From 1329115c6c4370e93813b44084ee06610c3279bd Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 16 May 2018 19:33:52 +0100 Subject: drm/i915: Split execlists/guc reset preparations 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 Cc: Michał Winiarski CC: Michel Thierry Cc: Jeff McGee Reviewed-by: Jeff McGee Link: https://patchwork.freedesktop.org/patch/msgid/20180516183355.10553-5-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_guc_submission.c | 34 +++++++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_lrc.c | 12 ++-------- 2 files changed, 36 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c index ca38ac9ff4fa..637e852888ec 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. + */ + __tasklet_disable_sync_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 +1306,9 @@ int intel_guc_submission_enable(struct intel_guc *guc) &engine->execlists; execlists->tasklet.func = guc_submission_tasklet; + + 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 a8f2704e377c..acbdf36d1c28 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1845,16 +1845,6 @@ execlists_reset_prepare(struct intel_engine_cs *engine) */ __tasklet_disable_sync_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); } @@ -2256,6 +2246,8 @@ static void execlists_set_default_submission(struct intel_engine_cs *engine) engine->schedule = execlists_schedule; engine->execlists.tasklet.func = execlists_submission_tasklet; + engine->reset.prepare = execlists_reset_prepare; + engine->park = NULL; engine->unpark = NULL; -- cgit v1.2.3-55-g7522