[PATCH v3 1/7] drm/xe: Add xe_ring_lrc_is_idle() helper

[Matthew Brost <matthew.brost@intel.com>]

Add helper to compare ring head and tail to determine if LRC is idle.

v2:
 - Fix kernel doc (CI, Zhanjun)

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
---
 drivers/gpu/drm/xe/xe_guc_submit.c |  2 +-
 drivers/gpu/drm/xe/xe_lrc.c        | 13 +++++++++++++
 drivers/gpu/drm/xe/xe_lrc.h        |  2 ++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index c70b75a3eb85..663ad4d97b34 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -1696,7 +1696,7 @@ static void guc_exec_queue_stop(struct xe_guc *guc, struct xe_exec_queue *q)
 				ban = true;
 			}
 		} else if (xe_exec_queue_is_lr(q) &&
-			   (xe_lrc_ring_head(q->lrc[0]) != xe_lrc_ring_tail(q->lrc[0]))) {
+			   !xe_lrc_ring_is_idle(q->lrc[0])) {
 			ban = true;
 		}
 
diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
index 4b65da77c6e0..e0d80e8201eb 100644
--- a/drivers/gpu/drm/xe/xe_lrc.c
+++ b/drivers/gpu/drm/xe/xe_lrc.c
@@ -1763,3 +1763,16 @@ u32 xe_lrc_update_timestamp(struct xe_lrc *lrc, u32 *old_ts)
 
 	return lrc->ctx_timestamp;
 }
+
+/**
+ * xe_lrc_ring_is_idle() - LRC is idle
+ * @lrc: Pointer to the lrc.
+ *
+ * Compare LRC ring head and tail to determine if idle.
+ *
+ * Return: True is ring is idle, False otherwise
+ */
+bool xe_lrc_ring_is_idle(struct xe_lrc *lrc)
+{
+	return xe_lrc_ring_head(lrc) == xe_lrc_ring_tail(lrc);
+}
diff --git a/drivers/gpu/drm/xe/xe_lrc.h b/drivers/gpu/drm/xe/xe_lrc.h
index 40d8f6906d3e..9d64cedc4d14 100644
--- a/drivers/gpu/drm/xe/xe_lrc.h
+++ b/drivers/gpu/drm/xe/xe_lrc.h
@@ -78,6 +78,8 @@ u32 xe_lrc_ring_head(struct xe_lrc *lrc);
 u32 xe_lrc_ring_space(struct xe_lrc *lrc);
 void xe_lrc_write_ring(struct xe_lrc *lrc, const void *data, size_t size);
 
+bool xe_lrc_ring_is_idle(struct xe_lrc *lrc);
+
 u32 xe_lrc_indirect_ring_ggtt_addr(struct xe_lrc *lrc);
 u32 xe_lrc_ggtt_addr(struct xe_lrc *lrc);
 u32 *xe_lrc_regs(struct xe_lrc *lrc);
-- 
2.34.1