powerpc: Remove all usages of NO_IRQ

NO_IRQ has been == 0 on powerpc for just over ten years (since commit
0ebfff1491 ("[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>

arch/powerpc/include/asm/machdep.h

@@ -61,7 +61,7 @@ struct machdep_calls {
 
 	void		(*init_IRQ)(void);
 
-	/* Return an irq, or NO_IRQ to indicate there are none pending. */
+	/* Return an irq, or 0 to indicate there are none pending. */
 	unsigned int	(*get_irq)(void);
 
 	/* PCI stuff */

arch/powerpc/include/asm/mpic_msgr.h

@@ -122,9 +122,9 @@ static inline void mpic_msgr_set_destination(struct mpic_msgr *msgr,
  * @msgr:	the message register whose IRQ is to be returned
  *
  * Returns the IRQ number associated with the given message register.
- * NO_IRQ is returned if this message register is not capable of
- * receiving interrupts.  What message register can and cannot receive
- * interrupts is specified in the device tree for the system.
+ * 0 is returned if this message register is not capable of receiving
+ * interrupts.  What message register can and cannot receive interrupts is
+ * specified in the device tree for the system.
  */
 static inline int mpic_msgr_get_irq(struct mpic_msgr *msgr)
 {

arch/powerpc/include/asm/parport.h

@@ -28,7 +28,7 @@ static int parport_pc_find_nonpci_ports (int autoirq, int autodma)
 		io1 = prop[1]; io2 = prop[2];
 
 		virq = irq_of_parse_and_map(np, 0);
-		if (virq == NO_IRQ)
+		if (!virq)
 			continue;
 
 		if (parport_pc_probe_port(io1, io2, virq, autodma, NULL, 0)

arch/powerpc/kernel/ibmebus.c

@@ -227,7 +227,7 @@ int ibmebus_request_irq(u32 ist, irq_handler_t handler,
 {
 	unsigned int irq = irq_create_mapping(NULL, ist);
 
-	if (irq == NO_IRQ)
+	if (!irq)
 		return -EINVAL;
 
 	return request_irq(irq, handler, irq_flags, devname, dev_id);

arch/powerpc/kernel/irq.c

@@ -519,7 +519,7 @@ void __do_irq(struct pt_regs *regs)
 	may_hard_irq_enable();
 
 	/* And finally process it */
-	if (unlikely(irq == NO_IRQ))
+	if (unlikely(!irq))
 		__this_cpu_inc(irq_stat.spurious_irqs);
 	else
 		generic_handle_irq(irq);

arch/powerpc/kernel/legacy_serial.c

@@ -193,10 +193,10 @@ static int __init add_legacy_soc_port(struct device_node *np,
 	 */
 	if (tsi && !strcmp(tsi->type, "tsi-bridge"))
 		return add_legacy_port(np, -1, UPIO_TSI, addr, addr,
-				       NO_IRQ, legacy_port_flags, 0);
+				       0, legacy_port_flags, 0);
 	else
 		return add_legacy_port(np, -1, UPIO_MEM, addr, addr,
-				       NO_IRQ, legacy_port_flags, 0);
+				       0, legacy_port_flags, 0);
 }
 
 static int __init add_legacy_isa_port(struct device_node *np,
@@ -242,7 +242,7 @@ static int __init add_legacy_isa_port(struct device_node *np,
 
 	/* Add port, irq will be dealt with later */
 	return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]),
-			       taddr, NO_IRQ, legacy_port_flags, 0);
+			       taddr, 0, legacy_port_flags, 0);
 
 }
 
@@ -314,7 +314,7 @@ static int __init add_legacy_pci_port(struct device_node *np,
 	/* Add port, irq will be dealt with later. We passed a translated
 	 * IO port value. It will be fixed up later along with the irq
 	 */
-	return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
+	return add_legacy_port(np, index, iotype, base, addr, 0,
 			       legacy_port_flags, np != pci_dev);
 }
 #endif
@@ -462,14 +462,14 @@ static void __init fixup_port_irq(int index,
 	DBG("fixup_port_irq(%d)\n", index);
 
 	virq = irq_of_parse_and_map(np, 0);
-	if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
+	if (!virq && legacy_serial_infos[index].irq_check_parent) {
 		np = of_get_parent(np);
 		if (np == NULL)
 			return;
 		virq = irq_of_parse_and_map(np, 0);
 		of_node_put(np);
 	}
-	if (virq == NO_IRQ)
+	if (!virq)
 		return;
 
 	port->irq = virq;
@@ -543,7 +543,7 @@ static int __init serial_dev_init(void)
 		struct plat_serial8250_port *port = &legacy_serial_ports[i];
 		struct device_node *np = legacy_serial_infos[i].np;
 
