STRUCT XE_SYSCTRL_MAILBOX_COMMAND(9)

✨ NAME ✨

struct xe_sysctrl_mailbox_command — the System Controller mailbox command, bestie 💌

okay so picture this: you're the driver, and the System Controller is that one friend who has ALL the tea but only replies if you format the message exactly right. That's literally what this struct is — the little envelope you fill out and slide across the counter. 📨 And yes it lives in the Kernel API Manual, which is giving very "official group chat rules" energy. 🎀

💅 SYNOPSIS 💅

struct xe_sysctrl_mailbox_command {
    struct xe_sysctrl_app_msg_hdr header;
    void *data_in;
    size_t data_in_len;
    void *data_out;
    size_t data_out_len;
 };

no cap, that's the whole shape of it — one header, then an in/out pair for the data and an in/out pair for the lengths. iconic symmetry, honestly. 🦋

🌸 MEMBERS 🌸

• header — the application message header, aka where all the command intel lives. This is the "who/what/where" part of your message, the main character of the struct. 👑
• data_in — pointer to your input payload data. It can be NULL if you've got no input data to send, so don't stress — sometimes you're just vibing with an empty message. 🙈
• data_in_len — the size of that input payload, in bytes. Set it to 0 if there's no input data. Numbers, not vibes. 🔢
• data_out — pointer to the output buffer where the response data lands. It can be NULL if there's no response coming — ghosted by the hardware, happens to the best of us. 😭
• data_out_len — the size of the output buffer, in bytes. Set it to 0 if you're not expecting a response. lowkey the most important "am I getting a reply" flag in the whole struct. 💀

🫶 SEE ALSO 🫶

Go read these next, they're the supporting cast and they ate:

• Kernel file ./drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
• enum xe_sysctrl_group(9)
• enum xe_sysctrl_gfsp_cmd(9)

and that's the whole page, periodt. 💖 this little masterpiece comes to you from ./drivers/gpu/drm/xe, dated October 2026, and it answers to the name struct xe_s...lbox_command(9) — yeah the name got truncated, we don't talk about it. slay. ✨🌈⭐