drm/i915: Mark up protected uses of 'i915_request_completed'

When we know that we are inside the timeline mutex, or inside the
submission flow (under active.lock or the holder's rcu lock), we know
that the rq->hwsp is stable and we can use the simpler direct version.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210114135612.13210-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/i915_gem_context.c

@@ -408,7 +408,7 @@ __active_engine(struct i915_request *rq, struct intel_engine_cs **active)
 	}
 
 	if (i915_request_is_active(rq)) {
-		if (!i915_request_completed(rq))
+		if (!__i915_request_is_complete(rq))
 			*active = locked;
 		ret = true;
 	}

drivers/gpu/drm/i915/gt/intel_breadcrumbs.c

@@ -517,8 +517,8 @@ static void print_signals(struct intel_breadcrumbs *b, struct drm_printer *p)
 		list_for_each_entry_rcu(rq, &ce->signals, signal_link)
 			drm_printf(p, "\t[%llx:%llx%s] @ %dms\n",
 				   rq->fence.context, rq->fence.seqno,
-				   i915_request_completed(rq) ? "!" :
-				   i915_request_started(rq) ? "*" :
+				   __i915_request_is_complete(rq) ? "!" :
+				   __i915_request_has_started(rq) ? "*" :
 				   "",
 				   jiffies_to_msecs(jiffies - rq->emitted_jiffies));
 	}

drivers/gpu/drm/i915/gt/intel_engine_cs.c

@@ -1811,7 +1811,7 @@ intel_engine_find_active_request(struct intel_engine_cs *engine)
 		struct intel_timeline *tl = request->context->timeline;
 
 		list_for_each_entry_from_reverse(request, &tl->requests, link) {
-			if (i915_request_completed(request))
+			if (__i915_request_is_complete(request))
 				break;
 
 			active = request;
@@ -1822,10 +1822,10 @@ intel_engine_find_active_request(struct intel_engine_cs *engine)
 		return active;
 
 	list_for_each_entry(request, &engine->active.requests, sched.link) {
-		if (i915_request_completed(request))
+		if (__i915_request_is_complete(request))
 			continue;
 
-		if (!i915_request_started(request))
+		if (!__i915_request_has_started(request))
 			continue;
 
 		/* More than one preemptible request may match! */

drivers/gpu/drm/i915/gt/intel_execlists_submission.c

@@ -3291,7 +3291,7 @@ static void rcu_virtual_context_destroy(struct work_struct *wrk)
 
 		old = fetch_and_zero(&ve->request);
 		if (old) {
-			GEM_BUG_ON(!i915_request_completed(old));
+			GEM_BUG_ON(!__i915_request_is_complete(old));
 			__i915_request_submit(old);
 			i915_request_put(old);
 		}
@@ -3568,7 +3568,7 @@ static void virtual_submit_request(struct i915_request *rq)
 	}
 
 	if (ve->request) { /* background completion from preempt-to-busy */
-		GEM_BUG_ON(!i915_request_completed(ve->request));
+		GEM_BUG_ON(!__i915_request_is_complete(ve->request));
 		__i915_request_submit(ve->request);
 		i915_request_put(ve->request);
 	}

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -151,8 +151,7 @@ static void mark_innocent(struct i915_request *rq)
 void __i915_request_reset(struct i915_request *rq, bool guilty)
 {
 	RQ_TRACE(rq, "guilty? %s\n", yesno(guilty));
-
-	GEM_BUG_ON(i915_request_completed(rq));
+	GEM_BUG_ON(__i915_request_is_complete(rq));
 
 	rcu_read_lock(); /* protect the GEM context */
 	if (guilty) {

drivers/gpu/drm/i915/gt/intel_ring_submission.c

@@ -389,12 +389,14 @@ static void reset_rewind(struct intel_engine_cs *engine, bool stalled)
 
 	rq = NULL;
 	spin_lock_irqsave(&engine->active.lock, flags);
+	rcu_read_lock();
 	list_for_each_entry(pos, &engine->active.requests, sched.link) {
-		if (!i915_request_completed(pos)) {
+		if (!__i915_request_is_complete(pos)) {
 			rq = pos;
 			break;
 		}
 	}
+	rcu_read_unlock();
 
 	/*
 	 * The guilty request will get skipped on a hung engine.

