spu2_cipher_req_finish(9)

💫 spu2_cipher_req_finish — a kernel API manual, bestie edition 💫

okay so this is spu2_cipher_req_finish(9) from the Kernel API Manual, and honestly? she's the glow-up finisher of SPU request headers. let's get into it 🎀

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✨ NAME ✨

spu2_cipher_req_finish — the girl who finishes building a SPU request message header for a block cipher request. she doesn't start it, she completes it. main character energy fr 💅

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🌸 SYNOPSIS 🌸

void spu2_cipher_req_finish (u8 *spu_hdr , u16 spu_req_hdr_len ,
       unsigned int is_inbound , struct spu_cipher_parms *cipher_parms ,
       unsigned int data_size );

literally just five args and a dream, no return value, we love a void function that simply does her job and leaves 🫶

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🦋 ARGUMENTS 🦋

• spu_hdr — the start of the request message header (the MH field, iykyk). this is where she does her work bestie.
• spu_req_hdr_len — length in bytes of the SPU request header. yes, bytes. count them. ⭐
• is_inbound — 0 = encrypt, 1 = decrypt. that's it. that's the whole vibe check. 🔥
• cipher_parms — parameters describing the cipher operation to be performed. a struct spu_cipher_parms *, obviously 💜
• data_size — length of the data in the BD field. know your data, know your BD field, periodt.

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💖 DESCRIPTION 💖

okay so here's the tea: this function assumes much of the header was already filled in at setkey time in spu_cipher_req_init. so like, the header's already had its little makeover moment — spu_cipher_req_init is the one who fills in the encryption key 🔑

then spu2_cipher_req_finish swoops in to finish the job. it's giving "i'm just here to put the final touches on an already iconic look" ✨

no cap: if you're calling this without having done the spu_cipher_req_init step first, that's not the move. she assumes it happened. 🙈

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🌈 SEE ALSO 🌈

bestie, the whole friend group is here. kernel file ./drivers/crypto/bcm/spu2.c plus literally every sibling function, and yes i'm listing all of them because we do NOT skip people in this group chat 💀:

• spu2_cipher_xlate(9)
• spu2_hash_xlate(9)
• spu2_fmd_init(9)
• spu2_fmd_ctrl0_write(9)
• spu2_fmd_ctrl1_write(9)
• spu2_fmd_ctrl2_write(9)
• spu2_fmd_ctrl3_write(9)
• spu2_ctx_max_payload(9)
• spu2_payload_length(9)
• spu2_response_hdr_len(9)
• spu2_hash_pad_len(9)
• spu2_gcm_ccm_pad_len(9)
• spu2_assoc_resp_len(9)
• spu2_aead_ivlen(9)
• spu2_hash_type(9)
• spu2_digest_size(9)
• spu2_create_request(9)
• spu2_cipher_req_init(9)
• spu2_request_pad(9)
• spu2_xts_tweak_in_payload(9)
• spu2_tx_status_len(9)
• spu2_rx_status_len(9)
• spu2_status_process(9)
• spu2_ccm_update_iv(9)
• spu2_wordalign_padlen(9)

also lowkey the kernel file lives at ./drivers/crypto/bcm — that's the whole directory, that's the whole source tree neighborhood 🧚

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and that's the page!! brought to you by the Kernel API Manual, source ./drivers/crypto/bcm, dated October 2026 — mwah, slay, go finish those headers responsibly 💅✨