From 69ff68332dc5005539ac37c5c85444aaaec7c914 Mon Sep 17 00:00:00 2001 From: "Jason-JH.Lin" Date: Thu, 7 Mar 2024 09:34:58 +0800 Subject: [PATCH] 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: Jason-JH.Lin Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20240307013458.23550-5-jason-jh.lin@mediatek.com Signed-off-by: AngeloGioacchino Del Regno --- drivers/soc/mediatek/mtk-cmdq-helper.c | 15 +++++++++++++++ include/linux/soc/mediatek/mtk-cmdq.h | 15 +++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c index ee55992f64911..d1ca4b21587e0 100644 --- a/drivers/soc/mediatek/mtk-cmdq-helper.c +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c @@ -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} }; diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h index f59f42e46ef17..d4a8e34505e6b 100644 --- a/include/linux/soc/mediatek/mtk-cmdq.h +++ b/include/linux/soc/mediatek/mtk-cmdq.h @@ -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 -- 2.30.2