drm/i915: Make sure execbuffer always passes ww state to i915_vma_pin.

As a preparation step for full object locking and wait/wound handling
during pin and object mapping, ensure that we always pass the ww context
in i915_gem_execbuffer.c to i915_vma_pin, use lockdep to ensure this
happens.

This also requires changing the order of eb_parse slightly, to ensure
we pass ww at a point where we could still handle -EDEADLK safely.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-15-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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

@@ -1154,7 +1154,7 @@ static int context_barrier_task(struct i915_gem_context *ctx,
 
 		i915_gem_ww_ctx_init(&ww, true);
 retry:
-		err = intel_context_pin(ce);
+		err = intel_context_pin_ww(ce, &ww);
 		if (err)
 			goto err;
 
@@ -1247,7 +1247,7 @@ static int pin_ppgtt_update(struct intel_context *ce, struct i915_gem_ww_ctx *ww
 
 	if (!HAS_LOGICAL_RING_CONTEXTS(vm->i915))
 		/* ppGTT is not part of the legacy context image */
-		return gen6_ppgtt_pin(i915_vm_to_ppgtt(vm));
+		return gen6_ppgtt_pin(i915_vm_to_ppgtt(vm), ww);
 
 	return 0;
 }

drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c

@@ -436,16 +436,17 @@ eb_pin_vma(struct i915_execbuffer *eb,
 		pin_flags |= PIN_GLOBAL;
 
 	/* Attempt to reuse the current location if available */
-	if (unlikely(i915_vma_pin(vma, 0, 0, pin_flags))) {
+	/* TODO: Add -EDEADLK handling here */
+	if (unlikely(i915_vma_pin_ww(vma, &eb->ww, 0, 0, pin_flags))) {
 		if (entry->flags & EXEC_OBJECT_PINNED)
 			return false;
 
 		/* Failing that pick any _free_ space if suitable */
-		if (unlikely(i915_vma_pin(vma,
-					  entry->pad_to_size,
-					  entry->alignment,
-					  eb_pin_flags(entry, ev->flags) |
-					  PIN_USER | PIN_NOEVICT)))
+		if (unlikely(i915_vma_pin_ww(vma, &eb->ww,
+					     entry->pad_to_size,
+					     entry->alignment,
+					     eb_pin_flags(entry, ev->flags) |
+					     PIN_USER | PIN_NOEVICT)))
 			return false;
 	}
 
@@ -586,7 +587,7 @@ static inline int use_cpu_reloc(const struct reloc_cache *cache,
 		obj->cache_level != I915_CACHE_NONE);
 }
 
-static int eb_reserve_vma(const struct i915_execbuffer *eb,
+static int eb_reserve_vma(struct i915_execbuffer *eb,
 			  struct eb_vma *ev,
 			  u64 pin_flags)
 {
@@ -601,7 +602,7 @@ static int eb_reserve_vma(const struct i915_execbuffer *eb,
 			return err;
 	}
 
-	err = i915_vma_pin(vma,
+	err = i915_vma_pin_ww(vma, &eb->ww,
 			   entry->pad_to_size, entry->alignment,
 			   eb_pin_flags(entry, ev->flags) | pin_flags);
 	if (err)
@@ -1132,9 +1133,10 @@ static void *reloc_kmap(struct drm_i915_gem_object *obj,
 }
 
 static void *reloc_iomap(struct drm_i915_gem_object *obj,
-			 struct reloc_cache *cache,
+			 struct i915_execbuffer *eb,
 			 unsigned long page)
 {
+	struct reloc_cache *cache = &eb->reloc_cache;
 	struct i915_ggtt *ggtt = cache_to_ggtt(cache);
 	unsigned long offset;
 	void *vaddr;
@@ -1156,10 +1158,13 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj,
 		if (err)
 			return ERR_PTR(err);
 
