mcpm_sync_init(9)

🌸 mcpm_sync_init(9) — the Kernel API Manual bestie era 🌸

okay so first things first, the manual name is mcpm_sync_init(9) and it lives in the Kernel API Manual, and honestly? she's niche but she's important. let's get into it 🫶

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✨ NAME ✨

mcpm_sync_init — Initialize the cluster synchronization support

like, she sets up the whole cluster-sync situation. that's her job. that's her moment. 👑

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🌈 SYNOPSIS 🌈

int mcpm_sync_init (void (*power_up_setup)(unsigned int affinity_level));

no cap, that's the whole signature. one function pointer, one int coming back at you. 💅

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🎀 ARGUMENTS 🎀

• power_up_setup — a platform specific function invoked during the very early CPU/cluster bringup stage. like very early. we're talking "barely awake, no coffee yet" early. ⭐

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💖 DESCRIPTION 💖

so what she actually does: this prepares the memory used by vlocks, plus the MCPM state machine that gets used across CPUs that may have their caches active or inactive. yes, both vibes. 🔥

⚠️ she must be called only after a successful call to mcpm_platform_register. not before. do not skip the line. the line is sacred. 🚨

okay now the power_up_setup argument, because this one is giving hardcore:

it's a pointer to assembly code 👀 called when the MMU and caches are still disabled during boot and no stack space is available. literally no stack. none. she's out here operating on pure willpower and vibes. 😭

the affinity level passed to that code corresponds to the resource that needs to be initialized — for example 1 for cluster level, 0 for CPU level. iykyk. 🧚

and the good news? proper exclusion mechanisms are already activated at that point. so like, don't stress about racing, it's handled. slay. ✨

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🦋 SEE ALSO 🦋

• Kernel file ./arch/arm/include/asm/mcpm.h
• mcpm_is_available(9)
• mcpm_cpu_power_up(9)
• mcpm_cpu_power_down(9)
• mcpm_wait_for_cpu_powerdown(9)
• mcpm_cpu_suspend(9)
• mcpm_cpu_powered_up(9)
• mcpm_platform_register(9)
• mcpm_loopback(9)

the whole friend group, fr fr. go read them all, they're iconic. 👑

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and that's the page bestie!! 💜 this whole thing lives in ./arch/arm/include/asm, dated October 2026 — so like, future vibes only. mwah, stan the kernel, bye!! 💅🌸🎀