drm/amd: add basic scheduling framework

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>

2 files changed, 691 insertions, 0 deletions

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 000000000000..296496ca22a0
--- /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 000000000000..a6226e1e924a
--- /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