Re: [PATCH 6/6] ARM: pm: allow generic sleep code to be used with SMP CPU idle

Colin Cross
2011-02-12T02:52:59Z

On Fri, Feb 11, 2011 at 8:19 AM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> Allow the generic sleep code to be used with SMP CPU idle by storing
> N CPU stack pointers rather than just one.
>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
>  arch/arm/kernel/sleep.S |   26 +++++++++++++++++++++++++-
>  1 files changed, 25 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
> index 9f106fa..e10618f 100644
> --- a/arch/arm/kernel/sleep.S
> +++ b/arch/arm/kernel/sleep.S
> @@ -25,7 +25,14 @@ ENTRY(cpu_suspend)
>        stmfd   sp!, {r1, r2, r3, ip}   @ save v:p, virt SP, retfn, phys resume fn
>        ldr     r3, =sleep_save_sp
>        add     r2, sp, r1              @ convert SP to phys
> +#ifdef CONFIG_SMP
> +       ALT_SMP(mrc p15, 0, lr, c0, c0, 5)
> +       ALT_UP(mov lr, #0)
> +       and     lr, lr, #15
> +       str     r2, [r3, lr, lsl #2]    @ save phys SP
> +#else
>        str     r2, [r3]                @ save phys SP
> +#endif
>        mov     lr, pc
>        ldr     pc, [r10, #CPU_DO_SUSPEND] @ save CPU state
>  #else
> @@ -36,7 +43,14 @@ ENTRY(cpu_suspend)
>        stmfd   sp!, {r1, r2, r3}       @ save v:p, virt SP, return fn
>        ldr     r3, =sleep_save_sp
>        add     r2, sp, r1              @ convert SP to phys
> +#ifdef CONFIG_SMP
> +       ALT_SMP(mrc p15, 0, lr, c0, c0, 5)
> +       ALT_UP(mov lr, #0)
> +       and     lr, lr, #15
> +       str     r2, [r3, lr, lsl #2]    @ save phys SP
> +#else
>        str     r2, [r3]                @ save phys SP
> +#endif
>        bl      cpu_do_suspend
>  #endif
>
> @@ -96,7 +110,15 @@ cpu_resume_after_mmu:
>        .data
>        .align
>  ENTRY(cpu_resume)
> +#ifdef CONFIG_SMP
> +       adr     r0, sleep_save_sp
> +       ALT_SMP(mrc p15, 0, r1, c0, c0, 5)
> +       ALT_UP(mov r1, #0)
> +       and     r1, r1, #15
> +       ldr     r0, [r0, r1, lsl #2]    @ stack phys addr
> +#else
>        ldr     r0, sleep_save_sp       @ stack phys addr
> +#endif
>        msr     cpsr_c, #PSR_I_BIT | PSR_F_BIT | SVC_MODE @ set SVC, irqs off
>  #ifdef MULTI_CPU
>        ldmia   r0!, {r1, sp, lr, pc}   @ load v:p, stack, return fn, resume fn
> @@ -107,4 +129,6 @@ ENTRY(cpu_resume)
>  ENDPROC(cpu_resume)
>
>  sleep_save_sp:
> -       .word   0                               @ preserve stack phys ptr here
> +       .rept   CONFIG_NR_CPUS
> +       .long   0                               @ preserve stack phys ptr here
> +       .endr
> --
> 1.6.2.5

Acked-by: Colin Cross <ccross@android.com>

Tested with idle and suspend on Tegra 2.
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