Re: [PATCH v5 08/12] soc: mediatek: cmdq: define the instruction struct

CK Hu
2019-05-08T05:40:46Z

Hi, Bibby:

On Tue, 2019-05-07 at 16:13 +0800, Bibby Hsieh wrote:
> Define a instruction structure for gce driver to append command.

I would like you to describe _WHY_ do this. I think you do this for
'code readability'.

>
> Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
> ---
> drivers/soc/mediatek/mtk-cmdq-helper.c | 113 +++++++++++++++--------
> include/linux/mailbox/mtk-cmdq-mailbox.h | 2 +
> include/linux/soc/mediatek/mtk-cmdq.h | 14 +--
> 3 files changed, 84 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index ff9fef5a032b..17ee8196fb3d 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 +122,8 @@ 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 struct cmdq_instruction *cmdq_pkt_append_command(struct cmdq_pkt *pkt)
> {
> - u64 *cmd_ptr;
>
> if (unlikely(pkt->cmd_buf_size + CMDQ_INST_SIZE > pkt->buf_size)) {
> /*
> @@ -127,81 +137,108 @@ static int cmdq_pkt_append_command(struct cmdq_pkt *pkt, enum cmdq_code code,
> pkt->cmd_buf_size += CMDQ_INST_SIZE;
> WARN_ONCE(1, "%s: buffer size %u is too small !\n",
> __func__, (u32)pkt->buf_size);
> - return -ENOMEM;
> + return NULL;
> }
> - 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;
>
> - return 0;
> + return pkt->va_base + pkt->cmd_buf_size - CMDQ_INST_SIZE;
> }
>
> -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);
> + struct cmdq_instruction *inst;
> +
> + inst = cmdq_pkt_append_command(pkt);
> + if (!inst)
> + return -ENOMEM;
> +
> + 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 0;
> }
> 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)
> {
> + struct cmdq_instruction *inst;
> u32 offset_mask = offset;
> - int err = 0;
>
> if (mask != 0xffffffff) {
> - err = cmdq_pkt_append_command(pkt, CMDQ_CODE_MASK, 0, ~mask);
> + inst = cmdq_pkt_append_command(pkt);
> + if (!inst)
> + return -ENOMEM;
> +
> + inst->op = CMDQ_CODE_MASK;
> + inst->mask = ~mask;
> offset_mask |= CMDQ_WRITE_ENABLE_MASK;
> }
> - err |= cmdq_pkt_write(pkt, value, subsys, offset_mask);
>
> - return err;
> + return cmdq_pkt_write(pkt, subsys, offset_mask, value);
> }
> 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;
> + struct cmdq_instruction *inst;
>
> 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 = cmdq_pkt_append_command(pkt);
> + if (!inst)
> + return -ENOMEM;
> +
> + 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 0;
> }
> 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)
> {
> + struct cmdq_instruction *inst;
> +
> if (event >= CMDQ_MAX_EVENT)
> return -EINVAL;
>
> - return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event,
> - CMDQ_WFE_UPDATE);
> + inst = cmdq_pkt_append_command(pkt);
> + if (!inst)
> + return -ENOMEM;
> +
> + inst->op = CMDQ_CODE_WFE;
> + inst->value = CMDQ_WFE_UPDATE;
> + inst->event = event;
> +
> + return 0;
> }
> EXPORT_SYMBOL(cmdq_pkt_clear_event);
>
> static int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
> {
> - int err;
> + struct cmdq_instruction *inst;
> +
> + inst = cmdq_pkt_append_command(pkt);
> + if (!inst)
> + return -ENOMEM;
>
> - /* 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;
>
> - /* JUMP to end */
> - err |= cmdq_pkt_append_command(pkt, CMDQ_CODE_JUMP, 0, CMDQ_JUMP_PASS);
> + inst = cmdq_pkt_append_command(pkt);
> + if (!inst)
> + return -ENOMEM;
> +
> + inst->op = CMDQ_CODE_JUMP;
> + inst->value = CMDQ_JUMP_PASS;
>
> - return err;
> + return 0;
> }
>
> static void cmdq_pkt_flush_async_cb(struct cmdq_cb_data data)
> 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 | \

Use a 'tab' to replace 8 white space.

> + 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);

Is the changing of parameter position about 'code readability'?

>
> /**
> * 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);

Is the changing from u32 to u16 about 'code readability'?

Regards,
CK
>
> /**
> * 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