powerpc/32: Allow __ioremap on RAM addresses for kdump kernel
powerpc/32: Allow __ioremap on RAM addresses for kdump kernel

While for debugging it is good to catch bogus users of ioremap, though
for kdump support it is more convenient to use __ioremap for
copy_oldmem_page() (exactly as we do for PPC64 currently).

Note that copy_oldmem_page() calls __ioremap with flags set to '0',
so it should be safe with the regard to the caches.

The other option is to use kmap_atomic_pfn()[1], but it will not work
for kernels compiled without HIGHMEM.

That is, on a board with 256MB RAM and crashkernel=64M@32M case, the
!HIGHMEM capturing kernel maps 0-96M range, which does not include all
the memory needed to capture the dump. And, obviously, accessing
anything upper than 96M will cause faults.

[1] http://ozlabs.org/pipermail/linuxppc-dev/2007-November/046747.html

Signed-off-by: Anton Vorontsov <f72eea26502475052d15bdce621d2155da84f214@ru.mvista.com>
Signed-off-by: Paul Mackerras <19a0ba370c443ba08d20b5061586430ab449ee8c@samba.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs