Re: [PATCH v4 08/12] soc: mediatek: cmdq: add packet encoder function

[CK Hu <ck.hu@mediatek.com>]

Hi, Bibby:

On Mon, 2019-04-15 at 20:58 +0800, Bibby Hsieh wrote:
> Implement a function can encode the GCE instructions
> 
> Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
> ---
>  drivers/soc/mediatek/mtk-cmdq-helper.c   | 125 ++++++++++++++++-------
>  include/linux/mailbox/mtk-cmdq-mailbox.h |   2 +
>  include/linux/soc/mediatek/mtk-cmdq.h    |  14 +--
>  3 files changed, 99 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index ff9fef5a032b..d3873ab21db3 100644
> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> @@ -9,11 +9,43 @@
>  #include <linux/mailbox_controller.h>
>  #include <linux/soc/mediatek/mtk-cmdq.h>
>  
> -#define CMDQ_ARG_A_WRITE_MASK	0xffff
> +#define CMDQ_GET_ARG_B(arg)	(((arg) & GENMASK(31, 16)) >> 16)
> +#define CMDQ_GET_ARG_C(arg)	((arg) & GENMASK(15, 0))
>  #define CMDQ_WRITE_ENABLE_MASK	BIT(0)
>  #define CMDQ_EOC_IRQ_EN		BIT(0)
>  #define CMDQ_EOC_CMD		((u64)((CMDQ_CODE_EOC << CMDQ_OP_CODE_SHIFT)) \
>  				<< 32 | CMDQ_EOC_IRQ_EN)
> +#define CMDQ_IMMEDIATE_VALUE	0
> +#define CMDQ_REG_TYPE		1
> +
> +struct cmdq_instruction {
> +	s16 arg_c:16;
> +	s16 arg_b:16;
> +	s16 arg_a:16;
> +	u8 s_op:5;
> +	u8 arg_c_type:1;
> +	u8 arg_b_type:1;
> +	u8 arg_a_type:1;
> +	u8 op:8;
> +};
> +
> +static void cmdq_pkt_instr_encoder(struct cmdq_pkt *pkt, s16 arg_c, s16 arg_b,
> +				   s16 arg_a, u8 s_op, u8 arg_c_type,
> +				   u8 arg_b_type, u8 arg_a_type, u8 op)
> +{
> +	struct cmdq_instruction *cmdq_inst;
> +
> +	cmdq_inst = pkt->va_base + pkt->cmd_buf_size;
> +	cmdq_inst->op = op;
> +	cmdq_inst->arg_a_type = arg_a_type;
> +	cmdq_inst->arg_b_type = arg_b_type;
> +	cmdq_inst->arg_c_type = arg_c_type;
> +	cmdq_inst->s_op = s_op;
> +	cmdq_inst->arg_a = arg_a;
> +	cmdq_inst->arg_b = arg_b;
> +	cmdq_inst->arg_c = arg_c;
> +	pkt->cmd_buf_size += CMDQ_INST_SIZE;
> +}
>  
>  static void cmdq_client_timeout(struct timer_list *t)
>  {
> @@ -110,10 +142,11 @@ void cmdq_pkt_destroy(struct cmdq_pkt *pkt)
>  }
>  EXPORT_SYMBOL(cmdq_pkt_destroy);
>  
> -static int cmdq_pkt_append_command(struct cmdq_pkt *pkt, enum cmdq_code code,
> -				   u32 arg_a, u32 arg_b)
> +static int cmdq_pkt_append_command(struct cmdq_pkt *pkt, s16 arg_c, s16 arg_b,
> +				   s16 arg_a, u8 s_op, u8 arg_c_type,
> +				   u8 arg_b_type, u8 arg_a_type,
> +				   enum cmdq_code code)
>  {
> -	u64 *cmd_ptr;
>  
>  	if (unlikely(pkt->cmd_buf_size + CMDQ_INST_SIZE > pkt->buf_size)) {
>  		/*
> @@ -129,65 +162,72 @@ static int cmdq_pkt_append_command(struct cmdq_pkt *pkt, enum cmdq_code code,
>  			__func__, (u32)pkt->buf_size);
>  		return -ENOMEM;
>  	}
> -	cmd_ptr = pkt->va_base + pkt->cmd_buf_size;
> -	(*cmd_ptr) = (u64)((code << CMDQ_OP_CODE_SHIFT) | arg_a) << 32 | arg_b;
> -	pkt->cmd_buf_size += CMDQ_INST_SIZE;
> +	cmdq_pkt_instr_encoder(pkt, arg_c, arg_b, arg_a, s_op, arg_c_type,
> +			       arg_b_type, arg_a_type, code);
>  
>  	return 0;
>  }
>  
> -int cmdq_pkt_write(struct cmdq_pkt *pkt, u32 value, u32 subsys, u32 offset)
> +int cmdq_pkt_write(struct cmdq_pkt *pkt, u8 subsys, u16 offset, u32 value)
>  {
> -	u32 arg_a = (offset & CMDQ_ARG_A_WRITE_MASK) |
> -		    (subsys << CMDQ_SUBSYS_SHIFT);
> -
> -	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WRITE, arg_a, value);
> +	return cmdq_pkt_append_command(pkt, CMDQ_GET_ARG_C(value),
> +				       CMDQ_GET_ARG_B(value), offset, subsys,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE, CMDQ_CODE_WRITE);

