drm/amdgpu: use fence_context to judge ctx switch v2

Use of the ctx pointer is not safe, because they are likely already
be assigned to another ctx when doing comparing.

v2: recreate from scratch, avoid all unnecessary changes.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Monk.Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -743,7 +743,7 @@ struct amdgpu_ib {
 	struct amdgpu_user_fence        *user;
 	unsigned			vm_id;
 	uint64_t			vm_pd_addr;
-	struct amdgpu_ctx		*ctx;
+	uint64_t			ctx;
 	uint32_t			gds_base, gds_size;
 	uint32_t			gws_base, gws_size;
 	uint32_t			oa_base, oa_size;
@@ -806,7 +806,7 @@ struct amdgpu_ring {
 	unsigned		wptr_offs;
 	unsigned		next_rptr_offs;
 	unsigned		fence_offs;
-	struct amdgpu_ctx	*current_ctx;
+	uint64_t		current_ctx;
 	enum amdgpu_ring_type	type;
 	char			name[16];
 	unsigned		cond_exe_offs;

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

@@ -741,7 +741,7 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device *adev,
 
 		ib->length_dw = chunk_ib->ib_bytes / 4;
 		ib->flags = chunk_ib->flags;
-		ib->ctx = parser->ctx;
+		ib->ctx = parser->ctx->rings[ring->idx].entity.fence_context;
 		j++;
 	}
 

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

@@ -121,7 +121,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs,
 {
 	struct amdgpu_device *adev = ring->adev;
 	struct amdgpu_ib *ib = &ibs[0];
-	struct amdgpu_ctx *ctx, *old_ctx;
+	uint64_t ctx, old_ctx;
 	struct fence *hwf;
 	struct amdgpu_vm *vm = NULL;
 	unsigned i, patch_offset = ~0;