STRUCT FWCTL_RPC_CXL_OUT(9)

✨ struct fwctl_rpc_cxl_out(9) ✨

okay so bestie, welcome to the Kernel API Manual 🎀 — this is the page for struct fwctl_rpc_cxl_out, and no cap, it's the output side of the ioctl(FWCTL_RPC) glow-up for CXL 💅 like, when the device talks back, this is the shape it talks back in. periodt.

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🌸 NAME 🌸

struct fwctl_rpc_cxl_out — the ioctl(FWCTL_RPC) output struct, but make it CXL 🦋

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⭐ SYNOPSIS ⭐

literally the whole vibe, verbatim, don't touch:

struct fwctl_rpc_cxl_out {
    struct {
      __u32 size;
      __u32 retval;
    };
    union {
      struct cxl_mbox_get_sup_feats_out get_sup_feats_out;
      __u8 payload[];
    };
 };

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👑 Members 👑

bestie there are two anonymous things in here and honestly they're both main character energy 🙈

• {unnamed_struct} — anonymous. that's it, that's the whole note 💀 she has no name, she has no drama, she's just vibing there unnamed.
• size — the size of the output payload 🍓 (yes, the payload. get to know her, she comes back later).
• retval — the return value from the device 🔥 this is where the hardware tells you what it thinks. listen to her.
• {unnamed_union} — also anonymous 🌈 another nameless icon, living her truth.
• get_sup_feats_out — Get Supported Features output ✨ type is struct cxl_mbox_get_sup_feats_out, and she is the structured option in the union.
• payload — raw byte stream of payload 💖 type __u8 payload[], the flexible-array member, just raw bytes doing raw byte things. no thoughts, head empty, bytes only 🧚

ngl the way this struct works: the anonymous struct gives you size + retval up front, then the anonymous union lets you read the same trailing bytes either as get_sup_feats_out (the supported-features shape) or as the raw payload[] stream. same bytes, two outfits 💅

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🦋 SEE ALSO 🦋

• Kernel file ./include/uapi/fwctl/cxl.h
• struct fwctl_rpc_cxl(9) 👀 go read her too, iykyk

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okay that's the whole page, you ate that 🫶💜 — this was brought to you by the kernel source tree at ./include/uapi/fwctl, dated October 2026, and honestly? iconic. mwah 💋✨