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@mediatek.com>
Link: https://lore.kernel.org/r/1594136714-11650-8-git-send-email-dennis-yc.hsieh@mediatek.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Author: Dennis YC Hsieh

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 {
@@ -407,6 +408,18 @@ 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 = {};
+
+	inst.op = CMDQ_CODE_JUMP;
+	inst.offset = CMDQ_JUMP_RELATIVE;
+	inst.value = addr >>
+		cmdq_get_shift_pa(((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} };

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

@@ -252,6 +252,17 @@ 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