Re: [PATCH v2 4/4] soc: mediatek: mtk-cmdq: Add cmdq_pkt_acquire_event() function

From: AngeloGioacchino Del Regno
Date: Thu Mar 07 2024 - 05:33:25 EST


Il 07/03/24 02:34, Jason-JH.Lin ha scritto:
Add cmdq_pkt_acquire_event() function to support CMDQ user making
an instruction for acquiring event.

CMDQ users can use cmdq_pkt_acquire_event() as `mutex_lock`
and cmdq_pkt_clear_event() as `mutex_unlock` to protect the global
resource modified instructions between them.

cmdq_pkt_acquire_event() would wait for event to be cleared.
After event is cleared by cmdq_pkt_clear_event() in other GCE threads,
cmdq_pkt_acquire_event() would set event and keep executing next
instruction. So the mutex would work like this:

cmdq_pkt_acquire_event() /* mutex lock */

/* critical secton instructions that modified global resource */

cmdq_pkt_clear_event() /* mutex unlock */

Prevent the critical section instructions from being affected by other
GCE threads.

Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>