diff options
| author | Anton Vorontsov <avorontsov@ru.mvista.com> | 2008-12-17 10:09:10 +0000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-12-23 15:13:29 +1100 |
| commit | 01695a9687e5a8d78589605037cc7828a5b67ac9 (patch) | |
| tree | 3d7f4ed52b1bbaffd62e6d04aaefc2f5989e32e6 | |
| parent | 6f29c3298b18216198631cbee01c349adecb225d (diff) | |
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 <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
| -rw-r--r-- | arch/powerpc/mm/pgtable_32.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index 341472440137..cd5609759d44 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -173,6 +173,7 @@ __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) if (p < 16*1024*1024) p += _ISA_MEM_BASE; +#ifndef CONFIG_CRASH_DUMP /* * Don't allow anybody to remap normal RAM that we're using. * mem_init() sets high_memory so only do the check after that. @@ -182,6 +183,7 @@ __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) (unsigned long long)p, __builtin_return_address(0)); return NULL; } +#endif if (size == 0) return NULL; |