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-rw-r--r--drivers/gpu/drm/scheduler/sched_main.c1208
1 files changed, 1208 insertions, 0 deletions
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
new file mode 100644
index 000000000..5a3a622fc
--- /dev/null
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -0,0 +1,1208 @@
+/*
+ * 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.
+ *
+ */
+
+/**
+ * DOC: Overview
+ *
+ * The GPU scheduler provides entities which allow userspace to push jobs
+ * into software queues which are then scheduled on a hardware run queue.
+ * The software queues have a priority among them. The scheduler selects the entities
+ * from the run queue using a FIFO. The scheduler provides dependency handling
+ * features among jobs. The driver is supposed to provide callback functions for
+ * backend operations to the scheduler like submitting a job to hardware run queue,
+ * returning the dependencies of a job etc.
+ *
+ * The organisation of the scheduler is the following:
+ *
+ * 1. Each hw run queue has one scheduler
+ * 2. Each scheduler has multiple run queues with different priorities
+ * (e.g., HIGH_HW,HIGH_SW, KERNEL, NORMAL)
+ * 3. Each scheduler run queue has a queue of entities to schedule
+ * 4. Entities themselves maintain a queue of jobs that will be scheduled on
+ * the hardware.
+ *
+ * The jobs in a entity are always scheduled in the order that they were pushed.
+ *
+ * Note that once a job was taken from the entities queue and pushed to the
+ * hardware, i.e. the pending queue, the entity must not be referenced anymore
+ * through the jobs entity pointer.
+ */
+
+#include <linux/kthread.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/dma-resv.h>
+#include <uapi/linux/sched/types.h>
+
+#include <drm/drm_print.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_syncobj.h>
+#include <drm/gpu_scheduler.h>
+#include <drm/spsc_queue.h>
+
+#define CREATE_TRACE_POINTS
+#include "gpu_scheduler_trace.h"
+
+#define to_drm_sched_job(sched_job) \
+ container_of((sched_job), struct drm_sched_job, queue_node)
+
+int drm_sched_policy = DRM_SCHED_POLICY_FIFO;
+
+/**
+ * DOC: sched_policy (int)
+ * Used to override default entities scheduling policy in a run queue.
+ */
+MODULE_PARM_DESC(sched_policy, "Specify the scheduling policy for entities on a run-queue, " __stringify(DRM_SCHED_POLICY_RR) " = Round Robin, " __stringify(DRM_SCHED_POLICY_FIFO) " = FIFO (default).");
+module_param_named(sched_policy, drm_sched_policy, int, 0444);
+
+static __always_inline bool drm_sched_entity_compare_before(struct rb_node *a,
+ const struct rb_node *b)
+{
+ struct drm_sched_entity *ent_a = rb_entry((a), struct drm_sched_entity, rb_tree_node);
+ struct drm_sched_entity *ent_b = rb_entry((b), struct drm_sched_entity, rb_tree_node);
+
+ return ktime_before(ent_a->oldest_job_waiting, ent_b->oldest_job_waiting);
+}
+
+static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity)
+{
+ struct drm_sched_rq *rq = entity->rq;
+
+ if (!RB_EMPTY_NODE(&entity->rb_tree_node)) {
+ rb_erase_cached(&entity->rb_tree_node, &rq->rb_tree_root);
+ RB_CLEAR_NODE(&entity->rb_tree_node);
+ }
+}
+
+void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts)
+{
+ /*
+ * Both locks need to be grabbed, one to protect from entity->rq change
+ * for entity from within concurrent drm_sched_entity_select_rq and the
+ * other to update the rb tree structure.
+ */
+ spin_lock(&entity->rq_lock);
+ spin_lock(&entity->rq->lock);
+
+ drm_sched_rq_remove_fifo_locked(entity);
+
+ entity->oldest_job_waiting = ts;
+
+ rb_add_cached(&entity->rb_tree_node, &entity->rq->rb_tree_root,
+ drm_sched_entity_compare_before);
+
+ spin_unlock(&entity->rq->lock);
+ spin_unlock(&entity->rq_lock);
+}
+
+/**
+ * drm_sched_rq_init - initialize a given run queue struct
+ *
+ * @sched: scheduler instance to associate with this run queue
+ * @rq: scheduler run queue
+ *
+ * Initializes a scheduler runqueue.
+ */
+static void drm_sched_rq_init(struct drm_gpu_scheduler *sched,
+ struct drm_sched_rq *rq)
+{
+ spin_lock_init(&rq->lock);
+ INIT_LIST_HEAD(&rq->entities);
+ rq->rb_tree_root = RB_ROOT_CACHED;
+ rq->current_entity = NULL;
+ rq->sched = sched;
+}
+
+/**
+ * drm_sched_rq_add_entity - add an entity
+ *
+ * @rq: scheduler run queue
+ * @entity: scheduler entity
+ *
+ * Adds a scheduler entity to the run queue.
