[patch 09/39] remap_file_pages protection support: improvement for UML bits

[blaisorblade@yahoo.it]

Recover one bit by additionally using _PAGE_NEWPROT. Since I wasn't sure this
would work, I've split this out. We rely on the fact that pte_newprot always
checks first if the PTE is marked present.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 linux-2.6.git-paolo/include/asm-um/pgtable-2level.h |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff -puN include/asm-um/pgtable-2level.h~rfp-arch-uml-improv include/asm-um/pgtable-2level.h
--- linux-2.6.git/include/asm-um/pgtable-2level.h~rfp-arch-uml-improv	2005-08-07 19:09:34.000000000 +0200
+++ linux-2.6.git-paolo/include/asm-um/pgtable-2level.h	2005-08-07 19:09:34.000000000 +0200
@@ -72,19 +72,19 @@ static inline void set_pte(pte_t *pteptr
 	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 
 /*
- * Bits 0 to 5 are taken, split up the 26 bits of offset
+ * Bits 0, 1, 3 to 5 are taken, split up the 27 bits of offset
  * into this range:
  */
-#define PTE_FILE_MAX_BITS	26
+#define PTE_FILE_MAX_BITS	27
 
-#define pte_to_pgoff(pte) (pte_val(pte) >> 6)
+#define pte_to_pgoff(pte) (((pte_val(pte) >> 6) << 1) | ((pte_val(pte) >> 2) & 0x1))
 #define pte_to_pgprot(pte) \
 	__pgprot((pte_val(pte) & (_PAGE_RW | _PAGE_PROTNONE)) \
 		| ((pte_val(pte) & _PAGE_PROTNONE) ? 0 : \
 			(_PAGE_USER | _PAGE_PRESENT)) | _PAGE_ACCESSED)
 
 #define pgoff_prot_to_pte(off, prot) \
-	((pte_t) { ((off) << 6) + \
-	 (pgprot_val(prot) & (_PAGE_RW | _PAGE_PROTNONE)) + _PAGE_FILE })
+	__pte((((off) >> 1) << 6) + (((off) & 0x1) << 2) + \
+	 (pgprot_val(prot) & (_PAGE_RW | _PAGE_PROTNONE)) + _PAGE_FILE)
 
 #endif
_
-
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