Re: [PATCH v6 03/25] rtrs: private headers with rtrs protocol structs and helpers

Bart Van Assche
2019-12-31T00:07:33Z

On 2019-12-30 02:29, Jack Wang wrote:
> +static inline u32 rtrs_to_io_rsp_imm(u32 msg_id, int errno, bool w_inval)
> +{
> + enum rtrs_imm_type type;
> + u32 payload;
> +
> + /* 9 bits for errno, 19 bits for msg_id */
> + payload = (abs(errno) & 0x1ff) << 19 | (msg_id & 0x7ffff);
> + type = (w_inval ? RTRS_IO_RSP_W_INV_IMM : RTRS_IO_RSP_IMM);
> +
> + return rtrs_to_imm(type, payload);
> +}
> +
> +static inline void rtrs_from_io_rsp_imm(u32 payload, u32 *msg_id, int *errno)
> +{
> + /* 9 bits for errno, 19 bits for msg_id */
> + *msg_id = (payload & 0x7ffff);
> + *errno = -(int)((payload >> 19) & 0x1ff);
> +}

The above comments mention that 19 bits are used for msg_id. The 0x7ffff
mask however has 23 bits set. Did I see that correctly? If so, does that
mean that the errno and msg_id bitfields overlap partially?

Thanks,

Bart.