+ */
+void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
+ struct drm_sched_entity *entity)
+{
+ if (!list_empty(&entity->list))
+ return;
+
+ spin_lock(&rq->lock);
+
+ atomic_inc(rq->sched->score);
+ list_add_tail(&entity->list, &rq->entities);
+
+ spin_unlock(&rq->lock);
+}
+
+/**
+ * drm_sched_rq_remove_entity - remove an entity
+ *
+ * @rq: scheduler run queue
+ * @entity: scheduler entity
+ *
+ * Removes a scheduler entity from the run queue.
+ */
+void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
+ struct drm_sched_entity *entity)
+{
+ if (list_empty(&entity->list))
+ return;
+
+ spin_lock(&rq->lock);
+
+ atomic_dec(rq->sched->score);
+ list_del_init(&entity->list);
+
+ if (rq->current_entity == entity)
+ rq->current_entity = NULL;
+
+ if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
+ drm_sched_rq_remove_fifo_locked(entity);
+
+ spin_unlock(&rq->lock);
+}
+
+/**
+ * drm_sched_rq_select_entity_rr - Select an entity which could provide a job to run
+ *
+ * @rq: scheduler run queue to check.
+ *
+ * Try to find a ready entity, returns NULL if none found.
+ */
+static struct drm_sched_entity *
+drm_sched_rq_select_entity_rr(struct drm_sched_rq *rq)
+{
+ struct drm_sched_entity *entity;
+
+ spin_lock(&rq->lock);
+
+ entity = rq->current_entity;
+ if (entity) {
+ list_for_each_entry_continue(entity, &rq->entities, list) {
+ if (drm_sched_entity_is_ready(entity)) {
+ rq->current_entity = entity;
+ reinit_completion(&entity->entity_idle);
+ spin_unlock(&rq->lock);
+ return entity;
+ }
+ }
+ }
+
+ list_for_each_entry(entity, &rq->entities, list) {
+
+ if (drm_sched_entity_is_ready(entity)) {
+ rq->current_entity = entity;
+ reinit_completion(&entity->entity_idle);
+ spin_unlock(&rq->lock);
+ return entity;
+ }
+
+ if (entity == rq->current_entity)
+ break;
+ }
+
+ spin_unlock(&rq->lock);
+
+ return NULL;
+}
+
+/**
+ * drm_sched_rq_select_entity_fifo - Select an entity which provides a job to run
+ *
+ * @rq: scheduler run queue to check.
+ *
+ * Find oldest waiting ready entity, returns NULL if none found.
+ */
+static struct drm_sched_entity *
+drm_sched_rq_select_entity_fifo(struct drm_sched_rq *rq)
+{
+ struct rb_node *rb;
+
+ spin_lock(&rq->lock);
+ for (rb = rb_first_cached(&rq->rb_tree_root); rb; rb = rb_next(rb)) {
+ struct drm_sched_entity *entity;
+
+ entity = rb_entry(rb, struct drm_sched_entity, rb_tree_node);
+ if (drm_sched_entity_is_ready(entity)) {
+ rq->current_entity = entity;
+ reinit_completion(&entity->entity_idle);
+ break;
+ }
+ }
+ spin_unlock(&rq->lock);
+
+ return rb ? rb_entry(rb, struct drm_sched_entity, rb_tree_node) : NULL;
+}
+
+/**
+ * drm_sched_job_done - complete a job
+ * @s_job: pointer to the job which is done
+ *
+ * Finish the job's fence and wake up the worker thread.
+ */
+static void drm_sched_job_done(struct drm_sched_job *s_job, int result)
+{
+ struct drm_sched_fence *s_fence = s_job->s_fence;
+ struct drm_gpu_scheduler *sched = s_fence->sched;
+
+ atomic_dec(&sched->hw_rq_count);
+ atomic_dec(sched->score);
+
+ trace_drm_sched_process_job(s_fence);
+
+ dma_fence_get(&s_fence->finished);
+ drm_sched_fence_finished(s_fence, result);
+ dma_fence_put(&s_fence->finished);
+ wake_up_interruptible(&sched->wake_up_worker);
+}
+
+/**
+ * drm_sched_job_done_cb - the callback for a done job
+ * @f: fence
+ * @cb: fence callbacks
+ */
+static void drm_sched_job_done_cb(struct dma_fence *f, struct dma_fence_cb *cb)
+{
+ struct drm_sched_job *s_job = container_of(cb, struct drm_sched_job, cb);
+
+ drm_sched_job_done(s_job, f->error);
+}
+
+/**
+ * drm_sched_start_timeout - start timeout for reset worker
+ *
+ * @sched: scheduler instance to start the worker for
+ *
+ * Start the timeout for the given scheduler.
+ */
+static void drm_sched_start_timeout(struct drm_gpu_scheduler *sched)
+{
+ if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
+ !list_empty(&sched->pending_list))
+ queue_delayed_work(sched->timeout_wq, &sched->work_tdr, sched->timeout);
+}
+
+/**
+ * drm_sched_fault - immediately start timeout handler
+ *
+ * @sched: scheduler where the timeout handling should be started.