-		vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,
-					       PIN_MAPPABLE |
-					       PIN_NONBLOCK /* NOWARN */ |
-					       PIN_NOEVICT);
+		vma = i915_gem_object_ggtt_pin_ww(obj, &eb->ww, NULL, 0, 0,
+						  PIN_MAPPABLE |
+						  PIN_NONBLOCK /* NOWARN */ |
+						  PIN_NOEVICT);
+		if (vma == ERR_PTR(-EDEADLK))
+			return vma;
+
 		if (IS_ERR(vma)) {
 			memset(&cache->node, 0, sizeof(cache->node));
 			mutex_lock(&ggtt->vm.mutex);
@@ -1195,9 +1200,10 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj,
 }
 
 static void *reloc_vaddr(struct drm_i915_gem_object *obj,
-			 struct reloc_cache *cache,
+			 struct i915_execbuffer *eb,
 			 unsigned long page)
 {
+	struct reloc_cache *cache = &eb->reloc_cache;
 	void *vaddr;
 
 	if (cache->page == page) {
@@ -1205,7 +1211,7 @@ static void *reloc_vaddr(struct drm_i915_gem_object *obj,
 	} else {
 		vaddr = NULL;
 		if ((cache->vaddr & KMAP) == 0)
-			vaddr = reloc_iomap(obj, cache, page);
+			vaddr = reloc_iomap(obj, eb, page);
 		if (!vaddr)
 			vaddr = reloc_kmap(obj, cache, page);
 	}
@@ -1292,7 +1298,7 @@ static int __reloc_gpu_alloc(struct i915_execbuffer *eb,
 		goto err_unmap;
 	}
 
-	err = i915_vma_pin(batch, 0, 0, PIN_USER | PIN_NONBLOCK);
+	err = i915_vma_pin_ww(batch, &eb->ww, 0, 0, PIN_USER | PIN_NONBLOCK);
 	if (err)
 		goto err_unmap;
 
@@ -1313,7 +1319,7 @@ static int __reloc_gpu_alloc(struct i915_execbuffer *eb,
 			eb->reloc_context = ce;
 		}
 
-		err = intel_context_pin(ce);
+		err = intel_context_pin_ww(ce, &eb->ww);
 		if (err)
 			goto err_unpin;
 
@@ -1536,8 +1542,7 @@ relocate_entry(struct i915_vma *vma,
 		void *vaddr;
 
 repeat:
-		vaddr = reloc_vaddr(vma->obj,
-				    &eb->reloc_cache,
+		vaddr = reloc_vaddr(vma->obj, eb,
 				    offset >> PAGE_SHIFT);
 		if (IS_ERR(vaddr))
 			return PTR_ERR(vaddr);
@@ -1953,6 +1958,7 @@ repeat_validate:
 	rq = eb_pin_engine(eb, false);
 	if (IS_ERR(rq)) {
 		err = PTR_ERR(rq);
+		rq = NULL;
 		goto err;
 	}
 
@@ -2236,7 +2242,8 @@ static int i915_reset_gen7_sol_offsets(struct i915_request *rq)
 }
 
 static struct i915_vma *
-shadow_batch_pin(struct drm_i915_gem_object *obj,
+shadow_batch_pin(struct i915_execbuffer *eb,
+		 struct drm_i915_gem_object *obj,
 		 struct i915_address_space *vm,
 		 unsigned int flags)
 {
@@ -2247,7 +2254,7 @@ shadow_batch_pin(struct drm_i915_gem_object *obj,
 	if (IS_ERR(vma))
 		return vma;
 
-	err = i915_vma_pin(vma, 0, 0, flags);
+	err = i915_vma_pin_ww(vma, &eb->ww, 0, 0, flags);
 	if (err)
 		return ERR_PTR(err);
 
