From 9eb143bbec7dfdfce8aa7f6a3b0f40af4e95e7b7 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 23 Feb 2017 07:44:16 +0000 Subject: drm/i915: Allow a request to be cancelled If we preempt a request and remove it from the execution queue, we need to undo its global seqno and restart any waiters. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/20170223074422.4125-11-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_breadcrumbs.c | 71 +++++++++++++++++++++++++------- 1 file changed, 56 insertions(+), 15 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_breadcrumbs.c') diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c index a35d59d00bfb..dd39e4f7a560 100644 --- a/drivers/gpu/drm/i915/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c @@ -356,22 +356,15 @@ static inline int wakeup_priority(struct intel_breadcrumbs *b, return tsk->prio; } -void intel_engine_remove_wait(struct intel_engine_cs *engine, - struct intel_wait *wait) +static void __intel_engine_remove_wait(struct intel_engine_cs *engine, + struct intel_wait *wait) { struct intel_breadcrumbs *b = &engine->breadcrumbs; - /* Quick check to see if this waiter was already decoupled from - * the tree by the bottom-half to avoid contention on the spinlock - * by the herd. - */ - if (RB_EMPTY_NODE(&wait->node)) - return; - - spin_lock_irq(&b->lock); + assert_spin_locked(&b->lock); if (RB_EMPTY_NODE(&wait->node)) - goto out_unlock; + goto out; if (b->first_wait == wait) { const int priority = wakeup_priority(b, wait->tsk); @@ -436,11 +429,27 @@ void intel_engine_remove_wait(struct intel_engine_cs *engine, GEM_BUG_ON(RB_EMPTY_NODE(&wait->node)); rb_erase(&wait->node, &b->waiters); -out_unlock: +out: GEM_BUG_ON(b->first_wait == wait); GEM_BUG_ON(rb_first(&b->waiters) != (b->first_wait ? &b->first_wait->node : NULL)); GEM_BUG_ON(!rcu_access_pointer(b->irq_seqno_bh) ^ RB_EMPTY_ROOT(&b->waiters)); +} + +void intel_engine_remove_wait(struct intel_engine_cs *engine, + struct intel_wait *wait) +{ + struct intel_breadcrumbs *b = &engine->breadcrumbs; + + /* Quick check to see if this waiter was already decoupled from + * the tree by the bottom-half to avoid contention on the spinlock + * by the herd. + */ + if (RB_EMPTY_NODE(&wait->node)) + return; + + spin_lock_irq(&b->lock); + __intel_engine_remove_wait(engine, wait); spin_unlock_irq(&b->lock); } @@ -506,11 +515,13 @@ static int intel_breadcrumbs_signaler(void *arg) dma_fence_signal(&request->fence); local_bh_enable(); /* kick start the tasklets */ + spin_lock_irq(&b->lock); + /* Wake up all other completed waiters and select the * next bottom-half for the next user interrupt. */ - intel_engine_remove_wait(engine, - &request->signaling.wait); + __intel_engine_remove_wait(engine, + &request->signaling.wait); /* Find the next oldest signal. Note that as we have * not been holding the lock, another client may @@ -518,7 +529,6 @@ static int intel_breadcrumbs_signaler(void *arg) * we just completed - so double check we are still * the oldest before picking the next one. */ - spin_lock_irq(&b->lock); if (request == rcu_access_pointer(b->first_signal)) { struct rb_node *rb = rb_next(&request->signaling.node); @@ -526,6 +536,8 @@ static int intel_breadcrumbs_signaler(void *arg) rb ? to_signaler(rb) : NULL); } rb_erase(&request->signaling.node, &b->signals); + RB_CLEAR_NODE(&request->signaling.node); + spin_unlock_irq(&b->lock); i915_gem_request_put(request); @@ -613,6 +625,35 @@ void intel_engine_enable_signaling(struct drm_i915_gem_request *request) wake_up_process(b->signaler); } +void intel_engine_cancel_signaling(struct drm_i915_gem_request *request) +{ + struct intel_engine_cs *engine = request->engine; + struct intel_breadcrumbs *b = &engine->breadcrumbs; + + assert_spin_locked(&request->lock); + GEM_BUG_ON(!request->signaling.wait.seqno); + + spin_lock(&b->lock); + + if (!RB_EMPTY_NODE(&request->signaling.node)) { + if (request == rcu_access_pointer(b->first_signal)) { + struct rb_node *rb = + rb_next(&request->signaling.node); + rcu_assign_pointer(b->first_signal, + rb ? to_signaler(rb) : NULL); + } + rb_erase(&request->signaling.node, &b->signals); + RB_CLEAR_NODE(&request->signaling.node); + i915_gem_request_put(request); + } + + __intel_engine_remove_wait(engine, &request->signaling.wait); + + spin_unlock(&b->lock); + + request->signaling.wait.seqno = 0; +} + int intel_engine_init_breadcrumbs(struct intel_engine_cs *engine) { struct intel_breadcrumbs *b = &engine->breadcrumbs; -- cgit