drm/radeon/kms: add irq mitigation code for sw interrupt.

We really don't need to process every irq that comes in, we only
really want to do SW irq processing when we are actually waiting for
a fence to pass. I'm not 100% sure this is race free esp on non-MSI systems
so it needs some testing.

Signed-off-by: Dave Airlie <airlied@redhat.com>

13 files changed, 35 insertions, 12 deletions

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 0862fa4b746d..04d4b4ca0ef3 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -3129,7 +3129,6 @@ static int r100_startup(struct radeon_device *rdev)
                         return r;
         }
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         r100_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/r300.c b/drivers/gpu/drm/radeon/r300.c
index 430fc2a984b2..6be3acdc9e7d 100644
--- a/drivers/gpu/drm/radeon/r300.c
+++ b/drivers/gpu/drm/radeon/r300.c
@@ -1205,7 +1205,6 @@ static int r300_startup(struct radeon_device *rdev)
                         return r;
         }
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         r100_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/r420.c b/drivers/gpu/drm/radeon/r420.c
index e7c34776a013..885610f8dd85 100644
--- a/drivers/gpu/drm/radeon/r420.c
+++ b/drivers/gpu/drm/radeon/r420.c
@@ -186,7 +186,6 @@ static int r420_startup(struct radeon_device *rdev)
         }
         r420_pipes_init(rdev);
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         r100_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/r520.c b/drivers/gpu/drm/radeon/r520.c
index 26c37792c8fe..92fbc982b889 100644
--- a/drivers/gpu/drm/radeon/r520.c
+++ b/drivers/gpu/drm/radeon/r520.c
@@ -185,7 +185,6 @@ static int r520_startup(struct radeon_device *rdev)
                         return r;
         }
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         rs600_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 5067ab7fdced..5966027aa967 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1571,7 +1571,6 @@ int r600_startup(struct radeon_device *rdev)
         }
 
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         r = r600_irq_init(rdev);
         if (r) {
                 DRM_ERROR("radeon: IH init failed (%d).\n", r);
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 0b8dad604ad8..bdad153953e6 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -352,11 +352,14 @@ struct radeon_irq {
         bool            sw_int;
         /* FIXME: use a define max crtc rather than hardcode it */
         bool            crtc_vblank_int[2];
+        spinlock_t sw_lock;
+        int sw_refcount;
 };
 
 int radeon_irq_kms_init(struct radeon_device *rdev);
 void radeon_irq_kms_fini(struct radeon_device *rdev);
-
+void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev);
+void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev);
 
 /*
  * CP & ring.
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index ab2a8b16836c..2ac31633d72c 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -193,14 +193,18 @@ retry:
         }
 
         if (intr) {
+                radeon_irq_kms_sw_irq_get(rdev);
                 r = wait_event_interruptible_timeout(rdev->fence_drv.queue,
                                 radeon_fence_signaled(fence), timeout);
+                radeon_irq_kms_sw_irq_put(rdev);
                 if (unlikely(r == -ERESTARTSYS)) {
                         return -EBUSY;
                 }
         } else {
+                radeon_irq_kms_sw_irq_get(rdev);
                 r = wait_event_timeout(rdev->fence_drv.queue,
                          radeon_fence_signaled(fence), timeout);
+                radeon_irq_kms_sw_irq_put(rdev);
         }
         if (unlikely(!radeon_fence_signaled(fence))) {
                 if (unlikely(r == 0)) {
diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 84f8a6fb0da3..26789970c5cf 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -87,7 +87,7 @@ int radeon_irq_kms_init(struct radeon_device *rdev)
 
         if (rdev->flags & RADEON_SINGLE_CRTC)
                 num_crtc = 1;
-
+        spin_lock_init(&rdev->irq.sw_lock);
         r = drm_vblank_init(rdev->ddev, num_crtc);
         if (r) {
                 return r;
@@ -122,3 +122,29 @@ void radeon_irq_kms_fini(struct radeon_device *rdev)
                         pci_disable_msi(rdev->pdev);
         }
 }
+
+void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev)
+{
+        unsigned long irqflags;
+
+        spin_lock_irqsave(&rdev->irq.sw_lock, irqflags);
+        if (rdev->ddev->irq_enabled && (++rdev->irq.sw_refcount == 1)) {
+                rdev->irq.sw_int = true;
+                radeon_irq_set(rdev);
+        }
+        spin_unlock_irqrestore(&rdev->irq.sw_lock, irqflags);
+}
+
+void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev)
+{
+        unsigned long irqflags;
+
+        spin_lock_irqsave(&rdev->irq.sw_lock, irqflags);
+        BUG_ON(rdev->ddev->irq_enabled && rdev->irq.sw_refcount <= 0);
+        if (rdev->ddev->irq_enabled && (--rdev->irq.sw_refcount == 0)) {
+                rdev->irq.sw_int = false;
+                radeon_irq_set(rdev);
+        }
+        spin_unlock_irqrestore(&rdev->irq.sw_lock, irqflags);
+}
+
diff --git a/drivers/gpu/drm/radeon/rs400.c b/drivers/gpu/drm/radeon/rs400.c
index 2e5b9450a804..50907f84461b 100644
--- a/drivers/gpu/drm/radeon/rs400.c
+++ b/drivers/gpu/drm/radeon/rs400.c
@@ -394,7 +394,6 @@ static int rs400_startup(struct radeon_device *rdev)
         if (r)
                 return r;
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         r100_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index d2dac45173c2..9b6303dd7d3a 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -388,7 +388,6 @@ static int rs600_startup(struct radeon_device *rdev)
         if (r)
                 return r;
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         rs600_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/rs690.c b/drivers/gpu/drm/radeon/rs690.c
index 7ffd6db1223f..4607025125c0 100644
--- a/drivers/gpu/drm/radeon/rs690.c
+++ b/drivers/gpu/drm/radeon/rs690.c
@@ -605,7 +605,6 @@ static int rs690_startup(struct radeon_device *rdev)
         if (r)
                 return r;
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         rs600_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/rv515.c b/drivers/gpu/drm/radeon/rv515.c
index 93de4a9807ab..0ecf5d939aa0 100644
--- a/drivers/gpu/drm/radeon/rv515.c
+++ b/drivers/gpu/drm/radeon/rv515.c
@@ -478,7 +478,6 @@ static int rv515_startup(struct radeon_device *rdev)
                         return r;
         }
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         rs600_irq_set(rdev);
         /* 1M ring buffer */
         r = r100_cp_init(rdev, 1024 * 1024);
diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index 479684bda7e2..a96be8b3a530 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -888,7 +888,6 @@ static int rv770_startup(struct radeon_device *rdev)
         }
 
         /* Enable IRQ */
-        rdev->irq.sw_int = true;
         r = r600_irq_init(rdev);
         if (r) {
                 DRM_ERROR("radeon: IH init failed (%d).\n", r);