mcpm_cpu_power_down(9)

📦 version 7.3.1, in nixpkgs unstable

🌸 mcpm_cpu_power_down 🌸

okay bestie, so this one is from the Kernel API Manual and it's lowkey a big deal — like, this is the function that literally turns the CPU you're running on off. main character energy fr. 💅

✨ NAME ✨

mcpm_cpu_power_down — power the calling CPU down 🫶

✨ SYNOPSIS ✨

void mcpm_cpu_power_down (void );

✨ ARGUMENTS ✨

  • void — no arguments, bestie. none. zero. the vibes are immaculate and the parameter list is empty 🎀

✨ DESCRIPTION ✨

The calling CPU is powered down. like, actually powered down. the CPU that called this function? yeah, that one. it's going night-night 😴

If this CPU is found to be the "last man standing" in the cluster then the cluster is prepared for power-down too. the whole friend group is leaving the party together 💀

⚠️ This must be called with interrupts disabled. no cap, do not skip this. if interrupts are still on you are doing it wrong.

On success this does not return. nope. it's gone. Re-entry in the kernel is expected via mcpm_entry_point — that's your way back in, iykyk 🦋

This will return if mcpm_platform_register has not been called previously, in which case the caller should take appropriate action. so basically if you skipped the registration step, this function comes right back at you and it's on you to deal with it 🙈

On success, the CPU is not guaranteed to be truly halted until mcpm_wait_for_cpu_powerdown subsequently returns non-zero for the specified cpu. Until then, other CPUs should make sure they do not trash memory the target CPU might be executing/accessing.

💀 fr fr, this one matters: that CPU is still out there touching memory while it's mid-power-down. do not stomp on its memory. the other CPUs need to chill and wait their turn. this is the "don't text your ex while they're moving out" of kernel programming.

✨ SEE ALSO ✨

okay that's the whole page and you ate it up 👑 this little gem lives in ./arch/arm/include/asm and the version is dated October 2026 — go forth and power down responsibly, bestie 💖✨🎀

📦 where this page comes from