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, 8 insertions, 7 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index 2ce78cef..3030c170 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -811,7 +811,7 @@ int nvgpu_vm_get_buffers(struct vm_gk20a *vm,
                 mapped_buffer = mapped_buffer_from_rbtree_node(node);
                 if (mapped_buffer->user_mapped) {
                         buffer_list[i] = mapped_buffer;
-                        kref_get(&mapped_buffer->ref);
+                        nvgpu_ref_get(&mapped_buffer->ref);
                         i++;
                 }
                 nvgpu_rbtree_enum_next(&node, node);
@@ -827,7 +827,7 @@ int nvgpu_vm_get_buffers(struct vm_gk20a *vm,
         return 0;
 }
 
-void gk20a_vm_unmap_locked_kref(struct kref *ref)
+void gk20a_vm_unmap_locked_ref(struct nvgpu_ref *ref)
 {
         struct nvgpu_mapped_buf *mapped_buffer =
                 container_of(ref, struct nvgpu_mapped_buf, ref);
@@ -849,8 +849,8 @@ void nvgpu_vm_put_buffers(struct vm_gk20a *vm,
         vm->kref_put_batch = &batch;
 
         for (i = 0; i < num_buffers; ++i)
-                kref_put(&mapped_buffers[i]->ref,
-                         gk20a_vm_unmap_locked_kref);
+                nvgpu_ref_put(&mapped_buffers[i]->ref,
+                         gk20a_vm_unmap_locked_ref);
 
         vm->kref_put_batch = NULL;
         nvgpu_vm_mapping_batch_finish_locked(vm, &batch);
@@ -882,8 +882,9 @@ static void nvgpu_vm_unmap_user(struct vm_gk20a *vm, u64 offset,
                 nvgpu_timeout_init(vm->mm->g, &timeout, 10000,
                                    NVGPU_TIMER_RETRY_TIMER);
                 do {
-                        if (atomic_read(&mapped_buffer->ref.refcount) == 1)
-                                break;
+                        if (nvgpu_atomic_read(
+                                &mapped_buffer->ref.refcount) == 1)
+                                        break;
                         nvgpu_udelay(5);
                 } while (!nvgpu_timeout_expired_msg(&timeout,
                                             "sync-unmap failed on 0x%llx"));
@@ -902,7 +903,7 @@ static void nvgpu_vm_unmap_user(struct vm_gk20a *vm, u64 offset,
                 vm->num_user_mapped_buffers--;
 
         vm->kref_put_batch = batch;
-        kref_put(&mapped_buffer->ref, gk20a_vm_unmap_locked_kref);
+        nvgpu_ref_put(&mapped_buffer->ref, gk20a_vm_unmap_locked_ref);
         vm->kref_put_batch = NULL;
 
         nvgpu_mutex_release(&vm->update_gmmu_lock);