[Intel-gfx] [PATCH 38/50] drm/i915/bdw: LR context switch interrupts

oscar.mateo at intel.com oscar.mateo at intel.com
Fri May 9 14:09:08 CEST 2014


From: Thomas Daniel <thomas.daniel at intel.com>

We need to attend context switch interrupts from all rings. Also, fixed writing
IMR/IER and added HWSTAM at ring init time.

Notice that, if added to irq_enable_mask, the context switch interrupts would
be incorrectly masked out when the user interrupts are due to no users waiting
on a sequence number. Therefore, this commit adds a bitmask of interrupts to
be kept unmasked at all times.

Signed-off-by: Thomas Daniel <thomas.daniel at intel.com>

v2: Disable HWSTAM, as suggested by Damien (nobody listens to these interrupts,
anyway).

Signed-off-by: Oscar Mateo <oscar.mateo at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c         | 27 ++++++++++++++++++-------
 drivers/gpu/drm/i915/i915_reg.h         |  2 ++
 drivers/gpu/drm/i915/intel_ringbuffer.c | 36 ++++++++++++++++++++-------------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  1 +
 4 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 873ae50..a28cf6c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1300,7 +1300,7 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
 				       struct drm_i915_private *dev_priv,
 				       u32 master_ctl)
 {
-	u32 rcs, bcs, vcs;
+	u32 rcs, bcs, vcs, vecs;
 	uint32_t tmp = 0;
 	irqreturn_t ret = IRQ_NONE;
 
@@ -1314,6 +1314,8 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
 				notify_ring(dev, &dev_priv->ring[RCS]);
 			if (bcs & GT_RENDER_USER_INTERRUPT)
 				notify_ring(dev, &dev_priv->ring[BCS]);
+			if ((rcs | bcs) & GEN8_GT_CONTEXT_SWITCH_INTERRUPT)
+			     DRM_DEBUG_DRIVER("TODO: Context switch\n");
 			I915_WRITE(GEN8_GT_IIR(0), tmp);
 		} else
 			DRM_ERROR("The master control interrupt lied (GT0)!\n");
@@ -1326,9 +1328,13 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
 			vcs = tmp >> GEN8_VCS1_IRQ_SHIFT;
 			if (vcs & GT_RENDER_USER_INTERRUPT)
 				notify_ring(dev, &dev_priv->ring[VCS]);
+			if (vcs & GEN8_GT_CONTEXT_SWITCH_INTERRUPT)
+			     DRM_DEBUG_DRIVER("TODO: Context switch\n");
 			vcs = tmp >> GEN8_VCS2_IRQ_SHIFT;
 			if (vcs & GT_RENDER_USER_INTERRUPT)
 				notify_ring(dev, &dev_priv->ring[VCS2]);
+			if (vcs & GEN8_GT_CONTEXT_SWITCH_INTERRUPT)
+			     DRM_DEBUG_DRIVER("TODO: Context switch\n");
 			I915_WRITE(GEN8_GT_IIR(1), tmp);
 		} else
 			DRM_ERROR("The master control interrupt lied (GT1)!\n");
@@ -1338,9 +1344,11 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
 		tmp = I915_READ(GEN8_GT_IIR(3));
 		if (tmp) {
 			ret = IRQ_HANDLED;
-			vcs = tmp >> GEN8_VECS_IRQ_SHIFT;
-			if (vcs & GT_RENDER_USER_INTERRUPT)
+			vecs = tmp >> GEN8_VECS_IRQ_SHIFT;
+			if (vecs & GT_RENDER_USER_INTERRUPT)
 				notify_ring(dev, &dev_priv->ring[VECS]);
+			if (vecs & GEN8_GT_CONTEXT_SWITCH_INTERRUPT)
+			     DRM_DEBUG_DRIVER("TODO: Context switch\n");
 			I915_WRITE(GEN8_GT_IIR(3), tmp);
 		} else
 			DRM_ERROR("The master control interrupt lied (GT3)!\n");
@@ -3243,12 +3251,17 @@ static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
 	/* These are interrupts we'll toggle with the ring mask register */
 	uint32_t gt_interrupts[] = {
 		GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
-			GT_RENDER_L3_PARITY_ERROR_INTERRUPT |
-			GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT,
+		GT_RENDER_L3_PARITY_ERROR_INTERRUPT |
+		GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
+		GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT |
+		GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_BCS_IRQ_SHIFT,
 		GT_RENDER_USER_INTERRUPT << GEN8_VCS1_IRQ_SHIFT |
-			GT_RENDER_USER_INTERRUPT << GEN8_VCS2_IRQ_SHIFT,
+		GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS1_IRQ_SHIFT |
+		GT_RENDER_USER_INTERRUPT << GEN8_VCS2_IRQ_SHIFT |
+		GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS2_IRQ_SHIFT,
 		0,
-		GT_RENDER_USER_INTERRUPT << GEN8_VECS_IRQ_SHIFT
+		GT_RENDER_USER_INTERRUPT << GEN8_VECS_IRQ_SHIFT |
+		GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT,
 		};
 
 	for (i = 0; i < ARRAY_SIZE(gt_interrupts); i++)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2e76ec0..97a51f8 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -823,6 +823,7 @@ enum punit_power_well {
 #define RING_ACTHD_UDW(base)	((base)+0x5c)
 #define RING_NOPID(base)	((base)+0x94)
 #define RING_IMR(base)		((base)+0xa8)
+#define RING_HWSTAM(base)	((base)+0x98)
 #define RING_TIMESTAMP(base)	((base)+0x358)
 #define   TAIL_ADDR		0x001FFFF8
 #define   HEAD_WRAP_COUNT	0xFFE00000
@@ -4269,6 +4270,7 @@ enum punit_power_well {
 #define GEN8_GT_IMR(which) (0x44304 + (0x10 * (which)))
 #define GEN8_GT_IIR(which) (0x44308 + (0x10 * (which)))
 #define GEN8_GT_IER(which) (0x4430c + (0x10 * (which)))
+#define   GEN8_GT_CONTEXT_SWITCH_INTERRUPT	(1<<8)
 
