Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux

[~andy/linux] / drivers / hv / vmbus_drv.c

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 8e1a9ec5300328eee7bb22a71c47c42f31ad5aa9..cf19dfa5ead187bf6c2eb535e31986ca5e671981 100644 (file)
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -33,6 +33,7 @@
 #include <acpi/acpi_bus.h>
 #include <linux/completion.h>
 #include <linux/hyperv.h>
+#include <linux/kernel_stat.h>
 #include <asm/hyperv.h>
 #include <asm/hypervisor.h>
 #include "hyperv_vmbus.h"
@@ -41,7 +42,6 @@
 static struct acpi_device  *hv_acpi_dev;
 
 static struct tasklet_struct msg_dpc;
-static struct tasklet_struct event_dpc;
 static struct completion probe_event;
 static int irq;
 
@@ -454,21 +454,40 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
        union hv_synic_event_flags *event;
        bool handled = false;
 
+       page_addr = hv_context.synic_event_page[cpu];
+       if (page_addr == NULL)
+               return IRQ_NONE;
+
+       event = (union hv_synic_event_flags *)page_addr +
+                                        VMBUS_MESSAGE_SINT;
        /*
         * Check for events before checking for messages. This is the order
         * in which events and messages are checked in Windows guests on
         * Hyper-V, and the Windows team suggested we do the same.
         */
 
-       page_addr = hv_context.synic_event_page[cpu];
-       event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
+       if ((vmbus_proto_version == VERSION_WS2008) ||
+               (vmbus_proto_version == VERSION_WIN7)) {
 
-       /* Since we are a child, we only need to check bit 0 */
-       if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
+               /* Since we are a child, we only need to check bit 0 */
+               if (sync_test_and_clear_bit(0,
+                       (unsigned long *) &event->flags32[0])) {
+                       handled = true;
+               }
+       } else {
+               /*
+                * Our host is win8 or above. The signaling mechanism
+                * has changed and we can directly look at the event page.
+                * If bit n is set then we have an interrup on the channel
+                * whose id is n.
+                */
                handled = true;
-               tasklet_schedule(&event_dpc);
        }
 
+       if (handled)
+               tasklet_schedule(hv_context.event_dpc[cpu]);
+
+
        page_addr = hv_context.synic_message_page[cpu];
        msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 
@@ -484,6 +503,19 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
                return IRQ_NONE;
 }
 
+/*
+ * vmbus interrupt flow handler:
+ * vmbus interrupts can concurrently occur on multiple CPUs and
+ * can be handled concurrently.
+ */
+
+static void vmbus_flow_handler(unsigned int irq, struct irq_desc *desc)
+{
+       kstat_incr_irqs_this_cpu(irq, desc);
+
+       desc->action->handler(irq, desc->action->dev_id);
+}
+
 /*
  * vmbus_bus_init -Main vmbus driver initialization routine.
  *
@@ -506,7 +538,6 @@ static int vmbus_bus_init(int irq)
        }
 
        tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
-       tasklet_init(&event_dpc, vmbus_on_event, 0);
 
        ret = bus_register(&hv_bus);
        if (ret)
@@ -520,6 +551,13 @@ static int vmbus_bus_init(int irq)
                goto err_unregister;
        }
 
+       /*
+        * Vmbus interrupts can be handled concurrently on
+        * different CPUs. Establish an appropriate interrupt flow
+        * handler that can support this model.
+        */
+       irq_set_handler(irq, vmbus_flow_handler);
+
        vector = IRQ0_VECTOR + irq;
 
        /*
@@ -575,8 +613,6 @@ int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, c
 
        ret = driver_register(&hv_driver->driver);
 
-       vmbus_request_offers();
-
        return ret;
 }
 EXPORT_SYMBOL_GPL(__vmbus_driver_register);