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/*
* Copyright 2015 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.
*
*/
#include <linux/kthread.h>
#include <linux/slab.h>
#include <drm/drm_print.h>
#include <drm/gpu_scheduler.h>
#include "gpu_scheduler_trace.h"
#define to_drm_sched_job(sched_job) \
container_of((sched_job), struct drm_sched_job, queue_node)
/**
* drm_sched_entity_init - Init a context entity used by scheduler when
* submit to HW ring.
*
* @entity: scheduler entity to init
* @rq_list: the list of run queue on which jobs from this
* entity can be submitted
* @num_rq_list: number of run queue in rq_list
* @guilty: atomic_t set to 1 when a job on this queue
* is found to be guilty causing a timeout
*
* Note: the rq_list should have atleast one element to schedule
* the entity
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_sched_entity_init(struct drm_sched_entity *entity,
struct drm_sched_rq **rq_list,
unsigned int num_rq_list,
atomic_t *guilty)
{
int i;
if (!(entity && rq_list && (num_rq_list == 0 || rq_list[0])))
return -EINVAL;
memset(entity, 0, sizeof(struct drm_sched_entity));
INIT_LIST_HEAD(&entity->list);
entity->rq = NULL;
entity->guilty = guilty;
entity->num_rq_list = num_rq_list;
entity->rq_list = kcalloc(num_rq_list, sizeof(struct drm_sched_rq *),
GFP_KERNEL);
if (!entity->rq_list)
return -ENOMEM;
for (i = 0; i < num_rq_list; ++i)
entity->rq_list[i] = rq_list[i];
if (num_rq_list)
entity->rq = rq_list[0];
entity->last_scheduled = NULL;
spin_lock_init(&entity->rq_lock);
spsc_queue_init(&entity->job_queue);
atomic_set(&entity->fence_seq, 0);
entity->fence_context = dma_fence_context_alloc(2);
return 0;
}
EXPORT_SYMBOL(drm_sched_entity_init);
/**
* drm_sched_entity_is_idle - Check if entity is idle
*
* @entity: scheduler entity
*
* Returns true if the entity does not have any unscheduled jobs.
*/
static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
{
rmb(); /* for list_empty to work without lock */
if (list_empty(&entity->list) ||
spsc_queue_count(&entity->job_queue) == 0)
return true;
return false;
}
/**
* drm_sched_entity_is_ready - Check if entity is ready
*
* @entity: scheduler entity
*
* Return true if entity could provide a job.
*/
bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
{
if (spsc_queue_peek(&entity->job_queue) == NULL)
return false;
if (READ_ONCE(entity->dependency))
return false;
return true;
}
/**
* drm_sched_entity_get_free_sched - Get the rq from rq_list with least load
*
* @entity: scheduler entity
*
* Return the pointer to the rq with least load.
*/
static struct drm_sched_rq *
drm_sched_entity_get_free_sched(struct drm_sched_entity *entity)
{
struct drm_sched_rq *rq = NULL;
unsigned int min_jobs = UINT_MAX, num_jobs;
int i;
for (i = 0; i < entity->num_rq_list; ++i) {
struct drm_gpu_scheduler *sched = entity->rq_list[i]->sched;
if (!entity->rq_list[i]->sched->ready) {
DRM_WARN("sched%s is not ready, skipping", sched->name);
continue;
}
num_jobs = atomic_read(&sched->num_jobs);
if (num_jobs < min_jobs) {
min_jobs = num_jobs;
rq = entity->rq_list[i];
}
}
return rq;
}
/**
* drm_sched_entity_flush - Flush a context entity
*
* @entity: scheduler entity
* @timeout: time to wait in for Q to become empty in jiffies.
*
* Splitting drm_sched_entity_fini() into two functions, The first one does the
* waiting, removes the entity from the runqueue and returns an error when the
* process was killed.
*
* Returns the remaining time in jiffies left from the input timeout
*/
long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
{
struct drm_gpu_scheduler *sched;
struct task_struct *last_user;
long ret = timeout;
if (!entity->rq)
return 0;
sched = entity->rq->sched;
/**
* The client will not queue more IBs during this fini, consume existing
* queued IBs or discard them on SIGKILL
*/
if (current->flags & PF_EXITING) {
if (timeout)
ret = wait_event_timeout(
sched->job_scheduled,
drm_sched_entity_is_idle(entity),
timeout);
} else {
wait_event_killable(sched->job_scheduled,
drm_sched_entity_is_idle(entity));
}
/* For killed process disable any more IBs enqueue right now */
last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
if ((!last_user || last_user == current->group_leader) &&
(current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) {
spin_lock(&entity->rq_lock);
entity->stopped = true;
drm_sched_rq_remove_entity(entity->rq, entity);
spin_unlock(&entity->rq_lock);
}
return ret;
}
EXPORT_SYMBOL(drm_sched_entity_flush);
/**
* drm_sched_entity_kill_jobs - helper for drm_sched_entity_kill_jobs
*
* @f: signaled fence
* @cb: our callback structure
*
* Signal the scheduler finished fence when the entity in question is killed.
