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, 6 insertions, 3 deletions

diff --git a/arch/powerpc/platforms/cell/spu_manage.c b/arch/powerpc/platforms/cell/spu_manage.c
index 21b4bfb97200..672d310dcf14 100644
--- a/arch/powerpc/platforms/cell/spu_manage.c
+++ b/arch/powerpc/platforms/cell/spu_manage.c
@@ -105,7 +105,10 @@ static int __init spu_map_interrupts_old(struct spu *spu,
 	spu->irqs[2] = irq_create_mapping(NULL, IIC_IRQ_CLASS_2 | isrc);
 
 	/* Right now, we only fail if class 2 failed */
-	return spu->irqs[2] == NO_IRQ ? -EINVAL : 0;
+	if (!spu->irqs[2])
+		return -EINVAL;
+
+	return 0;
 }
 
 static void __iomem * __init spu_map_prop_old(struct spu *spu,
@@ -191,7 +194,7 @@ static int __init spu_map_interrupts(struct spu *spu, struct device_node *np)
 		pr_debug("  irq %d no 0x%x on %s\n", i, oirq.args[0],
 			 oirq.np->full_name);
 		spu->irqs[i] = irq_create_of_mapping(&oirq);
-		if (spu->irqs[i] == NO_IRQ) {
+		if (!spu->irqs[i]) {
 			pr_debug("spu_new: failed to map it !\n");
 			goto err;
 		}
@@ -202,7 +205,7 @@ err:
 	pr_debug("failed to map irq %x for spu %s\n", *oirq.args,
 		spu->name);
 	for (; i >= 0; i--) {
-		if (spu->irqs[i] != NO_IRQ)
+		if (spu->irqs[i])
 			irq_dispose_mapping(spu->irqs[i]);
 	}
 	return ret;