[PATCH] i386: PARAVIRT: Add pagetable accessors to pack and unpack pagetable entries

Add a set of accessors to pack, unpack and modify page table entries
(at all levels).  This allows a paravirt implementation to control the
contents of pgd/pmd/pte entries.  For example, Xen uses this to
convert the (pseudo-)physical address into a machine address when
populating a pagetable entry, and converting back to pphys address
when an entry is read.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 21 insertions, 5 deletions

diff --git a/include/asm-i386/pgtable-2level.h b/include/asm-i386/pgtable-2level.h
index 38c3fcc0676d..043a2bcfa86a 100644
--- a/include/asm-i386/pgtable-2level.h
+++ b/include/asm-i386/pgtable-2level.h
@@ -11,10 +11,23 @@
  * within a page table are directly modified.  Thus, the following
  * hook is made available.
  */
+static inline void native_set_pte(pte_t *ptep , pte_t pte)
+{
+        *ptep = pte;
+}
+static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
+                                     pte_t *ptep , pte_t pte)
+{
+        native_set_pte(ptep, pte);
+}
+static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+        *pmdp = pmd;
+}
 #ifndef CONFIG_PARAVIRT
-#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
-#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
+#define set_pte(pteptr, pteval)         native_set_pte(pteptr, pteval)
+#define set_pte_at(mm,addr,ptep,pteval) native_set_pte_at(mm, addr, ptep, pteval)
+#define set_pmd(pmdptr, pmdval)         native_set_pmd(pmdptr, pmdval)
 #endif
 
 #define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval)
@@ -23,11 +36,14 @@
 #define pte_clear(mm,addr,xp)   do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
 #define pmd_clear(xp)   do { set_pmd(xp, __pmd(0)); } while (0)
 
-#define raw_ptep_get_and_clear(xp)      __pte(xchg(&(xp)->pte_low, 0))
+static inline pte_t native_ptep_get_and_clear(pte_t *xp)
+{
+        return __pte(xchg(&xp->pte_low, 0));
+}
 
 #define pte_page(x)             pfn_to_page(pte_pfn(x))
 #define pte_none(x)             (!(x).pte_low)
-#define pte_pfn(x)              ((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
+#define pte_pfn(x)              (pte_val(x) >> PAGE_SHIFT)
 #define pfn_pte(pfn, prot)      __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 #define pfn_pmd(pfn, prot)      __pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))