[PATCH 41/49] drm/i915/bdw: LR context switch interrupts

oscar.mateo
2014-03-27T17:12:49Z

From: Thomas Daniel <thomas.daniel@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@intel.com>
Acked-by: Oscar Mateo <oscar.mateo@intel.com>
---
drivers/gpu/drm/i915/i915_irq.c | 28 ++++++++++++++++++++--------
drivers/gpu/drm/i915/i915_reg.h | 2 ++
drivers/gpu/drm/i915/intel_ringbuffer.c | 33 +++++++++++++++++++--------------
drivers/gpu/drm/i915/intel_ringbuffer.h | 1 +
4 files changed, 42 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 1ba8bb3..56657b5 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1334,7 +1334,7 @@ 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;

@@ -1348,6 +1348,8 @@ 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");
@@ -1360,6 +1362,8 @@ 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");
I915_WRITE(GEN8_GT_IIR(1), tmp);
} else
DRM_ERROR("The master control interrupt lied (GT1)!\n");
@@ -1369,9 +1373,11 @@ 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");
@@ -3244,12 +3250,17 @@ 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++) {
@@ -3258,9 +3269,10 @@ static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
DRM_ERROR("Interrupt (%d) should have been masked in pre-install 0x%08x\n",
i, tmp);
I915_WRITE(GEN8_GT_IMR(i), ~gt_interrupts[i]);
+ POSTING_READ(GEN8_GT_IMR(i));
I915_WRITE(GEN8_GT_IER(i), gt_interrupts[i]);
+ POSTING_READ(GEN8_GT_IER(i));
}
- POSTING_READ(GEN8_GT_IER(0));
}

static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index adcb9c7..117825e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -709,6 +709,7 @@ enum punit_power_well {
#define RING_ACTHD(base) ((base)+0x74)
#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
@@ -4100,6 +4101,7 @@ 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 fba9b05..230740e 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -536,6 +536,8 @@ out:

static int init_ring_common_lrc(struct intel_engine *ring)
{
+ struct drm_device *dev = ring->dev;
+ drm_i915_private_t *dev_priv = dev->dev_private;
struct intel_ringbuffer *ringbuf = &ring->default_ringbuf;

ringbuf->head = 0;
@@ -543,6 +545,9 @@ static int init_ring_common_lrc(struct intel_engine *ring)
ringbuf->space = ringbuf->size;
ringbuf->last_retired_head = -1;

+ I915_WRITE_IMR(ring, ~(ring->irq_enable_mask | ring->irq_keep_mask));
+ I915_WRITE(RING_HWSTAM(ring->mmio_base), ~(ring->irq_enable_mask | ring->irq_keep_mask));
+
return 0;
}

@@ -1189,13 +1194,7 @@ 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);
@@ -1212,12 +1211,7 @@ 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);
@@ -2032,16 +2026,21 @@ int intel_init_render_ring(struct drm_device *dev)
if (dev_priv->lrc_enabled) {
ring->write_tail = gen8_write_tail_lrc;
ring->init = init_render_ring_lrc;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT;
}
ring->add_request = gen8_add_request;
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->sync_to = gen6_ring_sync;
@@ -2202,6 +2201,8 @@ int intel_init_bsd_ring(struct drm_device *dev)
if (dev_priv->lrc_enabled) {
ring->write_tail = gen8_write_tail_lrc;
ring->init = init_ring_common_lrc;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS1_IRQ_SHIFT;
}
ring->flush = gen8_ring_flush;
ring->add_request = gen8_add_request;
@@ -2262,6 +2263,8 @@ int intel_init_blt_ring(struct drm_device *dev)
if (dev_priv->lrc_enabled) {
ring->write_tail = gen8_write_tail_lrc;
ring->init = init_ring_common_lrc;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_BCS_IRQ_SHIFT;
}
ring->flush = gen8_ring_flush;
ring->add_request = gen8_add_request;
@@ -2304,6 +2307,8 @@ int intel_init_vebox_ring(struct drm_device *dev)
if (dev_priv->lrc_enabled) {
ring->write_tail = gen8_write_tail_lrc;
ring->init = init_ring_common_lrc;
+ ring->irq_keep_mask =
+ GEN8_GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT;
}
ring->flush = gen8_ring_flush;
ring->add_request = gen8_add_request;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 3b0f28b..9fbb2d5 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -93,6 +93,7 @@ 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;
u32 sync_seqno[I915_NUM_RINGS-1];
bool __must_check (*irq_get)(struct intel_engine *ring);
--
1.9.0