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>

3 files changed, 9 insertions, 9 deletions

diff --git a/arch/powerpc/platforms/ps3/interrupt.c b/arch/powerpc/platforms/ps3/interrupt.c
index b831638e6f4a..98f8c3611133 100644
--- a/arch/powerpc/platforms/ps3/interrupt.c
+++ b/arch/powerpc/platforms/ps3/interrupt.c
@@ -192,7 +192,7 @@ static int ps3_virq_setup(enum ps3_cpu_binding cpu, unsigned long outlet,
 
 	*virq = irq_create_mapping(NULL, outlet);
 
-	if (*virq == NO_IRQ) {
+	if (!*virq) {
 		FAIL("%s:%d: irq_create_mapping failed: outlet %lu\n",
 			__func__, __LINE__, outlet);
 		result = -ENOMEM;
@@ -339,7 +339,7 @@ int ps3_event_receive_port_setup(enum ps3_cpu_binding cpu, unsigned int *virq)
 	if (result) {
 		FAIL("%s:%d: lv1_construct_event_receive_port failed: %s\n",
 			__func__, __LINE__, ps3_result(result));
-		*virq = NO_IRQ;
+		*virq = 0;
 		return result;
 	}
 
@@ -418,7 +418,7 @@ int ps3_sb_event_receive_port_setup(struct ps3_system_bus_device *dev,
 			" failed: %s\n", __func__, __LINE__,
 			ps3_result(result));
 		ps3_event_receive_port_destroy(*virq);
-		*virq = NO_IRQ;
+		*virq = 0;
 		return result;
 	}
 
@@ -724,12 +724,12 @@ static unsigned int ps3_get_irq(void)
 	asm volatile("cntlzd %0,%1" : "=r" (plug) : "r" (x));
 	plug &= 0x3f;
 
-	if (unlikely(plug == NO_IRQ)) {
+	if (unlikely(!plug)) {
 		DBG("%s:%d: no plug found: thread_id %llu\n", __func__,
 			__LINE__, pd->thread_id);
 		dump_bmp(&per_cpu(ps3_private, 0));
 		dump_bmp(&per_cpu(ps3_private, 1));
-		return NO_IRQ;
+		return 0;
 	}
 
 #if defined(DEBUG)
diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c
index 3c7707af3384..60154d08debf 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);
diff --git a/arch/powerpc/platforms/ps3/spu.c b/arch/powerpc/platforms/ps3/spu.c
index 492b2575e0d2..b54850845466 100644
--- a/arch/powerpc/platforms/ps3/spu.c
+++ b/arch/powerpc/platforms/ps3/spu.c
@@ -284,7 +284,7 @@ fail_alloc_2:
 fail_alloc_1:
 	ps3_spe_irq_destroy(spu->irqs[0]);
 fail_alloc_0:
-	spu->irqs[0] = spu->irqs[1] = spu->irqs[2] = NO_IRQ;
+	spu->irqs[0] = spu->irqs[1] = spu->irqs[2] = 0;
 	return result;
 }
 
@@ -334,7 +334,7 @@ static int ps3_destroy_spu(struct spu *spu)
 	ps3_spe_irq_destroy(spu->irqs[1]);
 	ps3_spe_irq_destroy(spu->irqs[0]);
 
-	spu->irqs[0] = spu->irqs[1] = spu->irqs[2] = NO_IRQ;
+	spu->irqs[0] = spu->irqs[1] = spu->irqs[2] = 0;
 
 	spu_unmap(spu);