+ *
+ * Start timeout handling immediately when the driver detects a hardware fault.
+ */
+void drm_sched_fault(struct drm_gpu_scheduler *sched)
+{
+ if (sched->timeout_wq)
+ mod_delayed_work(sched->timeout_wq, &sched->work_tdr, 0);
+}
+EXPORT_SYMBOL(drm_sched_fault);
+
+/**
+ * drm_sched_suspend_timeout - Suspend scheduler job timeout
+ *
+ * @sched: scheduler instance for which to suspend the timeout
+ *
+ * Suspend the delayed work timeout for the scheduler. This is done by
+ * modifying the delayed work timeout to an arbitrary large value,
+ * MAX_SCHEDULE_TIMEOUT in this case.
+ *
+ * Returns the timeout remaining
+ *
+ */
+unsigned long drm_sched_suspend_timeout(struct drm_gpu_scheduler *sched)
+{
+ unsigned long sched_timeout, now = jiffies;
+
+ sched_timeout = sched->work_tdr.timer.expires;
+
+ /*
+ * Modify the timeout to an arbitrarily large value. This also prevents
+ * the timeout to be restarted when new submissions arrive
+ */
+ if (mod_delayed_work(sched->timeout_wq, &sched->work_tdr, MAX_SCHEDULE_TIMEOUT)
+ && time_after(sched_timeout, now))
+ return sched_timeout - now;
+ else
+ return sched->timeout;
+}
+EXPORT_SYMBOL(drm_sched_suspend_timeout);
+
+/**
+ * drm_sched_resume_timeout - Resume scheduler job timeout
+ *
+ * @sched: scheduler instance for which to resume the timeout
+ * @remaining: remaining timeout
+ *
+ * Resume the delayed work timeout for the scheduler.
+ */
+void drm_sched_resume_timeout(struct drm_gpu_scheduler *sched,
+ unsigned long remaining)
+{
+ spin_lock(&sched->job_list_lock);
+
+ if (list_empty(&sched->pending_list))
+ cancel_delayed_work(&sched->work_tdr);
+ else
+ mod_delayed_work(sched->timeout_wq, &sched->work_tdr, remaining);
+
+ spin_unlock(&sched->job_list_lock);
+}
+EXPORT_SYMBOL(drm_sched_resume_timeout);
+
+static void drm_sched_job_begin(struct drm_sched_job *s_job)
+{
+ struct drm_gpu_scheduler *sched = s_job->sched;
+
+ spin_lock(&sched->job_list_lock);
+ list_add_tail(&s_job->list, &sched->pending_list);
+ drm_sched_start_timeout(sched);
+ spin_unlock(&sched->job_list_lock);
+}
+
+static void drm_sched_job_timedout(struct work_struct *work)
+{
+ struct drm_gpu_scheduler *sched;
+ struct drm_sched_job *job;
+ enum drm_gpu_sched_stat status = DRM_GPU_SCHED_STAT_NOMINAL;
+
+ sched = container_of(work, struct drm_gpu_scheduler, work_tdr.work);
+
+ /* Protects against concurrent deletion in drm_sched_get_cleanup_job */
+ spin_lock(&sched->job_list_lock);
+ job = list_first_entry_or_null(&sched->pending_list,
+ struct drm_sched_job, list);
+
+ if (job) {
+ /*
+ * Remove the bad job so it cannot be freed by concurrent
+ * drm_sched_cleanup_jobs. It will be reinserted back after sched->thread
+ * is parked at which point it's safe.
+ */
+ list_del_init(&job->list);
+ spin_unlock(&sched->job_list_lock);
+
+ status = job->sched->ops->timedout_job(job);
+
+ /*
+ * Guilty job did complete and hence needs to be manually removed
+ * See drm_sched_stop doc.
+ */
+ if (sched->free_guilty) {
+ job->sched->ops->free_job(job);
+ sched->free_guilty = false;
+ }
+ } else {
+ spin_unlock(&sched->job_list_lock);
+ }
+
+ if (status != DRM_GPU_SCHED_STAT_ENODEV) {
+ spin_lock(&sched->job_list_lock);
+ drm_sched_start_timeout(sched);
+ spin_unlock(&sched->job_list_lock);
+ }
+}
+
+/**
+ * drm_sched_stop - stop the scheduler
+ *
+ * @sched: scheduler instance
+ * @bad: job which caused the time out
+ *
+ * Stop the scheduler and also removes and frees all completed jobs.
+ * Note: bad job will not be freed as it might be used later and so it's
+ * callers responsibility to release it manually if it's not part of the
+ * pending list any more.
+ *
+ */
+void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
+{
+ struct drm_sched_job *s_job, *tmp;
+
+ kthread_park(sched->thread);
+
+ /*
+ * Reinsert back the bad job here - now it's safe as
+ * drm_sched_get_cleanup_job cannot race against us and release the
+ * bad job at this point - we parked (waited for) any in progress
+ * (earlier) cleanups and drm_sched_get_cleanup_job will not be called
+ * now until the scheduler thread is unparked.
