powerpc/powernv: Add a virtual irqchip for opal events

Whenever an interrupt is received for opal the linux kernel gets a
bitfield indicating certain events that have occurred and need handling
by the various device drivers. Currently this is handled using a
notifier interface where we call every device driver that has
registered to receive opal events.

This approach has several drawbacks. For example each driver has to do
its own checking to see if the event is relevant as well as event
masking. There is also no easy method of recording the number of times
we receive particular events.

This patch solves these issues by exposing opal events via the
standard interrupt APIs by adding a new interrupt chip and
domain. Drivers can then register for the appropriate events using
standard kernel calls such as irq_of_parse_and_map().

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 12 insertions, 66 deletions

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index eb3decc67c43..3baca718261a 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -53,8 +53,6 @@ static int mc_recoverable_range_len;
 
 struct device_node *opal_node;
 static DEFINE_SPINLOCK(opal_write_lock);
-static unsigned int *opal_irqs;
-static unsigned int opal_irq_count;
 static ATOMIC_NOTIFIER_HEAD(opal_notifier_head);
 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
 static DEFINE_SPINLOCK(opal_notifier_lock);
@@ -251,7 +249,7 @@ int opal_notifier_unregister(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(opal_notifier_unregister);
 
-static void opal_do_notifier(uint64_t events)
+void opal_do_notifier(uint64_t events)
 {
 	unsigned long flags;
 	uint64_t changed_mask;
@@ -571,8 +569,10 @@ int opal_handle_hmi_exception(struct pt_regs *regs)
 
 	local_paca->hmi_event_available = 0;
 	rc = opal_poll_events(&evt);
-	if (rc == OPAL_SUCCESS && evt)
+	if (rc == OPAL_SUCCESS && evt) {
 		opal_do_notifier(be64_to_cpu(evt));
+		opal_handle_events(be64_to_cpu(evt));
+	}
 
 	return 1;
 }
@@ -609,17 +609,6 @@ out:
 	return !!recover_addr;
 }
 
-static irqreturn_t opal_interrupt(int irq, void *data)
-{
-	__be64 events;
-
-	opal_handle_interrupt(virq_to_hw(irq), &events);
-
-	opal_do_notifier(be64_to_cpu(events));
-
-	return IRQ_HANDLED;
-}
-
 static int opal_sysfs_init(void)
 {
 	opal_kobj = kobject_create_and_add("opal", firmware_kobj);
@@ -718,52 +707,15 @@ static void opal_i2c_create_devs(void)
 		of_platform_device_create(np, NULL, NULL);
 }
 
-static void __init opal_irq_init(struct device_node *dn)
-{
-	const __be32 *irqs;
-	int i, irqlen;
-
-	/* Get interrupt property */
-	irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
-	opal_irq_count = irqs ? (irqlen / 4) : 0;
-	pr_debug("Found %d interrupts reserved for OPAL\n", opal_irq_count);
-	if (!opal_irq_count)
-		return;
-
-	/* Install interrupt handlers */
-	opal_irqs = kzalloc(opal_irq_count * sizeof(unsigned int), GFP_KERNEL);
-	for (i = 0; irqs && i < opal_irq_count; i++, irqs++) {
-		unsigned int irq, virq;
-		int rc;
-
-		/* Get hardware and virtual IRQ */
-		irq = be32_to_cpup(irqs);
-		virq = irq_create_mapping(NULL, irq);
-		if (virq == NO_IRQ) {
-			pr_warn("Failed to map irq 0x%x\n", irq);
-			continue;
-		}
-
-		/* Install interrupt handler */
-		rc = request_irq(virq, opal_interrupt, 0, "opal", NULL);
-		if (rc) {
-			irq_dispose_mapping(virq);
-			pr_warn("Error %d requesting irq %d (0x%x)\n",
-				 rc, virq, irq);
-			continue;
-		}
-
-		/* Cache IRQ */
-		opal_irqs[i] = virq;
-	}
-}
-
 static int kopald(void *unused)
 {
+	__be64 events;
+
 	set_freezable();
 	do {
 		try_to_freeze();
-		opal_poll_events(NULL);
+		opal_poll_events(&events);
+		opal_handle_events(be64_to_cpu(events));
 		msleep_interruptible(opal_heartbeat);
 	} while (!kthread_should_stop());
 
@@ -792,6 +744,9 @@ static int __init opal_init(void)
 		return -ENODEV;
 	}
 
+	/* Initialise OPAL events */
+	opal_event_init();
+
 	/* Register OPAL consoles if any ports */
 	if (firmware_has_feature(FW_FEATURE_OPALv2))
 		consoles = of_find_node_by_path("/ibm,opal/consoles");
@@ -824,9 +779,6 @@ static int __init opal_init(void)
 	/* Setup a heatbeat thread if requested by OPAL */
 	opal_init_heartbeat();
 
-	/* Find all OPAL interrupts and request them */
-	opal_irq_init(opal_node);
-
 	/* Create "opal" kobject under /sys/firmware */
 	rc = opal_sysfs_init();
 	if (rc == 0) {
@@ -857,15 +809,9 @@ machine_subsys_initcall(powernv, opal_init);
 
 void opal_shutdown(void)
 {
-	unsigned int i;
 	long rc = OPAL_BUSY;
 
-	/* First free interrupts, which will also mask them */
-	for (i = 0; i < opal_irq_count; i++) {
-		if (opal_irqs[i])
-			free_irq(opal_irqs[i], NULL);
-		opal_irqs[i] = 0;
-	}
+	opal_event_shutdown();
 
 	/*
 	 * Then sync with OPAL which ensure anything that can