@@ -2397,16 +2404,33 @@ err_free:
 	return err;
 }
 
+static struct i915_vma *eb_dispatch_secure(struct i915_execbuffer *eb, struct i915_vma *vma)
+{
+	/*
+	 * snb/ivb/vlv conflate the "batch in ppgtt" bit with the "non-secure
+	 * batch" bit. Hence we need to pin secure batches into the global gtt.
+	 * hsw should have this fixed, but bdw mucks it up again. */
+	if (eb->batch_flags & I915_DISPATCH_SECURE)
+		return i915_gem_object_ggtt_pin_ww(vma->obj, &eb->ww, NULL, 0, 0, 0);
+
+	return NULL;
+}
+
 static int eb_parse(struct i915_execbuffer *eb)
 {
 	struct drm_i915_private *i915 = eb->i915;
 	struct intel_gt_buffer_pool_node *pool = eb->batch_pool;
-	struct i915_vma *shadow, *trampoline;
+	struct i915_vma *shadow, *trampoline, *batch;
 	unsigned int len;
 	int err;
 
-	if (!eb_use_cmdparser(eb))
-		return 0;
+	if (!eb_use_cmdparser(eb)) {
+		batch = eb_dispatch_secure(eb, eb->batch->vma);
+		if (IS_ERR(batch))
+			return PTR_ERR(batch);
+
+		goto secure_batch;
+	}
 
 	len = eb->batch_len;
 	if (!CMDPARSER_USES_GGTT(eb->i915)) {
@@ -2434,7 +2458,7 @@ static int eb_parse(struct i915_execbuffer *eb)
 	if (err)
 		goto err;
 
-	shadow = shadow_batch_pin(pool->obj, eb->context->vm, PIN_USER);
+	shadow = shadow_batch_pin(eb, pool->obj, eb->context->vm, PIN_USER);
 	if (IS_ERR(shadow)) {
 		err = PTR_ERR(shadow);
 		goto err;
@@ -2446,7 +2470,7 @@ static int eb_parse(struct i915_execbuffer *eb)
 	if (CMDPARSER_USES_GGTT(eb->i915)) {
 		trampoline = shadow;
 
-		shadow = shadow_batch_pin(pool->obj,
+		shadow = shadow_batch_pin(eb, pool->obj,
 					  &eb->engine->gt->ggtt->vm,
 					  PIN_GLOBAL);
 		if (IS_ERR(shadow)) {
@@ -2459,19 +2483,34 @@ static int eb_parse(struct i915_execbuffer *eb)
 		eb->batch_flags |= I915_DISPATCH_SECURE;
 	}
 
+	batch = eb_dispatch_secure(eb, shadow);
+	if (IS_ERR(batch)) {
+		err = PTR_ERR(batch);
+		goto err_trampoline;
+	}
+
 	err = eb_parse_pipeline(eb, shadow, trampoline);
 	if (err)
-		goto err_trampoline;
+		goto err_unpin_batch;
 
-	eb->vma[eb->buffer_count].vma = i915_vma_get(shadow);
-	eb->vma[eb->buffer_count].flags = __EXEC_OBJECT_HAS_PIN;
 	eb->batch = &eb->vma[eb->buffer_count++];
+	eb->batch->vma = i915_vma_get(shadow);
+	eb->batch->flags = __EXEC_OBJECT_HAS_PIN;
 
 	eb->trampoline = trampoline;
 	eb->batch_start_offset = 0;
 
+secure_batch:
+	if (batch) {
+		eb->batch = &eb->vma[eb->buffer_count++];
+		eb->batch->flags = __EXEC_OBJECT_HAS_PIN;
+		eb->batch->vma = i915_vma_get(batch);
+	}
 	return 0;
 
+err_unpin_batch:
+	if (batch)
+		i915_vma_unpin(batch);
 err_trampoline:
 	if (trampoline)
 		i915_vma_unpin(trampoline);
@@ -2613,7 +2652,7 @@ static struct i915_request *eb_pin_engine(struct i915_execbuffer *eb, bool throt
 	 * GGTT space, so do this first before we reserve a seqno for
 	 * ourselves.
 	 */
-	err = intel_context_pin(ce);
+	err = intel_context_pin_ww(ce, &eb->ww);
 	if (err)
 		return ERR_PTR(err);
 
@@ -3231,33 +3270,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
 
 	ww_acquire_done(&eb.ww.ctx);
 