+ */
+ if (bad && bad->sched == sched)
+ /*
+ * Add at the head of the queue to reflect it was the earliest
+ * job extracted.
+ */
+ list_add(&bad->list, &sched->pending_list);
+
+ /*
+ * Iterate the job list from later to earlier one and either deactive
+ * their HW callbacks or remove them from pending list if they already
+ * signaled.
+ * This iteration is thread safe as sched thread is stopped.
+ */
+ list_for_each_entry_safe_reverse(s_job, tmp, &sched->pending_list,
+ list) {
+ if (s_job->s_fence->parent &&
+ dma_fence_remove_callback(s_job->s_fence->parent,
+ &s_job->cb)) {
+ dma_fence_put(s_job->s_fence->parent);
+ s_job->s_fence->parent = NULL;
+ atomic_dec(&sched->hw_rq_count);
+ } else {
+ /*
+ * remove job from pending_list.
+ * Locking here is for concurrent resume timeout
+ */
+ spin_lock(&sched->job_list_lock);
+ list_del_init(&s_job->list);
+ spin_unlock(&sched->job_list_lock);
+
+ /*
+ * Wait for job's HW fence callback to finish using s_job
+ * before releasing it.
+ *
+ * Job is still alive so fence refcount at least 1
+ */
+ dma_fence_wait(&s_job->s_fence->finished, false);
+
+ /*
+ * We must keep bad job alive for later use during
+ * recovery by some of the drivers but leave a hint
+ * that the guilty job must be released.
+ */
+ if (bad != s_job)
+ sched->ops->free_job(s_job);
+ else
+ sched->free_guilty = true;
+ }
+ }
+
+ /*
+ * Stop pending timer in flight as we rearm it in drm_sched_start. This
+ * avoids the pending timeout work in progress to fire right away after
+ * this TDR finished and before the newly restarted jobs had a
+ * chance to complete.
+ */
+ cancel_delayed_work(&sched->work_tdr);
+}
+
+EXPORT_SYMBOL(drm_sched_stop);
+
+/**
+ * drm_sched_start - recover jobs after a reset
+ *
+ * @sched: scheduler instance
+ * @full_recovery: proceed with complete sched restart
+ *
+ */
+void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery)
+{
+ struct drm_sched_job *s_job, *tmp;
+ int r;
+
+ /*
+ * Locking the list is not required here as the sched thread is parked
+ * so no new jobs are being inserted or removed. Also concurrent
+ * GPU recovers can't run in parallel.
+ */
+ list_for_each_entry_safe(s_job, tmp, &sched->pending_list, list) {
+ struct dma_fence *fence = s_job->s_fence->parent;
+
+ atomic_inc(&sched->hw_rq_count);
+
+ if (!full_recovery)
+ continue;
+
+ if (fence) {
+ r = dma_fence_add_callback(fence, &s_job->cb,
+ drm_sched_job_done_cb);
+ if (r == -ENOENT)
+ drm_sched_job_done(s_job, fence->error);
+ else if (r)
+ DRM_DEV_ERROR(sched->dev, "fence add callback failed (%d)\n",
+ r);
+ } else
+ drm_sched_job_done(s_job, -ECANCELED);
+ }
+
+ if (full_recovery) {
+ spin_lock(&sched->job_list_lock);
+ drm_sched_start_timeout(sched);
+ spin_unlock(&sched->job_list_lock);
+ }
+
+ kthread_unpark(sched->thread);
+}
+EXPORT_SYMBOL(drm_sched_start);
+
+/**
+ * drm_sched_resubmit_jobs - Deprecated, don't use in new code!
+ *
+ * @sched: scheduler instance
+ *
+ * Re-submitting jobs was a concept AMD came up as cheap way to implement
+ * recovery after a job timeout.
+ *
+ * This turned out to be not working very well. First of all there are many
+ * problem with the dma_fence implementation and requirements. Either the
+ * implementation is risking deadlocks with core memory management or violating
+ * documented implementation details of the dma_fence object.
+ *
+ * Drivers can still save and restore their state for recovery operations, but
+ * we shouldn't make this a general scheduler feature around the dma_fence
+ * interface.