 #define GEN8_BCS_IRQ_SHIFT 16
 #define GEN8_RCS_IRQ_SHIFT 0
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index d38d824..847fec5 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -567,6 +567,12 @@ out:
 
 static int init_ring_common_lrc(struct intel_engine *ring)
 {
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	I915_WRITE_IMR(ring, ~(ring->irq_enable_mask | ring->irq_keep_mask));
+	I915_WRITE(RING_HWSTAM(ring->mmio_base), 0xffffffff);
+
 	return 0;
 }
 
@@ -1288,13 +1294,7 @@ gen8_ring_get_irq(struct intel_engine *ring)
 
 	spin_lock_irqsave(&dev_priv->irq_lock, flags);
 	if (ring->irq_refcount++ == 0) {
-		if (HAS_L3_DPF(dev) && ring->id == RCS) {
-			I915_WRITE_IMR(ring,
-				       ~(ring->irq_enable_mask |
-					 GT_RENDER_L3_PARITY_ERROR_INTERRUPT));
-		} else {
-			I915_WRITE_IMR(ring, ~ring->irq_enable_mask);
-		}
+		I915_WRITE_IMR(ring, ~(ring->irq_enable_mask | ring->irq_keep_mask));
 		POSTING_READ(RING_IMR(ring->mmio_base));
 	}
 	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
@@ -1311,12 +1311,7 @@ gen8_ring_put_irq(struct intel_engine *ring)
 
 	spin_lock_irqsave(&dev_priv->irq_lock, flags);
 	if (--ring->irq_refcount == 0) {
-		if (HAS_L3_DPF(dev) && ring->id == RCS) {
-			I915_WRITE_IMR(ring,
-				       ~GT_RENDER_L3_PARITY_ERROR_INTERRUPT);
-		} else {
-			I915_WRITE_IMR(ring, ~0);
-		}
+		I915_WRITE_IMR(ring, ~ring->irq_keep_mask);
 		POSTING_READ(RING_IMR(ring->mmio_base));
 	}
 	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
@@ -2108,15 +2103,20 @@ int intel_init_render_ring(struct drm_device *dev)
 				ring->submit = gen8_submit_ctx;
 				ring->init = init_render_ring_lrc;
 				ring->add_request = gen8_add_request_lrc;
+				ring->irq_keep_mask =
+					GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT;
 			}
 			ring->flush = gen8_render_ring_flush;
 			ring->irq_get = gen8_ring_get_irq;
 			ring->irq_put = gen8_ring_put_irq;
+			if (HAS_L3_DPF(dev))
+				ring->irq_keep_mask |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT;
 		} else {
 			ring->irq_get = gen6_ring_get_irq;
 			ring->irq_put = gen6_ring_put_irq;
 		}
-		ring->irq_enable_mask = GT_RENDER_USER_INTERRUPT;
+		ring->irq_enable_mask =
+			GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT;
 		ring->get_seqno = gen6_ring_get_seqno;
 		ring->set_seqno = ring_set_seqno;
 		ring->semaphore.sync_to = gen6_ring_sync;
@@ -2286,6 +2286,8 @@ int intel_init_bsd_ring(struct drm_device *dev)
 				ring->submit = gen8_submit_ctx;
 				ring->init = init_ring_common_lrc;
 				ring->add_request = gen8_nonrender_add_request_lrc;
+				ring->irq_keep_mask =
+					GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS1_IRQ_SHIFT;
 			}
 			ring->flush = gen8_ring_flush;
 			ring->irq_enable_mask =
@@ -2358,6 +2360,8 @@ int intel_init_bsd2_ring(struct drm_device *dev)
 		ring->submit = gen8_submit_ctx;
 		ring->add_request = gen8_nonrender_add_request_lrc;
 		ring->init = init_ring_common_lrc;
+		ring->irq_keep_mask =
+			GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS2_IRQ_SHIFT;
 	} else {
 		ring->submit = ring_write_tail;
 		ring->add_request = gen6_add_request;
@@ -2408,6 +2412,8 @@ int intel_init_blt_ring(struct drm_device *dev)
 			ring->submit = gen8_submit_ctx;
 			ring->init = init_ring_common_lrc;
 			ring->add_request = gen8_nonrender_add_request_lrc;
+			ring->irq_keep_mask =
+				GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_BCS_IRQ_SHIFT;
 		}
 		ring->flush = gen8_ring_flush;
 		ring->irq_enable_mask =
@@ -2460,6 +2466,8 @@ int intel_init_vebox_ring(struct drm_device *dev)
 			ring->submit = gen8_submit_ctx;
 			ring->init = init_ring_common_lrc;
 			ring->add_request = gen8_nonrender_add_request_lrc;
+			ring->irq_keep_mask =
+				GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT;
 		}
 		ring->flush = gen8_ring_flush;
 		ring->irq_enable_mask =
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index c224fdc..709b1f1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -96,6 +96,7 @@ struct intel_engine {
 
 	unsigned irq_refcount; /* protected by dev_priv->irq_lock */
 	u32		irq_enable_mask;	/* bitmask to enable ring interrupt */
+	u32		irq_keep_mask;		/* bitmask for interrupts that should not be masked */
 	u32		trace_irq_seqno;
 	bool __must_check (*irq_get)(struct intel_engine *ring);
 	void		(*irq_put)(struct intel_engine *ring);
-- 
1.9.0




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