[PATCH 23/43] drm/i915/bdw: Interrupts with logical rings

Thomas Daniel
2014-07-24T16:05:16Z

From: Oscar Mateo <oscar.mateo@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.

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

v3: Add new get/put_irq functions.

Signed-off-by: Thomas Daniel <thomas.daniel@intel.com> (v1)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com> (v2 & v3)
---
drivers/gpu/drm/i915/i915_irq.c | 19 ++++++++--
drivers/gpu/drm/i915/i915_reg.h | 3 ++
drivers/gpu/drm/i915/intel_lrc.c | 58 +++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_ringbuffer.h | 1 +
4 files changed, 78 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index a38b5c3..f77a4ca 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1643,6 +1643,8 @@ 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");
} else
DRM_ERROR("The master control interrupt lied (GT0)!\n");
}
@@ -1655,9 +1657,13 @@ 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");
} else
DRM_ERROR("The master control interrupt lied (GT1)!\n");
}
@@ -1681,6 +1687,8 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
vcs = tmp >> GEN8_VECS_IRQ_SHIFT;
if (vcs & GT_RENDER_USER_INTERRUPT)
notify_ring(dev, &dev_priv->ring[VECS]);
+ if (vcs & GEN8_GT_CONTEXT_SWITCH_INTERRUPT)
+ DRM_DEBUG_DRIVER("TODO: Context switch\n");
} else
DRM_ERROR("The master control interrupt lied (GT3)!\n");
}
@@ -3768,12 +3776,17 @@ 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 |
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
GT_RENDER_L3_PARITY_ERROR_INTERRUPT |
- GT_RENDER_USER_INTERRUPT << GEN8_BCS_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 70dddac..bfc0c01 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1062,6 +1062,7 @@ 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
@@ -4590,6 +4591,8 @@ enum punit_power_well {
#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
#define GEN8_VCS2_IRQ_SHIFT 16
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index c30518c..a6dcb3a 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -343,6 +343,9 @@ static int gen8_init_common_ring(struct intel_engine_cs *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);
+
I915_WRITE(RING_MODE_GEN7(ring),
_MASKED_BIT_DISABLE(GFX_REPLAY_MODE) |
_MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE));
@@ -381,6 +384,39 @@ static int gen8_init_render_ring(struct intel_engine_cs *ring)
return ret;
}

+static bool gen8_logical_ring_get_irq(struct intel_engine_cs *ring)
+{
+ struct drm_device *dev = ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ unsigned long flags;
+
+ if (!dev->irq_enabled)
+ return false;
+
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
+ if (ring->irq_refcount++ == 0) {
+ 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);
+
+ return true;
+}
+
+static void gen8_logical_ring_put_irq(struct intel_engine_cs *ring)
+{
+ struct drm_device *dev = ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
+ if (--ring->irq_refcount == 0) {
+ I915_WRITE_IMR(ring, ~ring->irq_keep_mask);
+ POSTING_READ(RING_IMR(ring->mmio_base));
+ }
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
+}
+
static int gen8_emit_flush(struct intel_ringbuffer *ringbuf,
u32 invalidate_domains,
u32 unused)
@@ -566,6 +602,10 @@ static int logical_render_ring_init(struct drm_device *dev)
ring->mmio_base = RENDER_RING_BASE;
ring->irq_enable_mask =
GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT;
+ if (HAS_L3_DPF(dev))
+ ring->irq_keep_mask |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT;

ring->init = gen8_init_render_ring;
ring->cleanup = intel_fini_pipe_control;
@@ -573,6 +613,8 @@ static int logical_render_ring_init(struct drm_device *dev)
ring->set_seqno = gen8_set_seqno;
ring->emit_request = gen8_emit_request;
ring->emit_flush = gen8_emit_flush_render;
+ ring->irq_get = gen8_logical_ring_get_irq;
+ ring->irq_put = gen8_logical_ring_put_irq;

return logical_ring_init(dev, ring);
}
@@ -587,12 +629,16 @@ static int logical_bsd_ring_init(struct drm_device *dev)
ring->mmio_base = GEN6_BSD_RING_BASE;
ring->irq_enable_mask =
GT_RENDER_USER_INTERRUPT << GEN8_VCS1_IRQ_SHIFT;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS1_IRQ_SHIFT;

ring->init = gen8_init_common_ring;
ring->get_seqno = gen8_get_seqno;
ring->set_seqno = gen8_set_seqno;
ring->emit_request = gen8_emit_request;
ring->emit_flush = gen8_emit_flush;
+ ring->irq_get = gen8_logical_ring_get_irq;
+ ring->irq_put = gen8_logical_ring_put_irq;

return logical_ring_init(dev, ring);
}
@@ -607,12 +653,16 @@ static int logical_bsd2_ring_init(struct drm_device *dev)
ring->mmio_base = GEN8_BSD2_RING_BASE;
ring->irq_enable_mask =
GT_RENDER_USER_INTERRUPT << GEN8_VCS2_IRQ_SHIFT;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS2_IRQ_SHIFT;

ring->init = gen8_init_common_ring;
ring->get_seqno = gen8_get_seqno;
ring->set_seqno = gen8_set_seqno;
ring->emit_request = gen8_emit_request;
ring->emit_flush = gen8_emit_flush;
+ ring->irq_get = gen8_logical_ring_get_irq;
+ ring->irq_put = gen8_logical_ring_put_irq;

return logical_ring_init(dev, ring);
}
@@ -627,12 +677,16 @@ static int logical_blt_ring_init(struct drm_device *dev)
ring->mmio_base = BLT_RING_BASE;
ring->irq_enable_mask =
GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_BCS_IRQ_SHIFT;

ring->init = gen8_init_common_ring;
ring->get_seqno = gen8_get_seqno;
ring->set_seqno = gen8_set_seqno;
ring->emit_request = gen8_emit_request;
ring->emit_flush = gen8_emit_flush;
+ ring->irq_get = gen8_logical_ring_get_irq;
+ ring->irq_put = gen8_logical_ring_put_irq;

return logical_ring_init(dev, ring);
}
@@ -647,12 +701,16 @@ static int logical_vebox_ring_init(struct drm_device *dev)
ring->mmio_base = VEBOX_RING_BASE;
ring->irq_enable_mask =
GT_RENDER_USER_INTERRUPT << GEN8_VECS_IRQ_SHIFT;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT;

ring->init = gen8_init_common_ring;
ring->get_seqno = gen8_get_seqno;
ring->set_seqno = gen8_set_seqno;
ring->emit_request = gen8_emit_request;
ring->emit_flush = gen8_emit_flush;
+ ring->irq_get = gen8_logical_ring_get_irq;
+ ring->irq_put = gen8_logical_ring_put_irq;

return logical_ring_init(dev, ring);
}
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 6e22866..09102b2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -223,6 +223,7 @@ struct intel_engine_cs {
} semaphore;

/* Execlists */
+ u32 irq_keep_mask; /* bitmask for interrupts that should not be masked */
int (*emit_request)(struct intel_ringbuffer *ringbuf);
int (*emit_flush)(struct intel_ringbuffer *ringbuf,
u32 invalidate_domains,
--
1.7.9.5