[PATCH 10/17] drm/i915: Update reset path to fix incomplete requests
Chris Wilson
chris at chris-wilson.co.uk
Fri Aug 26 12:34:57 UTC 2016
Update reset path in preparation for engine reset which requires
identification of incomplete requests and associated context and fixing
their state so that engine can resume correctly after reset.
The request that caused the hang will be skipped and head is reset to the
start of breadcrumb. This allows us to resume from where we left-off.
Since this request didn't complete normally we also need to cleanup elsp
queue manually. This is vital if we employ nonblocking request
submission where we may have a web of dependencies upon the hung request
and so advancing the seqno manually is no longer trivial.
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
Cc: Arun Siluvery <arun.siluvery at linux.intel.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_drv.c | 4 +-
drivers/gpu/drm/i915/i915_drv.h | 2 +-
drivers/gpu/drm/i915/i915_gem.c | 106 +++++++++++++++++---------------
drivers/gpu/drm/i915/i915_gem_context.c | 16 -----
drivers/gpu/drm/i915/intel_lrc.c | 34 +++++++++-
drivers/gpu/drm/i915/intel_ringbuffer.c | 33 ++++++----
drivers/gpu/drm/i915/intel_ringbuffer.h | 2 +
7 files changed, 116 insertions(+), 81 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index ea7d3e87815c..4a570ee80b26 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1602,7 +1602,7 @@ static int i915_drm_resume(struct drm_device *dev)
mutex_lock(&dev->struct_mutex);
if (i915_gem_init_hw(dev)) {
DRM_ERROR("failed to re-initialize GPU, declaring wedged!\n");
- set_bit(I915_WEDGED, &dev_priv->gpu_error.flags);
+ i915_gem_set_wedged(dev_priv);
}
mutex_unlock(&dev->struct_mutex);
@@ -1824,7 +1824,7 @@ int i915_reset(struct drm_i915_private *dev_priv)
return 0;
error:
- set_bit(I915_WEDGED, &error->flags);
+ i915_gem_set_wedged(dev_priv);
return ret;
}
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3ec437bc7a4b..7e94c0dee95c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3254,6 +3254,7 @@ static inline u32 i915_reset_count(struct i915_gpu_error *error)
}
void i915_gem_reset(struct drm_device *dev);
+void i915_gem_set_wedged(struct drm_i915_private *dev_priv);
bool i915_gem_clflush_object(struct drm_i915_gem_object *obj, bool force);
int __must_check i915_gem_init(struct drm_device *dev);
int __must_check i915_gem_init_hw(struct drm_device *dev);
@@ -3382,7 +3383,6 @@ void i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj);
int __must_check i915_gem_context_init(struct drm_device *dev);
void i915_gem_context_lost(struct drm_i915_private *dev_priv);
void i915_gem_context_fini(struct drm_device *dev);
-void i915_gem_context_reset(struct drm_device *dev);
int i915_gem_context_open(struct drm_device *dev, struct drm_file *file);
void i915_gem_context_close(struct drm_device *dev, struct drm_file *file);
int i915_switch_context(struct drm_i915_gem_request *req);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index cc565f785888..0108950e14f1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2554,30 +2554,73 @@ i915_gem_find_active_request(struct intel_engine_cs *engine)
return NULL;
}
-static void i915_gem_reset_engine_status(struct intel_engine_cs *engine)
+static void i915_gem_reset_engine(struct intel_engine_cs *engine)
{
struct drm_i915_gem_request *request;
+ struct i915_gem_context *incomplete_ctx;
bool ring_hung;
+ /* Ensure irq handler finishes, and not run again. */
+ tasklet_kill(&engine->irq_tasklet);
+
request = i915_gem_find_active_request(engine);
- if (request == NULL)
+ if (!request)
return;
ring_hung = engine->hangcheck.score >= HANGCHECK_SCORE_RING_HUNG;
-
i915_set_reset_status(request->ctx, ring_hung);
- list_for_each_entry_continue(request, &engine->request_list, link)
+
+ /* Setup the CS to resume from the breadcrumb of the hung request */
+ engine->reset_hw(engine, request);
+
+ /* Users of the default context do not rely on logical state
+ * preserved between batches. They have to emit full state on
+ * every batch and so it is safe to execute queued requests following
+ * the hang.
+ *
+ * Other contexts preserve state, now corrupt. We want to skip all
+ * queued requests that reference the corrupt context.
+ */
+ incomplete_ctx = request->ctx;
+ if (i915_gem_context_is_default(incomplete_ctx))
+ incomplete_ctx = NULL;
+
+ list_for_each_entry_continue(request, &engine->request_list, link) {
+ void *vaddr = request->ring->vaddr;
+ u32 head;
+
+ if (request->ctx != incomplete_ctx)
+ continue;
+
+ /* As this request likely depends on state from the lost
+ * context, clear out all the user operations leaving the
+ * breadcrumb at the end (so we get the fence notifications).
