spu_ahash_rx_sg_create(9)

💅 spu_ahash_rx_sg_create(9) — the Kernel API Manual, bestie edition 🎀

okay so real talk, this is a page from the Kernel API Manual (spu_ahash_rx_sg_create(9), section 9, kernel-flavoured) and it's literally about building the scatterlist that catches SPU response messages for an ahash request. it's giving ✨plumbing✨ but honestly? iconic plumbing.

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🌸 NAME 🌸

spu_ahash_rx_sg_create — bestie, this is the function that builds up the scatterlist of buffers used to receive a SPU response message for an ahash request. that's it, that's the whole gig. 🫶

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⭐ SYNOPSIS ⭐

int spu_ahash_rx_sg_create (struct brcm_message *mssg , struct
       iproc_reqctx_s *rctx , u8 rx_frag_num , unsigned int digestsize , u32
       stat_pad_len );

like, yes, it returns an int. we love a return type that tells you how it's feeling. 😌

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🦋 ARGUMENTS 🦋

• mssg — the mailbox message that's carrying the receive sg. it's the ride, the sg is the passenger. 🚗
• rctx — the crypto request context. the emotional support struct of this whole operation.
• rx_frag_num — how many scatterlist elements you need to hold the SPU response message. count 'em, bestie, u8 says there's only so many. 🔢
• digestsize — length of the hash digest, in bytes. (unsigned int, no games.)
• stat_pad_len — number of bytes required to pad the STAT field to a 4-byte boundary. yes this is a real job that someone has to do. alignment queen behavior. 👑

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💖 DESCRIPTION 💖

so here's the tea ☕: the scatterlist that gets allocated here is freed in spu_chunk_cleanup when the request completes — and the way that it does not care whether the request was handled successfully or there was an error is honestly so brave of it. success or flop, spu_chunk_cleanup cleans up. no cap. 🧹✨

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🔥 RETURN 🔥

• 0 if successful 🌈
• < 0 if an error 💀

that's the whole vibe check. negative means bad news.

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👑 SEE ALSO 👑

literally the entire friend group, in the order the page lists them — don't make me tap the sign:

kernel file ./drivers/crypto/bcm/cipher.c plus select_channel(9), spu_skcipher_rx_sg_create(9), spu_skcipher_tx_sg_create(9), handle_skcipher_req(9), handle_skcipher_resp(9), spu_ahash_tx_sg_create(9), handle_ahash_req(9), spu_hmac_outer_hash(9), ahash_req_done(9), handle_ahash_resp(9), spu_aead_rx_sg_create(9), spu_aead_tx_sg_create(9), handle_aead_req(9), handle_aead_resp(9), spu_chunk_cleanup(9), finish_req(9), spu_rx_callback(9), skcipher_enqueue(9), spu_no_incr_hash(9), aead_gcm_esp_setkey(9), rfc4543_gcm_esp_setkey(9), aead_ccm_esp_setkey(9), spu_functions_register(9), spu_mb_init(9).

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and that's the page, bestie!! 🧚💜 this little beauty lives in ./drivers/crypto/bcm, and the version vibes are dated October 2026 — so go forth, build your rx scatterlist, and remember: it always gets freed in spu_chunk_cleanup. mwah 💋🎀