Re: [PATCH v2 02/11] soc: mediatek: Support GCE jump to absolute

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

Hi, Hsiao-chien:

On Mon, 2023-09-18 at 16:41 +0800, Hsiao Chien Sung wrote:
> Add a new API to jump to the head of cmdq packet by
> appending a jump command at the end of it.
> 
> Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
> ---
>  drivers/soc/mediatek/mtk-cmdq-helper.c | 16 ++++++++++++++++
>  include/linux/soc/mediatek/mtk-cmdq.h  |  2 ++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c
> b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index b0cd071c4719..e029ce231df1 100644
> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> @@ -441,4 +441,20 @@ int cmdq_pkt_flush_async(struct cmdq_pkt *pkt)
>  }
>  EXPORT_SYMBOL(cmdq_pkt_flush_async);
>  
> +int cmdq_pkt_jump_absolute(struct cmdq_pkt *pkt)

CMDQ provide ability to jump to any physical address, but this
interface limit the jump to head of packet. So I would like the
interface to be

int cmdq_pkt_jump_absolute(struct cmdq_pkt *pkt, dma_addr_t pa);

For client driver, it could jump to anywhere it want.

Regards,
CK


> +{
> +	struct cmdq_instruction inst = { 0 };
> +	u8 shift_pa;
> +
> +	shift_pa = cmdq_get_shift_pa(((struct cmdq_client *)pkt->cl)-
> >chan);
> +
> +	/* jump to head of the packet */
> +	inst.op = CMDQ_CODE_JUMP;
> +	inst.offset = CMDQ_JUMP_RELATIVE;
> +	inst.value = pkt->pa_base >> shift_pa;
> +
> +	return cmdq_pkt_append_command(pkt, inst);
> +}
> +EXPORT_SYMBOL(cmdq_pkt_jump_absolute);
> +
>  MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h
> b/include/linux/soc/mediatek/mtk-cmdq.h
> index a253c001c861..106988cc5f01 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -276,6 +276,8 @@ int cmdq_pkt_jump(struct cmdq_pkt *pkt,
> dma_addr_t addr);
>   */
>  int cmdq_pkt_finalize(struct cmdq_pkt *pkt);
>  
> +int cmdq_pkt_jump_absolute(struct cmdq_pkt *pkt);
> +
>  /**
>   * cmdq_pkt_flush_async() - trigger CMDQ to asynchronously execute
> the CMDQ
>   *                          packet and call back at the end of done
> packet