*/
static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
struct dma_fence_cb *cb)
{
struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
finish_cb);
drm_sched_fence_finished(job->s_fence);
WARN_ON(job->s_fence->parent);
job->sched->ops->free_job(job);
}
/**
* drm_sched_entity_kill_jobs - Make sure all remaining jobs are killed
*
* @entity: entity which is cleaned up
*
* Makes sure that all remaining jobs in an entity are killed before it is
* destroyed.
*/
static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
{
struct drm_sched_job *job;
int r;
while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
struct drm_sched_fence *s_fence = job->s_fence;
drm_sched_fence_scheduled(s_fence);
dma_fence_set_error(&s_fence->finished, -ESRCH);
/*
* When pipe is hanged by older entity, new entity might
* not even have chance to submit it's first job to HW
* and so entity->last_scheduled will remain NULL
*/
if (!entity->last_scheduled) {
drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
continue;
}
r = dma_fence_add_callback(entity->last_scheduled,
&job->finish_cb,
drm_sched_entity_kill_jobs_cb);
if (r == -ENOENT)
drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
else if (r)
DRM_ERROR("fence add callback failed (%d)\n", r);
}
}
/**
* drm_sched_entity_cleanup - Destroy a context entity
*
* @entity: scheduler entity
*
* This should be called after @drm_sched_entity_do_release. It goes over the
* entity and signals all jobs with an error code if the process was killed.
*
*/
void drm_sched_entity_fini(struct drm_sched_entity *entity)
{
struct drm_gpu_scheduler *sched = NULL;
if (entity->rq) {
sched = entity->rq->sched;
drm_sched_rq_remove_entity(entity->rq, entity);
}
/* Consumption of existing IBs wasn't completed. Forcefully
* remove them here.
*/
if (spsc_queue_count(&entity->job_queue)) {
if (sched) {
/* Park the kernel for a moment to make sure it isn't processing
* our enity.
*/
kthread_park(sched->thread);
kthread_unpark(sched->thread);
}
if (entity->dependency) {
dma_fence_remove_callback(entity->dependency,
&entity->cb);
dma_fence_put(entity->dependency);
entity->dependency = NULL;
}
drm_sched_entity_kill_jobs(entity);
}
dma_fence_put(entity->last_scheduled);
entity->last_scheduled = NULL;
kfree(entity->rq_list);
}
EXPORT_SYMBOL(drm_sched_entity_fini);
/**
* drm_sched_entity_fini - Destroy a context entity
*
* @entity: scheduler entity
*
* Calls drm_sched_entity_do_release() and drm_sched_entity_cleanup()
*/
void drm_sched_entity_destroy(struct drm_sched_entity *entity)
{
drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
drm_sched_entity_fini(entity);
}
EXPORT_SYMBOL(drm_sched_entity_destroy);
/**
* drm_sched_entity_clear_dep - callback to clear the entities dependency
*/
static void drm_sched_entity_clear_dep(struct dma_fence *f,
struct dma_fence_cb *cb)
{
struct drm_sched_entity *entity =
container_of(cb, struct drm_sched_entity, cb);
entity->dependency = NULL;
dma_fence_put(f);
}
/**
* drm_sched_entity_clear_dep - callback to clear the entities dependency and
* wake up scheduler
*/
static void drm_sched_entity_wakeup(struct dma_fence *f,
struct dma_fence_cb *cb)
{
struct drm_sched_entity *entity =
container_of(cb, struct drm_sched_entity, cb);
drm_sched_entity_clear_dep(f, cb);
drm_sched_wakeup(entity->rq->sched);
}
/**
* drm_sched_entity_set_rq_priority - helper for drm_sched_entity_set_priority
*/
static void drm_sched_entity_set_rq_priority(struct drm_sched_rq **rq,
enum drm_sched_priority priority)
{
*rq = &(*rq)->sched->sched_rq[priority];
}
/**
* drm_sched_entity_set_priority - Sets priority of the entity
*
* @entity: scheduler entity
* @priority: scheduler priority
*
* Update the priority of runqueus used for the entity.
