cci_enable_port_for_self(9)

💅 cci_enable_port_for_self — like, the kernel API manual, bestie 🎀

Okay so this is cci_enable_port_for_self(9) from the Kernel API Manual, and honestly? It's giving very low-level, very iconic. Sit down, hydrate, and let's get into it 🫶

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✨ NAME ✨

cci_enable_port_for_self — enables a CCI port for the calling CPU, periodt 🔥

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✨ SYNOPSIS ✨

void __naked cci_enable_port_for_self (void );

Like, that's the whole thing. No cap.

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✨ ARGUMENTS ✨

• void — no arguments. Nothing. Zero. Nada. She takes nothing and she gives you a CCI port 🙈

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✨ DESCRIPTION ✨

So here's the tea ☕: enabling a CCI port for the calling CPU literally implies enabling the CCI port that controls that CPU's cluster. That's the whole vibe.

The caller must make sure that:

• the CPU running this code is the first active CPU in the cluster, and
• all other CPUs are either quiescent in a low power state, or waiting for this CPU to complete the CCI initialization.

Like, no pressure or anything, but you have to handle that. It's not optional, bestie 😭

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🦋 the "why is this in assembler" section 🦋

Not me having to explain this, but okay: this gets called when the MMU is still off and there's no stack. So the code must be position independent, and ideally it should rely on callee clobbered registers only.

To pull that off, we must code this function entirely in assembler. Yes. All of it. In assembler. She's built different 💅✨

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⭐ what happens after ⭐

On success, this returns with the proper CCI port enabled. Slay 🌈

But in case of any failure? It never returns. Because the inability to enable the CCI is fatal, and there is literally no possible recovery at this stage. Like, that's it, that's the situation 💀

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✨ SEE ALSO ✨

Go read these, iykyk 👑

• Kernel file ./drivers/bus/arm-cci.c
• __cci_ace_get_port(9)
• cci_port_control(9)
• cci_disable_port_by_cpu(9)
• __cci_control_port_by_device(9)
• __cci_control_port_by_index(9)

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and that's the whole page, bestie 🧚💖

Cute lil sign-off: this beauty lives over in ./drivers/bus, dated October 2026, and it's the cci_enable_port_for_self(9) page from the Kernel API Manual. Obsessed with her, ngl 🍓👑