/*
* 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/wait.h>
#include <linux/sched.h>
#include <drm/drmP.h>
#include "gpu_scheduler.h"
/* Initialize a given run queue struct */
static void init_rq(struct amd_run_queue *rq)
{
INIT_LIST_HEAD(&rq->head.list);
rq->head.belongto_rq = rq;
mutex_init(&rq->lock);
atomic_set(&rq->nr_entity, 0);
rq->current_entity = &rq->head;
}
/* Note: caller must hold the lock or in a atomic context */
static void rq_remove_entity(struct amd_run_queue *rq,
struct amd_sched_entity *entity)
{
if (rq->current_entity == entity)
rq->current_entity = list_entry(entity->list.prev,
typeof(*entity), list);
list_del_init(&entity->list);
atomic_dec(&rq->nr_entity);
}
static void rq_add_entity(struct amd_run_queue *rq,
struct amd_sched_entity *entity)
{
list_add_tail(&entity->list, &rq->head.list);
atomic_inc(&rq->nr_entity);
}
/**
* Select next entity from a specified run queue with round robin policy.
* It could return the same entity as current one if current is the only
* available one in the queue. Return NULL if nothing available.
*/
static struct amd_sched_entity *rq_select_entity(struct amd_run_queue *rq)
{
struct amd_sched_entity *p = rq->current_entity;
int i = atomic_read(&rq->nr_entity) + 1; /*real count + dummy head*/
while (i) {
p = list_entry(p->list.next, typeof(*p), list);
if (!rq->check_entity_status(p)) {
rq->current_entity = p;
break;
}
i--;
}
return i ? p : NULL;
}
static bool context_entity_is_waiting(struct amd_sched_entity *entity)
{
/* TODO: sync obj for multi-ring synchronization */
return false;
}
static int gpu_entity_check_status(struct amd_sched_entity *entity)
{
if (entity == &entity->belongto_rq->head)
return -1;
if (kfifo_is_empty(&entity->job_queue) ||
context_entity_is_waiting(entity))
return -1;
return 0;
}
/**
* Note: This function should only been called inside scheduler main
* function for thread safety, there is no other protection here.
* return ture if scheduler has something ready to run.
*
* For active_hw_rq, there is only one producer(scheduler thread) and
* one consumer(ISR). It should be safe to use this function in scheduler
* main thread to decide whether to continue emit more IBs.
*/
static bool is_scheduler_ready(struct amd_gpu_scheduler *sched)
{
unsigned long flags;
bool full;
spin_lock_irqsave(&sched->queue_lock, flags);
full = atomic64_read(&sched->hw_rq_count) <
sched->hw_submission_limit ? true : false;
spin_unlock_irqrestore(&sched->queue_lock, flags);
return full;
}
/**
* Select next entity from the kernel run queue, if not available,
* return null.
*/
static struct amd_sched_entity *
kernel_rq_select_context(struct amd_gpu_scheduler *sched)
{
struct amd_sched_entity *sched_entity;
struct amd_run_queue *rq = &sched->kernel_rq;
mutex_lock(&rq->lock);
sched_entity = rq_select_entity(rq);
mutex_unlock(&rq->lock);
return sched_entity;
}
/**
* Select next entity containing real IB submissions
*/
static struct amd_sched_entity *
select_context(struct amd_gpu_scheduler *sched)
{
struct amd_sched_entity *wake_entity = NULL;
struct amd_sched_entity *tmp;
struct amd_run_queue *rq;
if (!is_scheduler_ready(sched))
return NULL;
/* Kernel run queue has higher priority than normal run queue*/
tmp = kernel_rq_select_context(sched);
if (tmp != NULL)
goto exit;
rq = &sched->sched_rq;
mutex_lock(&rq->lock);
tmp = rq_select_entity(rq);
mutex_unlock(&rq->lock);
exit:
if (sched->current_entity && (sched->current_entity != tmp))
wake_entity = sched->current_entity;
sched->current_entity = tmp;
if (wake_entity)
wake_up(&wake_entity->wait_queue);
return tmp;
}
/**
* Init a context entity used by scheduler when submit to HW ring.
