[PATCH 2/2] drm/xe/oa: Allow subsequent OA streams to be opened on an exec_queue

[Ashutosh Dixit]

The restriction that OA not be enabled on an active exec queue only applies
to the first OA stream opened on the exec queue. Subsequent OA streams can
be opened on the exec queue since this will not toggle the
OAC_CONTEXT_ENABLE bit.

Fixes: 2f4a730fcd2d ("drm/xe/oa: Add OAR support")
Cc: stable at vger.kernel.org
Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
---
 drivers/gpu/drm/xe/xe_exec_queue_types.h | 2 ++
 drivers/gpu/drm/xe/xe_oa.c               | 8 ++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
index 1158b6062a6cd..6e3311c22404e 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
@@ -142,6 +142,8 @@ struct xe_exec_queue {
 	u64 tlb_flush_seqno;
 	/** @hw_engine_group_link: link into exec queues in the same hw engine group */
 	struct list_head hw_engine_group_link;
+	/** @oa: this exec_queue is used for OA (OAR/OAC) */
+	bool oa;
 	/** @lrc: logical ring context for this exec queue */
 	struct xe_lrc *lrc[] __counted_by(width);
 };
diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
index b0692b8ca0a3d..53d2946ea3052 100644
--- a/drivers/gpu/drm/xe/xe_oa.c
+++ b/drivers/gpu/drm/xe/xe_oa.c
@@ -1915,6 +1915,9 @@ static int xe_oa_stream_open_ioctl_locked(struct xe_oa *oa,
 		goto err_disable;
 	}
 
+	if (stream->exec_q && !stream->exec_q->oa)
+		stream->exec_q->oa = true;
+
 	/* Hold a reference on the drm device till stream_fd is released */
 	drm_dev_get(&stream->oa->xe->drm);
 
@@ -2068,9 +2071,10 @@ int xe_oa_stream_open_ioctl(struct drm_device *dev, u64 data, struct drm_file *f
 		/*
 		 * Disallow OA from being enabled on active exec_queue's. Enabling OA toggles
 		 * the OAC_CONTEXT_ENABLE bit in CTXT_SR_CTL register, which changes the size
-		 * and layout of the underlying HW context image and can cause hangs.
+		 * and layout of the underlying HW context image and can cause hangs. This
+		 * restriction holds only for the first OA stream opened on the exec queue.
 		 */
-		if (XE_IOCTL_DBG(oa->xe, exec_queue_enabled(param.exec_q))) {
+		if (XE_IOCTL_DBG(oa->xe, !param.exec_q->oa && exec_queue_enabled(param.exec_q))) {
 			ret = -EADDRINUSE;
 			goto err_exec_q;
 		}
-- 
2.41.0