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, 6 deletions

diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 4d16b368b6f5..a6bbbaba14a3 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -123,7 +123,7 @@ static void iic_ioexc_cascade(struct irq_desc *desc)
 				unsigned int cirq =
 					irq_linear_revmap(iic_host,
 							  base | cascade);
-				if (cirq != NO_IRQ)
+				if (cirq)
 					generic_handle_irq(cirq);
 			}
 		/* post-ack level interrupts */
@@ -153,10 +153,10 @@ static unsigned int iic_get_irq(void)
 	*(unsigned long *) &pending =
 		in_be64((u64 __iomem *) &iic->regs->pending_destr);
 	if (!(pending.flags & CBE_IIC_IRQ_VALID))
-		return NO_IRQ;
+		return 0;
 	virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending));
-	if (virq == NO_IRQ)
-		return NO_IRQ;
+	if (!virq)
+		return 0;
 	iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
 	BUG_ON(iic->eoi_ptr > 15);
 	return virq;
@@ -192,7 +192,7 @@ static void iic_request_ipi(int msg)
 	int virq;
 
 	virq = irq_create_mapping(iic_host, iic_msg_to_irq(msg));
-	if (virq == NO_IRQ) {
+	if (!virq) {
 		printk(KERN_ERR
 		       "iic: failed to map IPI %s\n", smp_ipi_name[msg]);
 		return;
@@ -347,7 +347,7 @@ static int __init setup_iic(void)
 		cascade |= 1 << IIC_IRQ_CLASS_SHIFT;
 		cascade |= IIC_UNIT_IIC;
 		cascade = irq_create_mapping(iic_host, cascade);
-		if (cascade == NO_IRQ)
+		if (!cascade)
 			continue;
 		/*
 		 * irq_data is a generic pointer that gets passed back