mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
1b1f42d8fd
This moves and renames the AMDGPU scheduler to a common location in DRM in order to facilitate re-use by other drivers. This is mostly a straight forward rename with no code changes. One notable exception is the function to_drm_sched_fence(), which is no longer a inline header function to avoid the need to export the drm_sched_fence_ops_scheduled and drm_sched_fence_ops_finished structures. Reviewed-by: Chunming Zhou <david1.zhou@amd.com> Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
123 lines
3.1 KiB
C
123 lines
3.1 KiB
C
/*
|
|
* Copyright 2017 Advanced Micro Devices, Inc.
|
|
*
|
|
* 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
|
|
*
|
|
*/
|
|
|
|
#ifndef DRM_SCHEDULER_SPSC_QUEUE_H_
|
|
#define DRM_SCHEDULER_SPSC_QUEUE_H_
|
|
|
|
#include <linux/atomic.h>
|
|
#include <linux/preempt.h>
|
|
|
|
/** SPSC lockless queue */
|
|
|
|
struct spsc_node {
|
|
|
|
/* Stores spsc_node* */
|
|
struct spsc_node *next;
|
|
};
|
|
|
|
struct spsc_queue {
|
|
|
|
struct spsc_node *head;
|
|
|
|
/* atomic pointer to struct spsc_node* */
|
|
atomic_long_t tail;
|
|
|
|
atomic_t job_count;
|
|
};
|
|
|
|
static inline void spsc_queue_init(struct spsc_queue *queue)
|
|
{
|
|
queue->head = NULL;
|
|
atomic_long_set(&queue->tail, (long)&queue->head);
|
|
atomic_set(&queue->job_count, 0);
|
|
}
|
|
|
|
static inline struct spsc_node *spsc_queue_peek(struct spsc_queue *queue)
|
|
{
|
|
return queue->head;
|
|
}
|
|
|
|
static inline int spsc_queue_count(struct spsc_queue *queue)
|
|
{
|
|
return atomic_read(&queue->job_count);
|
|
}
|
|
|
|
static inline bool spsc_queue_push(struct spsc_queue *queue, struct spsc_node *node)
|
|
{
|
|
struct spsc_node **tail;
|
|
|
|
node->next = NULL;
|
|
|
|
preempt_disable();
|
|
|
|
tail = (struct spsc_node **)atomic_long_xchg(&queue->tail, (long)&node->next);
|
|
WRITE_ONCE(*tail, node);
|
|
atomic_inc(&queue->job_count);
|
|
|
|
/*
|
|
* In case of first element verify new node will be visible to the consumer
|
|
* thread when we ping the kernel thread that there is new work to do.
|
|
*/
|
|
smp_wmb();
|
|
|
|
preempt_enable();
|
|
|
|
return tail == &queue->head;
|
|
}
|
|
|
|
|
|
static inline struct spsc_node *spsc_queue_pop(struct spsc_queue *queue)
|
|
{
|
|
struct spsc_node *next, *node;
|
|
|
|
/* Verify reading from memory and not the cache */
|
|
smp_rmb();
|
|
|
|
node = READ_ONCE(queue->head);
|
|
|
|
if (!node)
|
|
return NULL;
|
|
|
|
next = READ_ONCE(node->next);
|
|
WRITE_ONCE(queue->head, next);
|
|
|
|
if (unlikely(!next)) {
|
|
/* slowpath for the last element in the queue */
|
|
|
|
if (atomic_long_cmpxchg(&queue->tail,
|
|
(long)&node->next, (long) &queue->head) != (long)&node->next) {
|
|
/* Updating tail failed wait for new next to appear */
|
|
do {
|
|
smp_rmb();
|
|
} while (unlikely(!(queue->head = READ_ONCE(node->next))));
|
|
}
|
|
}
|
|
|
|
atomic_dec(&queue->job_count);
|
|
return node;
|
|
}
|
|
|
|
|
|
|
|
#endif /* DRM_SCHEDULER_SPSC_QUEUE_H_ */
|