linux-kernel - Re: [PATCH v5 15/19] ARM: LPAE: Add support for cpu_v7_do

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Date:	Wed, 18 May 2011 10:27:38 +0300
From:	Tony Lindgren <tony@...mide.com>
To:	Catalin Marinas <catalin.marinas@....com>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Russell King - ARM Linux <linux@....linux.org.uk>
Subject: Re: [PATCH v5 15/19] ARM: LPAE: Add support for
 cpu_v7_do_(suspend|resume)

Hi,

One question below regarding the ifdefs in this series.

* Catalin Marinas <catalin.marinas@....com> [110508 15:52]:
> With LPAE, the TTBRx size is 64-bit so make sure that all the
> information is saved and restored.
> 
> Signed-off-by: Catalin Marinas <catalin.marinas@....com>
> ---
>  arch/arm/mm/proc-v7.S |   22 ++++++++++++++++++++++
>  1 files changed, 22 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
> index ad22628..3e6999e 100644
> --- a/arch/arm/mm/proc-v7.S
> +++ b/arch/arm/mm/proc-v7.S
> @@ -260,19 +260,32 @@ cpu_v7_name:
>  
>  /* Suspend/resume support: derived from arch/arm/mach-s5pv210/sleep.S */
>  .globl	cpu_v7_suspend_size
> +#ifdef CONFIG_ARM_LPAE
> +.equ	cpu_v7_suspend_size, 4 * 10
> +#else
>  .equ	cpu_v7_suspend_size, 4 * 8
> +#endif
>  #ifdef CONFIG_PM_SLEEP
>  ENTRY(cpu_v7_do_suspend)
>  	stmfd	sp!, {r4 - r11, lr}
>  	mrc	p15, 0, r4, c13, c0, 0	@ FCSE/PID
>  	mrc	p15, 0, r5, c13, c0, 1	@ Context ID
>  	mrc	p15, 0, r6, c3, c0, 0	@ Domain ID
> +#ifdef CONFIG_ARM_LPAE
> +	mrrc	p15, 0, r7, r8, c2	@ TTB 0
> +	mrrc	p15, 1, r2, r3, c2	@ TTB 1
> +#else
>  	mrc	p15, 0, r7, c2, c0, 0	@ TTB 0
>  	mrc	p15, 0, r8, c2, c0, 1	@ TTB 1
> +#endif
>  	mrc	p15, 0, r9, c1, c0, 0	@ Control register
>  	mrc	p15, 0, r10, c1, c0, 1	@ Auxiliary control register
>  	mrc	p15, 0, r11, c1, c0, 2	@ Co-processor access control
> +#ifdef CONFIG_ARM_LPAE
> +	stmia	r0, {r2 - r11}
> +#else
>  	stmia	r0, {r4 - r11}
> +#endif
>  	ldmfd	sp!, {r4 - r11, pc}
>  ENDPROC(cpu_v7_do_suspend)
>  
> @@ -280,12 +293,21 @@ ENTRY(cpu_v7_do_resume)
>  	mov	ip, #0
>  	mcr	p15, 0, ip, c8, c7, 0	@ invalidate TLBs
>  	mcr	p15, 0, ip, c7, c5, 0	@ invalidate I cache
> +#ifdef CONFIG_ARM_LPAE
> +	ldmia	r0, {r2 - r11}
> +#else
>  	ldmia	r0, {r4 - r11}
> +#endif
>  	mcr	p15, 0, r4, c13, c0, 0	@ FCSE/PID
>  	mcr	p15, 0, r5, c13, c0, 1	@ Context ID
>  	mcr	p15, 0, r6, c3, c0, 0	@ Domain ID
> +#ifdef CONFIG_ARM_LPAE
> +	mcrr	p15, 0, r7, r8, c2	@ TTB 0
> +	mcrr	p15, 1, r2, r3, c2	@ TTB 1
> +#else
>  	mcr	p15, 0, r7, c2, c0, 0	@ TTB 0
>  	mcr	p15, 0, r8, c2, c0, 1	@ TTB 1
> +#endif
>  	mcr	p15, 0, ip, c2, c0, 2	@ TTB control register
>  	mcr	p15, 0, r10, c1, c0, 1	@ Auxiliary control register
>  	mcr	p15, 0, r11, c1, c0, 2	@ Co-processor access control

Do we really need all this ifdef else throughout this series?

I think we already have things in place to do this dynamically
like we already do for thumb, smp_on_up, v6 vs v7 and so on.

Otherwise we'll end up with every second line of ifdef else..

Regards,

Tony
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