[PATCH v3 2/2] drm/amdgpu: only keep most recent fence for each context

[Arvind Yadav]

Mesa passes shared bo, fence syncobj to userq_ioctl.
There can be duplicates here or some fences that are old.
This patch is remove duplicates fence and only keep the most
recent fence for each context.

v2: - Export this code from dma-fence-unwrap.c(by Christian).
v3: - To split this in a dma_buf patch and amd userq patch(by Sunil).
    - No need to add a new function just re-use existing(by Christian).

Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian Koenig <christian.koenig at amd.com>
Cc: Sunil Khatri <sunil.khatri at amd.com>
Cc: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam at amd.com>
Signed-off-by: Arvind Yadav <Arvind.Yadav at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
index 3288c2ff692e..0f4233b79a3b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
@@ -606,6 +606,7 @@ int amdgpu_userq_wait_ioctl(struct drm_device *dev, void *data,
 	struct drm_gem_object **gobj_read;
 	struct dma_fence **fences = NULL;
 	u16 num_points, num_fences = 0;
+	unsigned int num_shrink_fences = 0;
 	int r, i, rentry, wentry, cnt;
 	struct drm_exec exec;
 
@@ -851,6 +852,13 @@ int amdgpu_userq_wait_ioctl(struct drm_device *dev, void *data,
 			fences[num_fences++] = fence;
 		}
 
+		/*
+		 * Remove duplicates fence and only keep the most recent fence for
+		 * each context.
+		 */
+		dma_fence_unwrap_shrink_array(num_fences, fences, num_shrink_fences);
+		num_fences = num_shrink_fences;
+
 		waitq = idr_find(&userq_mgr->userq_idr, wait_info->waitq_id);
 		if (!waitq)
 			goto free_fences;
-- 
2.34.1