[PATCH 2/4] drm/amdgpu: Allow multiple VCE create commands with same handle

[David Rosca <david.rosca@amd.com>]

As long as it is done by the process that owns the session, additional
create commands should be allowed.
This is needed for Vulkan to reset existing session.

The image size is now staged locally and only committed when the IB
parses successfully, so a failed create can't change the size of
a live session.

Assisted-by: Claude:claude-opus-5-5
Signed-off-by: David Rosca <david.rosca@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c | 28 ++++++++++++++-----------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c
index 39d87f3df9e0..07c4434c4948 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c
@@ -788,6 +788,7 @@ int amdgpu_vce_ring_parse_cs(struct amdgpu_cs_parser *p,
 {
 	unsigned int fb_idx = 0, bs_idx = 0;
 	int session_idx = -1;
+	uint32_t img_size[AMDGPU_MAX_VCE_HANDLES];
 	uint32_t destroyed = 0;
 	uint32_t created = 0;
 	uint32_t allocated = 0;
@@ -878,7 +879,15 @@ int amdgpu_vce_ring_parse_cs(struct amdgpu_cs_parser *p,
 				r = session_idx;
 				goto out;
 			}
-			size = &p->adev->vce.img_size[session_idx];
+			/*
+			 * Stage the image size locally and only commit it once
+			 * the whole IB is valid, otherwise a failed create
+			 * could change the size of a live session.
+			 */
+			if (!(created & (1 << session_idx)))
+				img_size[session_idx] =
+					p->adev->vce.img_size[session_idx];
+			size = &img_size[session_idx];
 			break;
 
 		case 0x00000002: /* task info */
@@ -891,11 +900,6 @@ int amdgpu_vce_ring_parse_cs(struct amdgpu_cs_parser *p,
 			if (destroyed & (1 << session_idx)) {
 				destroyed &= ~(1 << session_idx);
 				allocated |= 1 << session_idx;
-
-			} else if (!(allocated & (1 << session_idx))) {
-				DRM_ERROR("Handle already in use!\n");
-				r = -EINVAL;
-				goto out;
 			}
 
 			uint32_t width, height;
@@ -1010,7 +1014,12 @@ int amdgpu_vce_ring_parse_cs(struct amdgpu_cs_parser *p,
 
 out:
 	if (!r) {
-		/* No error, free all destroyed handle slots */
+		/* No error, commit the image size of created sessions */
+		for (i = 0; i < AMDGPU_MAX_VCE_HANDLES; ++i)
+			if (created & (1 << i))
+				p->adev->vce.img_size[i] = img_size[i];
+
+		/* and free all destroyed handle slots */
 		tmp = destroyed;
 	} else {
 		/* Error during parsing, free all allocated handle slots */
@@ -1068,11 +1077,6 @@ int amdgpu_vce_ring_parse_cs_vm(struct amdgpu_cs_parser *p,
 			if (destroyed & (1 << session_idx)) {
 				destroyed &= ~(1 << session_idx);
 				allocated |= 1 << session_idx;
-
-			} else if (!(allocated & (1 << session_idx))) {
-				DRM_ERROR("Handle already in use!\n");
-				r = -EINVAL;
-				goto out;
 			}
 
 			break;
-- 
2.43.0