irq_domain/microblaze: Convert microblaze to use irq_domains

This patch converts Microblaze to use the irq_domain remapper and get
away from hard coding the offset between hwirq number and the linux irq
number space.  This also paves the way for multiple interrupt controllers.

v2: Don't enable SPARSE_IRQ and keep NR_IRQS set to 33

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Michal Simek <monstr@monstr.eu>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: John Williams <john.williams@petalogix.com>
Cc: John Linn <john.linn@xilinx.com>

1 files changed, 37 insertions, 24 deletions

diff --git a/arch/microblaze/kernel/intc.c b/arch/microblaze/kernel/intc.c
index 44b177e2ab12..ad120672cee5 100644
--- a/arch/microblaze/kernel/intc.c
+++ b/arch/microblaze/kernel/intc.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/irqdomain.h>
 #include <linux/irq.h>
 #include <asm/page.h>
 #include <linux/io.h>
@@ -25,8 +26,6 @@ static unsigned int intc_baseaddr;
 #define INTC_BASE       intc_baseaddr
 #endif
 
-unsigned int nr_irq;
-
 /* No one else should require these constants, so define them locally here. */
 #define ISR 0x00                        /* Interrupt Status Register */
 #define IPR 0x04                        /* Interrupt Pending Register */
@@ -84,24 +83,45 @@ static struct irq_chip intc_dev = {
         .irq_mask_ack = intc_mask_ack,
 };
 
-unsigned int get_irq(struct pt_regs *regs)
+static struct irq_domain *root_domain;
+
+unsigned int get_irq(void)
 {
-        int irq;
+        unsigned int hwirq, irq = -1;
 
-        /*
-         * NOTE: This function is the one that needs to be improved in
-         * order to handle multiple interrupt controllers. It currently
-         * is hardcoded to check for interrupts only on the first INTC.
-         */
-        irq = in_be32(INTC_BASE + IVR) + NO_IRQ_OFFSET;
-        pr_debug("get_irq: %d\n", irq);
+        hwirq = in_be32(INTC_BASE + IVR);
+        if (hwirq != -1U)
+                irq = irq_find_mapping(root_domain, hwirq);
+
+        pr_debug("get_irq: hwirq=%d, irq=%d\n", hwirq, irq);
 
         return irq;
 }
 
+int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
+{
+        u32 intr_mask = (u32)d->host_data;
+
+        if (intr_mask & (1 << hw)) {
+                irq_set_chip_and_handler_name(irq, &intc_dev,
+                                                handle_edge_irq, "edge");
+                irq_clear_status_flags(irq, IRQ_LEVEL);
+        } else {
+                irq_set_chip_and_handler_name(irq, &intc_dev,
+                                                handle_level_irq, "level");
+                irq_set_status_flags(irq, IRQ_LEVEL);
+        }
+        return 0;
+}
+
+static const struct irq_domain_ops xintc_irq_domain_ops = {
+        .xlate = irq_domain_xlate_onetwocell,
+        .map = xintc_map,
+};
+
 void __init init_IRQ(void)
 {
-        u32 i, intr_mask;
+        u32 nr_irq, intr_mask;
         struct device_node *intc = NULL;
 #ifdef CONFIG_SELFMOD_INTC
         unsigned int intc_baseaddr = 0;
@@ -146,16 +166,9 @@ void __init init_IRQ(void)
         /* Turn on the Master Enable. */
         out_be32(intc_baseaddr + MER, MER_HIE | MER_ME);
 
-        for (i = IRQ_OFFSET; i < (nr_irq + IRQ_OFFSET); ++i) {
-                if (intr_mask & (0x00000001 << (i - IRQ_OFFSET))) {
-                        irq_set_chip_and_handler_name(i, &intc_dev,
-                                handle_edge_irq, "edge");
-                        irq_clear_status_flags(i, IRQ_LEVEL);
-                } else {
-                        irq_set_chip_and_handler_name(i, &intc_dev,
-                                handle_level_irq, "level");
-                        irq_set_status_flags(i, IRQ_LEVEL);
-                }
-                irq_get_irq_data(i)->hwirq = i - IRQ_OFFSET;
-        }
+        /* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
+         * lazy and Michal can clean it up to something nicer when he tests
+         * and commits this patch.  ~~gcl */
+        root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops,
+                                                        (void *)intr_mask);
 }