drm/i915: Split i915_gem_timeline into individual timelines

We need to move to a more flexible timeline that doesn't assume one
fence context per engine, and so allow for a single timeline to be used
across a combination of engines. This means that preallocating a fence
context per engine is now a hindrance, and so we want to introduce the
singular timeline. From the code perspective, this has the notable
advantage of clearing up a lot of mirky semantics and some clumsy
pointer chasing.

By splitting the timeline up into a single entity rather than an array
of per-engine timelines, we can realise the goal of the previous patch
of tracking the timeline alongside the ring.

v2: Tweak wait_for_idle to stop the compiling thinking that ret may be
uninitialised.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180502163839.3248-2-chris@chris-wilson.co.uk

6 files changed, 72 insertions, 149 deletions

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
index 24ac648dc83a..7ecaed50d0b9 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
@@ -355,18 +355,6 @@ static int igt_ctx_exec(void *arg)
 
 		if (first_shared_gtt) {
 			ctx = __create_hw_context(i915, file->driver_priv);
-			if (!IS_ERR(ctx) && HAS_EXECLISTS(i915)) {
-				struct i915_gem_timeline *timeline;
-
-				timeline = i915_gem_timeline_create(i915, ctx->name);
-				if (IS_ERR(timeline)) {
-					__destroy_hw_context(ctx, file->driver_priv);
-					ctx = ERR_CAST(timeline);
-				} else {
-					ctx->timeline = timeline;
-				}
-			}
-
 			first_shared_gtt = false;
 		} else {
 			ctx = i915_gem_create_context(i915, file->driver_priv);
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_timeline.c b/drivers/gpu/drm/i915/selftests/i915_timeline.c
index 3000e6a7d82d..19f1c6a5c8fb 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_timeline.c
+++ b/drivers/gpu/drm/i915/selftests/i915_timeline.c
@@ -1,25 +1,7 @@
 /*
- * Copyright © 2017 Intel Corporation
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
+ * SPDX-License-Identifier: MIT
  *
+ * Copyright © 2017-2018 Intel Corporation
  */
 
 #include "../i915_selftest.h"
@@ -35,21 +17,21 @@ struct __igt_sync {
 	bool set;
 };
 
-static int __igt_sync(struct intel_timeline *tl,
+static int __igt_sync(struct i915_timeline *tl,
 		      u64 ctx,
 		      const struct __igt_sync *p,
 		      const char *name)
 {
 	int ret;
 
-	if (__intel_timeline_sync_is_later(tl, ctx, p->seqno) != p->expected) {
+	if (__i915_timeline_sync_is_later(tl, ctx, p->seqno) != p->expected) {
 		pr_err("%s: %s(ctx=%llu, seqno=%u) expected passed %s but failed\n",
 		       name, p->name, ctx, p->seqno, yesno(p->expected));
 		return -EINVAL;
 	}
 
 	if (p->set) {
-		ret = __intel_timeline_sync_set(tl, ctx, p->seqno);
+		ret = __i915_timeline_sync_set(tl, ctx, p->seqno);
 		if (ret)
 			return ret;
 	}
@@ -77,37 +59,31 @@ static int igt_sync(void *arg)
 		{ "unwrap", UINT_MAX, true, false },
 		{},
 	}, *p;
-	struct intel_timeline *tl;
+	struct i915_timeline tl;
 	int order, offset;
 	int ret = -ENODEV;
 
-	tl = mock_timeline(0);
-	if (!tl)
-		return -ENOMEM;
-
+	mock_timeline_init(&tl, 0);
 	for (p = pass; p->name; p++) {
 		for (order = 1; order < 64; order++) {
 			for (offset = -1; offset <= (order > 1); offset++) {
 				u64 ctx = BIT_ULL(order) + offset;
 
-				ret = __igt_sync(tl, ctx, p, "1");
+				ret = __igt_sync(&tl, ctx, p, "1");
 				if (ret)
 					goto out;
 			}
 		}
 	}
-	mock_timeline_destroy(tl);
-
-	tl = mock_timeline(0);
-	if (!tl)
-		return -ENOMEM;
+	mock_timeline_fini(&tl);
 