drivers/gpu/drm/i915/gt/intel_timeline.c

@@ -582,11 +582,11 @@ int intel_timeline_read_hwsp(struct i915_request *from,
 
 	rcu_read_lock();
 	cl = rcu_dereference(from->hwsp_cacheline);
-	if (i915_request_completed(from)) /* confirm cacheline is valid */
+	if (i915_request_signaled(from)) /* confirm cacheline is valid */
 		goto unlock;
 	if (unlikely(!i915_active_acquire_if_busy(&cl->active)))
 		goto unlock; /* seqno wrapped and completed! */
-	if (unlikely(i915_request_completed(from)))
+	if (unlikely(__i915_request_is_complete(from)))
 		goto release;
 	rcu_read_unlock();
 

drivers/gpu/drm/i915/i915_request.c

@@ -276,7 +276,7 @@ static void remove_from_engine(struct i915_request *rq)
 
 bool i915_request_retire(struct i915_request *rq)
 {
-	if (!i915_request_completed(rq))
+	if (!__i915_request_is_complete(rq))
 		return false;
 
 	RQ_TRACE(rq, "\n");
@@ -342,8 +342,7 @@ void i915_request_retire_upto(struct i915_request *rq)
 	struct i915_request *tmp;
 
 	RQ_TRACE(rq, "\n");
-
-	GEM_BUG_ON(!i915_request_completed(rq));
+	GEM_BUG_ON(!__i915_request_is_complete(rq));
 
 	do {
 		tmp = list_first_entry(&tl->requests, typeof(*tmp), link);
@@ -552,7 +551,7 @@ bool __i915_request_submit(struct i915_request *request)
 	 * dropped upon retiring. (Otherwise if resubmit a *retired*
 	 * request, this would be a horrible use-after-free.)
 	 */
-	if (i915_request_completed(request))
+	if (__i915_request_is_complete(request))
 		goto xfer;
 
 	if (unlikely(intel_context_is_banned(request->context)))
@@ -652,7 +651,7 @@ void __i915_request_unsubmit(struct i915_request *request)
 		i915_request_cancel_breadcrumb(request);
 
 	/* We've already spun, don't charge on resubmitting. */
-	if (request->sched.semaphores && i915_request_started(request))
+	if (request->sched.semaphores && __i915_request_has_started(request))
 		request->sched.semaphores = 0;
 
 	/*
@@ -864,7 +863,7 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
 	RCU_INIT_POINTER(rq->timeline, tl);
 	RCU_INIT_POINTER(rq->hwsp_cacheline, tl->hwsp_cacheline);
 	rq->hwsp_seqno = tl->hwsp_seqno;
-	GEM_BUG_ON(i915_request_completed(rq));
+	GEM_BUG_ON(__i915_request_is_complete(rq));
 
 	rq->rcustate = get_state_synchronize_rcu(); /* acts as smp_mb() */
 
@@ -978,7 +977,7 @@ i915_request_await_start(struct i915_request *rq, struct i915_request *signal)
 		struct i915_request *prev;
 
 		/* Confirm signal has not been retired, the link is valid */
-		if (unlikely(i915_request_started(signal)))
+		if (unlikely(__i915_request_has_started(signal)))
 			break;
 
 		/* Is signal the earliest request on its timeline? */
@@ -1520,7 +1519,7 @@ __i915_request_add_to_timeline(struct i915_request *rq)
 	 */
 	prev = to_request(__i915_active_fence_set(&timeline->last_request,
 						  &rq->fence));
-	if (prev && !i915_request_completed(prev)) {
+	if (prev && !__i915_request_is_complete(prev)) {
 		/*
 		 * The requests are supposed to be kept in order. However,
 		 * we need to be wary in case the timeline->last_request
@@ -1897,10 +1896,10 @@ static char queue_status(const struct i915_request *rq)
 
 static const char *run_status(const struct i915_request *rq)
 {
-	if (i915_request_completed(rq))
+	if (__i915_request_is_complete(rq))
 		return "!";
 
-	if (i915_request_started(rq))
+	if (__i915_request_has_started(rq))
 		return "*";
 
 	if (!i915_sw_fence_signaled(&rq->semaphore))

drivers/gpu/drm/i915/i915_scheduler.c

@@ -520,7 +520,7 @@ void i915_request_show_with_schedule(struct drm_printer *m,
 		if (signaler->timeline == rq->timeline)
 			continue;
 
-		if (i915_request_completed(signaler))
+		if (__i915_request_is_complete(signaler))
 			continue;
 
 		i915_request_show(m, signaler, prefix, indent + 2);