From 338aade97c061da0403dbb00128d938782f30dbd Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 15 Aug 2019 21:57:07 +0100 Subject: [PATCH] drm/i915/gt: Convert timeline tracking to spinlock Convert the active_list manipulation of timelines to use spinlocks so that we can perform the updates from underneath a quick interrupt callback, if need be. Signed-off-by: Chris Wilson Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20190815205709.24285-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_gt_types.h | 2 +- drivers/gpu/drm/i915/gt/intel_reset.c | 10 ++++++++-- drivers/gpu/drm/i915/gt/intel_timeline.c | 12 +++++------- drivers/gpu/drm/i915/i915_gem.c | 14 +++++++------- 4 files changed, 21 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt_types.h b/drivers/gpu/drm/i915/gt/intel_gt_types.h index adab4d2c29ac..143b2d78c2cc 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_types.h +++ b/drivers/gpu/drm/i915/gt/intel_gt_types.h @@ -40,7 +40,7 @@ struct intel_gt { struct intel_uc uc; struct intel_gt_timelines { - struct mutex mutex; /* protects list */ + spinlock_t lock; /* protects active_list */ struct list_head active_list; /* Pack multiple timelines' seqnos into the same page */ diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c index ec85740de942..077716442c90 100644 --- a/drivers/gpu/drm/i915/gt/intel_reset.c +++ b/drivers/gpu/drm/i915/gt/intel_reset.c @@ -811,7 +811,7 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt) * * No more can be submitted until we reset the wedged bit. */ - mutex_lock(&timelines->mutex); + spin_lock(&timelines->lock); list_for_each_entry(tl, &timelines->active_list, link) { struct i915_request *rq; @@ -819,6 +819,8 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt) if (!rq) continue; + spin_unlock(&timelines->lock); + /* * All internal dependencies (i915_requests) will have * been flushed by the set-wedge, but we may be stuck waiting @@ -828,8 +830,12 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt) */ dma_fence_default_wait(&rq->fence, false, MAX_SCHEDULE_TIMEOUT); i915_request_put(rq); + + /* Restart iteration after droping lock */ + spin_lock(&timelines->lock); + tl = list_entry(&timelines->active_list, typeof(*tl), link); } - mutex_unlock(&timelines->mutex); + spin_unlock(&timelines->lock); intel_gt_sanitize(gt, false); diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c index 4af0b9801d91..355dfc52c804 100644 --- a/drivers/gpu/drm/i915/gt/intel_timeline.c +++ b/drivers/gpu/drm/i915/gt/intel_timeline.c @@ -266,7 +266,7 @@ static void timelines_init(struct intel_gt *gt) { struct intel_gt_timelines *timelines = >->timelines; - mutex_init(&timelines->mutex); + spin_lock_init(&timelines->lock); INIT_LIST_HEAD(&timelines->active_list); spin_lock_init(&timelines->hwsp_lock); @@ -345,9 +345,9 @@ void intel_timeline_enter(struct intel_timeline *tl) return; GEM_BUG_ON(!tl->active_count); /* overflow? */ - mutex_lock(&timelines->mutex); + spin_lock(&timelines->lock); list_add(&tl->link, &timelines->active_list); - mutex_unlock(&timelines->mutex); + spin_unlock(&timelines->lock); } void intel_timeline_exit(struct intel_timeline *tl) @@ -358,9 +358,9 @@ void intel_timeline_exit(struct intel_timeline *tl) if (--tl->active_count) return; - mutex_lock(&timelines->mutex); + spin_lock(&timelines->lock); list_del(&tl->link); - mutex_unlock(&timelines->mutex); + spin_unlock(&timelines->lock); /* * Since this timeline is idle, all bariers upon which we were waiting @@ -548,8 +548,6 @@ static void timelines_fini(struct intel_gt *gt) GEM_BUG_ON(!list_empty(&timelines->active_list)); GEM_BUG_ON(!list_empty(&timelines->hwsp_free_list)); - - mutex_destroy(&timelines->mutex); } void intel_timelines_fini(struct drm_i915_private *i915) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 4752a3bf9636..29be25a7aade 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -897,18 +897,18 @@ static long wait_for_timelines(struct drm_i915_private *i915, unsigned int flags, long timeout) { - struct intel_gt_timelines *gt = &i915->gt.timelines; + struct intel_gt_timelines *timelines = &i915->gt.timelines; struct intel_timeline *tl; - mutex_lock(>->mutex); - list_for_each_entry(tl, >->active_list, link) { + spin_lock(&timelines->lock); + list_for_each_entry(tl, &timelines->active_list, link) { struct i915_request *rq; rq = i915_active_request_get_unlocked(&tl->last_request); if (!rq) continue; - mutex_unlock(>->mutex); + spin_unlock(&timelines->lock); /* * "Race-to-idle". @@ -928,10 +928,10 @@ wait_for_timelines(struct drm_i915_private *i915, return timeout; /* restart after reacquiring the lock */ - mutex_lock(>->mutex); - tl = list_entry(>->active_list, typeof(*tl), link); + spin_lock(&timelines->lock); + tl = list_entry(&timelines->active_list, typeof(*tl), link); } - mutex_unlock(>->mutex); + spin_unlock(&timelines->lock); return timeout; } -- 2.45.2