[PATCH 5.10/5.15] drm/amdgpu/vcn: set no_user_fence for VCN v2.0 enc/dec rings

[Mikhail Dmitrichenko]

From: Yinjie Yao <yinjie.yao@xxxxxxx>

commit 8d80b293b41fcb5e9396db93e788b0f4ebcbafb7 upstream.

VCN encoder and decoder rings do not support 64-bit user fence writes,
reject CS submissions with user fences.

Fixes: 1b61de45dfaf ("drm/amdgpu: add initial VCN2.0 support (v2)")
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Yinjie Yao <yinjie.yao@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
(cherry picked from commit e2b5499fca55f1a32960a311bbb62e35891eaf73)
[mdmitrichenko: Adjust the ring initializers to the 5.10/5.15 context,
 preserving the existing vmhub fields.]
Signed-off-by: Mikhail Dmitrichenko <mdmitrichenko@xxxxxxxxxxxxx>
---
Backport fix for CVE-2026-63856.

 drivers/gpu/drm/amd/amdgpu/vcn_v2_0.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v2_0.c b/drivers/gpu/drm/amd/amdgpu/vcn_v2_0.c
index e2744f172610a..da3809fef38ad 100644
--- a/drivers/gpu/drm/amd/amdgpu/vcn_v2_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/vcn_v2_0.c
@@ -2005,6 +2005,7 @@ static const struct amd_ip_funcs vcn_v2_0_ip_funcs = {
 static const struct amdgpu_ring_funcs vcn_v2_0_dec_ring_vm_funcs = {
 	.type = AMDGPU_RING_TYPE_VCN_DEC,
 	.align_mask = 0xf,
+	.no_user_fence = true,
 	.vmhub = AMDGPU_MMHUB_0,
 	.get_rptr = vcn_v2_0_dec_ring_get_rptr,
 	.get_wptr = vcn_v2_0_dec_ring_get_wptr,
@@ -2036,6 +2037,7 @@ static const struct amdgpu_ring_funcs vcn_v2_0_enc_ring_vm_funcs = {
 	.type = AMDGPU_RING_TYPE_VCN_ENC,
 	.align_mask = 0x3f,
 	.nop = VCN_ENC_CMD_NO_OP,
+	.no_user_fence = true,
 	.vmhub = AMDGPU_MMHUB_0,
 	.get_rptr = vcn_v2_0_enc_ring_get_rptr,
 	.get_wptr = vcn_v2_0_enc_ring_get_wptr,
-- 
2.43.0