drm/amdgpu: define and add extra dword for jpeg ring

Define extra dword for jpeg ring. Jpeg ring will allocate extra dword to store
the patch commands for fixing the known issue.

v2: dropping extra_dw for rings other than jpeg.

Signed-off-by: Boyuan Zhang <boyuan.zhang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c

@@ -304,7 +304,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 		0xffffffffffffffff : ring->buf_mask;
 	/* Allocate ring buffer */
 	if (ring->ring_obj == NULL) {
-		r = amdgpu_bo_create_kernel(adev, ring->ring_size, PAGE_SIZE,
+		r = amdgpu_bo_create_kernel(adev, ring->ring_size + ring->funcs->extra_dw, PAGE_SIZE,
 					    AMDGPU_GEM_DOMAIN_GTT,
 					    &ring->ring_obj,
 					    &ring->gpu_addr,

drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h

@@ -113,6 +113,7 @@ struct amdgpu_ring_funcs {
 	u32			nop;
 	bool			support_64bit_ptrs;
 	unsigned		vmhub;
+	unsigned		extra_dw;
 
 	/* ring read/write ptr handling */
 	u64 (*get_rptr)(struct amdgpu_ring *ring);

drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c

@@ -1690,6 +1690,7 @@ static const struct amdgpu_ring_funcs vcn_v1_0_jpeg_ring_vm_funcs = {
 	.nop = PACKET0(0x81ff, 0),
 	.support_64bit_ptrs = false,
 	.vmhub = AMDGPU_MMHUB,
+	.extra_dw = 64,
 	.get_rptr = vcn_v1_0_jpeg_ring_get_rptr,
 	.get_wptr = vcn_v1_0_jpeg_ring_get_wptr,
 	.set_wptr = vcn_v1_0_jpeg_ring_set_wptr,