--- /dev/null
+/*
+ * 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_context_entity *entity)
+{
+ /* TODO: sync obj for multi-ring synchronization */
+ return false;
+}
+
+static int gpu_entity_check_status(struct amd_sched_entity *entity)
+{
+ struct amd_context_entity *tmp = NULL;
+
+ if (entity == &entity->belongto_rq->head)
+ return -1;
+
+ tmp = container_of(entity, typeof(*tmp), generic_entity);
+ if (kfifo_is_empty(&tmp->job_queue) ||
+ context_entity_is_waiting(tmp))
+ 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)
+{
+ return !kfifo_is_full(&sched->active_hw_rq);
+}
+
+/**
+ * Select next entity from the kernel run queue, if not available,
+ * return null.
+*/
+static struct amd_context_entity *kernel_rq_select_context(
+ struct amd_gpu_scheduler *sched)
+{
+ struct amd_sched_entity *sched_entity = NULL;
+ struct amd_context_entity *tmp = NULL;
+ struct amd_run_queue *rq = &sched->kernel_rq;
+
+ mutex_lock(&rq->lock);
+ sched_entity = rq_select_entity(rq);
+ if (sched_entity)
+ tmp = container_of(sched_entity,
+ typeof(*tmp),
+ generic_entity);
+ mutex_unlock(&rq->lock);
+ return tmp;
+}
+
+/**
+ * Select next entity containing real IB submissions
+*/
+static struct amd_context_entity *select_context(
+ struct amd_gpu_scheduler *sched)
+{
+ struct amd_context_entity *wake_entity = NULL;
+ struct amd_context_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;
+
+ WARN_ON(offsetof(struct amd_context_entity, generic_entity) != 0);
+
+ rq = &sched->sched_rq;
+ mutex_lock(&rq->lock);
+ tmp = container_of(rq_select_entity(rq),
+ typeof(*tmp), generic_entity);
+ 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_context_entity
+ * @parent The parent entity of this amd_context_entity
+ * @rq The run queue this entity belongs
+ * @context_id The context id for this entity
+ *
+ * return 0 if succeed. negative error code on failure
+*/
+int amd_context_entity_init(struct amd_gpu_scheduler *sched,
+ struct amd_context_entity *entity,
+ struct amd_sched_entity *parent,
+ struct amd_run_queue *rq,
+ uint32_t context_id)
+{
+ uint64_t seq_ring = 0;
+
+ if (!(sched && entity && rq))
+ return -EINVAL;
+
+ memset(entity, 0, sizeof(struct amd_context_entity));
+ seq_ring = ((uint64_t)sched->ring_id) << 60;
+ spin_lock_init(&entity->lock);
+ entity->generic_entity.belongto_rq = rq;
+ entity->generic_entity.parent = parent;
+ entity->scheduler = sched;
+ init_waitqueue_head(&entity->wait_queue);
+ init_waitqueue_head(&entity->wait_emit);
+ if(kfifo_alloc(&entity->job_queue,
+ AMD_MAX_JOB_ENTRY_PER_CONTEXT * sizeof(void *),
+ GFP_KERNEL))
+ return -EINVAL;
+
+ spin_lock_init(&entity->queue_lock);
+ entity->tgid = (context_id == AMD_KERNEL_CONTEXT_ID) ?
+ AMD_KERNEL_PROCESS_ID : current->tgid;
+ entity->context_id = context_id;
+ atomic64_set(&entity->last_emitted_v_seq, seq_ring);
+ atomic64_set(&entity->last_queued_v_seq, seq_ring);
+ atomic64_set(&entity->last_signaled_v_seq, seq_ring);
+
+ /* Add the entity to the run queue */
+ mutex_lock(&rq->lock);
+ rq_add_entity(rq, &entity->generic_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_context_entity *entity)
+{
+ return entity->scheduler == sched &&
+ entity->generic_entity.belongto_rq != NULL;
+}
+
+static bool is_context_entity_idle(struct amd_gpu_scheduler *sched,
+ struct amd_context_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_context_entity_fini(struct amd_gpu_scheduler *sched,
+ struct amd_context_entity *entity)
+{
+ int r = 0;
+ struct amd_run_queue *rq = entity->generic_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 %u is in waiting state during fini,\
+ all pending ibs will be canceled.\n",
+ entity->context_id);
+ }
+
+ mutex_lock(&rq->lock);
+ rq_remove_entity(rq, &entity->generic_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_context_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_context_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;
+}
+
+/**
+ * Check the virtual sequence number for specified context
+ *
+ * @seq The virtual sequence number to check
+ * @c_entity The pointer to a valid amd_context_entity
+ *
+ * return 0 if signaled, -1 else.