+	mock_timeline_init(&tl, 0);
 	for (order = 1; order < 64; order++) {
 		for (offset = -1; offset <= (order > 1); offset++) {
 			u64 ctx = BIT_ULL(order) + offset;
 
 			for (p = pass; p->name; p++) {
-				ret = __igt_sync(tl, ctx, p, "2");
+				ret = __igt_sync(&tl, ctx, p, "2");
 				if (ret)
 					goto out;
 			}
@@ -115,7 +91,7 @@ static int igt_sync(void *arg)
 	}
 
 out:
-	mock_timeline_destroy(tl);
+	mock_timeline_fini(&tl);
 	return ret;
 }
 
@@ -127,15 +103,13 @@ static unsigned int random_engine(struct rnd_state *rnd)
 static int bench_sync(void *arg)
 {
 	struct rnd_state prng;
-	struct intel_timeline *tl;
+	struct i915_timeline tl;
 	unsigned long end_time, count;
 	u64 prng32_1M;
 	ktime_t kt;
 	int order, last_order;
 
-	tl = mock_timeline(0);
-	if (!tl)
-		return -ENOMEM;
+	mock_timeline_init(&tl, 0);
 
 	/* Lookups from cache are very fast and so the random number generation
 	 * and the loop itself becomes a significant factor in the per-iteration
@@ -167,7 +141,7 @@ static int bench_sync(void *arg)
 	do {
 		u64 id = i915_prandom_u64_state(&prng);
 
-		__intel_timeline_sync_set(tl, id, 0);
+		__i915_timeline_sync_set(&tl, id, 0);
 		count++;
 	} while (!time_after(jiffies, end_time));
 	kt = ktime_sub(ktime_get(), kt);
@@ -182,8 +156,8 @@ static int bench_sync(void *arg)
 	while (end_time--) {
 		u64 id = i915_prandom_u64_state(&prng);
 
-		if (!__intel_timeline_sync_is_later(tl, id, 0)) {
-			mock_timeline_destroy(tl);
+		if (!__i915_timeline_sync_is_later(&tl, id, 0)) {
+			mock_timeline_fini(&tl);
 			pr_err("Lookup of %llu failed\n", id);
 			return -EINVAL;
 		}
@@ -193,19 +167,17 @@ static int bench_sync(void *arg)
 	pr_info("%s: %lu random lookups, %lluns/lookup\n",
 		__func__, count, (long long)div64_ul(ktime_to_ns(kt), count));
 
-	mock_timeline_destroy(tl);
+	mock_timeline_fini(&tl);
 	cond_resched();
 
-	tl = mock_timeline(0);
-	if (!tl)
-		return -ENOMEM;
+	mock_timeline_init(&tl, 0);
 
 	/* Benchmark setting the first N (in order) contexts */
 	count = 0;
 	kt = ktime_get();
 	end_time = jiffies + HZ/10;
 	do {
-		__intel_timeline_sync_set(tl, count++, 0);
+		__i915_timeline_sync_set(&tl, count++, 0);
 	} while (!time_after(jiffies, end_time));
 	kt = ktime_sub(ktime_get(), kt);
 	pr_info("%s: %lu in-order insertions, %lluns/insert\n",
@@ -215,9 +187,9 @@ static int bench_sync(void *arg)
 	end_time = count;
 	kt = ktime_get();
 	while (end_time--) {
-		if (!__intel_timeline_sync_is_later(tl, end_time, 0)) {
+		if (!__i915_timeline_sync_is_later(&tl, end_time, 0)) {
 			pr_err("Lookup of %lu failed\n", end_time);
-			mock_timeline_destroy(tl);
+			mock_timeline_fini(&tl);
 			return -EINVAL;
 		}
 	}
@@ -225,12 +197,10 @@ static int bench_sync(void *arg)
 	pr_info("%s: %lu in-order lookups, %lluns/lookup\n",
 		__func__, count, (long long)div64_ul(ktime_to_ns(kt), count));
 
-	mock_timeline_destroy(tl);
+	mock_timeline_fini(&tl);
 	cond_resched();
 
-	tl = mock_timeline(0);
-	if (!tl)
-		return -ENOMEM;
+	mock_timeline_init(&tl, 0);
 
 	/* Benchmark searching for a random context id and maybe changing it */
 	prandom_seed_state(&prng, i915_selftest.random_seed);
@@ -241,8 +211,8 @@ static int bench_sync(void *arg)
 		u32 id = random_engine(&prng);
 		u32 seqno = prandom_u32_state(&prng);
 