*
* @sched The pointer to the scheduler
* @entity The pointer to a valid amd_sched_entity
* @rq The run queue this entity belongs
* @kernel If this is an entity for the kernel
* @jobs The max number of jobs in the job queue
*
* return 0 if succeed. negative error code on failure
*/
int amd_sched_entity_init(struct amd_gpu_scheduler *sched,
struct amd_sched_entity *entity,
struct amd_run_queue *rq,
uint32_t jobs)
{
uint64_t seq_ring = 0;
if (!(sched && entity && rq))
return -EINVAL;
memset(entity, 0, sizeof(struct amd_sched_entity));
seq_ring = ((uint64_t)sched->ring_id) << 60;
spin_lock_init(&entity->lock);
entity->belongto_rq = rq;
entity->scheduler = sched;
init_waitqueue_head(&entity->wait_queue);
init_waitqueue_head(&entity->wait_emit);
if(kfifo_alloc(&entity->job_queue,
jobs * sizeof(void *),
GFP_KERNEL))
return -EINVAL;
spin_lock_init(&entity->queue_lock);
atomic64_set(&entity->last_emitted_v_seq, seq_ring);
atomic64_set(&entity->last_queued_v_seq, seq_ring);
/* Add the entity to the run queue */
mutex_lock(&rq->lock);
rq_add_entity(rq, entity);
mutex_unlock(&rq->lock);
return 0;
}
/**
* Query if entity is initialized
*
* @sched Pointer to scheduler instance
* @entity The pointer to a valid scheduler entity
*
* return true if entity is initialized, false otherwise
*/
static bool is_context_entity_initialized(struct amd_gpu_scheduler *sched,
struct amd_sched_entity *entity)
{
return entity->scheduler == sched &&
entity->belongto_rq != NULL;
}
static bool is_context_entity_idle(struct amd_gpu_scheduler *sched,
struct amd_sched_entity *entity)
{
/**
* Idle means no pending IBs, and the entity is not
* currently being used.
*/
barrier();
if ((sched->current_entity != entity) &&
kfifo_is_empty(&entity->job_queue))
return true;
return false;
}
/**
* Destroy a context entity
*
* @sched Pointer to scheduler instance
* @entity The pointer to a valid scheduler entity
*
* return 0 if succeed. negative error code on failure
*/
int amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
struct amd_sched_entity *entity)
{
int r = 0;
struct amd_run_queue *rq = entity->belongto_rq;
if (!is_context_entity_initialized(sched, entity))
return 0;
/**
* The client will not queue more IBs during this fini, consume existing
* queued IBs
*/
r = wait_event_timeout(
entity->wait_queue,
is_context_entity_idle(sched, entity),
msecs_to_jiffies(AMD_GPU_WAIT_IDLE_TIMEOUT_IN_MS)
) ? 0 : -1;
if (r) {
if (entity->is_pending)
DRM_INFO("Entity %p is in waiting state during fini,\
all pending ibs will be canceled.\n",
entity);
}
mutex_lock(&rq->lock);
rq_remove_entity(rq, entity);
mutex_unlock(&rq->lock);
kfifo_free(&entity->job_queue);
return r;
}
/**
* Submit a normal job to the job queue
*
* @sched The pointer to the scheduler
* @c_entity The pointer to amd_sched_entity
* @job The pointer to job required to submit
* return 0 if succeed. -1 if failed.
* -2 indicate queue is full for this client, client should wait untill
* scheduler consum some queued command.
* -1 other fail.
*/
int amd_sched_push_job(struct amd_gpu_scheduler *sched,
struct amd_sched_entity *c_entity,
void *job)
{
while (kfifo_in_spinlocked(&c_entity->job_queue, &job, sizeof(void *),
&c_entity->queue_lock) != sizeof(void *)) {
/**
* Current context used up all its IB slots
* wait here, or need to check whether GPU is hung
*/
schedule();
}
wake_up_interruptible(&sched->wait_queue);
return 0;
}
/**
* Wait for a virtual sequence number to be emitted.
*
* @c_entity The pointer to a valid context entity
* @seq The virtual sequence number to wait
* @intr Interruptible or not
* @timeout Timeout in ms, wait infinitely if <0
* @emit wait for emit or signal
*
* return =0 signaled , <0 failed
*/
int amd_sched_wait_emit(struct amd_sched_entity *c_entity,
uint64_t seq,
bool intr,
long timeout)
{
atomic64_t *v_seq = &c_entity->last_emitted_v_seq;
wait_queue_head_t *wait_queue = &c_entity->wait_emit;
if (intr && (timeout < 0)) {
wait_event_interruptible(
*wait_queue,
seq <= atomic64_read(v_seq));
return 0;
} else if (intr && (timeout >= 0)) {
wait_event_interruptible_timeout(
*wait_queue,
seq <= atomic64_read(v_seq),
msecs_to_jiffies(timeout));
return (seq <= atomic64_read(v_seq)) ?
0 : -1;
} else if (!intr && (timeout < 0)) {
wait_event(
*wait_queue,
seq <= atomic64_read(v_seq));
return 0;
} else if (!intr && (timeout >= 0)) {
wait_event_timeout(
*wait_queue,
seq <= atomic64_read(v_seq),
msecs_to_jiffies(timeout));
return (seq <= atomic64_read(v_seq)) ?
