xen/irq: Add support to check if IRQ line is shared with other domains.

[pandora-kernel.git] / drivers / xen / events.c

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 036343b..0ac7a14 100644 (file)
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -5,7 +5,7 @@
  * domain gets 1024 event channels, but NR_IRQ is not that large, we
  * must dynamically map irqs<->event channels.  The event channels
  * interface with the rest of the kernel by defining a xen interrupt
- * chip.  When an event is recieved, it is mapped to an irq and sent
+ * chip.  When an event is received, it is mapped to an irq and sent
  * through the normal interrupt processing path.
  *
  * There are four kinds of events which can be mapped to an event
@@ -101,6 +101,7 @@ struct irq_info
                        unsigned short gsi;
                        unsigned char vector;
                        unsigned char flags;
+                       uint16_t domid;
                } pirq;
        } u;
 };
@@ -184,6 +185,7 @@ static void xen_irq_info_pirq_init(unsigned irq,
                                   unsigned short pirq,
                                   unsigned short gsi,
                                   unsigned short vector,
+                                  uint16_t domid,
                                   unsigned char flags)
 {
        struct irq_info *info = info_for_irq(irq);
@@ -193,6 +195,7 @@ static void xen_irq_info_pirq_init(unsigned irq,
        info->u.pirq.pirq = pirq;
        info->u.pirq.gsi = gsi;
        info->u.pirq.vector = vector;
+       info->u.pirq.domid = domid;
        info->u.pirq.flags = flags;
 }
 
@@ -416,7 +419,7 @@ static int __must_check xen_allocate_irq_dynamic(void)
 #ifdef CONFIG_X86_IO_APIC
        /*
         * For an HVM guest or domain 0 which see "real" (emulated or
-        * actual repectively) GSIs we allocate dynamic IRQs
+        * actual respectively) GSIs we allocate dynamic IRQs
         * e.g. those corresponding to event channels or MSIs
         * etc. from the range above those "real" GSIs to avoid
         * collisions.
@@ -655,7 +658,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
                goto out;
        }
 
-       xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector,
+       xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector, DOMID_SELF,
                               shareable ? PIRQ_SHAREABLE : 0);
 
 out:
@@ -680,7 +683,8 @@ int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 }
 
 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
-                            int pirq, int vector, const char *name)
+                            int pirq, int vector, const char *name,
+                            domid_t domid)
 {
        int irq, ret;
 
@@ -693,7 +697,7 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
        irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_level_irq,
                                      name);
 
-       xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, 0);
+       xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, domid, 0);
        ret = irq_set_msi_desc(irq, msidesc);
        if (ret < 0)
                goto error_irq;
@@ -722,7 +726,7 @@ int xen_destroy_irq(int irq)
 
        if (xen_initial_domain()) {
                unmap_irq.pirq = info->u.pirq.pirq;
-               unmap_irq.domid = DOMID_SELF;
+               unmap_irq.domid = info->u.pirq.domid;
                rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
                if (rc) {
                        printk(KERN_WARNING "unmap irq failed %d\n", rc);
@@ -1504,6 +1508,18 @@ void xen_poll_irq(int irq)
        xen_poll_irq_timeout(irq, 0 /* no timeout */);
 }
 
+/* Check whether the IRQ line is shared with other guests. */
+int xen_test_irq_shared(int irq)
+{
+       struct irq_info *info = info_for_irq(irq);
+       struct physdev_irq_status_query irq_status = { .irq = info->u.pirq.pirq };
+
+       if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
+               return 0;
+       return !(irq_status.flags & XENIRQSTAT_shared);
+}
+EXPORT_SYMBOL_GPL(xen_test_irq_shared);
+
 void xen_irq_resume(void)
 {
        unsigned int cpu, evtchn;