drm/sched: Add drm_sched_wqueue_* helpers

Add scheduler wqueue ready, stop, and start helpers to hide the
implementation details of the scheduler from the drivers.

v2:
  - s/sched_wqueue/sched_wqueue (Luben)
  - Remove the extra white line after the return-statement (Luben)
  - update drm_sched_wqueue_ready comment (Luben)

Cc: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://lore.kernel.org/r/20231031032439.1558703-2-matthew.brost@intel.com
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>

Author: mbrost05

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c

@@ -290,7 +290,7 @@ static int suspend_resume_compute_scheduler(struct amdgpu_device *adev, bool sus
 	for (i = 0; i < adev->gfx.num_compute_rings; i++) {
 		struct amdgpu_ring *ring = &adev->gfx.compute_ring[i];
 
-		if (!(ring && ring->sched.thread))
+		if (!(ring && drm_sched_wqueue_ready(&ring->sched)))
 			continue;
 
 		/* stop secheduler and drain ring. */

drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c

@@ -1659,9 +1659,9 @@ static int amdgpu_debugfs_test_ib_show(struct seq_file *m, void *unused)
 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 		struct amdgpu_ring *ring = adev->rings[i];
 
-		if (!ring || !ring->sched.thread)
+		if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 			continue;
-		kthread_park(ring->sched.thread);
+		drm_sched_wqueue_stop(&ring->sched);
 	}
 
 	seq_puts(m, "run ib test:\n");
@@ -1675,9 +1675,9 @@ static int amdgpu_debugfs_test_ib_show(struct seq_file *m, void *unused)
 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 		struct amdgpu_ring *ring = adev->rings[i];
 
-		if (!ring || !ring->sched.thread)
+		if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 			continue;
-		kthread_unpark(ring->sched.thread);
+		drm_sched_wqueue_start(&ring->sched);
 	}
 
 	up_write(&adev->reset_domain->sem);
@@ -1897,7 +1897,8 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)
 
 	ring = adev->rings[val];
 
-	if (!ring || !ring->funcs->preempt_ib || !ring->sched.thread)
+	if (!ring || !ring->funcs->preempt_ib ||
+	    !drm_sched_wqueue_ready(&ring->sched))
 		return -EINVAL;
 
 	/* the last preemption failed */
@@ -1915,7 +1916,7 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)
 		goto pro_end;
 
 	/* stop the scheduler */
-	kthread_park(ring->sched.thread);
+	drm_sched_wqueue_stop(&ring->sched);
 
 	/* preempt the IB */
 	r = amdgpu_ring_preempt_ib(ring);
@@ -1949,7 +1950,7 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)
 
 failure:
 	/* restart the scheduler */
-	kthread_unpark(ring->sched.thread);
+	drm_sched_wqueue_start(&ring->sched);
 
 	up_read(&adev->reset_domain->sem);
 

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -4601,7 +4601,7 @@ bool amdgpu_device_has_job_running(struct amdgpu_device *adev)
 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 		struct amdgpu_ring *ring = adev->rings[i];
 
-		if (!ring || !ring->sched.thread)
+		if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 			continue;
 
 		spin_lock(&ring->sched.job_list_lock);
@@ -4740,7 +4740,7 @@ int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 		struct amdgpu_ring *ring = adev->rings[i];
 
-		if (!ring || !ring->sched.thread)
+		if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 			continue;
 
 		/* Clear job fence from fence drv to avoid force_completion
@@ -5282,7 +5282,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 		for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 			struct amdgpu_ring *ring = tmp_adev->rings[i];
 
-			if (!ring || !ring->sched.thread)
+			if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 				continue;
 
 			drm_sched_stop(&ring->sched, job ? &job->base : NULL);
@@ -5357,7 +5357,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 		for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 			struct amdgpu_ring *ring = tmp_adev->rings[i];
 