0 : -1;
}
return 0;
}
static void amd_sched_process_job(struct fence *f, struct fence_cb *cb)
{
struct amd_sched_job *sched_job =
container_of(cb, struct amd_sched_job, cb);
struct amd_gpu_scheduler *sched;
unsigned long flags;
sched = sched_job->sched;
spin_lock_irqsave(&sched->queue_lock, flags);
list_del(&sched_job->list);
atomic64_dec(&sched->hw_rq_count);
spin_unlock_irqrestore(&sched->queue_lock, flags);
sched->ops->process_job(sched, sched_job->job);
kfree(sched_job);
wake_up_interruptible(&sched->wait_queue);
}
static int amd_sched_main(void *param)
{
int r;
void *job;
struct sched_param sparam = {.sched_priority = 1};
struct amd_sched_entity *c_entity = NULL;
struct amd_gpu_scheduler *sched = (struct amd_gpu_scheduler *)param;
sched_setscheduler(current, SCHED_FIFO, &sparam);
while (!kthread_should_stop()) {
struct amd_sched_job *sched_job = NULL;
struct fence *fence;
wait_event_interruptible(sched->wait_queue,
is_scheduler_ready(sched) &&
(c_entity = select_context(sched)));
r = kfifo_out(&c_entity->job_queue, &job, sizeof(void *));
if (r != sizeof(void *))
continue;
r = sched->ops->prepare_job(sched, c_entity, job);
if (!r) {
unsigned long flags;
sched_job = kzalloc(sizeof(struct amd_sched_job),
GFP_KERNEL);
if (!sched_job) {
WARN(true, "No memory to allocate\n");
continue;
}
sched_job->job = job;
sched_job->sched = sched;
spin_lock_irqsave(&sched->queue_lock, flags);
list_add_tail(&sched_job->list, &sched->active_hw_rq);
atomic64_inc(&sched->hw_rq_count);
spin_unlock_irqrestore(&sched->queue_lock, flags);
}
mutex_lock(&sched->sched_lock);
fence = sched->ops->run_job(sched, c_entity, sched_job);
if (fence) {
r = fence_add_callback(fence, &sched_job->cb,
amd_sched_process_job);
if (r == -ENOENT)
amd_sched_process_job(fence, &sched_job->cb);
else if (r)
DRM_ERROR("fence add callback failed (%d)\n", r);
fence_put(fence);
}
mutex_unlock(&sched->sched_lock);
}
return 0;
}
/**
* Create a gpu scheduler
*
* @device The device context for this scheduler
* @ops The backend operations for this scheduler.
* @id The scheduler is per ring, here is ring id.
* @granularity The minumum ms unit the scheduler will scheduled.
* @preemption Indicate whether this ring support preemption, 0 is no.
*
* return the pointer to scheduler for success, otherwise return NULL
*/
struct amd_gpu_scheduler *amd_sched_create(void *device,
struct amd_sched_backend_ops *ops,
unsigned ring,
unsigned granularity,
unsigned preemption,
unsigned hw_submission)
{
struct amd_gpu_scheduler *sched;
char name[20];
sched = kzalloc(sizeof(struct amd_gpu_scheduler), GFP_KERNEL);
if (!sched)
return NULL;
sched->device = device;
sched->ops = ops;
sched->granularity = granularity;
sched->ring_id = ring;
sched->preemption = preemption;
sched->hw_submission_limit = hw_submission;
snprintf(name, sizeof(name), "gpu_sched[%d]", ring);
mutex_init(&sched->sched_lock);
spin_lock_init(&sched->queue_lock);
init_rq(&sched->sched_rq);
sched->sched_rq.check_entity_status = gpu_entity_check_status;
init_rq(&sched->kernel_rq);
sched->kernel_rq.check_entity_status = gpu_entity_check_status;
init_waitqueue_head(&sched->wait_queue);
INIT_LIST_HEAD(&sched->active_hw_rq);
atomic64_set(&sched->hw_rq_count, 0);
/* Each scheduler will run on a seperate kernel thread */
sched->thread = kthread_create(amd_sched_main, sched, name);
if (sched->thread) {
wake_up_process(sched->thread);
return sched;
}
DRM_ERROR("Failed to create scheduler for id %d.\n", ring);
kfree(sched);
return NULL;
}
/**
* Destroy a gpu scheduler
*
* @sched The pointer to the scheduler
*
* return 0 if succeed. -1 if failed.
*/
int amd_sched_destroy(struct amd_gpu_scheduler *sched)
{
kthread_stop(sched->thread);
kfree(sched);
return 0;
}
/**
* Update emitted sequence and wake up the waiters, called by run_job
* in driver side
*
* @entity The context entity
* @seq The sequence number for the latest emitted job
*/
void amd_sched_emit(struct amd_sched_entity *c_entity, uint64_t seq)
{
atomic64_set(&c_entity->last_emitted_v_seq, seq);
wake_up_all(&c_entity->wait_emit);
}
/**
* Get next queued sequence number
*
* @entity The context entity
*
* return the next queued sequence number
*/
uint64_t amd_sched_next_queued_seq(struct amd_sched_entity *c_entity)
{
return atomic64_read(&c_entity->last_queued_v_seq) + 1;
}
