drm/amdgpu: add limitation for dedicated vm number v4

Limit reserved vmids to 1 to avoid taking too many
out of commission and starving the system.

v2: move #define to amdgpu_vm.h
v3: move reserved vmid counter to id_manager,
and increase counter before allocating vmid
v4: rename to reserved_vmid_num

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 24ccf677f5a5..fb25bb747730 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -84,6 +84,8 @@ struct amdgpu_bo_list_entry;
 
 /* hardcode that limit for now */
 #define AMDGPU_VA_RESERVED_SIZE                 (8 << 20)
+/* max vmids dedicated for process */
+#define AMDGPU_VM_MAX_RESERVED_VMID     1
 
 struct amdgpu_vm_pt {
         struct amdgpu_bo        *bo;
@@ -154,6 +156,7 @@ struct amdgpu_vm_id_manager {
         unsigned                num_ids;
         struct list_head        ids_lru;
         struct amdgpu_vm_id     ids[AMDGPU_NUM_VM];
+        atomic_t                reserved_vmid_num;
 };
 
 struct amdgpu_vm_manager {