ocs_aes_gcm_op(9)

💅 ocs_aes_gcm_op(9) — the Kernel API Manual, but make it make sense

okay so bestie, this is ocs_aes_gcm_op(9) from the kernel API manual and honestly? she's giving crypto girlboss. this is a function that performs a GCM operation ✨ (yes, that GCM — Galois/Counter Mode, the one with the tag). let's get into it 🎀

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🌸 SYNOPSIS 🌸

int ocs_aes_gcm_op (struct ocs_aes_dev *aes_dev , enum ocs_cipher cipher
, enum ocs_instruction instruction , dma_addr_t dst_dma_list ,
dma_addr_t src_dma_list , u32 src_size , const u8 *iv , dma_addr_t
aad_dma_list , u32 aad_size , u8 *out_tag , u32 tag_size );

she takes eleven arguments. eleven! main character energy fr fr 👑

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🦋 ARGUMENTS 🦋

• aes_dev — the OCS AES device you're using. your hardware boo 💖
• cipher — the cipher to use. your options are AES or SM4, pick your fighter 🥊
• instruction — what you actually want to do: encrypt or decrypt. no in-between, she doesn't do vibes 🌈
• dst_dma_list — the OCS DMA list that maps your output memory. where the magic lands ✨
• src_dma_list — the OCS DMA list mapping the input payload data. the lore going in 📥
• src_size — how much data src_dma_list actually maps. numbers, bestie, we love them 🔢
• iv — the input IV vector. yes, it's const u8 *, don't touch 👀
• aad_dma_list — the OCS DMA list mapping the input AAD data. additional authenticated data, doing her thing 🫶
• aad_size — the amount of data mapped by aad_dma_list 🍓
• out_tag — where to store the computed tag. the receipt, basically 🧾
• tag_size — the size, in bytes, of out_tag. keep it consistent or it's gonna be a whole situation 😭

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⭐ RETURN ⭐

0 on success 💚, and a negative error code otherwise 💀. no cap, that's the whole contract.

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👑 SEE ALSO 👑

• the kernel file ./drivers/crypto/intel/keembay/ocs-aes.c — go read the source, iykyk 📖
• ocs_dma_linked_list(9)
• ocs_aes_set_key(9)
• ocs_aes_op(9)
• ocs_aes_ccm_op(9)
• ocs_create_linked_list_from_sg(9)

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lowkey a reminder: iv is const u8 * and the DMA lists are dma_addr_t — so like, don't go passing random addresses and then acting surprised when it breaks 🙈

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and that's the page!! brought to you by ./drivers/crypto/intel/keembay, dated October 2026, under the header ocs_aes_gcm_op(9) — slay, go encrypt something responsibly 🔥💜