I do not understand why you invent a encoder function. It neither reduce
the code size, nor make code easier for reading. If for easier reading,
I suggest this way:

struct cmdq_instruction {
	union {
		struct {
			u32 value;
			u16 offset;
			u8 subsys;
		};

		struct {
			...
		};
	};
	u8 op;
};

struct cmdq_instruction *inst;

inst = cmdq_pkt_append_command(pkt);
if (!inst)
	return -ENOMEM;

inst->op = CMDQ_CODE_WRITE;
inst->subsys = subsys;
inst->offset = offset;
inst->value = value;

Regards,
CK

>  }
>  EXPORT_SYMBOL(cmdq_pkt_write);
>  
> -int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u32 value,
> -			u32 subsys, u32 offset, u32 mask)
> +int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys, u16 offset,
> +			u32 value, u32 mask)
>  {
>  	u32 offset_mask = offset;
>  	int err = 0;
>  
>  	if (mask != 0xffffffff) {
> -		err = cmdq_pkt_append_command(pkt, CMDQ_CODE_MASK, 0, ~mask);
> +		err = cmdq_pkt_append_command(pkt, CMDQ_GET_ARG_C(~mask),
> +					      CMDQ_GET_ARG_B(~mask),
> +					      CMDQ_IMMEDIATE_VALUE,
> +					      CMDQ_IMMEDIATE_VALUE,
> +					      CMDQ_IMMEDIATE_VALUE,
> +					      CMDQ_IMMEDIATE_VALUE,
> +					      CMDQ_IMMEDIATE_VALUE,
> +					      CMDQ_CODE_MASK);
>  		offset_mask |= CMDQ_WRITE_ENABLE_MASK;
>  	}
> -	err |= cmdq_pkt_write(pkt, value, subsys, offset_mask);
> +	err |= cmdq_pkt_write(pkt, subsys, offset_mask, value);
>  
>  	return err;
>  }
>  EXPORT_SYMBOL(cmdq_pkt_write_mask);
>  
> -int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u32 event)
> +int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event)
>  {
> -	u32 arg_b;
> -
>  	if (event >= CMDQ_MAX_EVENT)
>  		return -EINVAL;
>  
> -	/*
> -	 * WFE arg_b
> -	 * bit 0-11: wait value
> -	 * bit 15: 1 - wait, 0 - no wait
> -	 * bit 16-27: update value
> -	 * bit 31: 1 - update, 0 - no update
> -	 */
> -	arg_b = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
> -
> -	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event, arg_b);
> +	return cmdq_pkt_append_command(pkt, CMDQ_GET_ARG_C(CMDQ_WFE_OPTION),
> +				       CMDQ_GET_ARG_B(CMDQ_WFE_OPTION), event,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_CODE_WFE);
>  }
>  EXPORT_SYMBOL(cmdq_pkt_wfe);
>  
> -int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u32 event)
> +int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
>  {
>  	if (event >= CMDQ_MAX_EVENT)
>  		return -EINVAL;
>  
> -	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event,
> -				       CMDQ_WFE_UPDATE);
> +	return cmdq_pkt_append_command(pkt, CMDQ_GET_ARG_C(CMDQ_WFE_UPDATE),
> +				       CMDQ_GET_ARG_B(CMDQ_WFE_UPDATE), event,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_IMMEDIATE_VALUE,
> +				       CMDQ_CODE_WFE);
>  }
>  EXPORT_SYMBOL(cmdq_pkt_clear_event);
>  
> @@ -196,10 +236,25 @@ static int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
>  	int err;
>  
>  	/* insert EOC and generate IRQ for each command iteration */
> -	err = cmdq_pkt_append_command(pkt, CMDQ_CODE_EOC, 0, CMDQ_EOC_IRQ_EN);
> -
> +	err = cmdq_pkt_append_command(pkt, CMDQ_GET_ARG_C(CMDQ_EOC_IRQ_EN),
> +				      CMDQ_GET_ARG_B(CMDQ_EOC_IRQ_EN),
