genirq: Generic chip: Add big endian I/O accessors

Use io{read,write}32be if the caller specified IRQ_GC_BE_IO when creating
the irqchip.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/1415342669-30640-5-git-send-email-cernekee@gmail.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

include/linux/irq.h

@@ -738,12 +738,14 @@ struct irq_chip_generic {
  *				the parent irq. Usually GPIO implementations
  * @IRQ_GC_MASK_CACHE_PER_TYPE:	Mask cache is chip type private
  * @IRQ_GC_NO_MASK:		Do not calculate irq_data->mask
+ * @IRQ_GC_BE_IO:		Use big-endian register accesses (default: LE)
  */
 enum irq_gc_flags {
 	IRQ_GC_INIT_MASK_CACHE		= 1 << 0,
 	IRQ_GC_INIT_NESTED_LOCK		= 1 << 1,
 	IRQ_GC_MASK_CACHE_PER_TYPE	= 1 << 2,
 	IRQ_GC_NO_MASK			= 1 << 3,
+	IRQ_GC_BE_IO			= 1 << 4,
 };
 
 /*

kernel/irq/generic-chip.c

@@ -191,6 +191,16 @@ int irq_gc_set_wake(struct irq_data *d, unsigned int on)
 	return 0;
 }
 
+static u32 irq_readl_be(void __iomem *addr)
+{
+	return ioread32be(addr);
+}
+
+static void irq_writel_be(u32 val, void __iomem *addr)
+{
+	iowrite32be(val, addr);
+}
+
 static void
 irq_init_generic_chip(struct irq_chip_generic *gc, const char *name,
 		      int num_ct, unsigned int irq_base,
@@ -300,7 +310,13 @@ int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
 		dgc->gc[i] = gc = tmp;
 		irq_init_generic_chip(gc, name, num_ct, i * irqs_per_chip,
 				      NULL, handler);
+
 		gc->domain = d;
+		if (gcflags & IRQ_GC_BE_IO) {
+			gc->reg_readl = &irq_readl_be;
+			gc->reg_writel = &irq_writel_be;
+		}
+
 		raw_spin_lock_irqsave(&gc_lock, flags);
 		list_add_tail(&gc->list, &gc_list);
 		raw_spin_unlock_irqrestore(&gc_lock, flags);