[RFC] sh: Take into account the base of physical memory in virt_to_phys()

[Magnus Damm]

On Thu, Sep 15, 2011 at 8:12 PM, Simon Horman <horms at verge.net.au> wrote:
> Previously virt_to_phys() assumed that physical memory always started
> at address 0. This is not always the case.

I think most boards have NOR Flash or ROM mapped at physical address 0.

For more information please have a look at: arch/sh/boards/mach-ecovec24/setup.c

> --- a/kexec/arch/sh/kexec-sh.c
> +++ b/kexec/arch/sh/kexec-sh.c
> @@ -188,10 +188,18 @@ void kexec_sh_setup_zero_page(char *zero_page_buf, size_t zero_page_size,
>  unsigned long virt_to_phys(unsigned long addr)
>  {
>        unsigned long seg = addr & 0xe0000000;
> +       unsigned long long start, end;
> +       int ret;
> +
> +       /* Assume there is only one "System RAM" region */
> +       ret = parse_iomem_single("System RAM\n", &start, &end);
> +       if (ret)
> +               die("Could not parse System RAM region in /proc/iomem\n");
> +
>        if (seg != 0x80000000 && seg != 0xc0000000)
>                die("Virtual address %p is not in P1 or P2\n", (void *)addr);
>
> -       return addr - seg;
> +       return addr - seg + start;
>  }

This will most likely also change how 29-bit platforms translate their
addresses, not sure if that's what you want to do.

Thanks,

/ magnus