sound drivers, drivers/ps3,
and drivers/macintosh.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c
index 3c7707a..60154d0 100644
--- a/arch/powerpc/platforms/ps3/smp.c
+++ b/arch/powerpc/platforms/ps3/smp.c
@@ -91,7 +91,7 @@ static void __init ps3_smp_probe(void)
 			result = smp_request_message_ipi(virqs[i], i);
 
 			if (result)
-				virqs[i] = NO_IRQ;
+				virqs[i] = 0;
 			else
 				ps3_register_ipi_irq(cpu, virqs[i]);
 		}
@@ -112,7 +112,7 @@ void ps3_smp_cleanup_cpu(int cpu)
 	for (i = 0; i < MSG_COUNT; i++) {
 		/* Can't call free_irq from interrupt context. */
 		ps3_event_receive_port_destroy(virqs[i]);
-		virqs[i] = NO_IRQ;
+		virqs[i] = 0;
 	}
 
 	DBG(" <- %s:%d: (%d)\n", __func__, __LINE__, cpu);