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, 3 insertions, 3 deletions

diff --git a/arch/powerpc/sysdev/ppc4xx_msi.c b/arch/powerpc/sysdev/ppc4xx_msi.c
index 8fb806135043..590dab4f47d6 100644
--- a/arch/powerpc/sysdev/ppc4xx_msi.c
+++ b/arch/powerpc/sysdev/ppc4xx_msi.c
@@ -102,7 +102,7 @@ static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 					__func__);
 		}
 		virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
-		if (virq == NO_IRQ) {
+		if (!virq) {
 			dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
 			msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
 			return -ENOSPC;
@@ -129,7 +129,7 @@ void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
 	dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
 
 	for_each_pci_msi_entry(entry, dev) {
-		if (entry->irq == NO_IRQ)
+		if (!entry->irq)
 			continue;
 		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
@@ -201,7 +201,7 @@ static int ppc4xx_of_msi_remove(struct platform_device *dev)
 
 	for (i = 0; i < msi_irqs; i++) {
 		virq = msi->msi_virqs[i];
-		if (virq != NO_IRQ)
+		if (virq)
 			irq_dispose_mapping(virq);
 	}