--- /dev/null
+/*
+ * This file implements an irqchip for OPAL events. Whenever there is
+ * an interrupt that is handled by OPAL we get passed a list of events
+ * that Linux needs to do something about. These basically look like
+ * interrupts to Linux so we implement an irqchip to handle them.
+ *
+ * Copyright Alistair Popple, IBM Corporation 2014.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/irq_work.h>
+
+#include <asm/machdep.h>
+#include <asm/opal.h>
+
+#include "powernv.h"
+
+/* Maximum number of events supported by OPAL firmware */
+#define MAX_NUM_EVENTS 64
+
+struct opal_event_irqchip {
+       struct irq_chip irqchip;
+       struct irq_domain *domain;
+       unsigned long mask;
+};
+static struct opal_event_irqchip opal_event_irqchip;
+
+static unsigned int opal_irq_count;
+static unsigned int *opal_irqs;
+
+static void opal_handle_irq_work(struct irq_work *work);
+static __be64 last_outstanding_events;
+static struct irq_work opal_event_irq_work = {
+       .func = opal_handle_irq_work,
+};
+
+static void opal_event_mask(struct irq_data *d)
+{
+       clear_bit(d->hwirq, &opal_event_irqchip.mask);
+}
+
+static void opal_event_unmask(struct irq_data *d)
+{
+       set_bit(d->hwirq, &opal_event_irqchip.mask);
+
+       opal_poll_events(&last_outstanding_events);
+       if (last_outstanding_events & opal_event_irqchip.mask)
+               /* Need to retrigger the interrupt */
+               irq_work_queue(&opal_event_irq_work);
+}
+
+static int opal_event_set_type(struct irq_data *d, unsigned int flow_type)
+{
+       /*
+        * For now we only support level triggered events. The irq
+        * handler will be called continuously until the event has
+        * been cleared in OPAL.
+        */
+       if (flow_type != IRQ_TYPE_LEVEL_HIGH)
+               return -EINVAL;
+
+       return 0;
+}
+
+static struct opal_event_irqchip opal_event_irqchip = {
+       .irqchip = {
+               .name = "OPAL EVT",
+               .irq_mask = opal_event_mask,
+               .irq_unmask = opal_event_unmask,
+               .irq_set_type = opal_event_set_type,
+       },
+       .mask = 0,
+};
+
+static int opal_event_map(struct irq_domain *d, unsigned int irq,
+                       irq_hw_number_t hwirq)
+{
+       irq_set_chip_data(irq, &opal_event_irqchip);
+       irq_set_chip_and_handler(irq, &opal_event_irqchip.irqchip,
+                               handle_level_irq);
+
+       return 0;
+}
+
+void opal_handle_events(uint64_t events)
+{
+       int virq, hwirq = 0;
+       u64 mask = opal_event_irqchip.mask;
+       u64 notifier_mask = 0;
+
+       if (!in_irq() && (events & mask)) {
+               last_outstanding_events = events;
+               irq_work_queue(&opal_event_irq_work);
+               return;
+       }
+
+       while (events) {
+               hwirq = fls64(events) - 1;
+               virq = irq_find_mapping(opal_event_irqchip.domain,
+                                       hwirq);
+               if (virq) {
+                       if (BIT_ULL(hwirq) & mask)
+                               generic_handle_irq(virq);
+               } else
+                       notifier_mask |= BIT_ULL(hwirq);
+               events &= ~BIT_ULL(hwirq);
+       }
+
+       opal_do_notifier(notifier_mask);
+}
+
+static irqreturn_t opal_interrupt(int irq, void *data)
+{
+       __be64 events;
+
+       opal_handle_interrupt(virq_to_hw(irq), &events);
+       opal_handle_events(be64_to_cpu(events));
+
+       return IRQ_HANDLED;
+}
+
+static void opal_handle_irq_work(struct irq_work *work)
+{
+       opal_handle_events(be64_to_cpu(last_outstanding_events));
+}
+
+static int opal_event_match(struct irq_domain *h, struct device_node *node)
+{
+       return h->of_node == node;
+}
+
+static int opal_event_xlate(struct irq_domain *h, struct device_node *np,
+                          const u32 *intspec, unsigned int intsize,
+                          irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+{
+       *out_hwirq = intspec[0];
+       *out_flags = IRQ_TYPE_LEVEL_HIGH;
+
+       return 0;
+}
+
+static const struct irq_domain_ops opal_event_domain_ops = {
+       .match  = opal_event_match,
+       .map    = opal_event_map,
+       .xlate  = opal_event_xlate,
+};
+
+void opal_event_shutdown(void)
+{
+       unsigned int i;
+
+       /* 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;
+       }
+}
+
+int __init opal_event_init(void)
+{
+       struct device_node *dn, *opal_node;
+       const __be32 *irqs;
+       int i, irqlen, rc = 0;
+
+       opal_node = of_find_node_by_path("/ibm,opal");
+       if (!opal_node) {
+               pr_warn("opal: Node not found\n");
+               return -ENODEV;
+       }
+
+       /* If dn is NULL it means the domain won't be linked to a DT
+        * node so therefore irq_of_parse_and_map(...) wont work. But
+        * that shouldn't be problem because if we're running a
+        * version of skiboot that doesn't have the dn then the
+        * devices won't have the correct properties and will have to
+        * fall back to the legacy method (opal_event_request(...))
+        * anyway. */
+       dn = of_find_compatible_node(NULL, NULL, "ibm,opal-event");
+       opal_event_irqchip.domain = irq_domain_add_linear(dn, MAX_NUM_EVENTS,
+                               &opal_event_domain_ops, &opal_event_irqchip);
+       of_node_put(dn);
+       if (!opal_event_irqchip.domain) {
+               pr_warn("opal: Unable to create irq domain\n");
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       /* 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);
+
+       /* Install interrupt handlers */
+       opal_irqs = kcalloc(opal_irq_count, sizeof(*opal_irqs), GFP_KERNEL);
+       for (i = 0; irqs && i < opal_irq_count; i++, irqs++) {
+               unsigned int irq, virq;
+
+               /* 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;
+       }
+
+out:
+       of_node_put(opal_node);
+       return rc;
+}
+
+/**
+ * opal_event_request(unsigned int opal_event_nr) - Request an event
+ * @opal_event_nr: the opal event number to request
+ *
+ * This routine can be used to find the linux virq number which can
+ * then be passed to request_irq to assign a handler for a particular
+ * opal event. This should only be used by legacy devices which don't
+ * have proper device tree bindings. Most devices should use
+ * irq_of_parse_and_map() instead.
+ */
+int opal_event_request(unsigned int opal_event_nr)
+{
+       return irq_create_mapping(opal_event_irqchip.domain, opal_event_nr);
+}
+EXPORT_SYMBOL(opal_event_request);
 
 
 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);
 }
 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;
 
        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;
 }
        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);
                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());
 
                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");
        /* 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) {
 
 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