Re: [PATCH v2 3/9] soc: mailbox: Add cmdq_pkt_logic_command to support math operation

AngeloGioacchino Del Regno
2023-10-23T09:50:41Z

Il 23/10/23 06:37, Jason-JH.Lin ha scritto:
> Add cmdq_pkt_logic_command to support match operation.
>
> cmdq_pkt_logic_command can append logic command to the CMDQ packet,
> ask GCE to execute a arithematic calculate instruction,
> such as add, subtract, multiply, AND, OR and NOT, etc.
>
> Note that all instructions just accept unsigned calculate.
> If there are any overflows, GCE will sent the invalid IRQ to notify
> CMDQ driver.
>
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>

Please always run `git log` on the file that you're changing to properly format the
commit title.

In this case, this should be:

soc: mediatek: cmdq: .....

> ---
> drivers/soc/mediatek/mtk-cmdq-helper.c | 36 ++++++++++++++++++++++
> include/linux/soc/mediatek/mtk-cmdq.h | 41 ++++++++++++++++++++++++++
> 2 files changed, 77 insertions(+)
>
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index b0cd071c4719..5194d66dfc0a 100644
> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> @@ -13,9 +13,18 @@
> #define CMDQ_WRITE_ENABLE_MASK BIT(0)
> #define CMDQ_POLL_ENABLE_MASK BIT(0)
> #define CMDQ_EOC_IRQ_EN BIT(0)
> +#define CMDQ_IMMEDIATE_VALUE 0
> #define CMDQ_REG_TYPE 1
> #define CMDQ_JUMP_RELATIVE 1
>
> +#define CMDQ_OPERAND_GET_IDX_VALUE(operand) \
> + ({ \
> + struct cmdq_operand *op = operand; \
> + op->reg ? op->idx : op->value; \
> + })
> +#define CMDQ_OPERAND_TYPE(operand) \
> + ((operand)->reg ? CMDQ_REG_TYPE : CMDQ_IMMEDIATE_VALUE)
> +
> struct cmdq_instruction {
> union {
> u32 value;
> @@ -380,6 +389,33 @@ int cmdq_pkt_poll_mask(struct cmdq_pkt *pkt, u8 subsys,
> }
> EXPORT_SYMBOL(cmdq_pkt_poll_mask);
>
> +int cmdq_pkt_logic_command(struct cmdq_pkt *pkt, enum CMDQ_LOGIC_ENUM s_op,
> + u16 result_reg_idx,
> + struct cmdq_operand *left_operand,
> + struct cmdq_operand *right_operand)
> +{
> + struct cmdq_instruction inst = { {0} };
> + u32 left_idx_value;
> + u32 right_idx_value;
> +
> + if (!left_operand || !right_operand)

I would also check that the requested logic operation is actually implemented:

if (!left_operand || !right_operand || s_op >= CMDQ_LOGIC_MAX)
return -EINVAL;

> + return -EINVAL;
> +
> + left_idx_value = CMDQ_OPERAND_GET_IDX_VALUE(left_operand);
> + right_idx_value = CMDQ_OPERAND_GET_IDX_VALUE(right_operand);
> + inst.op = CMDQ_CODE_LOGIC;
> + inst.dst_t = CMDQ_REG_TYPE;
> + inst.src_t = CMDQ_OPERAND_TYPE(left_operand);
> + inst.arg_c_t = CMDQ_OPERAND_TYPE(right_operand);
> + inst.sop = s_op;
> + inst.arg_c = right_idx_value;
> + inst.src_reg = left_idx_value;
> + inst.reg_dst = result_reg_idx;
> +
> + return cmdq_pkt_append_command(pkt, inst);
> +}
> +EXPORT_SYMBOL(cmdq_pkt_logic_command);
> +
> int cmdq_pkt_assign(struct cmdq_pkt *pkt, u16 reg_idx, u32 value)
> {
> struct cmdq_instruction inst = {};
> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> index a253c001c861..ea4fadfb5443 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -26,6 +26,30 @@
>
> struct cmdq_pkt;
>
> +enum CMDQ_LOGIC_ENUM {

Please no capital letters in enumeration names.
Besides, it's clearer if you named this

enum cmdq_logic_operation {

or

enum cmdq_logic_op {

> + CMDQ_LOGIC_ASSIGN = 0,
> + CMDQ_LOGIC_ADD = 1,
> + CMDQ_LOGIC_SUBTRACT = 2,
> + CMDQ_LOGIC_MULTIPLY = 3,
> + CMDQ_LOGIC_XOR = 8,
> + CMDQ_LOGIC_NOT = 9,
> + CMDQ_LOGIC_OR = 10,
> + CMDQ_LOGIC_AND = 11,
> + CMDQ_LOGIC_LEFT_SHIFT = 12,
> + CMDQ_LOGIC_RIGHT_SHIFT = 13,

You should also add a `CMDQ_LOGIC_MAX,` here to use it in the code for validation.

> +};
> +
> +struct cmdq_operand {
> + /* register type */
> + bool reg;
> + union {
> + /* index */
> + u16 idx;
> + /* value */
> + u16 value;
> + };
> +};
> +
> struct cmdq_client_reg {
> u8 subsys;
> u16 offset;
> @@ -244,6 +268,23 @@ int cmdq_pkt_poll(struct cmdq_pkt *pkt, u8 subsys,
> int cmdq_pkt_poll_mask(struct cmdq_pkt *pkt, u8 subsys,
> u16 offset, u32 value, u32 mask);
>
> +/**
> + * cmdq_pkt_logic_command() - Append logic command to the CMDQ packet, ask GCE to
> + * execute an instruction that store the result of logic operation
> + * with left and right operand into result_reg_idx.
> + * @pkt: the CMDQ packet
> + * @s_op: the logic operator enum
> + * @result_reg_idx: SPR index that store operation result of left_operand and right_operand
> + * @left_operand: left operand
> + * @right_operand: right operand
> + *

I think that there's a way to dramatically increase human readability of calls to
this function: being this a request to perform calculations, it would be way easier
to read it like an actual calculation :-)

cmdq_pkt_logic_command(pkt, result, op_x, CMDQ_LOGIC_ADD, op_y);

At least in my head, this easily resembles "result = op_x + op_y".

I therefore propose to change this to:

int cmdq_pkt_logic_command(struct cmdq_pkt *pkt, u16 result_reg_idx,
struct cmdq_operand *left_operand,
enum cmdq_logic_operation s_op,
struct cmdq_operand *right_operand);

> + * Return: 0 for success; else the error code is returned
> + */
> +int cmdq_pkt_logic_command(struct cmdq_pkt *pkt, enum CMDQ_LOGIC_ENUM s_op,
> + u16 result_reg_idx,
> + struct cmdq_operand *left_operand,
> + struct cmdq_operand *right_operand);
> +
> /**
> * cmdq_pkt_assign() - Append logic assign command to the CMDQ packet, ask GCE
> * to execute an instruction that set a constant value into

Regards,
Angelo