-		if (!__intel_timeline_sync_is_later(tl, id, seqno))
-			__intel_timeline_sync_set(tl, id, seqno);
+		if (!__i915_timeline_sync_is_later(&tl, id, seqno))
+			__i915_timeline_sync_set(&tl, id, seqno);
 
 		count++;
 	} while (!time_after(jiffies, end_time));
@@ -250,7 +220,7 @@ static int bench_sync(void *arg)
 	kt = ktime_sub_ns(kt, (count * prng32_1M * 2) >> 20);
 	pr_info("%s: %lu repeated insert/lookups, %lluns/op\n",
 		__func__, count, (long long)div64_ul(ktime_to_ns(kt), count));
-	mock_timeline_destroy(tl);
+	mock_timeline_fini(&tl);
 	cond_resched();
 
 	/* Benchmark searching for a known context id and changing the seqno */
@@ -258,9 +228,7 @@ static int bench_sync(void *arg)
 	     ({ int tmp = last_order; last_order = order; order += tmp; })) {
 		unsigned int mask = BIT(order) - 1;
 
-		tl = mock_timeline(0);
-		if (!tl)
-			return -ENOMEM;
+		mock_timeline_init(&tl, 0);
 
 		count = 0;
 		kt = ktime_get();
@@ -272,8 +240,8 @@ static int bench_sync(void *arg)
 			 */
 			u64 id = (u64)(count & mask) << order;
 
-			__intel_timeline_sync_is_later(tl, id, 0);
-			__intel_timeline_sync_set(tl, id, 0);
+			__i915_timeline_sync_is_later(&tl, id, 0);
+			__i915_timeline_sync_set(&tl, id, 0);
 
 			count++;
 		} while (!time_after(jiffies, end_time));
@@ -281,7 +249,7 @@ static int bench_sync(void *arg)
 		pr_info("%s: %lu cyclic/%d insert/lookups, %lluns/op\n",
 			__func__, count, order,
 			(long long)div64_ul(ktime_to_ns(kt), count));
-		mock_timeline_destroy(tl);
+		mock_timeline_fini(&tl);
 		cond_resched();
 	}
 
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index 6752498e2c73..26bf29d97007 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -25,6 +25,11 @@
 #include "mock_engine.h"
 #include "mock_request.h"
 
+struct mock_ring {
+	struct intel_ring base;
+	struct i915_timeline timeline;
+};
+
 static struct mock_request *first_request(struct mock_engine *engine)
 {
 	return list_first_entry_or_null(&engine->hw_queue,
@@ -132,7 +137,7 @@ static void mock_submit_request(struct i915_request *request)
 static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
 {
 	const unsigned long sz = PAGE_SIZE / 2;
-	struct intel_ring *ring;
+	struct mock_ring *ring;
 
 	BUILD_BUG_ON(MIN_SPACE_FOR_ADD_REQUEST > sz);
 
@@ -140,20 +145,24 @@ static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
 	if (!ring)
 		return NULL;
 
-	ring->timeline = &engine->i915->gt.legacy_timeline.engine[engine->id];
+	i915_timeline_init(engine->i915, &ring->timeline, engine->name);
 
-	ring->size = sz;
-	ring->effective_size = sz;
-	ring->vaddr = (void *)(ring + 1);
+	ring->base.size = sz;
+	ring->base.effective_size = sz;
+	ring->base.vaddr = (void *)(ring + 1);
+	ring->base.timeline = &ring->timeline;
 
-	INIT_LIST_HEAD(&ring->request_list);
-	intel_ring_update_space(ring);
+	INIT_LIST_HEAD(&ring->base.request_list);
+	intel_ring_update_space(&ring->base);
 
-	return ring;
+	return &ring->base;
 }
 
-static void mock_ring_free(struct intel_ring *ring)
+static void mock_ring_free(struct intel_ring *base)
 {
+	struct mock_ring *ring = container_of(base, typeof(*ring), base);
+
+	i915_timeline_fini(&ring->timeline);
 	kfree(ring);
 }
 
@@ -182,8 +191,7 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
 	engine->base.emit_breadcrumb = mock_emit_breadcrumb;
 	engine->base.submit_request = mock_submit_request;
 
-	intel_engine_init_timeline(&engine->base);
-
+	i915_timeline_init(i915, &engine->base.timeline, engine->base.name);
 	intel_engine_init_breadcrumbs(&engine->base);
 	engine->base.breadcrumbs.mock = true; /* prevent touching HW for irqs */
 
