On Fri, Sep 28, 2018 at 8:09 AM <sunil.kovv...@gmail.com> wrote:
>
> +/* scratchx(0) CSR used for ATF->non-secure SW communication.
> + * This acts as the status register
> + * Provides details on command ack/status, link status, error details
> + */
> +struct cgx_evt_sts {
> + uint64_t ack:1;
> + uint64_t evt_type:1; /* cgx_evt_type */
> + uint64_t stat:1; /* cgx_stat */
> + uint64_t id:6; /* cgx_evt_id/cgx_cmd_id */
> + uint64_t reserved:55;
> +};
> +
> +/* Response to command IDs with command status as CGX_STAT_FAIL
> + *
> + * Not applicable for commands :
> + * CGX_CMD_LINK_BRING_UP/DOWN/CGX_EVT_LINK_CHANGE
> + * check struct cgx_lnk_sts comments
> + */
> +struct cgx_err_sts_s {
> + uint64_t reserved1:9;
> + uint64_t type:10; /* cgx_error_type */
> + uint64_t reserved2:35;
> +};
> +
> +/* Response to cmd ID as CGX_CMD_GET_FW_VER with cmd status as
> + * CGX_STAT_SUCCESS
> + */
> +struct cgx_ver_s {
> + uint64_t reserved1:9;
> + uint64_t major_ver:4;
> + uint64_t minor_ver:4;
> + uint64_t reserved2:47;
> +};
>From what I can tell, you pass these structures to the device, so they
are a binary interface. I don't think you can rely on bitfields to work
correctly here, they are generally not portable and I wouldn't rely
on them doing the right thing if you build a big-endian kernel.
It's better to use bitmasks on a u64 value instead to make it obviously
portable.
Arnd
