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Subject: Re: [PATCH v14 07/10] soc: mediatek: cmdq: define the instruction
 struct
From:   houlong wei <houlong.wei@mediatek.com>
To:     Bibby Hsieh <bibby.hsieh@mediatek.com>
CC:     Jassi Brar <jassisinghbrar@gmail.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        CK Hu =?UTF-8?Q?=28=E8=83=A1=E4=BF=8A=E5=85=89=29?= 
        <ck.hu@mediatek.com>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-mediatek@lists.infradead.org" 
        <linux-mediatek@lists.infradead.org>,
        srv_heupstream <srv_heupstream@mediatek.com>,
        Nicolas Boichat <drinkcat@chromium.org>,
        Dennis-YC Hsieh =?UTF-8?Q?=28=E8=AC=9D=E5=AE=87=E5=93=B2=29?= 
        <Dennis-YC.Hsieh@mediatek.com>, <houlong.wei@mediatek.com>
Date:   Fri, 30 Aug 2019 10:23:43 +0800
In-Reply-To: <20190829014817.25482-9-bibby.hsieh@mediatek.com>
References: <20190829014817.25482-1-bibby.hsieh@mediatek.com>
         <20190829014817.25482-9-bibby.hsieh@mediatek.com>
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On Thu, 2019-08-29 at 09:48 +0800, Bibby Hsieh wrote:
> Define an instruction structure for gce driver to append command.
> This structure can make the client's code more readability.
> 
> Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
> Reviewed-by: CK Hu <ck.hu@mediatek.com>
> Reviewed-by: Houlong Wei <houlong.wei@mediatek.com>
> ---
>  drivers/soc/mediatek/mtk-cmdq-helper.c   | 77 ++++++++++++++++--------
>  include/linux/mailbox/mtk-cmdq-mailbox.h | 10 +++
>  2 files changed, 61 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index 7aa0517ff2f3..9472526ab076 100644
> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> @@ -9,12 +9,24 @@
>  #include <linux/mailbox_controller.h>
>  #include <linux/soc/mediatek/mtk-cmdq.h>
>  
> -#define CMDQ_ARG_A_WRITE_MASK	0xffff
>  #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)
>  
> +struct cmdq_instruction {
> +	union {
> +		u32 value;
> +		u32 mask;
> +	};
> +	union {
> +		u16 offset;
> +		u16 event;
> +	};
> +	u8 subsys;
> +	u8 op;
> +};
> +
>  static void cmdq_client_timeout(struct timer_list *t)
>  {
>  	struct cmdq_client *client = from_timer(client, t, timer);
> @@ -110,10 +122,10 @@ 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,
> +				   struct cmdq_instruction inst)

Can we use 'struct cmdq_instruction *inst' instead of 'struct
cmdq_instruction inst' to reduce stack memory consumption a bit?

>  {
> -	u64 *cmd_ptr;
> +	struct cmdq_instruction *cmd_ptr;
>  
>  	if (unlikely(pkt->cmd_buf_size + CMDQ_INST_SIZE > pkt->buf_size)) {
>  		/*
> @@ -129,8 +141,9 @@ 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;
> +	*cmd_ptr = inst;
>  	pkt->cmd_buf_size += CMDQ_INST_SIZE;
>  
>  	return 0;
> @@ -138,24 +151,31 @@ static int cmdq_pkt_append_command(struct cmdq_pkt *pkt, enum cmdq_code code,
>  
>  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);
> +	struct cmdq_instruction inst;
> +
> +	inst.op = CMDQ_CODE_WRITE;
> +	inst.value = value;
> +	inst.offset = offset;
> +	inst.subsys = subsys;
>  
> -	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WRITE, arg_a, value);
> +	return cmdq_pkt_append_command(pkt, inst);
>  }
>  EXPORT_SYMBOL(cmdq_pkt_write);
>  
>  int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys,
>  			u16 offset, u32 value, u32 mask)
>  {
> -	u32 offset_mask = offset;
> +	struct cmdq_instruction inst = { {0} };
> +	u16 offset_mask = offset;
>  	int err = 0;
>  
>  	if (mask != 0xffffffff) {
> -		err = cmdq_pkt_append_command(pkt, CMDQ_CODE_MASK, 0, ~mask);
> +		inst.op = CMDQ_CODE_MASK;
> +		inst.mask = ~mask;
> +		err = cmdq_pkt_append_command(pkt, inst);
>  		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;
>  }
> @@ -163,43 +183,48 @@ EXPORT_SYMBOL(cmdq_pkt_write_mask);
>  
>  int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event)
>  {
> -	u32 arg_b;
> +	struct cmdq_instruction inst = { {0} };
>  
>  	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;
> +	inst.op = CMDQ_CODE_WFE;
> +	inst.value = CMDQ_WFE_OPTION;
> +	inst.event = event;
>  
> -	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event, arg_b);
> +	return cmdq_pkt_append_command(pkt, inst);
>  }
>  EXPORT_SYMBOL(cmdq_pkt_wfe);
>  
>  int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
>  {
> +	struct cmdq_instruction inst = { {0} };
> +
>  	if (event >= CMDQ_MAX_EVENT)
>  		return -EINVAL;
>  
> -	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event,
> -				       CMDQ_WFE_UPDATE);
> +	inst.op = CMDQ_CODE_WFE;
> +	inst.value = CMDQ_WFE_UPDATE;
> +	inst.event = event;
> +
> +	return cmdq_pkt_append_command(pkt, inst);
>  }
>  EXPORT_SYMBOL(cmdq_pkt_clear_event);
>  
>  static int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
>  {
> -	int err;
> +	struct cmdq_instruction inst = { {0} };
> +	int err = 0;
>  
>  	/* insert EOC and generate IRQ for each command iteration */
> -	err = cmdq_pkt_append_command(pkt, CMDQ_CODE_EOC, 0, CMDQ_EOC_IRQ_EN);
> +	inst.op = CMDQ_CODE_EOC;
> +	inst.value = CMDQ_EOC_IRQ_EN;
> +	err = cmdq_pkt_append_command(pkt, inst);
>  
>  	/* JUMP to end */
> -	err |= cmdq_pkt_append_command(pkt, CMDQ_CODE_JUMP, 0, CMDQ_JUMP_PASS);
> +	inst.op = CMDQ_CODE_JUMP;
> +	inst.value = CMDQ_JUMP_PASS;
> +	err |= cmdq_pkt_append_command(pkt, inst);
>  
>  	return err;
>  }
> diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
> index e6f54ef6698b..678760548791 100644
> --- a/include/linux/mailbox/mtk-cmdq-mailbox.h
> +++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
> @@ -20,6 +20,16 @@
>  #define CMDQ_WFE_WAIT			BIT(15)
>  #define CMDQ_WFE_WAIT_VALUE		0x1
>  
> +/*
> + * 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
> + */
> +#define CMDQ_WFE_OPTION			(CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | \
> +					CMDQ_WFE_WAIT_VALUE)
> +
>  /** cmdq event maximum */
>  #define CMDQ_MAX_EVENT			0x3ff
>