STRUCT UFSHCD_LRB(9)

💅 struct ufshcd_lrb(9) — the local reference block, bestie

okay so like, this is from the Kernel API Manual, and it's literally the glow-up guide to struct ufshcd_lrb. no cap, this is the main character of UFS command tracking 🎀

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🌸 NAME 🌸

struct ufshcd_lrb — local reference block. that's it. that's the vibe. it's the little block that holds all the deets for one command. iconic behavior honestly 💖

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✨ SYNOPSIS ✨

struct ufshcd_lrb {
    struct utp_transfer_req_desc *utr_descriptor_ptr;
    struct utp_upiu_req *ucd_req_ptr;
    struct utp_upiu_rsp *ucd_rsp_ptr;
    struct ufshcd_sg_entry *ucd_prdt_ptr;
    dma_addr_t utrd_dma_addr;
    dma_addr_t ucd_req_dma_addr;
    dma_addr_t ucd_rsp_dma_addr;
    dma_addr_t ucd_prdt_dma_addr;
    int scsi_status;
    int command_type;
    u8 lun;
    bool intr_cmd;
    bool req_abort_skip;
    ktime_t issue_time_stamp;
    u64 issue_time_stamp_local_clock;
    ktime_t compl_time_stamp;
    u64 compl_time_stamp_local_clock;
  #ifdef CONFIG_SCSI_UFS_CRYPTO;
    int crypto_key_slot;
    u64 data_unit_num;
  #endif;
};

look at all those fields, bestie. it's giving organized. it's giving prepared. it's giving everything u need in one place 🦋

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🧚 Members 🧚

the pointers (the real ones)

• utr_descriptor_ptr — the UTRD address of the command. like, where the whole thing lives in memory, yk?
• ucd_req_ptr — the UCD address of the command 🫶
• ucd_rsp_ptr — the Response UPIU address for this command. the reply guy, basically.
• ucd_prdt_ptr — the PRDT address of the command. slay.

the dma addresses (for debug, lowkey important)

• utrd_dma_addr — UTRD dma address for debug. yes, for debug. 👀
• ucd_req_dma_addr — UPIU request dma address for debug 🔥
• ucd_rsp_dma_addr — UPIU response dma address for debug 💀
• ucd_prdt_dma_addr — PRDT dma address for debug. we love a debug trail, fr fr.

the status + type girlies

• scsi_status — SCSI status of the command. how did it go? this knows.
• command_type — literally says "SCSI, UFS, Query." pick a lane, babe 💅

the identifiers

• lun — LUN of the command. the whole logical unit number, not a vibe check.

the booleans (yes/no energy)

• intr_cmd — Interrupt command. and here's the tea: it doesn't participate in interrupt aggregation. not invited to the party, periodt 🙈
• req_abort_skip — skip request abort task flag. it's a flag, bestie, it does what it says on the tin.

the timestamps (for the girlies who love data)

• issue_time_stamp — time stamp for debug purposes (CLOCK_MONOTONIC) ⏱️
• issue_time_stamp_local_clock — time stamp for debug purposes (local_clock). different clock, same debug energy.
• compl_time_stamp — time stamp for statistics (CLOCK_MONOTONIC). this one's for the numbers, the stats, the math ✨
• compl_time_stamp_local_clock — time stamp for debug purposes (local_clock). yes another one. we love thorough documentation.

the crypto section (conditional! very exclusive)

only here if CONFIG_SCSI_UFS_CRYPTO is defined, so it's giving VIP section 🧚‍♀️

• crypto_key_slot — the key slot to use for inline crypto (-1 if none). so if it's -1, no key, no crypto, no tea.
• data_unit_num — the data unit number for the first block for inline crypto. the first block! the opener! the main character of the data unit.

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💜 SEE ALSO 💜

like, go read the Kernel file ./include/ufs/ufshcd.h first, and then these icons:

struct uic_command(9), struct ufs_query_req(9), struct ufs_query_res(9), struct ufs_query(9), struct ufs_dev_cmd(9), struct ufs_clk_info(9), struct tx_eqtr_iter(9), struct ufshcd_tx_eq_settings(9), struct ufshcd_tx_eqtr_data(9), struct ufshcd_tx_eqtr_record(9), struct ufshcd_tx_eq_params(9), struct ufs_hba_variant_ops(9), struct ufs_clk_gating(9), struct ufs_clk_scaling(9), struct ufs_event_hist(9), struct ufs_stats(9), enum ufshcd_state(9), enum ufshcd_pmc_policy(9), struct ufshcd_mcq_opr_info_t(9), struct ufs_hba(9), struct ufs_hw_queue(9), ufshcd_rmwl(9), ufshcd_set_variant(9), ufshcd_get_variant(9)

that's the whole friend group right there. no skips. 🌈

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okay and finally, the sign-off bestie: this page is from ./include/ufs and it says October 2026 on the cover. so like, it's literally from the future or whatever. periodt. 💅✨

current mood: struct ufshcd_lrb is the blueprint, and everyone else is just living in it.