1 files changed, 64 insertions, 39 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
index 6ad93a09968c..ddda468241ef 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
@@ -4,21 +4,23 @@
  * Copyright © 2014-2016 Intel Corporation
  */
 
+#include <linux/dma-fence-array.h>
+
 #include "gt/intel_engine.h"
 
 #include "i915_gem_ioctls.h"
 #include "i915_gem_object.h"
 
-static __always_inline u32 __busy_read_flag(u8 id)
+static __always_inline u32 __busy_read_flag(u16 id)
 {
-	if (id == (u8)I915_ENGINE_CLASS_INVALID)
+	if (id == (u16)I915_ENGINE_CLASS_INVALID)
 		return 0xffff0000u;
 
 	GEM_BUG_ON(id >= 16);
 	return 0x10000u << id;
 }
 
-static __always_inline u32 __busy_write_id(u8 id)
+static __always_inline u32 __busy_write_id(u16 id)
 {
 	/*
 	 * The uABI guarantees an active writer is also amongst the read
@@ -29,14 +31,14 @@ static __always_inline u32 __busy_write_id(u8 id)
 	 * last_read - hence we always set both read and write busy for
 	 * last_write.
 	 */
-	if (id == (u8)I915_ENGINE_CLASS_INVALID)
+	if (id == (u16)I915_ENGINE_CLASS_INVALID)
 		return 0xffffffffu;
 
 	return (id + 1) | __busy_read_flag(id);
 }
 
 static __always_inline unsigned int
-__busy_set_if_active(const struct dma_fence *fence, u32 (*flag)(u8 id))
+__busy_set_if_active(struct dma_fence *fence, u32 (*flag)(u16 id))
 {
 	const struct i915_request *rq;
 
@@ -46,29 +48,60 @@ __busy_set_if_active(const struct dma_fence *fence, u32 (*flag)(u8 id))
 	 * to eventually flush us, but to minimise latency just ask the
 	 * hardware.
 	 *
-	 * Note we only report on the status of native fences.
+	 * Note we only report on the status of native fences and we currently
+	 * have two native fences:
+	 *
+	 * 1. A composite fence (dma_fence_array) constructed of i915 requests
+	 * created during a parallel submission. In this case we deconstruct the
+	 * composite fence into individual i915 requests and check the status of
+	 * each request.
+	 *
+	 * 2. A single i915 request.
 	 */
-	if (!dma_fence_is_i915(fence))
+	if (dma_fence_is_array(fence)) {
+		struct dma_fence_array *array = to_dma_fence_array(fence);
+		struct dma_fence **child = array->fences;
+		unsigned int nchild = array->num_fences;
+
+		do {
+			struct dma_fence *current_fence = *child++;
+
+			/* Not an i915 fence, can't be busy per above */
+			if (!dma_fence_is_i915(current_fence) ||
+			    !test_bit(I915_FENCE_FLAG_COMPOSITE,
+				      &current_fence->flags)) {
+				return 0;
+			}
+
+			rq = to_request(current_fence);
+			if (!i915_request_completed(rq))
+				return flag(rq->engine->uabi_class);
+		} while (--nchild);
+
+		/* All requests in array complete, not busy */
 		return 0;
+	} else {
+		if (!dma_fence_is_i915(fence))
+			return 0;
 
-	/* opencode to_request() in order to avoid const warnings */
-	rq = container_of(fence, const struct i915_request, fence);
-	if (i915_request_completed(rq))
-		return 0;
+		rq = to_request(fence);
+		if (i915_request_completed(rq))
+			return 0;
 
-	/* Beware type-expansion follies! */
-	BUILD_BUG_ON(!typecheck(u8, rq->engine->uabi_class));
-	return flag(rq->engine->uabi_class);
+		/* Beware type-expansion follies! */
+		BUILD_BUG_ON(!typecheck(u16, rq->engine->uabi_class));
+		return flag(rq->engine->uabi_class);
+	}
 }
 
 static __always_inline unsigned int
-busy_check_reader(const struct dma_fence *fence)
+busy_check_reader(struct dma_fence *fence)
 {
 	return __busy_set_if_active(fence, __busy_read_flag);
 }
 
 static __always_inline unsigned int
-busy_check_writer(const struct dma_fence *fence)
+busy_check_writer(struct dma_fence *fence)
 {
 	if (!fence)
 		return 0;
@@ -82,8 +115,8 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 {
 	struct drm_i915_gem_busy *args = data;
 	struct drm_i915_gem_object *obj;
-	struct reservation_object_list *list;
-	unsigned int seq;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	int err;
 
 	err = -ENOENT;
@@ -105,32 +138,24 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 	 * Alternatively, we can trade that extra information on read/write
 	 * activity with
 	 *	args->busy =
-	 *		!reservation_object_test_signaled_rcu(obj->resv, true);
+	 *		!dma_resv_test_signaled(obj->resv, DMA_RESV_USAGE_READ);
 	 * to report the overall busyness. This is what the wait-ioctl does.
 	 *
 	 */
-retry:
-	seq = raw_read_seqcount(&obj->base.resv->seq);
-
-	/* Translate the exclusive fence to the READ *and* WRITE engine */
-	args->busy =
-		busy_check_writer(rcu_dereference(obj->base.resv->fence_excl));
-
-	/* Translate shared fences to READ set of engines */
-	list = rcu_dereference(obj->base.resv->fence);
-	if (list) {
-		unsigned int shared_count = list->shared_count, i;
-
-		for (i = 0; i < shared_count; ++i) {
-			struct dma_fence *fence =
-				rcu_dereference(list->shared[i]);
-
+	args->busy = 0;
+	dma_resv_iter_begin(&cursor, obj->base.resv, DMA_RESV_USAGE_READ);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		if (dma_resv_iter_is_restarted(&cursor))
+			args->busy = 0;
+
+		if (dma_resv_iter_usage(&cursor) <= DMA_RESV_USAGE_WRITE)
+			/* Translate the write fences to the READ *and* WRITE engine */
+			args->busy |= busy_check_writer(fence);
+		else
+			/* Translate read fences to READ set of engines */
 			args->busy |= busy_check_reader(fence);
-		}
 	}
-
-	if (args->busy && read_seqcount_retry(&obj->base.resv->seq, seq))
-		goto retry;
+	dma_resv_iter_end(&cursor);
 
 	err = 0;
 out: