gpu: nvgpu: Replace kref for refcounting in nvgpu

- added wrapper struct nvgpu_ref over nvgpu_atomic_t
- added nvgpu_ref_* APIs to access the above struct

JIRA NVGPU-140

Change-Id: Id47f897995dd4721751f7610b6d4d4fbfe4d6b9a
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1540899
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/vm.c b/drivers/gpu/nvgpu/common/linux/vm.c
index 3d1219b6..c84f531d 100644
--- a/drivers/gpu/nvgpu/common/linux/vm.c
+++ b/drivers/gpu/nvgpu/common/linux/vm.c
@@ -155,7 +155,7 @@ static u64 __nvgpu_vm_find_mapping(struct vm_gk20a *vm,
                 else
                         mapped_buffer->own_mem_ref = true;
         }
-        kref_get(&mapped_buffer->ref);
+        nvgpu_ref_get(&mapped_buffer->ref);
 
         nvgpu_log(g, gpu_dbg_map,
                   "gv: 0x%04x_%08x + 0x%-7zu "
@@ -380,7 +380,7 @@ u64 nvgpu_vm_map(struct vm_gk20a *vm,
         mapped_buffer->user_mapped = user_mapped ? 1 : 0;
         mapped_buffer->own_mem_ref = user_mapped;
         nvgpu_init_list_node(&mapped_buffer->buffer_list);
-        kref_init(&mapped_buffer->ref);
+        nvgpu_ref_init(&mapped_buffer->ref);
 
         err = nvgpu_insert_mapped_buf(vm, mapped_buffer);
         if (err) {
@@ -425,6 +425,6 @@ void nvgpu_vm_unmap(struct vm_gk20a *vm, u64 offset)
                 return;
         }
 
-        kref_put(&mapped_buffer->ref, gk20a_vm_unmap_locked_kref);
+        nvgpu_ref_put(&mapped_buffer->ref, gk20a_vm_unmap_locked_ref);
         nvgpu_mutex_release(&vm->update_gmmu_lock);
 }