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_CODE_EOC);
> +	if (err < 0)
> +		return err;
>  	/* JUMP to end */
> -	err |= cmdq_pkt_append_command(pkt, CMDQ_CODE_JUMP, 0, CMDQ_JUMP_PASS);
> +	err = cmdq_pkt_append_command(pkt, CMDQ_GET_ARG_C(CMDQ_JUMP_PASS),
> +				      CMDQ_GET_ARG_B(CMDQ_JUMP_PASS),
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_IMMEDIATE_VALUE,
> +				      CMDQ_CODE_JUMP);
>  
>  	return err;
>  }
> diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
> index 911475da7a53..f21801d32a3a 100644
> --- a/include/linux/mailbox/mtk-cmdq-mailbox.h
> +++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
> @@ -19,6 +19,8 @@
>  #define CMDQ_WFE_UPDATE			BIT(31)
>  #define CMDQ_WFE_WAIT			BIT(15)
>  #define CMDQ_WFE_WAIT_VALUE		0x1
> +#define CMDQ_WFE_OPTION                 (CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | \
> +					CMDQ_WFE_WAIT_VALUE)
>  /** cmdq event maximum */
>  #define CMDQ_MAX_EVENT			0x3ff
>  
> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> index 4e8899972db4..52f69c8db8de 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -60,26 +60,26 @@ void cmdq_pkt_destroy(struct cmdq_pkt *pkt);
>  /**
>   * cmdq_pkt_write() - append write command to the CMDQ packet
>   * @pkt:	the CMDQ packet
> - * @value:	the specified target register value
>   * @subsys:	the CMDQ sub system code
>   * @offset:	register offset from CMDQ sub system
> + * @value:	the specified target register value
>   *
>   * Return: 0 for success; else the error code is returned
>   */
> -int cmdq_pkt_write(struct cmdq_pkt *pkt, u32 value, u32 subsys, u32 offset);
> +int cmdq_pkt_write(struct cmdq_pkt *pkt, u8 subsys, u16 offset, u32 value);
>  
>  /**
>   * cmdq_pkt_write_mask() - append write command with mask to the CMDQ packet
>   * @pkt:	the CMDQ packet
> - * @value:	the specified target register value
>   * @subsys:	the CMDQ sub system code
>   * @offset:	register offset from CMDQ sub system
> + * @value:	the specified target register value
>   * @mask:	the specified target register mask
>   *
>   * Return: 0 for success; else the error code is returned
>   */
> -int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u32 value,
> -			u32 subsys, u32 offset, u32 mask);
> +int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys, u16 offset,
> +			u32 value, u32 mask);
>  
>  /**
>   * cmdq_pkt_wfe() - append wait for event command to the CMDQ packet
> @@ -88,7 +88,7 @@ int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u32 value,
>   *
>   * Return: 0 for success; else the error code is returned
>   */
> -int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u32 event);
> +int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event);
>  
>  /**
>   * cmdq_pkt_clear_event() - append clear event command to the CMDQ packet
> @@ -97,7 +97,7 @@ int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u32 event);
>   *
>   * Return: 0 for success; else the error code is returned
>   */
> -int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u32 event);
> +int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event);
>  
>  /**
>   * cmdq_pkt_flush_async() - trigger CMDQ to asynchronously execute the CMDQ