@@ -200,6 +208,7 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
 
 err_breadcrumbs:
 	intel_engine_fini_breadcrumbs(&engine->base);
+	i915_timeline_fini(&engine->base.timeline);
 	kfree(engine);
 	return NULL;
 }
@@ -238,6 +247,7 @@ void mock_engine_free(struct intel_engine_cs *engine)
 	mock_ring_free(engine->buffer);
 
 	intel_engine_fini_breadcrumbs(engine);
+	i915_timeline_fini(&engine->timeline);
 
 	kfree(engine);
 }
diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index f11c83e8ff32..a662c0450e77 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -73,10 +73,8 @@ static void mock_device_release(struct drm_device *dev)
 
 	mutex_lock(&i915->drm.struct_mutex);
 	mock_fini_ggtt(i915);
-	i915_gem_timeline_fini(&i915->gt.legacy_timeline);
-	i915_gem_timeline_fini(&i915->gt.execution_timeline);
-	WARN_ON(!list_empty(&i915->gt.timelines));
 	mutex_unlock(&i915->drm.struct_mutex);
+	WARN_ON(!list_empty(&i915->gt.timelines));
 
 	destroy_workqueue(i915->wq);
 
@@ -230,12 +228,6 @@ struct drm_i915_private *mock_gem_device(void)
 	INIT_LIST_HEAD(&i915->gt.active_rings);
 
 	mutex_lock(&i915->drm.struct_mutex);
-	err = i915_gem_timeline_init__global(i915);
-	if (err) {
-		mutex_unlock(&i915->drm.struct_mutex);
-		goto err_priorities;
-	}
-
 	mock_init_ggtt(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 
diff --git a/drivers/gpu/drm/i915/selftests/mock_timeline.c b/drivers/gpu/drm/i915/selftests/mock_timeline.c
index 47b1f47c5812..dcf3b16f5a07 100644
--- a/drivers/gpu/drm/i915/selftests/mock_timeline.c
+++ b/drivers/gpu/drm/i915/selftests/mock_timeline.c
@@ -1,45 +1,28 @@
 /*
- * Copyright © 2017 Intel Corporation
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
+ * SPDX-License-Identifier: MIT
  *
+ * Copyright © 2017-2018 Intel Corporation
  */
 
+#include "../i915_timeline.h"
+
 #include "mock_timeline.h"
 
-struct intel_timeline *mock_timeline(u64 context)
+void mock_timeline_init(struct i915_timeline *timeline, u64 context)
 {
-	static struct lock_class_key class;
-	struct intel_timeline *tl;
+	timeline->fence_context = context;
+
+	spin_lock_init(&timeline->lock);
 
-	tl = kzalloc(sizeof(*tl), GFP_KERNEL);
-	if (!tl)
-		return NULL;
+	init_request_active(&timeline->last_request, NULL);
+	INIT_LIST_HEAD(&timeline->requests);
 
-	__intel_timeline_init(tl, NULL, context, &class, "mock");
+	i915_syncmap_init(&timeline->sync);
 
-	return tl;
+	INIT_LIST_HEAD(&timeline->link);
 }
 
-void mock_timeline_destroy(struct intel_timeline *tl)
+void mock_timeline_fini(struct i915_timeline *timeline)
 {
-	__intel_timeline_fini(tl);
-	kfree(tl);
+	i915_timeline_fini(timeline);
 }
diff --git a/drivers/gpu/drm/i915/selftests/mock_timeline.h b/drivers/gpu/drm/i915/selftests/mock_timeline.h
index c27ff4639b8b..b6deaa61110d 100644
--- a/drivers/gpu/drm/i915/selftests/mock_timeline.h
+++ b/drivers/gpu/drm/i915/selftests/mock_timeline.h
@@ -1,33 +1,15 @@
 /*
- * Copyright © 2017 Intel Corporation
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
+ * SPDX-License-Identifier: MIT
  *
+ * Copyright © 2017-2018 Intel Corporation
  */
 
 #ifndef __MOCK_TIMELINE__
 #define __MOCK_TIMELINE__
 
-#include "../i915_gem_timeline.h"
+struct i915_timeline;
 
-struct intel_timeline *mock_timeline(u64 context);
-void mock_timeline_destroy(struct intel_timeline *tl);
+void mock_timeline_init(struct i915_timeline *timeline, u64 context);
+void mock_timeline_fini(struct i915_timeline *timeline);
 
 #endif /* !__MOCK_TIMELINE__ */