powerpc/powernv: Register and handle OPAL interrupts

We do the minimum which is to "pass" interrupts to HAL, which
makes the console smoother and will allow us to implement
interrupt based completion and console.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/powernv/opal.c

@@ -14,6 +14,7 @@
 #include <linux/types.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#include <linux/interrupt.h>
 #include <asm/opal.h>
 #include <asm/firmware.h>
 
@@ -135,9 +136,22 @@ int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
 	return written;
 }
 
+static irqreturn_t opal_interrupt(int irq, void *data)
+{
+	uint64_t events;
+
+	opal_handle_interrupt(virq_to_hw(irq), &events);
+
+	/* XXX TODO: Do something with the events */
+
+	return IRQ_HANDLED;
+}
+
 static int __init opal_init(void)
 {
 	struct device_node *np, *consoles;
+	const u32 *irqs;
+	int rc, i, irqlen;
 
 	opal_node = of_find_node_by_path("/ibm,opal");
 	if (!opal_node) {
@@ -156,6 +170,23 @@ static int __init opal_init(void)
 		of_platform_device_create(np, NULL, NULL);
 	}
 	of_node_put(consoles);
+
+	/* Find all OPAL interrupts and request them */
+	irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
+	pr_debug("opal: Found %d interrupts reserved for OPAL\n",
+		 irqs ? (irqlen / 4) : 0);
+	for (i = 0; irqs && i < (irqlen / 4); i++, irqs++) {
+		unsigned int hwirq = be32_to_cpup(irqs);
+		unsigned int irq = irq_create_mapping(NULL, hwirq);
+		if (irq == NO_IRQ) {
+			pr_warning("opal: Failed to map irq 0x%x\n", hwirq);
+			continue;
+		}
+		rc = request_irq(irq, opal_interrupt, 0, "opal", NULL);
+		if (rc)
+			pr_warning("opal: Error %d requesting irq %d"
+				   " (0x%x)\n", rc, irq, hwirq);
+	}
 	return 0;
 }
 subsys_initcall(opal_init);