[PATCH v7 5/8] drm/xe/exec_queue: Introduce xe_exec_queue_reinit()

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

In preparation of usecases which require re-initializing exec queue
after PCIe FLR, introduce xe_exec_queue_reinit() helper. All the exec
queue LCRs already exist but the context is lost on PCIe FLR and needs
re-initialization.

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Tested-by: Lukasz Laguna <lukasz.laguna@intel.com>
---
v2: Re-initialize migrate context (Matthew Brost)
v6: Add IS_DGFX() and EXEC_QUEUE_FLAG_KERNEL asserts (Daniele)
---
 drivers/gpu/drm/xe/xe_exec_queue.c | 42 +++++++++++++++++++++++++++---
 drivers/gpu/drm/xe/xe_exec_queue.h |  1 +
 drivers/gpu/drm/xe/xe_lrc.c        | 17 ++++++++++++
 drivers/gpu/drm/xe/xe_lrc.h        |  2 ++
 4 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
index 1b5ca3ce578a..cabce61c2b7f 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue.c
+++ b/drivers/gpu/drm/xe/xe_exec_queue.c
@@ -335,9 +335,8 @@ static void __xe_exec_queue_fini(struct xe_exec_queue *q)
 		xe_lrc_put(q->lrc[i]);
 }
 
-static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
+static u32 xe_lrc_init_flags(struct xe_exec_queue *q, u32 exec_queue_flags)
 {
-	int i, err;
 	u32 flags = 0;
 
 	/*
@@ -360,6 +359,13 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
 	if (q->flags & EXEC_QUEUE_FLAG_DISABLE_STATE_CACHE_PERF_FIX)
 		flags |= XE_LRC_DISABLE_STATE_CACHE_PERF_FIX;
 
+	return flags;
+}
+
+static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
+{
+	int i, err;
+
 	err = q->ops->init(q);
 	if (err)
 		return err;
@@ -383,8 +389,8 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
 
 			marker = xe_gt_sriov_vf_wait_valid_ggtt(q->gt);
 
-			lrc = xe_lrc_create(q->hwe, q->vm, q->replay_state,
-					    xe_lrc_ring_size(), q->msix_vec, flags);
+			lrc = xe_lrc_create(q->hwe, q->vm, q->replay_state, xe_lrc_ring_size(),
+					    q->msix_vec, xe_lrc_init_flags(q, exec_queue_flags));
 			if (IS_ERR(lrc)) {
 				err = PTR_ERR(lrc);
 				goto err_lrc;
@@ -406,6 +412,34 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
 	return err;
 }
 
+/**
+ * xe_exec_queue_reinit() - Re-initialize exec queue
+ * @q: exec queue to re-initialize
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_exec_queue_reinit(struct xe_exec_queue *q)
+{
+	int i, err;
+
+	/* Re-initialization only allowed for kernel queues */
+	xe_assert(gt_to_xe(q->gt), q->flags & EXEC_QUEUE_FLAG_KERNEL);
+	/* TODO: Re-initialize GSC and PXP queues */
+	xe_assert(gt_to_xe(q->gt), IS_DGFX(gt_to_xe(q->gt)));
+
+	/* Re-initialize submission backend */
+	q->ops->reinit(q);
+
+	for (i = 0; i < q->width; i++) {
+		err = xe_lrc_reinit(q->lrc[i], q->hwe, q->vm, q->replay_state,
+				    q->msix_vec, xe_lrc_init_flags(q, q->flags));
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 /**
  * xe_exec_queue_create() - Create an exec queue
  * @xe: Xe device
diff --git a/drivers/gpu/drm/xe/xe_exec_queue.h b/drivers/gpu/drm/xe/xe_exec_queue.h
index a82d99bd77bc..445867d4da26 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue.h
@@ -34,6 +34,7 @@ struct xe_exec_queue *xe_exec_queue_create_bind(struct xe_device *xe,
 void xe_exec_queue_fini(struct xe_exec_queue *q);
 void xe_exec_queue_destroy(struct kref *ref);
 void xe_exec_queue_assign_name(struct xe_exec_queue *q, u32 instance);
+int xe_exec_queue_reinit(struct xe_exec_queue *q);
 
 static inline struct xe_exec_queue *
 xe_exec_queue_get_unless_zero(struct xe_exec_queue *q)
diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
index a4292a11391d..c425269893fe 100644
--- a/drivers/gpu/drm/xe/xe_lrc.c
+++ b/drivers/gpu/drm/xe/xe_lrc.c
@@ -1629,6 +1629,23 @@ static int xe_lrc_ctx_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct
 	return err;
 }
 
+/**
+ * xe_lrc_reinit() - Re-initialize LRC
+ * @lrc: Pointer to the LRC
+ * @hwe: Hardware Engine
+ * @vm: The VM (address space)
+ * @replay_state: GPU hang replay state
+ * @msix_vec: MSI-X interrupt vector (for platforms that support it)
+ * @init_flags: LRC initialization flags
+ *
+ * Returns: 0 on success, negative error code otherwise.
+ */
+int xe_lrc_reinit(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct xe_vm *vm,
+		  void *replay_state, u16 msix_vec, u32 init_flags)
+{
+	return xe_lrc_ctx_init(lrc, hwe, vm, replay_state, msix_vec, init_flags);
+}
+
 static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct xe_vm *vm,
 		       void *replay_state, u32 ring_size, u16 msix_vec, u32 init_flags)
 {
diff --git a/drivers/gpu/drm/xe/xe_lrc.h b/drivers/gpu/drm/xe/xe_lrc.h
index 0a3a611391ee..333b11f739ea 100644
--- a/drivers/gpu/drm/xe/xe_lrc.h
+++ b/drivers/gpu/drm/xe/xe_lrc.h
@@ -56,6 +56,8 @@ struct xe_lrc_snapshot {
 
 struct xe_lrc *xe_lrc_create(struct xe_hw_engine *hwe, struct xe_vm *vm,
 			     void *replay_state, u32 ring_size, u16 msix_vec, u32 flags);
+int xe_lrc_reinit(struct xe_lrc *lrc, struct xe_hw_engine *hwe, struct xe_vm *vm,
+		  void *replay_state, u16 msix_vec, u32 init_flags);
 void xe_lrc_destroy(struct kref *ref);
 
 /**
-- 
2.43.0