-	/*
-	 * snb/ivb/vlv conflate the "batch in ppgtt" bit with the "non-secure
-	 * batch" bit. Hence we need to pin secure batches into the global gtt.
-	 * hsw should have this fixed, but bdw mucks it up again. */
-	if (eb.batch_flags & I915_DISPATCH_SECURE) {
-		struct i915_vma *vma;
-
-		/*
-		 * So on first glance it looks freaky that we pin the batch here
-		 * outside of the reservation loop. But:
-		 * - The batch is already pinned into the relevant ppgtt, so we
-		 *   already have the backing storage fully allocated.
-		 * - No other BO uses the global gtt (well contexts, but meh),
-		 *   so we don't really have issues with multiple objects not
-		 *   fitting due to fragmentation.
-		 * So this is actually safe.
-		 */
-		vma = i915_gem_object_ggtt_pin(eb.batch->vma->obj, NULL, 0, 0, 0);
-		if (IS_ERR(vma)) {
-			err = PTR_ERR(vma);
-			goto err_vma;
-		}
-
-		batch = vma;
-	} else {
-		batch = eb.batch->vma;
-	}
+	batch = eb.batch->vma;
 
 	/* All GPU relocation batches must be submitted prior to the user rq */
 	GEM_BUG_ON(eb.reloc_cache.rq);
@@ -3266,7 +3279,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
 	eb.request = i915_request_create(eb.context);
 	if (IS_ERR(eb.request)) {
 		err = PTR_ERR(eb.request);
-		goto err_batch_unpin;
+		goto err_vma;
 	}
 
 	if (in_fence) {
@@ -3327,9 +3340,6 @@ err_request:
 	}
 	i915_request_put(eb.request);
 
-err_batch_unpin:
-	if (eb.batch_flags & I915_DISPATCH_SECURE)
-		i915_vma_unpin(batch);
 err_vma:
 	eb_release_vmas(&eb, true);
 	if (eb.trampoline)
@@ -3417,7 +3427,9 @@ i915_gem_execbuffer_ioctl(struct drm_device *dev, void *data,
 	/* Copy in the exec list from userland */
 	exec_list = kvmalloc_array(count, sizeof(*exec_list),
 				   __GFP_NOWARN | GFP_KERNEL);
-	exec2_list = kvmalloc_array(count + 1, eb_element_size(),
+
+	/* Allocate extra slots for use by the command parser */
+	exec2_list = kvmalloc_array(count + 2, eb_element_size(),
 				    __GFP_NOWARN | GFP_KERNEL);
 	if (exec_list == NULL || exec2_list == NULL) {
 		drm_dbg(&i915->drm,
@@ -3494,8 +3506,8 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
 	if (err)
 		return err;
 
-	/* Allocate an extra slot for use by the command parser */
-	exec2_list = kvmalloc_array(count + 1, eb_element_size(),
+	/* Allocate extra slots for use by the command parser */
+	exec2_list = kvmalloc_array(count + 2, eb_element_size(),
 				    __GFP_NOWARN | GFP_KERNEL);
 	if (exec2_list == NULL) {
 		drm_dbg(&i915->drm, "Failed to allocate exec list for %zd buffers\n",

drivers/gpu/drm/i915/gem/selftests/i915_gem_execbuffer.c

@@ -36,7 +36,7 @@ static int __igt_gpu_reloc(struct i915_execbuffer *eb,
 	if (err)
 		return err;
 
-	err = i915_vma_pin(vma, 0, 0, PIN_USER | PIN_HIGH);
+	err = i915_vma_pin_ww(vma, &eb->ww, 0, 0, PIN_USER | PIN_HIGH);
 	if (err)
 		return err;
 
@@ -139,7 +139,7 @@ static int igt_gpu_reloc(void *arg)
 
 		i915_gem_ww_ctx_init(&eb.ww, false);
 retry:
-		err = intel_context_pin(eb.context);
+		err = intel_context_pin_ww(eb.context, &eb.ww);
 		if (!err) {
 			err = __igt_gpu_reloc(&eb, scratch);