Re: [PATCH v5 11/13] soc: mediatek: cmdq: add jump function

[CK Hu]

Hi, Dennis:

On Sun, 2020-03-08 at 18:52 +0800, Dennis YC Hsieh wrote:
> Add jump function so that client can jump to any address which
> contains instruction.
> 

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> Signed-off-by: Dennis YC Hsieh <dennis-yc.hsieh@xxxxxxxxxxxx>
> ---
>  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 59bc1164b411..bb5be20fc70a 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 {
> @@ -372,6 +373,18 @@ 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 99e77155f967..1a6c56f3bec1 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -213,6 +213,17 @@ 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