1 files changed, 241 insertions, 2 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 7d24b0d94ed4..bc69a9d92abc 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -16,7 +16,7 @@
  *    (typically dom0).
  * 2. VIRQs, typically used for timers.  These are per-cpu events.
  * 3. IPIs.
- * 4. Hardware interrupts. Not supported at present.
+ * 4. PIRQs - Hardware interrupts.
  *
  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
  */
@@ -46,6 +46,9 @@
 #include <xen/interface/hvm/hvm_op.h>
 #include <xen/interface/hvm/params.h>
 
+/* Leave low irqs free for identity mapping */
+#define LEGACY_IRQS     16
+
 /*
  * This lock protects updates to the following mapping and reference-count
  * arrays. The lock does not need to be acquired to read the mapping tables.
@@ -89,10 +92,12 @@ struct irq_info
                 enum ipi_vector ipi;
                 struct {
                         unsigned short gsi;
-                        unsigned short vector;
+                        unsigned char vector;
+                        unsigned char flags;
                 } pirq;
         } u;
 };
+#define PIRQ_NEEDS_EOI  (1 << 0)
 
 static struct irq_info irq_info[NR_IRQS];
 
@@ -113,6 +118,7 @@ static inline unsigned long *cpu_evtchn_mask(int cpu)
 
 static struct irq_chip xen_dynamic_chip;
 static struct irq_chip xen_percpu_chip;
+static struct irq_chip xen_pirq_chip;
 
 /* Constructor for packed IRQ information. */
 static struct irq_info mk_unbound_info(void)
@@ -225,6 +231,15 @@ static unsigned int cpu_from_evtchn(unsigned int evtchn)
         return ret;
 }
 
+static bool pirq_needs_eoi(unsigned irq)
+{
+        struct irq_info *info = info_for_irq(irq);
+
+        BUG_ON(info->type != IRQT_PIRQ);
+
+        return info->u.pirq.flags & PIRQ_NEEDS_EOI;
+}
+
 static inline unsigned long active_evtchns(unsigned int cpu,
                                            struct shared_info *sh,
                                            unsigned int idx)
@@ -365,6 +380,210 @@ static int find_unbound_irq(void)
         return irq;
 }
 
