[PATCH v9 02/10] drm/xe/guc_submit: Introduce guc_exec_queue_reinit_kernel()

[Raag Jadav <raag.jadav@intel.com>]

In preparation of usecases which require re-initializing GuC submission
after PCIe FLR, introduce guc_exec_queue_reinit_kernel() helper. This will
restore kernel queues which might have been killed before PCIe FLR.

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Tested-by: Lukasz Laguna <lukasz.laguna@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
---
v4: Teardown exec queues instead of mangling scheduler pending list (Matthew Brost)
v5: Re-initialize kernel queues through submission backend (Matthew Brost)
v8: Introduce xe_sched_reinit() (Daniele)
    Maintain timeout per scheduler instance (Daniele)
    s/reinit/reinit_kernel (Daniele)
v9: Move drm_sched_is_stopped() assert to xe_sched_reinit() (Daniele)
---
 drivers/gpu/drm/xe/xe_exec_queue_types.h    |  2 ++
 drivers/gpu/drm/xe/xe_execlist.c            |  6 ++++++
 drivers/gpu/drm/xe/xe_gpu_scheduler.c       | 17 +++++++++++++++++
 drivers/gpu/drm/xe/xe_gpu_scheduler.h       |  1 +
 drivers/gpu/drm/xe/xe_gpu_scheduler_types.h |  5 +++++
 drivers/gpu/drm/xe/xe_guc_submit.c          |  9 +++++++++
 6 files changed, 40 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
index d27ce24daae5..ac0b3474132c 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
@@ -274,6 +274,8 @@ struct xe_exec_queue {
 struct xe_exec_queue_ops {
 	/** @init: Initialize exec queue for submission backend */
 	int (*init)(struct xe_exec_queue *q);
+	/** @reinit_kernel: Re-initialize kernel queue for submission backend */
+	void (*reinit_kernel)(struct xe_exec_queue *q);
 	/** @kill: Kill inflight submissions for backend */
 	void (*kill)(struct xe_exec_queue *q);
 	/** @fini: Undoes the init() for submission backend */
diff --git a/drivers/gpu/drm/xe/xe_execlist.c b/drivers/gpu/drm/xe/xe_execlist.c
index 6b86b4f9cc1c..a0572b72e96e 100644
--- a/drivers/gpu/drm/xe/xe_execlist.c
+++ b/drivers/gpu/drm/xe/xe_execlist.c
@@ -403,6 +403,11 @@ static void execlist_exec_queue_destroy_async(struct work_struct *w)
 	xe_exec_queue_fini(q);
 }
 
+static void execlist_exec_queue_reinit_kernel(struct xe_exec_queue *q)
+{
+	/* NIY */
+}
+
 static void execlist_exec_queue_kill(struct xe_exec_queue *q)
 {
 	/* NIY */
@@ -460,6 +465,7 @@ static bool execlist_exec_queue_reset_status(struct xe_exec_queue *q)
 
 static const struct xe_exec_queue_ops execlist_exec_queue_ops = {
 	.init = execlist_exec_queue_init,
+	.reinit_kernel = execlist_exec_queue_reinit_kernel,
 	.kill = execlist_exec_queue_kill,
 	.fini = execlist_exec_queue_fini,
 	.destroy = execlist_exec_queue_destroy,
diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler.c b/drivers/gpu/drm/xe/xe_gpu_scheduler.c
index 67d8ce368486..e85bc4077809 100644
--- a/drivers/gpu/drm/xe/xe_gpu_scheduler.c
+++ b/drivers/gpu/drm/xe/xe_gpu_scheduler.c
@@ -3,7 +3,10 @@
  * Copyright © 2023 Intel Corporation
  */
 
+#include "xe_assert.h"
+#include "xe_exec_queue_types.h"
 #include "xe_gpu_scheduler.h"
+#include "xe_guc_exec_queue_types.h"
 
 static void xe_sched_process_msg_queue(struct xe_gpu_scheduler *sched)
 {
@@ -76,6 +79,7 @@ int xe_sched_init(struct xe_gpu_scheduler *sched,
 	};
 
 	sched->ops = xe_ops;
+	sched->timeout = timeout;
 	spin_lock_init(&sched->msg_lock);
 	INIT_LIST_HEAD(&sched->msgs);
 	INIT_WORK(&sched->work_process_msg, xe_sched_process_msg_work);
@@ -83,6 +87,19 @@ int xe_sched_init(struct xe_gpu_scheduler *sched,
 	return drm_sched_init(&sched->base, &args);
 }
 
+void xe_sched_reinit(struct xe_gpu_scheduler *sched)
+{
+	struct xe_guc_exec_queue *ge = container_of(sched, struct xe_guc_exec_queue, sched);
+
+	xe_gt_assert(ge->q->gt, drm_sched_is_stopped(&sched->base));
+
+	/*
+	 * TODO: Implement drm_sched_reinit() instead of requiring the
+	 * driver to restore individual fields.
+	 */
+	sched->base.timeout = sched->timeout;
+}
+
 void xe_sched_fini(struct xe_gpu_scheduler *sched)
 {
 	xe_sched_submission_stop(sched);
diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler.h b/drivers/gpu/drm/xe/xe_gpu_scheduler.h
index 664c2db56af3..22e24b4b7171 100644
--- a/drivers/gpu/drm/xe/xe_gpu_scheduler.h
+++ b/drivers/gpu/drm/xe/xe_gpu_scheduler.h
@@ -17,6 +17,7 @@ int xe_sched_init(struct xe_gpu_scheduler *sched,
 		  long timeout, struct workqueue_struct *timeout_wq,
 		  atomic_t *score, const char *name,
 		  struct device *dev);
+void xe_sched_reinit(struct xe_gpu_scheduler *sched);
 void xe_sched_fini(struct xe_gpu_scheduler *sched);
 
 void xe_sched_submission_start(struct xe_gpu_scheduler *sched);
diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h b/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h
index 63d9bf92583c..e73fdacca164 100644
--- a/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h
+++ b/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h
@@ -51,6 +51,11 @@ struct xe_gpu_scheduler {
 	spinlock_t				msg_lock;
 	/** @work_process_msg: processes messages */
 	struct work_struct		work_process_msg;
+	/**
+	 * @timeout: timeout for the scheduler instance, to be restored
+	 * during exec queue re-initialization
+	 */
+	long				timeout;
 };
 
 #define xe_sched_entity		drm_sched_entity
diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index 9458bf477fa6..8774c8baeacd 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -2018,6 +2018,14 @@ static int guc_exec_queue_init(struct xe_exec_queue *q)
 	return err;
 }
 
+static void guc_exec_queue_reinit_kernel(struct xe_exec_queue *q)
+{
+	xe_gt_assert(q->gt, q->flags & EXEC_QUEUE_FLAG_KERNEL);
+
+	atomic_set(&q->guc->state, 0);
+	xe_sched_reinit(&q->guc->sched);
+}
+
 static void guc_exec_queue_kill(struct xe_exec_queue *q)
 {
 	trace_xe_exec_queue_kill(q);
@@ -2252,6 +2260,7 @@ static bool guc_exec_queue_reset_status(struct xe_exec_queue *q)
  */
 static const struct xe_exec_queue_ops guc_exec_queue_ops = {
 	.init = guc_exec_queue_init,
+	.reinit_kernel = guc_exec_queue_reinit_kernel,
 	.kill = guc_exec_queue_kill,
 	.fini = guc_exec_queue_fini,
 	.destroy = guc_exec_queue_destroy,
-- 
2.43.0