[PATCH 1/6] ARM: fix be8 support for phys/virt address conversion

[Nicolas Pitre]

On Tue, 15 Nov 2011, Junxiao Bi wrote:

> phys_to_virt() and virt_to_phys() is implemented by one assembler instruction,
> add/sub an offset between the physical and virtual address. For some arm machines
> with CONFIG_ARM_PATCH_PHYS_VIRT defined, this offset is unknown at compile time,
> it is calculated dynamically at run time and then patched to the add/sub instruction.
> To support BE8 mode, firstly we need to convert the instruntion to big-endian after
> loading it from the memory, and then modify its offset field, at last convert it to
> little-endian and write it back to the memory.
> 
> Signed-off-by: Junxiao Bi <junxiao.bi at windriver.com>

Reviewed-by: Nicolas Pitre <nico at linaro.org>

> ---
>  arch/arm/kernel/head.S |   12 ++++++++++++
>  1 files changed, 12 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
> index 566c54c..838fb0c 100644
> --- a/arch/arm/kernel/head.S
> +++ b/arch/arm/kernel/head.S
> @@ -522,8 +522,14 @@ __fixup_a_pv_table:
>  	b	2f
>  1:	add     r7, r3
>  	ldrh	ip, [r7, #2]
> +#ifdef CONFIG_CPU_ENDIAN_BE8
> +	rev16	ip, ip
> +#endif
>  	and	ip, 0x8f00
>  	orr	ip, r6	@ mask in offset bits 31-24
> +#ifdef CONFIG_CPU_ENDIAN_BE8
> +	rev16	ip, ip
> +#endif
>  	strh	ip, [r7, #2]
>  2:	cmp	r4, r5
>  	ldrcc	r7, [r4], #4	@ use branch for delay slot
> @@ -532,8 +538,14 @@ __fixup_a_pv_table:
>  #else
>  	b	2f
>  1:	ldr	ip, [r7, r3]
> +#ifdef CONFIG_CPU_ENDIAN_BE8
> +	rev	ip, ip
> +#endif
>  	bic	ip, ip, #0x000000ff
>  	orr	ip, ip, r6	@ mask in offset bits 31-24
> +#ifdef CONFIG_CPU_ENDIAN_BE8
> +	rev	ip, ip
> +#endif
>  	str	ip, [r7, r3]
>  2:	cmp	r4, r5
>  	ldrcc	r7, [r4], #4	@ use branch for delay slot
> -- 
> 1.7.0.4
> 
> 
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