+ */
+ head = request->head;
+ if (request->postfix < head) {
+ memset(vaddr + head, 0, request->ring->size - head);
+ head = 0;
+ }
+ memset(vaddr + head, 0, request->postfix - head);
+
i915_set_reset_status(request->ctx, false);
+ }
}
-static void i915_gem_reset_engine_cleanup(struct intel_engine_cs *engine)
+void i915_gem_reset(struct drm_device *dev)
{
- struct drm_i915_gem_request *request;
- struct intel_ring *ring;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ struct intel_engine_cs *engine;
- /* Ensure irq handler finishes, and not run again. */
- tasklet_kill(&engine->irq_tasklet);
+ for_each_engine(engine, dev_priv)
+ i915_gem_reset_engine(engine);
+
+ i915_gem_context_lost(dev_priv);
+ i915_gem_restore_fences(dev);
+}
+static void i915_gem_cleanup_engine(struct intel_engine_cs *engine)
+{
/* Mark all pending requests as complete so that any concurrent
* (lockless) lookup doesn't try and wait upon the request as we
* reset it.
@@ -2599,54 +2642,19 @@ static void i915_gem_reset_engine_cleanup(struct intel_engine_cs *engine)
spin_unlock(&engine->execlist_lock);
}
- /*
- * We must free the requests after all the corresponding objects have
- * been moved off active lists. Which is the same order as the normal
- * retire_requests function does. This is important if object hold
- * implicit references on things like e.g. ppgtt address spaces through
- * the request.
- */
- request = i915_gem_active_raw(&engine->last_request,
- &engine->i915->drm.struct_mutex);
- if (request)
- i915_gem_request_retire_upto(request);
- GEM_BUG_ON(intel_engine_is_active(engine));
-
- /* Having flushed all requests from all queues, we know that all
- * ringbuffers must now be empty. However, since we do not reclaim
- * all space when retiring the request (to prevent HEADs colliding
- * with rapid ringbuffer wraparound) the amount of available space
- * upon reset is less than when we start. Do one more pass over
- * all the ringbuffers to reset last_retired_head.
- */
- list_for_each_entry(ring, &engine->buffers, link) {
- ring->last_retired_head = ring->tail;
- intel_ring_update_space(ring);
- }
-
engine->i915->gt.active_engines &= ~intel_engine_flag(engine);
}
-void i915_gem_reset(struct drm_device *dev)
+void i915_gem_set_wedged(struct drm_i915_private *dev_priv)
{
- struct drm_i915_private *dev_priv = to_i915(dev);
struct intel_engine_cs *engine;
- /*
- * Before we free the objects from the requests, we need to inspect
- * them for finding the guilty party. As the requests only borrow
- * their reference to the objects, the inspection must be done first.
- */
- for_each_engine(engine, dev_priv)
- i915_gem_reset_engine_status(engine);
+ lockdep_assert_held(&dev_priv->drm.struct_mutex);
+ set_bit(I915_WEDGED, &dev_priv->gpu_error.flags);
for_each_engine(engine, dev_priv)
- i915_gem_reset_engine_cleanup(engine);
+ i915_gem_cleanup_engine(engine);
mod_delayed_work(dev_priv->wq, &dev_priv->gt.idle_work, 0);
-
- i915_gem_context_reset(dev);
-
- i915_gem_restore_fences(dev);
}
static void
@@ -4526,7 +4534,7 @@ int i915_gem_init(struct drm_device *dev)
* for all other failure, such as an allocation failure, bail.
*/
DRM_ERROR("Failed to initialize GPU, declaring it wedged\n");
- set_bit(I915_WEDGED, &dev_priv->gpu_error.flags);
+ i915_gem_set_wedged(dev_priv);
ret = 0;
}
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 35950ee46a1d..df10f4e95736 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -420,22 +420,6 @@ static void i915_gem_context_unpin(struct i915_gem_context *ctx,
}
}
-void i915_gem_context_reset(struct drm_device *dev)
-{
- struct drm_i915_private *dev_priv = to_i915(dev);
-
- lockdep_assert_held(&dev->struct_mutex);
-
- if (i915.enable_execlists) {
- struct i915_gem_context *ctx;
-
- list_for_each_entry(ctx, &dev_priv->context_list, link)
- intel_lr_context_reset(dev_priv, ctx);
- }
-
- i915_gem_context_lost(dev_priv);
-}
-
int i915_gem_context_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 32a12a66e06d..88fba2253802 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1219,6 +1219,7 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
{
struct drm_i915_private *dev_priv = engine->i915;
+ intel_mocs_init_engine(engine);
lrc_init_hws(engine);
I915_WRITE_IMR(engine,
@@ -1238,7 +1239,10 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
intel_engine_init_hangcheck(engine);
- return intel_mocs_init_engine(engine);
+ if (!execlists_elsp_idle(engine))
