[PATCH v4 5/9] mailbox: mtk-cmdq: Support GCE loop packets in interrupt handler

[Shawn Sung]

From: "Jason-JH.Lin" <jason-jh.lin at mediatek.com>

1. Add a loop flag for CMDQ packet struct.
CMDQ helper will use a loop flag to mark CMDQ packet as lopping command
and make current command buffer jumps to the beginning when GCE executes
to the end of command buffer.

2. Add a looping task handle flow in irq handler.
GCE irq occurs when GCE executes to the end of command(EOC) instruction.
If the CMDQ packet is a loopping command, GCE irq handler can not
delete the CMDQ task and disable the GCE thread.

Signed-off-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
Signed-off-by: Hsiao Chien Sung <shawn.sung at mediatek.com>
---
 drivers/mailbox/mtk-cmdq-mailbox.c       | 11 +++++++++++
 include/linux/mailbox/mtk-cmdq-mailbox.h |  1 +
 2 files changed, 12 insertions(+)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index ead2200f39ba0..5906e0343d1fc 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -267,6 +267,17 @@ static void cmdq_thread_irq_handler(struct cmdq *cmdq,
 
 	curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) << cmdq->pdata->shift;
 
+	task = list_first_entry_or_null(&thread->task_busy_list,
+					struct cmdq_task, list_entry);
+	if (task && task->pkt->loop) {
+		struct cmdq_cb_data data;
+
+		data.sta = err;
+		data.pkt = task->pkt;
+		mbox_chan_received_data(task->thread->chan, &data);
+		return;
+	}
+
 	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
 				 list_entry) {
 		task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
index a8f0070c7aa98..f78a08e7c6ede 100644
--- a/include/linux/mailbox/mtk-cmdq-mailbox.h
+++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
@@ -76,6 +76,7 @@ struct cmdq_pkt {
 	size_t			cmd_buf_size; /* command occupied size */
 	size_t			buf_size; /* real buffer size */
 	void			*cl;
+	bool			loop;
 };
 
 u8 cmdq_get_shift_pa(struct mbox_chan *chan);
-- 
2.18.0