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@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240307013458.23550-5-jason-jh.lin@mediatek.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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