+ */
+void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched)
+{
+ struct drm_sched_job *s_job, *tmp;
+ uint64_t guilty_context;
+ bool found_guilty = false;
+ struct dma_fence *fence;
+
+ list_for_each_entry_safe(s_job, tmp, &sched->pending_list, list) {
+ struct drm_sched_fence *s_fence = s_job->s_fence;
+
+ if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) {
+ found_guilty = true;
+ guilty_context = s_job->s_fence->scheduled.context;
+ }
+
+ if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
+ dma_fence_set_error(&s_fence->finished, -ECANCELED);
+
+ fence = sched->ops->run_job(s_job);
+
+ if (IS_ERR_OR_NULL(fence)) {
+ if (IS_ERR(fence))
+ dma_fence_set_error(&s_fence->finished, PTR_ERR(fence));
+
+ s_job->s_fence->parent = NULL;
+ } else {
+
+ s_job->s_fence->parent = dma_fence_get(fence);
+
+ /* Drop for orignal kref_init */
+ dma_fence_put(fence);
+ }
+ }
+}
+EXPORT_SYMBOL(drm_sched_resubmit_jobs);
+
+/**
+ * drm_sched_job_init - init a scheduler job
+ * @job: scheduler job to init
+ * @entity: scheduler entity to use
+ * @owner: job owner for debugging
+ *
+ * Refer to drm_sched_entity_push_job() documentation
+ * for locking considerations.
+ *
+ * Drivers must make sure drm_sched_job_cleanup() if this function returns
+ * successfully, even when @job is aborted before drm_sched_job_arm() is called.
+ *
+ * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware
+ * has died, which can mean that there's no valid runqueue for a @entity.
+ * This function returns -ENOENT in this case (which probably should be -EIO as
+ * a more meanigful return value).
+ *
+ * Returns 0 for success, negative error code otherwise.
+ */
+int drm_sched_job_init(struct drm_sched_job *job,
+ struct drm_sched_entity *entity,
+ void *owner)
+{
+ if (!entity->rq)
+ return -ENOENT;
+
+ job->entity = entity;
+ job->s_fence = drm_sched_fence_alloc(entity, owner);
+ if (!job->s_fence)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&job->list);
+
+ xa_init_flags(&job->dependencies, XA_FLAGS_ALLOC);
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_sched_job_init);
+
+/**
+ * drm_sched_job_arm - arm a scheduler job for execution
+ * @job: scheduler job to arm
+ *
+ * This arms a scheduler job for execution. Specifically it initializes the
+ * &drm_sched_job.s_fence of @job, so that it can be attached to struct dma_resv
+ * or other places that need to track the completion of this job.
+ *
+ * Refer to drm_sched_entity_push_job() documentation for locking
+ * considerations.
+ *
+ * This can only be called if drm_sched_job_init() succeeded.
+ */
+void drm_sched_job_arm(struct drm_sched_job *job)
+{
+ struct drm_gpu_scheduler *sched;
+ struct drm_sched_entity *entity = job->entity;
+
+ BUG_ON(!entity);
+ drm_sched_entity_select_rq(entity);
+ sched = entity->rq->sched;
+
+ job->sched = sched;
+ job->s_priority = entity->rq - sched->sched_rq;
+ job->id = atomic64_inc_return(&sched->job_id_count);
+
+ drm_sched_fence_init(job->s_fence, job->entity);
+}
+EXPORT_SYMBOL(drm_sched_job_arm);
+
+/**
+ * drm_sched_job_add_dependency - adds the fence as a job dependency
+ * @job: scheduler job to add the dependencies to
+ * @fence: the dma_fence to add to the list of dependencies.
+ *
+ * Note that @fence is consumed in both the success and error cases.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_add_dependency(struct drm_sched_job *job,
+ struct dma_fence *fence)
+{
+ struct dma_fence *entry;
+ unsigned long index;
+ u32 id = 0;
+ int ret;
+
+ if (!fence)
+ return 0;
+
+ /* Deduplicate if we already depend on a fence from the same context.
+ * This lets the size of the array of deps scale with the number of
+ * engines involved, rather than the number of BOs.
+ */
+ xa_for_each(&job->dependencies, index, entry) {
+ if (entry->context != fence->context)
+ continue;
+
+ if (dma_fence_is_later(fence, entry)) {
+ dma_fence_put(entry);
+ xa_store(&job->dependencies, index, fence, GFP_KERNEL);
+ } else {
+ dma_fence_put(fence);
+ }
+ return 0;
+ }
+
+ ret = xa_alloc(&job->dependencies, &id, fence, xa_limit_32b, GFP_KERNEL);
+ if (ret != 0)
+ dma_fence_put(fence);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_sched_job_add_dependency);
+
+/**
+ * drm_sched_job_add_syncobj_dependency - adds a syncobj's fence as a job dependency
+ * @job: scheduler job to add the dependencies to
+ * @file: drm file private pointer
+ * @handle: syncobj handle to lookup
+ * @point: timeline point
+ *
+ * This adds the fence matching the given syncobj to @job.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_add_syncobj_dependency(struct drm_sched_job *job,
+ struct drm_file *file,
+ u32 handle,
+ u32 point)
+{
+ struct dma_fence *fence;
+ int ret;
+
+ ret = drm_syncobj_find_fence(file, handle, point, 0, &fence);
+ if (ret)
+ return ret;
+
+ return drm_sched_job_add_dependency(job, fence);
+}
+EXPORT_SYMBOL(drm_sched_job_add_syncobj_dependency);
+
+/**
+ * drm_sched_job_add_resv_dependencies - add all fences from the resv to the job
+ * @job: scheduler job to add the dependencies to
+ * @resv: the dma_resv object to get the fences from
+ * @usage: the dma_resv_usage to use to filter the fences
+ *
+ * This adds all fences matching the given usage from @resv to @job.
