Re: [RESEND, PATCH 2/5] soc: mediatek: mtk-cmdq: Add cmdq_pkt_mem_move() function

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

Hi, Jason:

On Fri, 2024-03-01 at 22:44 +0800, Jason-JH.Lin wrote:
> Add cmdq_pkt_mem_move() function to support CMDQ user making
> an instruction for moving a value from a source address to a
> destination address.
> 
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
>  drivers/soc/mediatek/mtk-cmdq-helper.c | 26
> ++++++++++++++++++++++++++
>  include/linux/soc/mediatek/mtk-cmdq.h  | 10 ++++++++++
>  2 files changed, 36 insertions(+)
> 
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c
> b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index b0cd071c4719..3a1e47ad8a41 100644
> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> @@ -299,6 +299,32 @@ int cmdq_pkt_write_s_mask_value(struct cmdq_pkt
> *pkt, u8 high_addr_reg_idx,
>  }
>  EXPORT_SYMBOL(cmdq_pkt_write_s_mask_value);
>  
> +s32 cmdq_pkt_mem_move(struct cmdq_pkt *pkt, dma_addr_t src_addr,
> dma_addr_t dst_addr)

return type int.

> +{
> +	s32 err;

It may not error, so I prefer to use 'ret'.
Move this after the next two declaration.

> +	const u16 tmp_reg_idx = CMDQ_THR_SPR_IDX0;
> +	const u16 swap_reg_idx = CMDQ_THR_SPR_IDX1;

I would like tmp_reg_idx to be high_addr_reg_idx and swap_reg_idx to be
value_reg_idx.

Regards,
CK

> +
> +	/* read the value of src_addr into swap_reg_idx */
> +	err = cmdq_pkt_assign(pkt, tmp_reg_idx,
> CMDQ_ADDR_HIGH(src_addr));
> +	if (err < 0)
> +		return err;
> +	err = cmdq_pkt_read_s(pkt, tmp_reg_idx,
> CMDQ_ADDR_LOW(src_addr), swap_reg_idx);
> +	if (err < 0)
> +		return err;
> +
> +	/* write the value of swap_reg_idx into dst_addr */
> +	err = cmdq_pkt_assign(pkt, tmp_reg_idx,
> CMDQ_ADDR_HIGH(dst_addr));
> +	if (err < 0)
> +		return err;
> +	err = cmdq_pkt_write_s(pkt, tmp_reg_idx,
> CMDQ_ADDR_LOW(dst_addr), swap_reg_idx);
> +	if (err < 0)
> +		return err;
> +
> +	return err;
> +}
> +EXPORT_SYMBOL(cmdq_pkt_mem_move);
> +
>  int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear)
>  {
>  	struct cmdq_instruction inst = { {0} };
> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h
> b/include/linux/soc/mediatek/mtk-cmdq.h
> index 1dae80185f9f..b6dbe2d8f16a 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -182,6 +182,16 @@ int cmdq_pkt_write_s_value(struct cmdq_pkt *pkt,
> u8 high_addr_reg_idx,
>  int cmdq_pkt_write_s_mask_value(struct cmdq_pkt *pkt, u8
> high_addr_reg_idx,
>  				u16 addr_low, u32 value, u32 mask);
>  
> +/**
> + * cmdq_pkt_mem_move() - append memory move command to the CMDQ
> packet
> + * @pkt:	the CMDQ packet
> + * @src_addr:	source address
> + * @dma_addr_t: destination address
> + *
> + * Return: 0 for success; else the error code is returned
> + */
> +int cmdq_pkt_mem_move(struct cmdq_pkt *pkt, dma_addr_t src_addr,
> dma_addr_t dst_addr);
> +
>  /**
>   * cmdq_pkt_wfe() - append wait for event command to the CMDQ packet
>   * @pkt:	the CMDQ packet