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 0862fa4b746..04d4b4ca0ef 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 430fc2a984b..6be3acdc9e7 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 e7c34776a01..885610f8dd8 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 26c37792c8f..92fbc982b88 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 5067ab7fdce..5966027aa96 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 0b8dad604ad..bdad153953e 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 ab2a8b16836..2ac31633d72 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 84f8a6fb0da..26789970c5c 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 2e5b9450a80..50907f84461 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 d2dac45173c..9b6303dd7d3 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 7ffd6db1223..4607025125c 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 93de4a9807a..0ecf5d939aa 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 479684bda7e..a96be8b3a53 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);