+ * Must be called with the @resv lock held.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_add_resv_dependencies(struct drm_sched_job *job,
+ struct dma_resv *resv,
+ enum dma_resv_usage usage)
+{
+ struct dma_resv_iter cursor;
+ struct dma_fence *fence;
+ int ret;
+
+ dma_resv_assert_held(resv);
+
+ dma_resv_for_each_fence(&cursor, resv, usage, fence) {
+ /* Make sure to grab an additional ref on the added fence */
+ dma_fence_get(fence);
+ ret = drm_sched_job_add_dependency(job, fence);
+ if (ret) {
+ dma_fence_put(fence);
+ return ret;
+ }
+ }
+ return 0;
+}
+EXPORT_SYMBOL(drm_sched_job_add_resv_dependencies);
+
+/**
+ * drm_sched_job_add_implicit_dependencies - adds implicit dependencies as job
+ * dependencies
+ * @job: scheduler job to add the dependencies to
+ * @obj: the gem object to add new dependencies from.
+ * @write: whether the job might write the object (so we need to depend on
+ * shared fences in the reservation object).
+ *
+ * This should be called after drm_gem_lock_reservations() on your array of
+ * GEM objects used in the job but before updating the reservations with your
+ * own fences.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_add_implicit_dependencies(struct drm_sched_job *job,
+ struct drm_gem_object *obj,
+ bool write)
+{
+ return drm_sched_job_add_resv_dependencies(job, obj->resv,
+ dma_resv_usage_rw(write));
+}
+EXPORT_SYMBOL(drm_sched_job_add_implicit_dependencies);
+
+/**
+ * drm_sched_job_cleanup - clean up scheduler job resources
+ * @job: scheduler job to clean up
+ *
+ * Cleans up the resources allocated with drm_sched_job_init().
+ *
+ * Drivers should call this from their error unwind code if @job is aborted
+ * before drm_sched_job_arm() is called.
+ *
+ * After that point of no return @job is committed to be executed by the
+ * scheduler, and this function should be called from the
+ * &drm_sched_backend_ops.free_job callback.
+ */
+void drm_sched_job_cleanup(struct drm_sched_job *job)
+{
+ struct dma_fence *fence;
+ unsigned long index;
+
+ if (kref_read(&job->s_fence->finished.refcount)) {
+ /* drm_sched_job_arm() has been called */
+ dma_fence_put(&job->s_fence->finished);
+ } else {
+ /* aborted job before committing to run it */
+ drm_sched_fence_free(job->s_fence);
+ }
+
+ job->s_fence = NULL;
+
+ xa_for_each(&job->dependencies, index, fence) {
+ dma_fence_put(fence);
+ }
+ xa_destroy(&job->dependencies);
+
+}
+EXPORT_SYMBOL(drm_sched_job_cleanup);
+
+/**
+ * drm_sched_can_queue -- Can we queue more to the hardware?
+ * @sched: scheduler instance
+ *
+ * Return true if we can push more jobs to the hw, otherwise false.
+ */
+static bool drm_sched_can_queue(struct drm_gpu_scheduler *sched)
+{
+ return atomic_read(&sched->hw_rq_count) <
+ sched->hw_submission_limit;
+}
+
+/**
+ * drm_sched_wakeup_if_can_queue - Wake up the scheduler
+ * @sched: scheduler instance
+ *
+ * Wake up the scheduler if we can queue jobs.
+ */
+void drm_sched_wakeup_if_can_queue(struct drm_gpu_scheduler *sched)
+{
+ if (drm_sched_can_queue(sched))
+ wake_up_interruptible(&sched->wake_up_worker);
+}
+
+/**
+ * drm_sched_select_entity - Select next entity to process
+ *
+ * @sched: scheduler instance
+ *
+ * Returns the entity to process or NULL if none are found.
+ */
+static struct drm_sched_entity *
+drm_sched_select_entity(struct drm_gpu_scheduler *sched)
+{
+ struct drm_sched_entity *entity;
+ int i;
+
+ if (!drm_sched_can_queue(sched))
+ return NULL;
+
+ /* Kernel run queue has higher priority than normal run queue*/
+ for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
+ entity = drm_sched_policy == DRM_SCHED_POLICY_FIFO ?
+ drm_sched_rq_select_entity_fifo(&sched->sched_rq[i]) :
+ drm_sched_rq_select_entity_rr(&sched->sched_rq[i]);
+ if (entity)
+ break;
+ }
+
+ return entity;
+}
+
+/**
+ * drm_sched_get_cleanup_job - fetch the next finished job to be destroyed
+ *
+ * @sched: scheduler instance
+ *
+ * Returns the next finished job from the pending list (if there is one)
+ * ready for it to be destroyed.
