Re: [PATCH] [7/8] Implement true end_pfn_mapped for 32bit

Thomas Gleixner
2008-02-12T19:40:21Z

On Mon, 11 Feb 2008, Andi Kleen wrote:
> Even on 32bit 2MB pages can map more memory than is in the true
> max_low_pfn if end_pfn is not highmem and not aligned to 2MB.
> Add a end_pfn_map similar to x86-64 that accounts for this
> fact. This is important for code that really needs to know about
> all mapping aliases. Needed for followup patches (in this case EFI)

It's not only necessary for followup patches, it is a question of
general correctness.

> @@ -36,7 +36,7 @@
> #define max_pfn_mapped end_pfn_map
> #else
> #include <asm/page_32.h>
> -#define max_pfn_mapped max_low_pfn
> +#define max_pfn_mapped end_pfn_map

We can nuke either max_pfn_mapped or end_pfn_map completely. I don't
care about which one, but keeping both makes no sense at all.

Thanks,

tglx