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 0862fa4..04d4b4c 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 430fc2a..6be3acd 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 e7c3477..885610f 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 26c37792..92fbc98 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 5067ab7..5966027 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 0b8dad6..bdad153 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 ab2a8b1..2ac3163 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 84f8a6f..2678997 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 2e5b945..50907f8 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 d2dac45..9b6303d 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 7ffd6db1..4607025 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 93de4a9..0ecf5d93 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 479684b..a96be8b 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);