[PATCH] ppc: make phys_mem_access_prot() work with pfns instead of addresses
Change the phys_mem_access_prot() function to take a pfn instead of an
address. This allows mmap64() to work on /dev/mem for addresses above 4G
on 32-bit architectures. We start with a pfn in mmap_mem(), so there's no
need to convert to an address; in fact, it's actively bad, since the
conversion can overflow when the address is above 4G.
Similarly fix the ppc32 page_is_ram() function to avoid a conversion to an
address by directly comparing to max_pfn. Working with max_pfn instead of
high_memory fixes page_is_ram() to give the right answer for highmem pages.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h
index eee601b..b28a713 100644
--- a/include/asm-ppc/pgtable.h
+++ b/include/asm-ppc/pgtable.h
@@ -705,7 +705,7 @@
#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | _PAGE_NO_CACHE | _PAGE_GUARDED))
struct file;
-extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot);
#define __HAVE_PHYS_MEM_ACCESS_PROT