MIPS: OCTEON: Remove some code limiting NR_IRQS to 255

Follow-on patches for OCTEON III will increase the number of irqs to
potentially more than 256.

Increase the width of the octeon_irq_ciu_to_irq to int to be able to
handle this case.  Remove the hacky code that verified that u8 would
not be overflowed.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12495/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/cavium-octeon/octeon-irq.c

@@ -3,7 +3,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2004-2014 Cavium, Inc.
+ * Copyright (C) 2004-2016 Cavium, Inc.
  */
 
 #include <linux/of_address.h>
@@ -28,7 +28,7 @@ struct octeon_irq_ciu_domain_data {
 	int num_sum;  /* number of sum registers (2 or 3). */
 };
 
-static __read_mostly u8 octeon_irq_ciu_to_irq[8][64];
+static __read_mostly int octeon_irq_ciu_to_irq[8][64];
 
 struct octeon_ciu_chip_data {
 	union {
@@ -1158,16 +1158,6 @@ static struct irq_chip *octeon_irq_ciu_chip;
 static struct irq_chip *octeon_irq_ciu_chip_edge;
 static struct irq_chip *octeon_irq_gpio_chip;
 
-static bool octeon_irq_virq_in_range(unsigned int virq)
-{
-	/* We cannot let it overflow the mapping array. */
-	if (virq < (1ul << 8 * sizeof(octeon_irq_ciu_to_irq[0][0])))
-		return true;
-
-	WARN_ONCE(true, "virq out of range %u.\n", virq);
-	return false;
-}
-
 static int octeon_irq_ciu_map(struct irq_domain *d,
 			      unsigned int virq, irq_hw_number_t hw)
 {
@@ -1176,13 +1166,6 @@ static int octeon_irq_ciu_map(struct irq_domain *d,
 	unsigned int bit = hw & 63;
 	struct octeon_irq_ciu_domain_data *dd = d->host_data;
 
-	if (!octeon_irq_virq_in_range(virq))
-		return -EINVAL;
-
-	/* Don't map irq if it is reserved for GPIO. */
-	if (line == 0 && bit >= 16 && bit <32)
-		return 0;
-
 	if (line >= dd->num_sum || octeon_irq_ciu_to_irq[line][bit] != 0)
 		return -EINVAL;
 
@@ -1215,9 +1198,6 @@ static int octeon_irq_gpio_map(struct irq_domain *d,
 	unsigned int line, bit;
 	int r;
 
-	if (!octeon_irq_virq_in_range(virq))
-		return -EINVAL;
-
 	line = (hw + gpiod->base_hwirq) >> 6;
 	bit = (hw + gpiod->base_hwirq) & 63;
 	if (line > ARRAY_SIZE(octeon_irq_ciu_to_irq) ||
@@ -1899,9 +1879,6 @@ static int octeon_irq_ciu2_map(struct irq_domain *d,
 	unsigned int line = hw >> 6;
 	unsigned int bit = hw & 63;
 
-	if (!octeon_irq_virq_in_range(virq))
-		return -EINVAL;
-
 	/*
 	 * Don't map irq if it is reserved for GPIO.
 	 * (Line 7 are the GPIO lines.)