mirror of
git://nv-tegra.nvidia.com/linux-nvgpu.git
synced 2025-12-23 18:16:01 +03:00
7885500a42
Change license of OS independent source code files to MIT. JIRA NVGPU-218 Change-Id: I1474065f4b552112786974a16cdf076c5179540e Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/1565880 Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com> Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
87 lines
2.8 KiB
C
87 lines
2.8 KiB
C
/*
|
|
* Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
|
* copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
* DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
/*
|
|
* The following structure is used for reference counting of objects in nvgpu.
|
|
*/
|
|
#ifndef __NVGPU_KREF_H__
|
|
#define __NVGPU_KREF_H__
|
|
|
|
#include <nvgpu/atomic.h>
|
|
|
|
struct nvgpu_ref {
|
|
nvgpu_atomic_t refcount;
|
|
};
|
|
|
|
/*
|
|
* Initialize object.
|
|
* @ref: the nvgpu_ref object to initialize
|
|
*/
|
|
static inline void nvgpu_ref_init(struct nvgpu_ref *ref)
|
|
{
|
|
nvgpu_atomic_set(&ref->refcount, 1);
|
|
}
|
|
|
|
/*
|
|
* Increment reference count for the object
|
|
* @ref: the nvgpu_ref object
|
|
*/
|
|
static inline void nvgpu_ref_get(struct nvgpu_ref *ref)
|
|
{
|
|
nvgpu_atomic_inc(&ref->refcount);
|
|
}
|
|
|
|
/*
|
|
* Decrement reference count for the object and call release() if it becomes
|
|
* zero.
|
|
* @ref: the nvgpu_ref object
|
|
* @release: pointer to the function that would be invoked to clean up the
|
|
* object when the reference count becomes zero, i.e. the last
|
|
* reference corresponding to this object is removed.
|
|
* Return 1 if object was removed, otherwise return 0. The user should not
|
|
* make any assumptions about the status of the object in the memory when
|
|
* the function returns 0 and should only use it to know that there are no
|
|
* further references to this object.
|
|
*/
|
|
static inline int nvgpu_ref_put(struct nvgpu_ref *ref,
|
|
void (*release)(struct nvgpu_ref *r))
|
|
{
|
|
if (nvgpu_atomic_sub_and_test(1, &ref->refcount)) {
|
|
if (release != NULL)
|
|
release(ref);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Increment reference count for the object unless it is zero.
|
|
* @ref: the nvgpu_ref object
|
|
* Return non-zero if the increment succeeds, Otherwise return 0.
|
|
*/
|
|
static inline int __must_check nvgpu_ref_get_unless_zero(struct nvgpu_ref *ref)
|
|
{
|
|
return nvgpu_atomic_add_unless(&ref->refcount, 1, 0);
|
|
}
|
|
|
|
#endif /* __NVGPU_KREF_H__ */
|