+*/
+int amd_sched_check_ts(struct amd_context_entity *c_entity, uint64_t seq)
+{
+ return (seq <= atomic64_read(&c_entity->last_signaled_v_seq)) ? 0 : -1;
+}
+
+/**
+ * Wait for a virtual sequence number to be signaled or timeout
+ *
+ * @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
+*/
+static int amd_sched_wait(struct amd_context_entity *c_entity,
+ uint64_t seq,
+ bool intr,
+ long timeout,
+ bool emit)
+{
+ atomic64_t *v_seq = emit ? &c_entity->last_emitted_v_seq :
+ &c_entity->last_signaled_v_seq;
+ wait_queue_head_t *wait_queue = emit ? &c_entity->wait_emit :
+ &c_entity->wait_queue;
+
+ 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;
+}
+
+int amd_sched_wait_signal(struct amd_context_entity *c_entity,
+ uint64_t seq,
+ bool intr,
+ long timeout)
+{
+ return amd_sched_wait(c_entity, seq, intr, timeout, false);
+}
+
+int amd_sched_wait_emit(struct amd_context_entity *c_entity,
+ uint64_t seq,
+ bool intr,
+ long timeout)
+{
+ return amd_sched_wait(c_entity, seq, intr, timeout, true);
+}
+
+static int amd_sched_main(void *param)
+{
+ int r;
+ void *job;
+ struct sched_param sparam = {.sched_priority = 1};
+ struct amd_context_entity *c_entity = NULL;
+ struct amd_gpu_scheduler *sched = (struct amd_gpu_scheduler *)param;
+
+ sched_setscheduler(current, SCHED_FIFO, &sparam);
+
+ while (!kthread_should_stop()) {
+ 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)
+ WARN_ON(kfifo_in_spinlocked(
+ &sched->active_hw_rq,
+ &job,
+ sizeof(void *),
+ &sched->queue_lock) != sizeof(void *));
+ mutex_lock(&sched->sched_lock);
+ sched->ops->run_job(sched, c_entity, job);
+ mutex_unlock(&sched->sched_lock);
+ }
+ return 0;
+}
+
+uint64_t amd_sched_get_handled_seq(struct amd_gpu_scheduler *sched)
+{
+ return sched->last_handled_seq;
+}
+
+/**
+ * ISR to handle EOP inetrrupts
+ *
+ * @sched: gpu scheduler
+ *
+*/
+void amd_sched_isr(struct amd_gpu_scheduler *sched)
+{
+ int r;
+ void *job;
+ r = kfifo_out_spinlocked(&sched->active_hw_rq,
+ &job, sizeof(void *),
+ &sched->queue_lock);
+
+ if (r != sizeof(void *))
+ job = NULL;
+
+ sched->ops->process_job(sched, job);
+ sched->last_handled_seq++;
+ wake_up_interruptible(&sched->wait_queue);
+}
+
+/**
+ * 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)
+{
+ struct amd_gpu_scheduler *sched;
+ char name[20] = "gpu_sched[0]";
+
+ 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->last_handled_seq = 0;
+
+ 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);
+ if(kfifo_alloc(&sched->active_hw_rq,
+ AMD_MAX_ACTIVE_HW_SUBMISSION * sizeof(void *),
+ GFP_KERNEL)) {
+ kfree(sched);
+ return NULL;
+ }
+
+ /* 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);
+ DRM_INFO("Create gpu scheduler for id %d successfully.\n",
+ ring);
+ return sched;
+ }
+
+ DRM_ERROR("Failed to create scheduler for id %d.\n", ring);
+ kfifo_free(&sched->active_hw_rq);
+ 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);
+ kfifo_free(&sched->active_hw_rq);
+ kfree(sched);
+ return 0;
+}
+
--- /dev/null
+/*
+ * 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.
+ *
+ */
+
+#ifndef _GPU_SCHEDULER_H_
+#define _GPU_SCHEDULER_H_
+
+#include <linux/kfifo.h>
+
+#define AMD_MAX_ACTIVE_HW_SUBMISSION 2
+#define AMD_MAX_JOB_ENTRY_PER_CONTEXT 16
+
+#define AMD_KERNEL_CONTEXT_ID 0
+#define AMD_KERNEL_PROCESS_ID 0
+
+#define AMD_GPU_WAIT_IDLE_TIMEOUT_IN_MS 3000
+
+struct amd_gpu_scheduler;
+struct amd_run_queue;
+
+/**
+ * A scheduler entity is a wrapper around a job queue or a group
+ * of other entities. Entities take turns emitting jobs from their
+ * job queues to corresponding hardware ring based on scheduling
+ * policy.