+static bool identity_mapped_irq(unsigned irq)
+{
+        /* only identity map legacy irqs */
+        return irq < LEGACY_IRQS;
+}
+
+static void pirq_unmask_notify(int irq)
+{
+        struct physdev_eoi eoi = { .irq = irq };
+
+        if (unlikely(pirq_needs_eoi(irq))) {
+                int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
+                WARN_ON(rc);
+        }
+}
+
+static void pirq_query_unmask(int irq)
+{
+        struct physdev_irq_status_query irq_status;
+        struct irq_info *info = info_for_irq(irq);
+
+        BUG_ON(info->type != IRQT_PIRQ);
+
+        irq_status.irq = irq;
+        if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
+                irq_status.flags = 0;
+
+        info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
+        if (irq_status.flags & XENIRQSTAT_needs_eoi)
+                info->u.pirq.flags |= PIRQ_NEEDS_EOI;
+}
+
+static bool probing_irq(int irq)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+
+        return desc && desc->action == NULL;
+}
+
+static unsigned int startup_pirq(unsigned int irq)
+{
+        struct evtchn_bind_pirq bind_pirq;
+        struct irq_info *info = info_for_irq(irq);
+        int evtchn = evtchn_from_irq(irq);
+
+        BUG_ON(info->type != IRQT_PIRQ);
+
+        if (VALID_EVTCHN(evtchn))
+                goto out;
+
+        bind_pirq.pirq = irq;
+        /* NB. We are happy to share unless we are probing. */
+        bind_pirq.flags = probing_irq(irq) ? 0 : BIND_PIRQ__WILL_SHARE;
+        if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq) != 0) {
+                if (!probing_irq(irq))
+                        printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
+                               irq);
+                return 0;
+        }
+        evtchn = bind_pirq.port;
+
+        pirq_query_unmask(irq);
+
+        evtchn_to_irq[evtchn] = irq;
+        bind_evtchn_to_cpu(evtchn, 0);
+        info->evtchn = evtchn;
+
+out:
+        unmask_evtchn(evtchn);
+        pirq_unmask_notify(irq);
+
+        return 0;
+}
+
+static void shutdown_pirq(unsigned int irq)
+{
+        struct evtchn_close close;
+        struct irq_info *info = info_for_irq(irq);
+        int evtchn = evtchn_from_irq(irq);
+
+        BUG_ON(info->type != IRQT_PIRQ);
+
+        if (!VALID_EVTCHN(evtchn))
+                return;
+
+        mask_evtchn(evtchn);
+
+        close.port = evtchn;
+        if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
+                BUG();
+
+        bind_evtchn_to_cpu(evtchn, 0);
+        evtchn_to_irq[evtchn] = -1;
+        info->evtchn = 0;
+}
+
+static void enable_pirq(unsigned int irq)
+{
+        startup_pirq(irq);
+}
+
+static void disable_pirq(unsigned int irq)
+{
+}
+
+static void ack_pirq(unsigned int irq)
+{
+        int evtchn = evtchn_from_irq(irq);
+
+        move_native_irq(irq);
+
+        if (VALID_EVTCHN(evtchn)) {
+                mask_evtchn(evtchn);
+                clear_evtchn(evtchn);
+        }
+}
+
+static void end_pirq(unsigned int irq)
+{
+        int evtchn = evtchn_from_irq(irq);
+        struct irq_desc *desc = irq_to_desc(irq);
+
+        if (WARN_ON(!desc))
+                return;
+
+        if ((desc->status & (IRQ_DISABLED|IRQ_PENDING)) ==
+            (IRQ_DISABLED|IRQ_PENDING)) {
+                shutdown_pirq(irq);
+        } else if (VALID_EVTCHN(evtchn)) {
+                unmask_evtchn(evtchn);
+                pirq_unmask_notify(irq);
+        }
+}
+
+static int find_irq_by_gsi(unsigned gsi)
+{
+        int irq;
+
+        for (irq = 0; irq < NR_IRQS; irq++) {
+                struct irq_info *info = info_for_irq(irq);
+
+                if (info == NULL || info->type != IRQT_PIRQ)
+                        continue;
+
+                if (gsi_from_irq(irq) == gsi)
+                        return irq;
+        }
+
+        return -1;
+}
+
+/*
+ * Allocate a physical irq, along with a vector.  We don't assign an
+ * event channel until the irq actually started up.  Return an
+ * existing irq if we've already got one for the gsi.
+ */
+int xen_allocate_pirq(unsigned gsi)
+{
+        int irq;
+        struct physdev_irq irq_op;
+
+        spin_lock(&irq_mapping_update_lock);
+
+        irq = find_irq_by_gsi(gsi);
+        if (irq != -1) {
+                printk(KERN_INFO "xen_allocate_pirq: returning irq %d for gsi %u\n",
+                       irq, gsi);
+                goto out;       /* XXX need refcount? */
+        }
+
+        if (identity_mapped_irq(gsi)) {
+                irq = gsi;
+                dynamic_irq_init(irq);
+        } else
+                irq = find_unbound_irq();
+
+        set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
+                                      handle_level_irq, "pirq");
+
+        irq_op.irq = irq;
+        if (HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
+                dynamic_irq_cleanup(irq);
+                irq = -ENOSPC;
+                goto out;
+        }
+
+        irq_info[irq] = mk_pirq_info(0, gsi, irq_op.vector);
+
+out:
+        spin_unlock(&irq_mapping_update_lock);
+
+        return irq;
+}
+
+int xen_vector_from_irq(unsigned irq)
+{
+        return vector_from_irq(irq);
+}
+
+int xen_gsi_from_irq(unsigned irq)
+{
+        return gsi_from_irq(irq);
+}
+
 int bind_evtchn_to_irq(unsigned int evtchn)
 {
         int irq;
@@ -964,6 +1183,26 @@ static struct irq_chip xen_dynamic_chip __read_mostly = {
         .retrigger      = retrigger_dynirq,
 };
 
+static struct irq_chip xen_pirq_chip __read_mostly = {
+        .name           = "xen-pirq",
+
+        .startup        = startup_pirq,
+        .shutdown       = shutdown_pirq,
+
+        .enable         = enable_pirq,
+        .unmask         = enable_pirq,
+
+        .disable        = disable_pirq,
+        .mask           = disable_pirq,
+
+        .ack            = ack_pirq,
+        .end            = end_pirq,
+
+        .set_affinity   = set_affinity_irq,
+
+        .retrigger      = retrigger_dynirq,
+};
+
 static struct irq_chip xen_percpu_chip __read_mostly = {
         .name           = "xen-percpu",