STRUCT MPT3_DIAG_QUERY(9)

💖 struct mpt3_diag_query(9) 💖

okay so bestie, welcome to the kernel API manual — this one is struct mpt3_diag_query, and its whole job is querying relevant info associated with diag buffers. that's the vibe. now let me introduce you to the whole friend group:

• @hdr — the generic header 🎀
• @reserved — (literally nothing else to say about it, it's reserved, leave it alone 🙈)
• @buffer_type — specifies either TRACE, SNAPSHOT, or EXTENDED ✨
• @application_flags — misc flags
• @diagnostic_flags — specifies flags affecting command processing
• @product_specific — product specific information
• @total_buffer_size — diag buffer size in bytes
• @driver_added_buffer_size — size of extra space appended to end of buffer
• @unique_id — unique id associated with this buffer

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✨ SYNOPSIS ✨

struct mpt3_diag_query {
    struct mpt3_ioctl_header hdr;
    uint8_t reserved;
    uint8_t buffer_type;
    uint16_t application_flags;
    uint32_t diagnostic_flags;
    uint32_t product_specific[MPT3_PRODUCT_SPECIFIC_DWORDS];
    uint32_t total_buffer_size;
    uint32_t driver_added_buffer_size;
    uint32_t unique_id;
 };

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🫶 Members 🫶

like, the members!! the cast!! see the roster up top in the NAME section, they're all there 💅

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🌸 Description 🌸

so here's the tea, bestie ☕ — the application will send only buffer_type and unique_id. that's it, that's the whole ask.

then the driver does its little investigation: it inspects unique_id first, and if that's valid, it fills in all the info. slay 💅

but if unique_id is 0x00? then the driver will return info specified by Buffer Type instead. iconic behaviour, no cap ✨

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👑 SEE ALSO 👑

Kernel file ./drivers/scsi/mpt3sas/mpt3sas_ctl.h, plus the whole entourage:

• struct mpt3_ioctl_header(9)
• struct mpt3_ioctl_diag_reset(9)
• struct mpt3_ioctl_pci_info(9)
• struct mpt3_ioctl_iocinfo(9)
• struct mpt3_ioctl_eventquery(9)
• struct mpt3_ioctl_eventenable(9)
• struct MPT3_IOCTL_EVENTS(9)
• struct mpt3_ioctl_eventreport(9)
• struct mpt3_ioctl_command(9)
• struct mpt3_ioctl_btdh_mapping(9)
• struct mpt3_diag_register(9)
• struct mpt3_diag_unregister(9)
• struct mpt3_diag_release(9)
• struct mpt3_diag_read_buffer(9)
• struct mpt3_addnl_diag_query(9)
• struct mpt3_enable_diag_sbr_reload(9)
• struct mpt3_passthru_command(9)

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💀 fr fr bestie, don't forget: unique_id gets checked before anything else. that's the main character of this struct, periodt.

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okay that's the whole page!! mwah 🫶 this came from ./drivers/scsi/mpt3sas, dated October 2026, and it's filed under struct mpt3_diag_query(9) — go be iconic with it 💖✨🎀