Commit c7f005f7 authored by Viresh Kumar's avatar Viresh Kumar
Browse files

rust: cpu: Add CpuId::current() to retrieve current CPU ID 



Introduce `CpuId::current()`, a constructor that wraps the C function
`raw_smp_processor_id()` to retrieve the current CPU identifier without
guaranteeing stability.

This function should be used only when the caller can ensure that
the CPU ID won't change unexpectedly due to preemption or migration.

Suggested-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarBoqun Feng <boqun.feng@gmail.com>
parent 33db8c97

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -6254,6 +6254,7 @@ F: include/linux/cpuhotplug.h 
F:	include/linux/smpboot.h

F:	kernel/cpu.c

F:	kernel/smpboot.*

F:	rust/helper/cpu.c

F:	rust/kernel/cpu.rs









CPU IDLE TIME MANAGEMENT FRAMEWORK
































rust/helpers/cpu.c
0 → 100644



+8
−0






























Original line number
Diff line number
Diff line









// SPDX-License-Identifier: GPL-2.0



















#include <linux/smp.h>



















unsigned int rust_helper_raw_smp_processor_id(void)









{









	return raw_smp_processor_id();









}
























rust/helpers/helpers.c



+1
−0






























Original line number
Diff line number
Diff line







@@ -13,6 +13,7 @@







#include "build_assert.c"









#include "build_bug.c"









#include "clk.c"









#include "cpu.c"









#include "cpufreq.c"









#include "cpumask.c"









#include "cred.c"
































rust/kernel/cpu.rs



+11
−0






























Original line number
Diff line number
Diff line







@@ -102,6 +102,17 @@ pub fn from_u32(id: u32) -> Option<Self> {







    pub fn as_u32(&self) -> u32 {









        self.0









    }



















    /// Returns the ID of the CPU the code is currently running on.









    ///









    /// The returned value is considered unstable because it may change









    /// unexpectedly due to preemption or CPU migration. It should only be









    /// used when the context ensures that the task remains on the same CPU









    /// or the users could use a stale (yet valid) CPU ID.









    pub fn current() -> Self {









        // SAFETY: raw_smp_processor_id() always returns a valid CPU ID.









        unsafe { Self::from_u32_unchecked(bindings::raw_smp_processor_id()) }









    }









}



















impl From<CpuId> for u32 {