In the next patch, we will make the execlists reset prepare callback
take into account preemption by flushing the context-switch handler.
This is not applicable to the GuC submission backend, so split the two
into their own backend callbacks.
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiar...@intel.com>
CC: Michel Thierry <michel.thie...@intel.com>
Cc: Jeff McGee <jeff.mc...@intel.com>
Reviewed-by: Jeff McGee <jeff.mc...@intel.com>
---
drivers/gpu/drm/i915/intel_guc_submission.c | 32 +++++++++++++++++++++
drivers/gpu/drm/i915/intel_lrc.c | 12 ++------
2 files changed, 34 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c
b/drivers/gpu/drm/i915/intel_guc_submission.c
index 89b9863091df..a89b3982b302 100644
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -815,6 +815,37 @@ static void guc_submission_tasklet(unsigned long data)
guc_dequeue(engine);
}
+static struct i915_request *
+guc_reset_prepare(struct intel_engine_cs *engine)
+{
+ struct intel_engine_execlists * const execlists = &engine->execlists;
+
+ GEM_TRACE("%s\n", engine->name);
+
+ /*
+ * Prevent request submission to the hardware until we have
+ * completed the reset in i915_gem_reset_finish(). If a request
+ * is completed by one engine, it may then queue a request
+ * to a second via its execlists->tasklet *just* as we are
+ * calling engine->init_hw() and also writing the ELSP.
+ * Turning off the execlists->tasklet until the reset is over
+ * prevents the race.
+ */
+ i915_tasklet_disable_once(&execlists->tasklet);
+
+ /*
+ * We're using worker to queue preemption requests from the tasklet in
+ * GuC submission mode.
+ * Even though tasklet was disabled, we may still have a worker queued.
+ * Let's make sure that all workers scheduled before disabling the
+ * tasklet are completed before continuing with the reset.
+ */
+ if (engine->i915->guc.preempt_wq)
+ flush_workqueue(engine->i915->guc.preempt_wq);
+
+ return i915_gem_find_active_request(engine);
+}
+
/*
* Everything below here is concerned with setup & teardown, and is
* therefore not part of the somewhat time-critical batch-submission
@@ -1275,6 +1306,7 @@ int intel_guc_submission_enable(struct intel_guc *guc)
guc_submission_tasklet,
(unsigned long)engine);
+ engine->reset.prepare = guc_reset_prepare;
engine->park = guc_submission_park;
engine->unpark = guc_submission_unpark;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 39e546858667..dfee673366e5 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1844,16 +1844,6 @@ execlists_reset_prepare(struct intel_engine_cs *engine)
*/
i915_tasklet_disable_once(&execlists->tasklet);
- /*
- * We're using worker to queue preemption requests from the tasklet in
- * GuC submission mode.
- * Even though tasklet was disabled, we may still have a worker queued.
- * Let's make sure that all workers scheduled before disabling the
- * tasklet are completed before continuing with the reset.
- */
- if (engine->i915->guc.preempt_wq)
- flush_workqueue(engine->i915->guc.preempt_wq);
-
return i915_gem_find_active_request(engine);
}
@@ -2260,6 +2250,8 @@ static void execlists_set_default_submission(struct
intel_engine_cs *engine)
execlists_submission_tasklet,
(unsigned long)engine);
+ engine->reset.prepare = execlists_reset_prepare;
+
engine->park = NULL;
engine->unpark = NULL;
--
2.17.0
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