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authorRoland Dreier <rolandd@cisco.com>2005-10-28 20:46:18 -0400
committerPaul Mackerras <paulus@samba.org>2005-10-29 00:25:49 -0400
commit8b150478aeb1a8edb9015c2f7ac4da637ff65c45 (patch)
tree621b038b9c041fe82b708c6c5cbee655be2a519a /arch/powerpc/mm/mem.c
parentd49b340124a34fcb8bceda472558ccef7232c16f (diff)
[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>
Diffstat (limited to 'arch/powerpc/mm/mem.c')
-rw-r--r--arch/powerpc/mm/mem.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 695db6a588ce..3ca331728d21 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -88,13 +88,13 @@ int page_is_ram(unsigned long pfn)
88} 88}
89EXPORT_SYMBOL(page_is_ram); 89EXPORT_SYMBOL(page_is_ram);
90 90
91pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr, 91pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
92 unsigned long size, pgprot_t vma_prot) 92 unsigned long size, pgprot_t vma_prot)
93{ 93{
94 if (ppc_md.phys_mem_access_prot) 94 if (ppc_md.phys_mem_access_prot)
95 return ppc_md.phys_mem_access_prot(file, addr, size, vma_prot); 95 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
96 96
97 if (!page_is_ram(addr >> PAGE_SHIFT)) 97 if (!page_is_ram(pfn))
98 vma_prot = __pgprot(pgprot_val(vma_prot) 98 vma_prot = __pgprot(pgprot_val(vma_prot)
99 | _PAGE_GUARDED | _PAGE_NO_CACHE); 99 | _PAGE_GUARDED | _PAGE_NO_CACHE);
100 return vma_prot; 100 return vma_prot;