From: Jammy Zhou Jammy.Zhou@amd.com
run queue: A set of entities scheduling commands for the same ring. It implements the scheduling policy that selects the next entity to emit commands from.
entity: A scheduler entity is a wrapper around a job queue or a group of other entities. This can be used to build hierarchies of entities. For example all job queue entities belonging to the same process may be placed in a higher level entity and scheduled against other process entities. Entities take turns emitting jobs from their job queue to the corresponding hardware ring, in accordance with the scheduler policy.
Signed-off-by: Shaoyun Liu Shaoyun.Liu@amd.com Signed-off-by: Chunming Zhou David1.Zhou@amd.com Signed-off-by: Jammy Zhou Jammy.Zhou@amd.com Acked-by: Christian K?nig christian.koenig@amd.com Reviewed-by: Jammy Zhou Jammy.Zhou@amd.com --- drivers/gpu/drm/amd/scheduler/gpu_scheduler.c | 531 ++++++++++++++++++++++++++ drivers/gpu/drm/amd/scheduler/gpu_scheduler.h | 160 ++++++++ 2 files changed, 691 insertions(+) create mode 100644 drivers/gpu/drm/amd/scheduler/gpu_scheduler.c create mode 100644 drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c new file mode 100644 index 0000000..296496c --- /dev/null +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c @@ -0,0 +1,531 @@ +/* + * 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; +} + diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h new file mode 100644 index 0000000..a6226e1 --- /dev/null +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h @@ -0,0 +1,160 @@ +/* + * 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