scp_ipi_send(9)

📦 version 7.3.1, in nixpkgs unstable

💖 scp_ipi_send(9) — like, the Kernel API Manual, bestie 💖

okay so we're doing a deep dive into scp_ipi_send today, and honestly? she's kind of a big deal in the Kernel API Manual. This is the function that yeets data from the AP over to the SCP. main character energy fr fr 🫶

✨ NAME ✨

scp_ipi_send — send data from AP to scp. that's it, that's the whole vibe 💅

🌸 SYNOPSIS 🌸

int scp_ipi_send (struct mtk_scp *scp , u32 id , const void *buf ,
unsigned int len , unsigned int wait );

look at her. iconic signature. no notes. 🎀

🦋 ARGUMENTS 🦋

  • scp — the mtk_scp structure. yes bestie, you gotta hand her the whole struct 🫶
  • id — the IPI ID. it's giving "which mailbox is this going to" 🍓
  • buf — the data buffer. this is the actual payload, the moment, the content 💖
  • len — the data buffer length. gotta tell her how much you're sending, no cap ✨
  • wait — number of msecs to wait for ack. 0 to skip waiting. zero means zero patience, we love a boundaries queen 💀

🔥 DESCRIPTION 🔥

Okay so real talk: this function is thread-safe. Multiple threads can call her and she will NOT be messy about it. icon behaviour 👑

When this function returns, SCP has received the data and starts the processing. like, the handoff is DONE, the data is literally there, SCP is already on it. ⭐

When the processing completes, the IPI handler registered by scp_ipi_register will be called in interrupt context. so heads up: interrupt context, bestie — keep that in mind for whatever you register in there 🙈

🌈 RETURN 🌈

  • 0 if sending data successfully — slay, it worked 💅
  • -error on error — iykyk, something went sideways 😭

🧚 SEE ALSO 🧚

Kernel file ./drivers/remoteproc/mtk_scp_ipi.c plus her besties:

go read those too, they're all part of the friend group 🫶

and that's the whole page, bestie — every flag, every value, every return code, all present and accounted for. no details were harmed in the making of this rewrite 💖

so yeah, that's scp_ipi_send(9) from the Kernel API Manual, brought to you by ./drivers/remoteproc in October 2026 💜 stay safe, ship good code, and remember: interrupt context is NOT the place to be doing the most. periodt. 🌸💅✨

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