-		if (port->irq == NO_IRQ)
+		if (!port->irq)
 			fixup_port_irq(i, np, port);
 		if (port->iotype == UPIO_PORT)
 			fixup_port_pio(i, np, port);

arch/powerpc/kernel/pci-common.c

@@ -360,7 +360,7 @@ static int pci_read_irq_line(struct pci_dev *pci_dev)
 			 line, pin);
 
 		virq = irq_create_mapping(NULL, line);
-		if (virq != NO_IRQ)
+		if (virq)
 			irq_set_irq_type(virq, IRQ_TYPE_LEVEL_LOW);
 	} else {
 		pr_debug(" Got one, spec %d cells (0x%08x 0x%08x...) on %s\n",
@@ -369,7 +369,8 @@ static int pci_read_irq_line(struct pci_dev *pci_dev)
 
 		virq = irq_create_of_mapping(&oirq);
 	}
-	if(virq == NO_IRQ) {
+
+	if (!virq) {
 		pr_debug(" Failed to map !\n");
 		return -1;
 	}

arch/powerpc/kernel/pci_of_scan.c

@@ -178,7 +178,7 @@ struct pci_dev *of_create_pci_dev(struct device_node *node,
 		dev->hdr_type = PCI_HEADER_TYPE_NORMAL;
 		dev->rom_base_reg = PCI_ROM_ADDRESS;
 		/* Maybe do a default OF mapping here */
-		dev->irq = NO_IRQ;
+		dev->irq = 0;
 	}
 
 	of_pci_parse_addrs(node, dev);

arch/powerpc/platforms/44x/warp.c

@@ -204,7 +204,7 @@ static void pika_setup_critical_temp(struct device_node *np,
 	i2c_smbus_write_byte_data(client, 3,  0); /* Tlow */
 
 	irq = irq_of_parse_and_map(np, 0);
-	if (irq  == NO_IRQ) {
+	if (!irq) {
 		printk(KERN_ERR __FILE__ ": Unable to get ad7414 irq\n");
 		return;
 	}

arch/powerpc/platforms/512x/mpc5121_ads_cpld.c

@@ -97,7 +97,7 @@ cpld_pic_get_irq(int offset, u8 ignore, u8 __iomem *statusp,
 	status |= (ignore | mask);
 
 	if (status == 0xff)
-		return NO_IRQ;
+		return 0;
 
 	cpld_irq = ffz(status) + offset;
 
@@ -110,14 +110,14 @@ static void cpld_pic_cascade(struct irq_desc *desc)
 
 	irq = cpld_pic_get_irq(0, PCI_IGNORE, &cpld_regs->pci_status,
 		&cpld_regs->pci_mask);
-	if (irq != NO_IRQ) {
+	if (irq) {
 		generic_handle_irq(irq);
 		return;
 	}
 
 	irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status,
 		&cpld_regs->misc_mask);
-	if (irq != NO_IRQ) {
+	if (irq) {
 		generic_handle_irq(irq);
 		return;
 	}
@@ -177,7 +177,7 @@ mpc5121_ads_cpld_pic_init(void)
 		goto end;
 
 	cascade_irq = irq_of_parse_and_map(np, 0);
-	if (cascade_irq == NO_IRQ)
+	if (!cascade_irq)
 		goto end;
 
 	/*

arch/powerpc/platforms/512x/mpc512x_lpbfifo.c

@@ -473,7 +473,7 @@ static int mpc512x_lpbfifo_probe(struct platform_device *pdev)
 	}
 
 	lpbfifo.irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
-	if (lpbfifo.irq == NO_IRQ) {
+	if (!lpbfifo.irq) {
 		dev_err(&pdev->dev, "mapping irq failed\n");
 		ret = -ENODEV;
 		goto err0;

arch/powerpc/platforms/52xx/mpc52xx_pic.c

@@ -511,7 +511,7 @@ unsigned int mpc52xx_get_irq(void)
 			irq |= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET);
 		}
 	} else {
-		return NO_IRQ;
+		return 0;
 	}
 
 	return irq_linear_revmap(mpc52xx_irqhost, irq);

arch/powerpc/platforms/82xx/pq2ads-pci-pic.c

@@ -131,7 +131,7 @@ int __init pq2ads_pci_init_irq(void)
 	}
 
 	irq = irq_of_parse_and_map(np, 0);
-	if (irq == NO_IRQ) {
+	if (!irq) {
 		printk(KERN_ERR "No interrupt in pci pic node.\n");
 		of_node_put(np);
 		goto out;

arch/powerpc/platforms/83xx/mpc832x_rdb.c

@@ -89,7 +89,7 @@ static int __init of_fsl_spi_probe(char *type, char *compatible, u32 sysclk,
 			goto err;
 
 		ret = of_irq_to_resource(np, 0, &res[1]);
-		if (ret == NO_IRQ)
+		if (!ret)
 			goto err;
 
 		pdev = platform_device_alloc("mpc83xx_spi", i);

arch/powerpc/platforms/83xx/suspend.c

@@ -352,7 +352,7 @@ static int pmc_probe(struct platform_device *ofdev)
 		return -ENODEV;
 
 	pmc_irq = irq_of_parse_and_map(np, 0);
-	if (pmc_irq != NO_IRQ) {
+	if (pmc_irq) {
 		ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
 		                  "pmc", ofdev);
 
