[PATCH v2 2/3] ARM: Exynos4: Add ioremap interceptor for statically remapped regions

[Marek Szyprowski]

Hello,

On Tuesday, November 01, 2011 2:01 AM Thomas Abraham wrote:

> ioremap() request for statically remapped regions are intercepted and the
> statically assigned virtual address is returned. For requests for which
> there are no statically remapped regions, the requests are let through.
> 
> Cc: Kukjin Kim <kgene.kim at samsung.com>
> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
> ---
>  arch/arm/mach-exynos4/cpu.c             |   16 ++++++++++++++++
>  arch/arm/mach-exynos4/include/mach/io.h |    5 +++++
>  2 files changed, 21 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mach-exynos4/cpu.c b/arch/arm/mach-exynos4/cpu.c
> index 5b1765b..358624d 100644
> --- a/arch/arm/mach-exynos4/cpu.c
> +++ b/arch/arm/mach-exynos4/cpu.c
> @@ -137,6 +137,22 @@ static struct map_desc exynos4_iodesc1[] __initdata = {
>  	},
>  };
> 
> +/*
> + * For all ioremap requests of statically mapped regions, intercept ioremap and
> + * return virtual address from the iodesc table.
> + */
> +void __iomem *exynos4_ioremap(unsigned long phy, size_t size, unsigned int type)
> +{
> +	struct map_desc *desc = exynos4_iodesc;
> +	unsigned int idx;
> +
> +	for (idx = 0; idx < ARRAY_SIZE(exynos4_iodesc); idx++, desc++)
> +		if (desc->pfn == __phys_to_pfn(phy) && desc->type == type)
> +			return (void __iomem *)desc->virtual;

I've just noticed that this function make access to exynos4_iodesc array which is
placed in initdata section. This might cause a lot of strange unpredictable issues,
so this patch should probably remove __initdata annotations in iodesc arrays.

> +
> +	return __arm_ioremap(phy, size, type);
> +}
> +
>  static void exynos4_idle(void)
>  {
>  	if (!need_resched())
> diff --git a/arch/arm/mach-exynos4/include/mach/io.h b/arch/arm/mach-exynos4/include/mach/io.h
> index d5478d2..c1b21d5 100644
> --- a/arch/arm/mach-exynos4/include/mach/io.h
> +++ b/arch/arm/mach-exynos4/include/mach/io.h
> @@ -22,5 +22,10 @@
>  #define __mem_pci(a)	(a)
> 
>  #define IO_SPACE_LIMIT (0xFFFFFFFF)
> +#define __arch_ioremap	exynos4_ioremap
> +#define __arch_iounmap	__iounmap
> +
> +void __iomem *exynos4_ioremap(unsigned long phy, size_t size,
> +					unsigned int type);
> 
>  #endif /* __ASM_ARM_ARCH_IO_H */
> --
> 1.7.4.4
> 

Best regards
-- 
Marek Szyprowski
Samsung Poland R&D Center