Unverified Commit 69ff6833 authored by Jason-JH.Lin's avatar Jason-JH.Lin Committed by AngeloGioacchino Del Regno
Browse files

soc: mediatek: mtk-cmdq: Add cmdq_pkt_acquire_event() function 



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: default avatarJason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240307013458.23550-5-jason-jh.lin@mediatek.com


Signed-off-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
parent 400e2fa8

drivers/soc/mediatek/mtk-cmdq-helper.c

+15 −0
Original line number Diff line number Diff line
@@ -334,6 +334,21 @@ int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear) 
}

EXPORT_SYMBOL(cmdq_pkt_wfe);



int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event)

{

	struct cmdq_instruction inst = {};



	if (event >= CMDQ_MAX_EVENT)

		return -EINVAL;



	inst.op = CMDQ_CODE_WFE;

	inst.value = CMDQ_WFE_UPDATE | CMDQ_WFE_UPDATE_VALUE | CMDQ_WFE_WAIT;

	inst.event = event;



	return cmdq_pkt_append_command(pkt, inst);

}

EXPORT_SYMBOL(cmdq_pkt_acquire_event);



int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)

{

	struct cmdq_instruction inst = { {0} };

include/linux/soc/mediatek/mtk-cmdq.h

+15 −0
Original line number Diff line number Diff line
@@ -206,6 +206,21 @@ int cmdq_pkt_mem_move(struct cmdq_pkt *pkt, dma_addr_t src_addr, dma_addr_t dst_ 
 */

int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear);



/**

 * cmdq_pkt_acquire_event() - append acquire event command to the CMDQ packet

 * @pkt:	the CMDQ packet

 * @event:	the desired event to be acquired

 *

 * User can use cmdq_pkt_acquire_event() as `mutex_lock` and cmdq_pkt_clear_event()

 * as `mutex_unlock` to protect some `critical section` 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.

 *

 * Return: 0 for success; else the error code is returned

 */

int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event);



/**

 * cmdq_pkt_clear_event() - append clear event command to the CMDQ packet

 * @pkt:	the CMDQ packet