@@ -400,7 +400,7 @@ out_syscr:
 out_pmc:
 	iounmap(pmc_regs);
 out:
-	if (pmc_irq != NO_IRQ)
+	if (pmc_irq)
 		free_irq(pmc_irq, ofdev);
 
 	return ret;

arch/powerpc/platforms/85xx/common.c

@@ -76,7 +76,7 @@ void __init mpc85xx_cpm2_pic_init(void)
 		return;
 	}
 	irq = irq_of_parse_and_map(np, 0);
-	if (irq == NO_IRQ) {
+	if (!irq) {
 		of_node_put(np);
 		printk(KERN_ERR "PIC init: got no IRQ for cpm cascade\n");
 		return;

arch/powerpc/platforms/85xx/mpc85xx_cds.c

@@ -196,7 +196,7 @@ static void mpc85xx_8259_cascade_handler(struct irq_desc *desc)
 {
 	unsigned int cascade_irq = i8259_irq();
 
-	if (cascade_irq != NO_IRQ)
+	if (cascade_irq)
 		/* handle an interrupt from the 8259 */
 		generic_handle_irq(cascade_irq);
 
@@ -247,7 +247,7 @@ static int mpc85xx_cds_8259_attach(void)
 	}
 
 	cascade_irq = irq_of_parse_and_map(cascade_node, 0);
-	if (cascade_irq == NO_IRQ) {
+	if (!cascade_irq) {
 		printk(KERN_ERR "Failed to map cascade interrupt\n");
 		return -ENXIO;
 	}

arch/powerpc/platforms/85xx/mpc85xx_ds.c

@@ -51,7 +51,7 @@ static void mpc85xx_8259_cascade(struct irq_desc *desc)
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	unsigned int cascade_irq = i8259_irq();
 
-	if (cascade_irq != NO_IRQ) {
+	if (cascade_irq) {
 		generic_handle_irq(cascade_irq);
 	}
 	chip->irq_eoi(&desc->irq_data);
@@ -96,7 +96,7 @@ void __init mpc85xx_ds_pic_init(void)
 	}
 
 	cascade_irq = irq_of_parse_and_map(cascade_node, 0);
-	if (cascade_irq == NO_IRQ) {
+	if (!cascade_irq) {
 		printk(KERN_ERR "Failed to map cascade interrupt\n");
 		return;
 	}

arch/powerpc/platforms/85xx/socrates_fpga_pic.c

@@ -78,7 +78,7 @@ static inline unsigned int socrates_fpga_pic_get_irq(unsigned int irq)
 			break;
 	}
 	if (i == 3)
-		return NO_IRQ;
+		return 0;
 
 	raw_spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
 	cause = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(i));
@@ -103,7 +103,7 @@ static void socrates_fpga_pic_cascade(struct irq_desc *desc)
 	 */
 	cascade_irq = socrates_fpga_pic_get_irq(irq);
 
-	if (cascade_irq != NO_IRQ)
+	if (cascade_irq)
 		generic_handle_irq(cascade_irq);
 	chip->irq_eoi(&desc->irq_data);
 }
@@ -292,7 +292,7 @@ void socrates_fpga_pic_init(struct device_node *pic)
 
 	for (i = 0; i < 3; i++) {
 		socrates_fpga_irqs[i] = irq_of_parse_and_map(pic, i);
-		if (socrates_fpga_irqs[i] == NO_IRQ) {
+		if (!socrates_fpga_irqs[i]) {
 			pr_warning("FPGA PIC: can't get irq%d.\n", i);
 			continue;
 		}

arch/powerpc/platforms/86xx/pic.c

@@ -22,7 +22,7 @@ static void mpc86xx_8259_cascade(struct irq_desc *desc)
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	unsigned int cascade_irq = i8259_irq();
 
-	if (cascade_irq != NO_IRQ)
+	if (cascade_irq)
 		generic_handle_irq(cascade_irq);
 
 	chip->irq_eoi(&desc->irq_data);
@@ -58,7 +58,7 @@ void __init mpc86xx_init_irq(void)
 	}
 
 	cascade_irq = irq_of_parse_and_map(cascade_node, 0);
-	if (cascade_irq == NO_IRQ) {
+	if (!cascade_irq) {
 		printk(KERN_ERR "Failed to map cascade interrupt\n");
 		return;
 	}