linux内核中的__cpu_suspend是在哪里实现的呀?

1. 内核版本

　　4.19

2. 在arch/arm/kernel/sleep.S中实现如下:

/*
 * Save CPU state for a suspend.  This saves the CPU general purpose
 * registers, and allocates space on the kernel stack to save the CPU
 * specific registers and some other data for resume.
 *  r0 = suspend function arg0
 *  r1 = suspend function
 *  r2 = MPIDR value the resuming CPU will use
 */
ENTRY(__cpu_suspend)
        stmfd   sp!, {r4 - r11, lr}
#ifdef MULTI_CPU
        ldr     r10, =processor
        ldr     r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
#else
        ldr     r4, =cpu_suspend_size
#endif
        mov     r5, sp                  @ current virtual SP
        add     r4, r4, #             @ Space for pgd, virt sp, phys resume fn
        sub     sp, sp, r4              @ allocate CPU state on stack
        ldr     r3, =sleep_save_sp
        stmfd   sp!, {r0, r1}           @ save suspend func arg and pointer
        ldr     r3, [r3, #SLEEP_SAVE_SP_VIRT]
        ALT_SMP(ldr r0, =mpidr_hash)
        ALT_UP_B(1f)
        /* This ldmia relies on the memory layout of the mpidr_hash struct */
        ldmia   r0, {r1, r6-r8} @ r1 = mpidr mask (r6,r7,r8) = l[,,] shifts
        compute_mpidr_hash      r0, r6, r7, r8, r2, r1
        add     r3, r3, r0, lsl #
:      mov     r2, r5                  @ virtual SP
        mov     r1, r4                  @ size of save block
        add     r0, sp, #              @ pointer to save block
        bl      __cpu_suspend_save
        badr    lr, cpu_suspend_abort
        ldmfd   sp!, {r0, pc}           @ call suspend fn
ENDPROC(__cpu_suspend)