[patch 6/7] powerpc: implement pte_special

[npiggin@suse.de]

[-- Attachment #1: powerpc-implement-pte_special.patch --]
[-- Type: text/plain, Size: 2929 bytes --]

Implement PTE_SPECIAL for powerpc. At the moment I only have a spare bit for
the 4k pages config, but Ben has freed up another one for 64k pages that I
can use, so this patch should include that before it goes upstream.

Signed-off-by: Nick Piggin <npiggin@suse.de>
---
Index: linux-2.6/include/asm-powerpc/pgtable-ppc64.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/pgtable-ppc64.h
+++ linux-2.6/include/asm-powerpc/pgtable-ppc64.h
@@ -239,7 +239,7 @@ static inline int pte_write(pte_t pte) {
 static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY;}
 static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED;}
 static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
-static inline int pte_special(pte_t pte) { return 0; }
+static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
 
 static inline void pte_uncache(pte_t pte) { pte_val(pte) |= _PAGE_NO_CACHE; }
 static inline void pte_cache(pte_t pte)   { pte_val(pte) &= ~_PAGE_NO_CACHE; }
@@ -259,7 +259,7 @@ static inline pte_t pte_mkyoung(pte_t pt
 static inline pte_t pte_mkhuge(pte_t pte) {
 	return pte; }
 static inline pte_t pte_mkspecial(pte_t pte) {
-	return pte; }
+	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
 
 /* Atomic PTE updates */
 static inline unsigned long pte_update(struct mm_struct *mm,
Index: linux-2.6/include/asm-powerpc/pgtable-4k.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/pgtable-4k.h
+++ linux-2.6/include/asm-powerpc/pgtable-4k.h
@@ -45,6 +45,8 @@
 #define _PAGE_GROUP_IX  0x7000 /* software: HPTE index within group */
 #define _PAGE_F_SECOND  _PAGE_SECONDARY
 #define _PAGE_F_GIX     _PAGE_GROUP_IX
+#define _PAGE_SPECIAL	0x10000 /* software: special page */
+#define __HAVE_ARCH_PTE_SPECIAL
 
 /* PTE flags to conserve for HPTE identification */
 #define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | \
Index: linux-2.6/include/asm-powerpc/pgtable-64k.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/pgtable-64k.h
+++ linux-2.6/include/asm-powerpc/pgtable-64k.h
@@ -74,6 +74,7 @@ static inline struct subpage_prot_table 
 #define _PAGE_HPTE_SUB0	0x08000000 /* combo only: first sub page */
 #define _PAGE_COMBO	0x10000000 /* this is a combo 4k page */
 #define _PAGE_4K_PFN	0x20000000 /* PFN is for a single 4k page */
+#define _PAGE_SPECIAL	0x0	   /* don't have enough room for this yet */
 
 /* Note the full page bits must be in the same location as for normal
  * 4k pages as the same asssembly will be used to insert 64K pages

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