+*/
+struct amd_sched_entity {
+ struct list_head list;
+ struct amd_run_queue *belongto_rq;
+ struct amd_sched_entity *parent;
+};
+
+/**
+ * Run queue is a set of entities scheduling command submissions for
+ * one specific ring. It implements the scheduling policy that selects
+ * the next entity to emit commands from.
+*/
+struct amd_run_queue {
+ struct mutex lock;
+ atomic_t nr_entity;
+ struct amd_sched_entity head;
+ struct amd_sched_entity *current_entity;
+ /**
+ * Return 0 means this entity can be scheduled
+ * Return -1 means this entity cannot be scheduled for reasons,
+ * i.e, it is the head, or these is no job, etc
+ */
+ int (*check_entity_status)(struct amd_sched_entity *entity);
+};
+
+/**
+ * Context based scheduler entity, there can be multiple entities for
+ * each context, and one entity per ring
+*/
+struct amd_context_entity {
+ struct amd_sched_entity generic_entity;
+ spinlock_t lock;
+ /* the virtual_seq is unique per context per ring */
+ atomic64_t last_queued_v_seq;
+ atomic64_t last_emitted_v_seq;
+ atomic64_t last_signaled_v_seq;
+ pid_t tgid;
+ uint32_t context_id;
+ /* the job_queue maintains the jobs submitted by clients */
+ struct kfifo job_queue;
+ spinlock_t queue_lock;
+ struct amd_gpu_scheduler *scheduler;
+ wait_queue_head_t wait_queue;
+ wait_queue_head_t wait_emit;
+ bool is_pending;
+};
+
+/**
+ * Define the backend operations called by the scheduler,
+ * these functions should be implemented in driver side
+*/
+struct amd_sched_backend_ops {
+ int (*prepare_job)(struct amd_gpu_scheduler *sched,
+ struct amd_context_entity *c_entity,
+ void *job);
+ void (*run_job)(struct amd_gpu_scheduler *sched,
+ struct amd_context_entity *c_entity,
+ void *job);
+ void (*process_job)(struct amd_gpu_scheduler *sched, void *job);
+};
+
+/**
+ * One scheduler is implemented for each hardware ring
+*/
+struct amd_gpu_scheduler {
+ void *device;
+ struct task_struct *thread;
+ struct amd_run_queue sched_rq;
+ struct amd_run_queue kernel_rq;
+ struct kfifo active_hw_rq;
+ struct amd_sched_backend_ops *ops;
+ uint32_t ring_id;
+ uint32_t granularity; /* in ms unit */
+ uint32_t preemption;
+ uint64_t last_handled_seq;
+ wait_queue_head_t wait_queue;
+ struct amd_context_entity *current_entity;
+ struct mutex sched_lock;
+ spinlock_t queue_lock;
+};
+
+
+struct amd_gpu_scheduler *amd_sched_create(void *device,
+ struct amd_sched_backend_ops *ops,
+ uint32_t ring,
+ uint32_t granularity,
+ uint32_t preemption);
+
+int amd_sched_destroy(struct amd_gpu_scheduler *sched);
+
+int amd_sched_push_job(struct amd_gpu_scheduler *sched,
+ struct amd_context_entity *c_entity,
+ void *job);
+
+int amd_sched_check_ts(struct amd_context_entity *c_entity, uint64_t seq);
+
+int amd_sched_wait_signal(struct amd_context_entity *c_entity,
+ uint64_t seq, bool intr, long timeout);
+int amd_sched_wait_emit(struct amd_context_entity *c_entity,
+ uint64_t seq,
+ bool intr,
+ long timeout);
+
+void amd_sched_isr(struct amd_gpu_scheduler *sched);
+uint64_t amd_sched_get_handled_seq(struct amd_gpu_scheduler *sched);
+
+int amd_context_entity_fini(struct amd_gpu_scheduler *sched,
+ struct amd_context_entity *entity);
+
+int amd_context_entity_init(struct amd_gpu_scheduler *sched,
+ struct amd_context_entity *entity,
+ struct amd_sched_entity *parent,
+ struct amd_run_queue *rq,
+ uint32_t context_id);
+
+#endif
projects / deliverable / linux.git / commitdiff
