linux-kernel - [PATCH v6 14/16] soc: mediatek: cmdq: add jump function

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Date:   Fri, 29 May 2020 01:04:49 +0800
From:   Dennis YC Hsieh <dennis-yc.hsieh@...iatek.com>
To:     Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Jassi Brar <jassisinghbrar@...il.com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>
CC:     <linux-kernel@...r.kernel.org>,
        <linux-mediatek@...ts.infradead.org>, <devicetree@...r.kernel.org>,
        <wsd_upstream@...iatek.com>, <dri-devel@...ts.freedesktop.org>,
        Bibby Hsieh <bibby.hsieh@...iatek.com>,
        CK Hu <ck.hu@...iatek.com>,
        Houlong Wei <houlong.wei@...iatek.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        HS Liao <hs.liao@...iatek.com>,
        Dennis YC Hsieh <dennis-yc.hsieh@...iatek.com>
Subject: [PATCH v6 14/16] soc: mediatek: cmdq: add jump function

Add jump function so that client can jump to any address which
contains instruction.

Signed-off-by: Dennis YC Hsieh <dennis-yc.hsieh@...iatek.com>
Reviewed-by: CK Hu <ck.hu@...iatek.com>
---
 drivers/soc/mediatek/mtk-cmdq-helper.c | 13 +++++++++++++
 include/linux/soc/mediatek/mtk-cmdq.h  | 11 +++++++++++
 2 files changed, 24 insertions(+)

diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
index ebcdd30cd783..5cf9e71b7900 100644
--- a/drivers/soc/mediatek/mtk-cmdq-helper.c
+++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
@@ -13,6 +13,7 @@
 #define CMDQ_POLL_ENABLE_MASK	BIT(0)
 #define CMDQ_EOC_IRQ_EN		BIT(0)
 #define CMDQ_REG_TYPE		1
+#define CMDQ_JUMP_RELATIVE	1
 
 struct cmdq_instruction {
 	union {
@@ -391,6 +392,18 @@ int cmdq_pkt_assign(struct cmdq_pkt *pkt, u16 reg_idx, u32 value)
 }
 EXPORT_SYMBOL(cmdq_pkt_assign);
 
+int cmdq_pkt_jump(struct cmdq_pkt *pkt, dma_addr_t addr)
+{
+	struct cmdq_instruction inst = { {0} };
+
+	inst.op = CMDQ_CODE_JUMP;
+	inst.offset = CMDQ_JUMP_RELATIVE;
+	inst.value = addr >>
+		cmdq_mbox_shift(((struct cmdq_client *)pkt->cl)->chan);
+	return cmdq_pkt_append_command(pkt, inst);
+}
+EXPORT_SYMBOL(cmdq_pkt_jump);
+
 int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
 {
 	struct cmdq_instruction inst = { {0} };
diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
index 703cffcd55bd..9494b293bad9 100644
--- a/include/linux/soc/mediatek/mtk-cmdq.h
+++ b/include/linux/soc/mediatek/mtk-cmdq.h
@@ -244,6 +244,17 @@ int cmdq_pkt_poll_mask(struct cmdq_pkt *pkt, u8 subsys,
  */
 int cmdq_pkt_assign(struct cmdq_pkt *pkt, u16 reg_idx, u32 value);
 
+/**
+ * cmdq_pkt_jump() - Append jump command to the CMDQ packet, ask GCE
+ *		     to execute an instruction that change current thread PC to
+ *		     a physical address which should contains more instruction.
+ * @pkt:        the CMDQ packet
+ * @addr:       physical address of target instruction buffer
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_pkt_jump(struct cmdq_pkt *pkt, dma_addr_t addr);
+
 /**
  * cmdq_pkt_finalize() - Append EOC and jump command to pkt.
  * @pkt:	the CMDQ packet
-- 
2.18.0