Pagetables to use normal kernel types

This is my first step in the migration of page_tables.c to the kernel
types and functions/macros (2.6.23-rc3).  Seems to be working OK.
Signed-off-by: Matias Zabaljauregui <matias.zabaljauregui@cern.ch>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/lguest/hypercalls.c

@@ -83,7 +83,7 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
 		guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
 		break;
 	case LHCALL_SET_PTE:
-		guest_set_pte(lg, args->arg1, args->arg2, mkgpte(args->arg3));
+		guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
 		break;
 	case LHCALL_SET_PMD:
 		guest_set_pmd(lg, args->arg1, args->arg2);

drivers/lguest/lg.h

@@ -28,45 +28,10 @@ struct lguest_dma_info
 	u8 interrupt; 	/* 0 when not registered */
 };
 
-/*H:310 The page-table code owes a great debt of gratitude to Andi Kleen.  He
- * reviewed the original code which used "u32" for all page table entries, and
- * insisted that it would be far clearer with explicit typing.  I thought it
- * was overkill, but he was right: it is much clearer than it was before.
- *
- * We have separate types for the Guest's ptes & pgds and the shadow ptes &
- * pgds.  There's already a Linux type for these (pte_t and pgd_t) but they
- * change depending on kernel config options (PAE). */
-
-/* Each entry is identical: lower 12 bits of flags and upper 20 bits for the
- * "page frame number" (0 == first physical page, etc).  They are different
- * types so the compiler will warn us if we mix them improperly. */
-typedef union {
-	struct { unsigned flags:12, pfn:20; };
-	struct { unsigned long val; } raw;
-} spgd_t;
-typedef union {
-	struct { unsigned flags:12, pfn:20; };
-	struct { unsigned long val; } raw;
-} spte_t;
-typedef union {
-	struct { unsigned flags:12, pfn:20; };
-	struct { unsigned long val; } raw;
-} gpgd_t;
-typedef union {
-	struct { unsigned flags:12, pfn:20; };
-	struct { unsigned long val; } raw;
-} gpte_t;
-
-/* We have two convenient macros to convert a "raw" value as handed to us by
- * the Guest into the correct Guest PGD or PTE type. */
-#define mkgpte(_val) ((gpte_t){.raw.val = _val})
-#define mkgpgd(_val) ((gpgd_t){.raw.val = _val})
-/*:*/
-
 struct pgdir
 {
 	unsigned long cr3;
-	spgd_t *pgdir;
+	pgd_t *pgdir;
 };
 
 /* We have two pages shared with guests, per cpu.  */
@@ -157,6 +122,12 @@ int lguest_address_ok(const struct lguest *lg,
 		      unsigned long addr, unsigned long len);
 int run_guest(struct lguest *lg, unsigned long __user *user);
 
+/* Helper macros to obtain the first 12 or the last 20 bits, this is only the
+ * first step in the migration to the kernel types.  pte_pfn is already defined
+ * in the kernel. */
+#define pgd_flags(x)	(pgd_val(x) & ~PAGE_MASK)
+#define pte_flags(x)	(pte_val(x) & ~PAGE_MASK)
+#define pgd_pfn(x)	(pgd_val(x) >> PAGE_SHIFT)
 
 /* interrupts_and_traps.c: */
 void maybe_do_interrupt(struct lguest *lg);
@@ -187,7 +158,7 @@ void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 i);
 void guest_pagetable_clear_all(struct lguest *lg);
 void guest_pagetable_flush_user(struct lguest *lg);
 void guest_set_pte(struct lguest *lg, unsigned long cr3,
-		   unsigned long vaddr, gpte_t val);
+		   unsigned long vaddr, pte_t val);
 void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
 int demand_page(struct lguest *info, unsigned long cr2, int errcode);
 void pin_page(struct lguest *lg, unsigned long vaddr);