*/
void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
enum drm_sched_priority priority)
{
unsigned int i;
spin_lock(&entity->rq_lock);
for (i = 0; i < entity->num_rq_list; ++i)
drm_sched_entity_set_rq_priority(&entity->rq_list[i], priority);
if (entity->rq) {
drm_sched_rq_remove_entity(entity->rq, entity);
drm_sched_entity_set_rq_priority(&entity->rq, priority);
drm_sched_rq_add_entity(entity->rq, entity);
}
spin_unlock(&entity->rq_lock);
}
EXPORT_SYMBOL(drm_sched_entity_set_priority);
/**
* drm_sched_entity_add_dependency_cb - add callback for the entities dependency
*
* @entity: entity with dependency
*
* Add a callback to the current dependency of the entity to wake up the
* scheduler when the entity becomes available.
*/
static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
{
struct drm_gpu_scheduler *sched = entity->rq->sched;
struct dma_fence *fence = entity->dependency;
struct drm_sched_fence *s_fence;
if (fence->context == entity->fence_context ||
fence->context == entity->fence_context + 1) {
/*
* Fence is a scheduled/finished fence from a job
* which belongs to the same entity, we can ignore
* fences from ourself
*/
dma_fence_put(entity->dependency);
return false;
}
s_fence = to_drm_sched_fence(fence);
if (s_fence && s_fence->sched == sched) {
/*
* Fence is from the same scheduler, only need to wait for
* it to be scheduled
*/
fence = dma_fence_get(&s_fence->scheduled);
dma_fence_put(entity->dependency);
entity->dependency = fence;
if (!dma_fence_add_callback(fence, &entity->cb,
drm_sched_entity_clear_dep))
return true;
/* Ignore it when it is already scheduled */
dma_fence_put(fence);
return false;
}
if (!dma_fence_add_callback(entity->dependency, &entity->cb,
drm_sched_entity_wakeup))
return true;
dma_fence_put(entity->dependency);
return false;
}
/**
* drm_sched_entity_pop_job - get a ready to be scheduled job from the entity
*
* @entity: entity to get the job from
*
* Process all dependencies and try to get one job from the entities queue.
*/
struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
{
struct drm_gpu_scheduler *sched = entity->rq->sched;
struct drm_sched_job *sched_job;
sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
if (!sched_job)
return NULL;
while ((entity->dependency =
sched->ops->dependency(sched_job, entity))) {
trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
if (drm_sched_entity_add_dependency_cb(entity))
return NULL;
}
/* skip jobs from entity that marked guilty */
if (entity->guilty && atomic_read(entity->guilty))
dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);
dma_fence_put(entity->last_scheduled);
entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);
spsc_queue_pop(&entity->job_queue);
return sched_job;
}
/**
* drm_sched_entity_select_rq - select a new rq for the entity
*
* @entity: scheduler entity
*
* Check all prerequisites and select a new rq for the entity for load
* balancing.
*/
void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
{
struct dma_fence *fence;
struct drm_sched_rq *rq;
if (spsc_queue_count(&entity->job_queue) || entity->num_rq_list <= 1)
return;
fence = READ_ONCE(entity->last_scheduled);
if (fence && !dma_fence_is_signaled(fence))
return;
rq = drm_sched_entity_get_free_sched(entity);
if (rq == entity->rq)
return;
spin_lock(&entity->rq_lock);
drm_sched_rq_remove_entity(entity->rq, entity);
entity->rq = rq;
spin_unlock(&entity->rq_lock);
}
/**
* drm_sched_entity_push_job - Submit a job to the entity's job queue
*
* @sched_job: job to submit
* @entity: scheduler entity
*
* Note: To guarantee that the order of insertion to queue matches
* the job's fence sequence number this function should be
* called with drm_sched_job_init under common lock.
*
* Returns 0 for success, negative error code otherwise.
*/
void drm_sched_entity_push_job(struct drm_sched_job *sched_job,
struct drm_sched_entity *entity)
{
bool first;
trace_drm_sched_job(sched_job, entity);
atomic_inc(&entity->rq->sched->num_jobs);
WRITE_ONCE(entity->last_user, current->group_leader);
first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
/* first job wakes up scheduler */
if (first) {
/* Add the entity to the run queue */
spin_lock(&entity->rq_lock);
if (entity->stopped) {
spin_unlock(&entity->rq_lock);
DRM_ERROR("Trying to push to a killed entity\n");
return;
}
drm_sched_rq_add_entity(entity->rq, entity);
spin_unlock(&entity->rq_lock);
drm_sched_wakeup(entity->rq->sched);
}
}
EXPORT_SYMBOL(drm_sched_entity_push_job);
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