ARM: iop32x: offset IRQ numbers by 1

iop32x is one of the last platforms to use IRQ 0, and this has apparently
stopped working in a 2014 cleanup without anyone noticing. This interrupt
is used for the DMA engine, so most likely this has not actually worked
in the past 7 years, but it's also not essential for using this board.

I'm splitting out this change from my GENERIC_IRQ_MULTI_HANDLER
conversion so it can be backported if anyone cares.

Fixes: a71b092a ("ARM: Convert handle_IRQ to use __handle_domain_irq")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ardb: take +1 offset into account in mask/unmask and init as well]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/mach-iop32x/include/mach/entry-macro.S

@@ -20,7 +20,7 @@
 	mrc     p6, 0, \irqstat, c8, c0, 0	@ Read IINTSRC
 	cmp     \irqstat, #0
 	clzne   \irqnr, \irqstat
-	rsbne   \irqnr, \irqnr, #31
+	rsbne   \irqnr, \irqnr, #32
 	.endm
 
 	.macro arch_ret_to_user, tmp1, tmp2

arch/arm/mach-iop32x/include/mach/irqs.h

@@ -9,6 +9,6 @@
 #ifndef __IRQS_H
 #define __IRQS_H
 
-#define NR_IRQS			32
+#define NR_IRQS			33
 
 #endif

arch/arm/mach-iop32x/irq.c

@@ -32,14 +32,14 @@ static void intstr_write(u32 val)
 static void
 iop32x_irq_mask(struct irq_data *d)
 {
-	iop32x_mask &= ~(1 << d->irq);
+	iop32x_mask &= ~(1 << (d->irq - 1));
 	intctl_write(iop32x_mask);
 }
 
 static void
 iop32x_irq_unmask(struct irq_data *d)
 {
-	iop32x_mask |= 1 << d->irq;
+	iop32x_mask |= 1 << (d->irq - 1);
 	intctl_write(iop32x_mask);
 }
 
@@ -65,7 +65,7 @@ void __init iop32x_init_irq(void)
 	    machine_is_em7210())
 		*IOP3XX_PCIIRSR = 0x0f;
 
-	for (i = 0; i < NR_IRQS; i++) {
+	for (i = 1; i < NR_IRQS; i++) {
 		irq_set_chip_and_handler(i, &ext_chip, handle_level_irq);
 		irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
 	}

arch/arm/mach-iop32x/irqs.h

@@ -7,36 +7,40 @@
 #ifndef __IOP32X_IRQS_H
 #define __IOP32X_IRQS_H
 
+/* Interrupts in Linux start at 1, hardware starts at 0 */
+
+#define IOP_IRQ(x) ((x) + 1)
+
 /*
  * IOP80321 chipset interrupts
  */
-#define IRQ_IOP32X_DMA0_EOT	0
-#define IRQ_IOP32X_DMA0_EOC	1
-#define IRQ_IOP32X_DMA1_EOT	2
-#define IRQ_IOP32X_DMA1_EOC	3
-#define IRQ_IOP32X_AA_EOT	6
-#define IRQ_IOP32X_AA_EOC	7
-#define IRQ_IOP32X_CORE_PMON	8
-#define IRQ_IOP32X_TIMER0	9
-#define IRQ_IOP32X_TIMER1	10
-#define IRQ_IOP32X_I2C_0	11
-#define IRQ_IOP32X_I2C_1	12
-#define IRQ_IOP32X_MESSAGING	13
-#define IRQ_IOP32X_ATU_BIST	14
-#define IRQ_IOP32X_PERFMON	15
-#define IRQ_IOP32X_CORE_PMU	16
-#define IRQ_IOP32X_BIU_ERR	17
-#define IRQ_IOP32X_ATU_ERR	18
-#define IRQ_IOP32X_MCU_ERR	19
-#define IRQ_IOP32X_DMA0_ERR	20
-#define IRQ_IOP32X_DMA1_ERR	21
-#define IRQ_IOP32X_AA_ERR	23
-#define IRQ_IOP32X_MSG_ERR	24
-#define IRQ_IOP32X_SSP		25
-#define IRQ_IOP32X_XINT0	27
-#define IRQ_IOP32X_XINT1	28
-#define IRQ_IOP32X_XINT2	29
-#define IRQ_IOP32X_XINT3	30
-#define IRQ_IOP32X_HPI		31
+#define IRQ_IOP32X_DMA0_EOT	IOP_IRQ(0)
+#define IRQ_IOP32X_DMA0_EOC	IOP_IRQ(1)
+#define IRQ_IOP32X_DMA1_EOT	IOP_IRQ(2)
+#define IRQ_IOP32X_DMA1_EOC	IOP_IRQ(3)
+#define IRQ_IOP32X_AA_EOT	IOP_IRQ(6)
+#define IRQ_IOP32X_AA_EOC	IOP_IRQ(7)
+#define IRQ_IOP32X_CORE_PMON	IOP_IRQ(8)
+#define IRQ_IOP32X_TIMER0	IOP_IRQ(9)
+#define IRQ_IOP32X_TIMER1	IOP_IRQ(10)
+#define IRQ_IOP32X_I2C_0	IOP_IRQ(11)
+#define IRQ_IOP32X_I2C_1	IOP_IRQ(12)
+#define IRQ_IOP32X_MESSAGING	IOP_IRQ(13)
+#define IRQ_IOP32X_ATU_BIST	IOP_IRQ(14)
+#define IRQ_IOP32X_PERFMON	IOP_IRQ(15)
+#define IRQ_IOP32X_CORE_PMU	IOP_IRQ(16)
+#define IRQ_IOP32X_BIU_ERR	IOP_IRQ(17)
+#define IRQ_IOP32X_ATU_ERR	IOP_IRQ(18)
+#define IRQ_IOP32X_MCU_ERR	IOP_IRQ(19)
+#define IRQ_IOP32X_DMA0_ERR	IOP_IRQ(20)
+#define IRQ_IOP32X_DMA1_ERR	IOP_IRQ(21)
+#define IRQ_IOP32X_AA_ERR	IOP_IRQ(23)
+#define IRQ_IOP32X_MSG_ERR	IOP_IRQ(24)
+#define IRQ_IOP32X_SSP		IOP_IRQ(25)
+#define IRQ_IOP32X_XINT0	IOP_IRQ(27)
+#define IRQ_IOP32X_XINT1	IOP_IRQ(28)
+#define IRQ_IOP32X_XINT2	IOP_IRQ(29)
+#define IRQ_IOP32X_XINT3	IOP_IRQ(30)
+#define IRQ_IOP32X_HPI		IOP_IRQ(31)
 
 #endif