drm_flip_work.c
/*
* Copyright (C) 2013 Red Hat
*
* 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 (including the next
* paragraph) 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.
*/
#include <drm/drmP.h>
#include <drm/drm_util.h>
#include <drm/drm_flip_work.h>
/**
* drm_flip_work_allocate_task - allocate a flip-work task
* @data: data associated to the task
* @flags: allocator flags
*
* Allocate a drm_flip_task object and attach private data to it.
*/
struct drm_flip_task *drm_flip_work_allocate_task(void *data, gfp_t flags)
{
struct drm_flip_task *task;
task = kzalloc(sizeof(*task), flags);
if (task)
task->data = data;
return task;
}
EXPORT_SYMBOL(drm_flip_work_allocate_task);
/**
* drm_flip_work_queue_task - queue a specific task
* @work: the flip-work
* @task: the task to handle
*
* Queues task, that will later be run (passed back to drm_flip_func_t
* func) on a work queue after drm_flip_work_commit() is called.
*/
void drm_flip_work_queue_task(struct drm_flip_work *work,
struct drm_flip_task *task)
{
unsigned long flags;
spin_lock_irqsave(&work->lock, flags);
list_add_tail(&task->node, &work->queued);
spin_unlock_irqrestore(&work->lock, flags);
}
EXPORT_SYMBOL(drm_flip_work_queue_task);
/**
* drm_flip_work_queue - queue work
* @work: the flip-work
* @val: the value to queue
*
* Queues work, that will later be run (passed back to drm_flip_func_t
* func) on a work queue after drm_flip_work_commit() is called.
*/
void drm_flip_work_queue(struct drm_flip_work *work, void *val)
{
struct drm_flip_task *task;
task = drm_flip_work_allocate_task(val,
drm_can_sleep() ? GFP_KERNEL : GFP_ATOMIC);
if (task) {
drm_flip_work_queue_task(work, task);
} else {
DRM_ERROR("%s could not allocate task!\n", work->name);
work->func(work, val);
}
}
EXPORT_SYMBOL(drm_flip_work_queue);
/**
* drm_flip_work_commit - commit queued work
* @work: the flip-work
* @wq: the work-queue to run the queued work on
*
* Trigger work previously queued by drm_flip_work_queue() to run
* on a workqueue. The typical usage would be to queue work (via
* drm_flip_work_queue()) at any point (from vblank irq and/or
* prior), and then from vblank irq commit the queued work.
*/
void drm_flip_work_commit(struct drm_flip_work *work,
struct workqueue_struct *wq)
{
unsigned long flags;
spin_lock_irqsave(&work->lock, flags);
list_splice_tail(&work->queued, &work->commited);
INIT_LIST_HEAD(&work->queued);
spin_unlock_irqrestore(&work->lock, flags);
queue_work(wq, &work->worker);
}
EXPORT_SYMBOL(drm_flip_work_commit);
static void flip_worker(struct work_struct *w)
{
struct drm_flip_work *work = container_of(w, struct drm_flip_work, worker);
struct list_head tasks;
unsigned long flags;
while (1) {
struct drm_flip_task *task, *tmp;
INIT_LIST_HEAD(&tasks);
spin_lock_irqsave(&work->lock, flags);
list_splice_tail(&work->commited, &tasks);
INIT_LIST_HEAD(&work->commited);
spin_unlock_irqrestore(&work->lock, flags);
if (list_empty(&tasks))
break;
list_for_each_entry_safe(task, tmp, &tasks, node) {
work->func(work, task->data);
kfree(task);
}
}
}
/**
* drm_flip_work_init - initialize flip-work
* @work: the flip-work to initialize
* @name: debug name
* @func: the callback work function
*
* Initializes/allocates resources for the flip-work
*/
void drm_flip_work_init(struct drm_flip_work *work,
const char *name, drm_flip_func_t func)
{
work->name = name;
INIT_LIST_HEAD(&work->queued);
INIT_LIST_HEAD(&work->commited);
spin_lock_init(&work->lock);
work->func = func;
INIT_WORK(&work->worker, flip_worker);
}
EXPORT_SYMBOL(drm_flip_work_init);
/**
* drm_flip_work_cleanup - cleans up flip-work
* @work: the flip-work to cleanup
*
* Destroy resources allocated for the flip-work
*/
void drm_flip_work_cleanup(struct drm_flip_work *work)
{
WARN_ON(!list_empty(&work->queued) || !list_empty(&work->commited));
}
EXPORT_SYMBOL(drm_flip_work_cleanup);