+ */
+static struct drm_sched_job *
+drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)
+{
+ struct drm_sched_job *job, *next;
+
+ spin_lock(&sched->job_list_lock);
+
+ job = list_first_entry_or_null(&sched->pending_list,
+ struct drm_sched_job, list);
+
+ if (job && dma_fence_is_signaled(&job->s_fence->finished)) {
+ /* remove job from pending_list */
+ list_del_init(&job->list);
+
+ /* cancel this job's TO timer */
+ cancel_delayed_work(&sched->work_tdr);
+ /* make the scheduled timestamp more accurate */
+ next = list_first_entry_or_null(&sched->pending_list,
+ typeof(*next), list);
+
+ if (next) {
+ next->s_fence->scheduled.timestamp =
+ dma_fence_timestamp(&job->s_fence->finished);
+ /* start TO timer for next job */
+ drm_sched_start_timeout(sched);
+ }
+ } else {
+ job = NULL;
+ }
+
+ spin_unlock(&sched->job_list_lock);
+
+ return job;
+}
+
+/**
+ * drm_sched_pick_best - Get a drm sched from a sched_list with the least load
+ * @sched_list: list of drm_gpu_schedulers
+ * @num_sched_list: number of drm_gpu_schedulers in the sched_list
+ *
+ * Returns pointer of the sched with the least load or NULL if none of the
+ * drm_gpu_schedulers are ready
+ */
+struct drm_gpu_scheduler *
+drm_sched_pick_best(struct drm_gpu_scheduler **sched_list,
+ unsigned int num_sched_list)
+{
+ struct drm_gpu_scheduler *sched, *picked_sched = NULL;
+ int i;
+ unsigned int min_score = UINT_MAX, num_score;
+
+ for (i = 0; i < num_sched_list; ++i) {
+ sched = sched_list[i];
+
+ if (!sched->ready) {
+ DRM_WARN("scheduler %s is not ready, skipping",
+ sched->name);
+ continue;
+ }
+
+ num_score = atomic_read(sched->score);
+ if (num_score < min_score) {
+ min_score = num_score;
+ picked_sched = sched;
+ }
+ }
+
+ return picked_sched;
+}
+EXPORT_SYMBOL(drm_sched_pick_best);
+
+/**
+ * drm_sched_blocked - check if the scheduler is blocked
+ *
+ * @sched: scheduler instance
+ *
+ * Returns true if blocked, otherwise false.
+ */
+static bool drm_sched_blocked(struct drm_gpu_scheduler *sched)
+{
+ if (kthread_should_park()) {
+ kthread_parkme();
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * drm_sched_main - main scheduler thread
+ *
+ * @param: scheduler instance
+ *
+ * Returns 0.
+ */
+static int drm_sched_main(void *param)
+{
+ struct drm_gpu_scheduler *sched = (struct drm_gpu_scheduler *)param;
+ int r;
+
+ sched_set_fifo_low(current);
+
+ while (!kthread_should_stop()) {
+ struct drm_sched_entity *entity = NULL;
+ struct drm_sched_fence *s_fence;
+ struct drm_sched_job *sched_job;
+ struct dma_fence *fence;
+ struct drm_sched_job *cleanup_job = NULL;
+
+ wait_event_interruptible(sched->wake_up_worker,
+ (cleanup_job = drm_sched_get_cleanup_job(sched)) ||
+ (!drm_sched_blocked(sched) &&
+ (entity = drm_sched_select_entity(sched))) ||
+ kthread_should_stop());
+
+ if (cleanup_job)
+ sched->ops->free_job(cleanup_job);
+
+ if (!entity)
+ continue;
+
+ sched_job = drm_sched_entity_pop_job(entity);
+
+ if (!sched_job) {
+ complete_all(&entity->entity_idle);
+ continue;
+ }
+
+ s_fence = sched_job->s_fence;
+
+ atomic_inc(&sched->hw_rq_count);
+ drm_sched_job_begin(sched_job);
+
+ trace_drm_run_job(sched_job, entity);
+ fence = sched->ops->run_job(sched_job);
+ complete_all(&entity->entity_idle);
+ drm_sched_fence_scheduled(s_fence, fence);
+
+ if (!IS_ERR_OR_NULL(fence)) {
+ /* Drop for original kref_init of the fence */
+ dma_fence_put(fence);
+
+ r = dma_fence_add_callback(fence, &sched_job->cb,
+ drm_sched_job_done_cb);
+ if (r == -ENOENT)
+ drm_sched_job_done(sched_job, fence->error);
+ else if (r)
+ DRM_DEV_ERROR(sched->dev, "fence add callback failed (%d)\n",
+ r);
+ } else {
+ drm_sched_job_done(sched_job, IS_ERR(fence) ?
