STRUCT CXL_POISON_STATE(9)

✨ struct cxl_poison_state(9) ✨

okay bestie, welcome to the Kernel API Manual 💖 — this one's a struct page, and it's literally the vibe check for driver poison state info. no cap, it's short but it matters.

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🌸 NAME 🌸

struct cxl_poison_state — driver poison state info. yep, that's it, that's the whole name. iconic brevity honestly 🎀

🦋 SYNOPSIS 🦋

here's the whole shape of it, bestie — do NOT touch the formatting, this is copy-paste sacred:

struct cxl_poison_state {
    u32 max_errors;
    unsigned long enabled_cmds[BITS_TO_LONGS( CXL_POISON_ENABLED_MAX)];
    struct cxl_mbox_poison_out *list_out;
    struct mutex mutex;
 };

look at her. four members. main character energy 👑

💅 Members 💅

• max_errors — the max number of media error records the device cache can hold. like, the ceiling, the limit, the cap fr fr 🍓
• enabled_cmds — every poison command that's enabled in the CEL. all the ones that made the cut, stored as unsigned long enabled_cmds[BITS_TO_LONGS( CXL_POISON_ENABLED_MAX)] ⭐
• list_out — the poison list payload that the device hands back to you. struct cxl_mbox_poison_out *list_out, the actual goods 📦
• mutex — a struct mutex that protects reads of the poison list. the bouncer at the club, keeping things orderly 🫶

🔥 Description 🔥

okay so here's the tea ☕ — reads of the poison list are synchronized. why? because you do NOT want a reader getting an incomplete list just because their request overlapped another read request of the same DPA range.

and "overlapped" here covers both flavors of mess, so listen up: their request was interrupted by another read request of the same DPA range, or preceded by one. either way, no half-list for you 🙈

the receipts on this one? CXL Spec 3.0 Section 8.2.9.8.4.1 — go read it, iykyk 📚

lowkey important: the sync is the whole point of the mutex. no mutex, no clean list. periodt 💀

🌈 SEE ALSO 🌈

go poke around the kernel file ./drivers/cxl/cxlmem.h and also say hi to these legends 👑:

• struct cxl_memdev(9)
• struct cxl_attach_region(9)
• struct cxl_event_state(9)
• struct cxl_fw_state(9)
• struct cxl_security_state(9)
• struct cxl_memdev_state(9)
• struct cxl_mem_command(9)
• struct cxl_hdm(9)

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and that's the page, bestie 🧚💜 this lil masterpiece lives over in ./drivers/cxl, dated October 2026, and it answers to struct cxl_poison_state(9) — slay, go read some kernel headers, you got this 💖✨