+ execlists_submit_ports(engine);
+
+ return 0;
}
static int gen8_init_render_ring(struct intel_engine_cs *engine)
@@ -1274,6 +1278,33 @@ static int gen9_init_render_ring(struct intel_engine_cs *engine)
return init_workarounds_ring(engine);
}
+static void reset_common_ring(struct intel_engine_cs *engine,
+ struct drm_i915_gem_request *request)
+{
+ struct drm_i915_private *dev_priv = engine->i915;
+ struct execlist_port *port = engine->execlist_port;
+ struct intel_context *ce = &request->ctx->engine[engine->id];
+
+ /* Move the RING_HEAD onto the breadcrumb, past the hanging batch */
+ ce->lrc_reg_state[CTX_RING_HEAD+1] = request->postfix;
+ request->ring->head = request->postfix;
+ request->ring->last_retired_head = -1;
+ intel_ring_update_space(request->ring);
+
+ /* Catch up with any missed context-switch interrupts */
+ I915_WRITE(RING_CONTEXT_STATUS_PTR(engine), _MASKED_FIELD(0xffff, 0));
+ if (request->ctx != port[0].request->ctx) {
+ i915_gem_request_put(port[0].request);
+ port[0] = port[1];
+ memset(&port[1], 0, sizeof(port[1]));
+ }
+
+ /* CS is stopped, and we will resubmit both ports on resume */
+ GEM_BUG_ON(request->ctx != port[0].request->ctx);
+ port[0].count = 0;
+ port[1].count = 0;
+}
+
static int intel_logical_ring_emit_pdps(struct drm_i915_gem_request *req)
{
struct i915_hw_ppgtt *ppgtt = req->ctx->ppgtt;
@@ -1636,6 +1667,7 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
{
/* Default vfuncs which can be overriden by each engine. */
engine->init_hw = gen8_init_common_ring;
+ engine->reset_hw = reset_common_ring;
engine->emit_flush = gen8_emit_flush;
engine->emit_request = gen8_emit_request;
engine->submit_request = execlists_submit_request;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index fa4f3731be29..c516c4312301 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -577,34 +577,33 @@ static int init_ring_common(struct intel_engine_cs *engine)
if (I915_READ_HEAD(engine))
DRM_DEBUG("%s initialization failed [head=%08x], fudging\n",
engine->name, I915_READ_HEAD(engine));
- I915_WRITE_HEAD(engine, 0);
- (void)I915_READ_HEAD(engine);
+
+ intel_ring_update_space(ring);
+ I915_WRITE_HEAD(engine, ring->head);
+ I915_WRITE_TAIL(engine, ring->tail);
+ (void)I915_READ_TAIL(engine);
I915_WRITE_CTL(engine,
((ring->size - PAGE_SIZE) & RING_NR_PAGES)
| RING_VALID);
/* If the head is still not zero, the ring is dead */
- if (wait_for((I915_READ_CTL(engine) & RING_VALID) != 0 &&
- I915_READ_START(engine) == i915_ggtt_offset(ring->vma) &&
- (I915_READ_HEAD(engine) & HEAD_ADDR) == 0, 50)) {
+ if (intel_wait_for_register_fw(dev_priv, RING_CTL(engine->mmio_base),
+ RING_VALID, RING_VALID,
+ 50)) {
DRM_ERROR("%s initialization failed "
- "ctl %08x (valid? %d) head %08x tail %08x start %08x [expected %08x]\n",
+ "ctl %08x (valid? %d) head %08x [%08x] tail %08x [%08x] start %08x [expected %08x]\n",
engine->name,
I915_READ_CTL(engine),
I915_READ_CTL(engine) & RING_VALID,
- I915_READ_HEAD(engine), I915_READ_TAIL(engine),
+ I915_READ_HEAD(engine), ring->head,
+ I915_READ_TAIL(engine), ring->tail,
I915_READ_START(engine),
i915_ggtt_offset(ring->vma));
ret = -EIO;
goto out;
}
- ring->last_retired_head = -1;
- ring->head = I915_READ_HEAD(engine);
- ring->tail = I915_READ_TAIL(engine) & TAIL_ADDR;
- intel_ring_update_space(ring);
-
intel_engine_init_hangcheck(engine);
out:
@@ -613,6 +612,15 @@ out:
return ret;
}
+static void reset_ring_common(struct intel_engine_cs *engine,
+ struct drm_i915_gem_request *request)
+{
+ struct intel_ring *ring = request->ring;
+
+ ring->head = request->postfix;
+ ring->last_retired_head = -1;
+}
+
static int intel_ring_workarounds_emit(struct drm_i915_gem_request *req)
{
struct intel_ring *ring = req->ring;
@@ -2654,6 +2662,7 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
intel_ring_init_semaphores(dev_priv, engine);
engine->init_hw = init_ring_common;
+ engine->reset_hw = reset_ring_common;
engine->emit_request = i9xx_emit_request;
if (i915.semaphores)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 2181d0a41a96..c037577585bf 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -211,6 +211,8 @@ struct intel_engine_cs {
void (*irq_disable)(struct intel_engine_cs *engine);
int (*init_hw)(struct intel_engine_cs *engine);
+ void (*reset_hw)(struct intel_engine_cs *engine,
+ struct drm_i915_gem_request *req);
int (*init_context)(struct drm_i915_gem_request *req);
--
2.9.3
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