From ab9c1f64259e7846c34e1117855e0988265a2a87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Tue, 15 Jun 2021 15:36:44 +0200
Subject: drm/i915: use the new iterator in i915_gem_busy_ioctl v2
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Git-commit: 912ff2ebd695c582ca4cebf833ad73a378a99f23
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

This makes the function much simpler since the complex
retry logic is now handled else where.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211116102431.198905-2-christian.koenig@amd.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gem/i915_gem_busy.c | 35 ++++++++++--------------
 1 file changed, 14 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
index 7358bebef15c..470fdfd61a0f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
@@ -115,8 +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 dma_resv_list *list;
-	unsigned int seq;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	int err;
 
 	err = -ENOENT;
@@ -142,27 +142,20 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 	 * 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(dma_resv_excl_fence(obj->base.resv));
-
-	/* Translate shared fences to READ set of engines */
-	list = dma_resv_shared_list(obj->base.resv);
-	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, true);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		if (dma_resv_iter_is_restarted(&cursor))
+			args->busy = 0;
+
+		if (dma_resv_iter_is_exclusive(&cursor))
+			/* Translate the exclusive fence to the READ *and* WRITE engine */
+			args->busy |= busy_check_writer(fence);
+		else
+			/* Translate shared 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:
-- 
2.38.1