linux-kernel - Re: [PATCH 2/2] ARM: l2c: Maintain CPU endianness for early resume function

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Message-ID: <20150311101845.GL19577@ulmo.nvidia.com>
Date:	Wed, 11 Mar 2015 11:18:46 +0100
From:	Thierry Reding <thierry.reding@...il.com>
To:	Russell King <linux@....linux.org.uk>,
	Dmitry Osipenko <digetx@...il.com>,
	linux-tegra@...r.kernel.org, Ben Dooks <ben.dooks@...ethink.co.uk>,
	linux-arm-kernel@...ts.infradead.org,
	Bob Mottram <bob.mottram@...ethink.co.uk>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] ARM: l2c: Maintain CPU endianness for early resume
 function

On Tue, Jan 20, 2015 at 03:36:55PM +0300, Dmitry Osipenko wrote:
> In big endian CPU mode l2x0_saved_regs structure stores registers values in BE
> format. In order to maintain BE CPU mode, these values and immediate constants
> must be converted back to LE format before writing them to cache controller.
> 
> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> ---
>  arch/arm/mm/l2c-l2x0-resume.S | 10 ++++++++++
>  1 file changed, 10 insertions(+)

Hi Russell,

Did you get a chance yet to review this patch? It's a dependency for
enabling big-endian support on Tegra. As such, I wonder if you would be
willing to ack it, so that I can take it through the Tegra tree along
with the rest of the patches.

If you prefer to take it through the ARM tree, that's fine, too. In that
case would you be able to provide a stable branch that I can merge into
the Tegra tree to resolve the dependency?

Thanks,
Thierry

> diff --git a/arch/arm/mm/l2c-l2x0-resume.S b/arch/arm/mm/l2c-l2x0-resume.S
> index fda415e..9f99c7e 100644
> --- a/arch/arm/mm/l2c-l2x0-resume.S
> +++ b/arch/arm/mm/l2c-l2x0-resume.S
> @@ -30,6 +30,15 @@ ENTRY(l2c310_early_resume)
>  	teq	r1, #0
>  	reteq	lr
>  
> +	@ Reverse for big endian kernel
> +ARM_BE8(rev	r2, r2)
> +ARM_BE8(rev	r3, r3)
> +ARM_BE8(rev	r4, r4)
> +ARM_BE8(rev	r5, r5)
> +ARM_BE8(rev	r6, r6)
> +ARM_BE8(rev	r7, r7)
> +ARM_BE8(rev	r8, r8)
> +
>  	@ The prefetch and power control registers are revision dependent
>  	@ and can be written whether or not the L2 cache is enabled
>  	ldr	r0, [r1, #L2X0_CACHE_ID]
> @@ -51,6 +60,7 @@ ENTRY(l2c310_early_resume)
>  
>  	str	r2, [r1, #L2X0_AUX_CTRL]
>  	mov	r9, #L2X0_CTRL_EN
> +ARM_BE8(rev	r9, r9)
>  	str	r9, [r1, #L2X0_CTRL]
>  	ret	lr
>  ENDPROC(l2c310_early_resume)
> -- 
> 2.2.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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