+ PTR_ERR(fence) : 0);
+ }
+
+ wake_up(&sched->job_scheduled);
+ }
+ return 0;
+}
+
+/**
+ * drm_sched_init - Init a gpu scheduler instance
+ *
+ * @sched: scheduler instance
+ * @ops: backend operations for this scheduler
+ * @hw_submission: number of hw submissions that can be in flight
+ * @hang_limit: number of times to allow a job to hang before dropping it
+ * @timeout: timeout value in jiffies for the scheduler
+ * @timeout_wq: workqueue to use for timeout work. If NULL, the system_wq is
+ * used
+ * @score: optional score atomic shared with other schedulers
+ * @name: name used for debugging
+ * @dev: target &struct device
+ *
+ * Return 0 on success, otherwise error code.
+ */
+int drm_sched_init(struct drm_gpu_scheduler *sched,
+ const struct drm_sched_backend_ops *ops,
+ unsigned hw_submission, unsigned hang_limit,
+ long timeout, struct workqueue_struct *timeout_wq,
+ atomic_t *score, const char *name, struct device *dev)
+{
+ int i, ret;
+ sched->ops = ops;
+ sched->hw_submission_limit = hw_submission;
+ sched->name = name;
+ sched->timeout = timeout;
+ sched->timeout_wq = timeout_wq ? : system_wq;
+ sched->hang_limit = hang_limit;
+ sched->score = score ? score : &sched->_score;
+ sched->dev = dev;
+ for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++)
+ drm_sched_rq_init(sched, &sched->sched_rq[i]);
+
+ init_waitqueue_head(&sched->wake_up_worker);
+ init_waitqueue_head(&sched->job_scheduled);
+ INIT_LIST_HEAD(&sched->pending_list);
+ spin_lock_init(&sched->job_list_lock);
+ atomic_set(&sched->hw_rq_count, 0);
+ INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout);
+ atomic_set(&sched->_score, 0);
+ atomic64_set(&sched->job_id_count, 0);
+
+ /* Each scheduler will run on a seperate kernel thread */
+ sched->thread = kthread_run(drm_sched_main, sched, sched->name);
+ if (IS_ERR(sched->thread)) {
+ ret = PTR_ERR(sched->thread);
+ sched->thread = NULL;
+ DRM_DEV_ERROR(sched->dev, "Failed to create scheduler for %s.\n", name);
+ return ret;
+ }
+
+ sched->ready = true;
+ return 0;
+}
+EXPORT_SYMBOL(drm_sched_init);
+
+/**
+ * drm_sched_fini - Destroy a gpu scheduler
+ *
+ * @sched: scheduler instance
+ *
+ * Tears down and cleans up the scheduler.
+ */
+void drm_sched_fini(struct drm_gpu_scheduler *sched)
+{
+ struct drm_sched_entity *s_entity;
+ int i;
+
+ if (sched->thread)
+ kthread_stop(sched->thread);
+
+ for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
+ struct drm_sched_rq *rq = &sched->sched_rq[i];
+
+ spin_lock(&rq->lock);
+ list_for_each_entry(s_entity, &rq->entities, list)
+ /*
+ * Prevents reinsertion and marks job_queue as idle,
+ * it will removed from rq in drm_sched_entity_fini
+ * eventually
+ */
+ s_entity->stopped = true;
+ spin_unlock(&rq->lock);
+
+ }
+
+ /* Wakeup everyone stuck in drm_sched_entity_flush for this scheduler */
+ wake_up_all(&sched->job_scheduled);
+
+ /* Confirm no work left behind accessing device structures */
+ cancel_delayed_work_sync(&sched->work_tdr);
+
+ sched->ready = false;
+}
+EXPORT_SYMBOL(drm_sched_fini);
+
+/**
+ * drm_sched_increase_karma - Update sched_entity guilty flag
+ *
+ * @bad: The job guilty of time out
+ *
+ * Increment on every hang caused by the 'bad' job. If this exceeds the hang
+ * limit of the scheduler then the respective sched entity is marked guilty and
+ * jobs from it will not be scheduled further
+ */
+void drm_sched_increase_karma(struct drm_sched_job *bad)
+{
+ int i;
+ struct drm_sched_entity *tmp;
+ struct drm_sched_entity *entity;
+ struct drm_gpu_scheduler *sched = bad->sched;
+
+ /* don't change @bad's karma if it's from KERNEL RQ,
+ * because sometimes GPU hang would cause kernel jobs (like VM updating jobs)
+ * corrupt but keep in mind that kernel jobs always considered good.
+ */
+ if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
+ atomic_inc(&bad->karma);
+
+ for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL;
+ i++) {
+ struct drm_sched_rq *rq = &sched->sched_rq[i];
+
+ spin_lock(&rq->lock);
+ list_for_each_entry_safe(entity, tmp, &rq->entities, list) {
+ if (bad->s_fence->scheduled.context ==
+ entity->fence_context) {
+ if (entity->guilty)
+ atomic_set(entity->guilty, 1);
+ break;
+ }
+ }
+ spin_unlock(&rq->lock);
+ if (&entity->list != &rq->entities)
+ break;
+ }
+ }
+}
+EXPORT_SYMBOL(drm_sched_increase_karma);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-23 05:25:44 +0000