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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-07-23 21:27:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 10:47:15 -0700
commita1f242ff460e4b50a045fa237c3c56cce9eabf83 (patch)
tree657766b55251042b38967422dc9c3ea893b98747 /arch/powerpc/mm/pgtable_64.c
parent7ae8ed5053a39082d224a3f48409e016baca9c16 (diff)
powerpc ioremap_prot
This adds ioremap_prot and pte_pgprot() so that one can extract protection bits from a PTE and use them to ioremap_prot() (in order to support ptrace of VM_IO | VM_PFNMAP as per Rik's patch). This moves a couple of flag checks around in the ioremap implementations of arch/powerpc. There's a side effect of allowing non-cacheable and non-guarded mappings on ppc32 which before would always have _PAGE_GUARDED set whenever _PAGE_NO_CACHE is. (standard ioremap will still set _PAGE_GUARDED, but ioremap_prot will be capable of setting such a non guarded mapping). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Dave Airlie <airlied@linux.ie> Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/powerpc/mm/pgtable_64.c')
-rw-r--r--arch/powerpc/mm/pgtable_64.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 3ef0ad2f9ca0..365e61ae5dbc 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -107,9 +107,18 @@ void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
{
unsigned long i;
+ /* Make sure we have the base flags */
if ((flags & _PAGE_PRESENT) == 0)
flags |= pgprot_val(PAGE_KERNEL);
+ /* Non-cacheable page cannot be coherent */
+ if (flags & _PAGE_NO_CACHE)
+ flags &= ~_PAGE_COHERENT;
+
+ /* We don't support the 4K PFN hack with ioremap */
+ if (flags & _PAGE_4K_PFN)
+ return NULL;
+
WARN_ON(pa & ~PAGE_MASK);
WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
WARN_ON(size & ~PAGE_MASK);
@@ -190,6 +199,13 @@ void __iomem * ioremap(phys_addr_t addr, unsigned long size)
void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size,
unsigned long flags)
{
+ /* writeable implies dirty for kernel addresses */
+ if (flags & _PAGE_RW)
+ flags |= _PAGE_DIRTY;
+
+ /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
+ flags &= ~(_PAGE_USER | _PAGE_EXEC);
+
if (ppc_md.ioremap)
return ppc_md.ioremap(addr, size, flags);
return __ioremap(addr, size, flags);