-			if (!ring || !ring->sched.thread)
+			if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 				continue;
 
 			drm_sched_start(&ring->sched, true);
@@ -5683,7 +5683,7 @@ pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_sta
 		for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 			struct amdgpu_ring *ring = adev->rings[i];
 
-			if (!ring || !ring->sched.thread)
+			if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 				continue;
 
 			drm_sched_stop(&ring->sched, NULL);
@@ -5811,7 +5811,7 @@ void amdgpu_pci_resume(struct pci_dev *pdev)
 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 		struct amdgpu_ring *ring = adev->rings[i];
 
-		if (!ring || !ring->sched.thread)
+		if (!ring || !drm_sched_wqueue_ready(&ring->sched))
 			continue;
 
 		drm_sched_start(&ring->sched, true);

drivers/gpu/drm/msm/adreno/adreno_device.c

@@ -809,7 +809,8 @@ static void suspend_scheduler(struct msm_gpu *gpu)
 	 */
 	for (i = 0; i < gpu->nr_rings; i++) {
 		struct drm_gpu_scheduler *sched = &gpu->rb[i]->sched;
-		kthread_park(sched->thread);
+
+		drm_sched_wqueue_stop(sched);
 	}
 }
 
@@ -819,7 +820,8 @@ static void resume_scheduler(struct msm_gpu *gpu)
 
 	for (i = 0; i < gpu->nr_rings; i++) {
 		struct drm_gpu_scheduler *sched = &gpu->rb[i]->sched;
-		kthread_unpark(sched->thread);
+
+		drm_sched_wqueue_start(sched);
 	}
 }
 

drivers/gpu/drm/scheduler/sched_main.c

@@ -439,7 +439,7 @@ 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);
+	drm_sched_wqueue_stop(sched);
 
 	/*
 	 * Reinsert back the bad job here - now it's safe as
@@ -552,7 +552,7 @@ void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery)
 		spin_unlock(&sched->job_list_lock);
 	}
 
-	kthread_unpark(sched->thread);
+	drm_sched_wqueue_start(sched);
 }
 EXPORT_SYMBOL(drm_sched_start);
 
@@ -1252,3 +1252,38 @@ void drm_sched_increase_karma(struct drm_sched_job *bad)
 	}
 }
 EXPORT_SYMBOL(drm_sched_increase_karma);
+
+/**
+ * drm_sched_wqueue_ready - Is the scheduler ready for submission
+ *
+ * @sched: scheduler instance
+ *
+ * Returns true if submission is ready
+ */
+bool drm_sched_wqueue_ready(struct drm_gpu_scheduler *sched)
+{
+	return !!sched->thread;
+}
+EXPORT_SYMBOL(drm_sched_wqueue_ready);
+
+/**
+ * drm_sched_wqueue_stop - stop scheduler submission
+ *
+ * @sched: scheduler instance
+ */
+void drm_sched_wqueue_stop(struct drm_gpu_scheduler *sched)
+{
+	kthread_park(sched->thread);
+}
+EXPORT_SYMBOL(drm_sched_wqueue_stop);
+
+/**
+ * drm_sched_wqueue_start - start scheduler submission
+ *
+ * @sched: scheduler instance
+ */
+void drm_sched_wqueue_start(struct drm_gpu_scheduler *sched)
+{
+	kthread_unpark(sched->thread);
+}
+EXPORT_SYMBOL(drm_sched_wqueue_start);

include/drm/gpu_scheduler.h

@@ -553,6 +553,9 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
 
 void drm_sched_job_cleanup(struct drm_sched_job *job);
 void drm_sched_wakeup_if_can_queue(struct drm_gpu_scheduler *sched);
+bool drm_sched_wqueue_ready(struct drm_gpu_scheduler *sched);
+void drm_sched_wqueue_stop(struct drm_gpu_scheduler *sched);
+void drm_sched_wqueue_start(struct drm_gpu_scheduler *sched);
 void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad);
 void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery);
 void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);