sh: Abstract the number of page table levels

Keep the dimensions of the page tables in a separate header file in
preparation for allowing a three level page table structure.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/pgalloc.h

@@ -4,9 +4,10 @@
 #include <linux/quicklist.h>
 #include <asm/page.h>
 
-#define QUICK_PGD 0	/* We preserve special mappings over free */
 #define QUICK_PT 1	/* Other page table pages that are zero on free */
 
+#include <asm/pgalloc_nopmd.h>
+
 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
 				       pte_t *pte)
 {
@@ -20,28 +21,9 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 }
 #define pmd_pgtable(pmd) pmd_page(pmd)
 
-static inline void pgd_ctor(void *x)
-{
-	pgd_t *pgd = x;
-
-	memcpy(pgd + USER_PTRS_PER_PGD,
-	       swapper_pg_dir + USER_PTRS_PER_PGD,
-	       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
-}
-
 /*
  * Allocate and free page tables.
  */
-static inline pgd_t *pgd_alloc(struct mm_struct *mm)
-{
-	return quicklist_alloc(QUICK_PGD, GFP_KERNEL | __GFP_REPEAT, pgd_ctor);
-}
-
-static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
-{
-	quicklist_free(QUICK_PGD, NULL, pgd);
-}
-
 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 					  unsigned long address)
 {
@@ -81,7 +63,7 @@ do {							\
 
 static inline void check_pgt_cache(void)
 {
-	quicklist_trim(QUICK_PGD, NULL, 25, 16);
+	__check_pgt_cache();
 	quicklist_trim(QUICK_PT, NULL, 25, 16);
 }
 

arch/sh/include/asm/pgalloc_nopmd.h

+#ifndef __ASM_SH_PGALLOC_NOPMD_H
+#define __ASM_SH_PGALLOC_NOPMD_H
+
+#define QUICK_PGD 0	/* We preserve special mappings over free */
+
+static inline void pgd_ctor(void *x)
+{
+	pgd_t *pgd = x;
+
+	memcpy(pgd + USER_PTRS_PER_PGD,
+	       swapper_pg_dir + USER_PTRS_PER_PGD,
+	       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+}
+
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	return quicklist_alloc(QUICK_PGD, GFP_KERNEL | __GFP_REPEAT, pgd_ctor);
+}
+
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+	quicklist_free(QUICK_PGD, NULL, pgd);
+}
+
+static inline void __check_pgt_cache(void)
+{
+	quicklist_trim(QUICK_PGD, NULL, 25, 16);
+}
+
+#endif /* __ASM_SH_PGALLOC_NOPMD_H */

arch/sh/include/asm/pgtable.h

@@ -12,7 +12,7 @@
 #ifndef __ASM_SH_PGTABLE_H
 #define __ASM_SH_PGTABLE_H
 
-#include <asm-generic/pgtable-nopmd.h>
+#include <asm/pgtable_nopmd.h>
 #include <asm/page.h>
 
 #ifndef __ASSEMBLY__
@@ -51,28 +51,12 @@ static inline unsigned long long neff_sign_extend(unsigned long val)
 #define	NPHYS_SIGN	(1LL << (NPHYS - 1))
 #define	NPHYS_MASK	(-1LL << NPHYS)
 
-/*
- * traditional two-level paging structure
- */
-/* PTE bits */
-#if defined(CONFIG_X2TLB) || defined(CONFIG_SUPERH64)
-# define PTE_MAGNITUDE	3	/* 64-bit PTEs on extended mode SH-X2 TLB */
-#else
-# define PTE_MAGNITUDE	2	/* 32-bit PTEs */
-#endif
-#define PTE_SHIFT	PAGE_SHIFT
-#define PTE_BITS	(PTE_SHIFT - PTE_MAGNITUDE)
-
-/* PGD bits */
-#define PGDIR_SHIFT	(PTE_SHIFT + PTE_BITS)
 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
 
 /* Entries per level */
 #define PTRS_PER_PTE	(PAGE_SIZE / (1 << PTE_MAGNITUDE))
-#define PTRS_PER_PGD	(PAGE_SIZE / sizeof(pgd_t))
 
-#define USER_PTRS_PER_PGD	(TASK_SIZE/PGDIR_SIZE)
 #define FIRST_USER_ADDRESS	0
 
 #define PHYS_ADDR_MASK29		0x1fffffff

arch/sh/include/asm/pgtable_nopmd.h

+#ifndef __ASM_SH_PGTABLE_NOPMD_H
+#define __ASM_SH_PGTABLE_NOPMD_H
+
+#include <asm-generic/pgtable-nopmd.h>
+
+/*
+ * traditional two-level paging structure
+ */
+
+/* PTE bits */
+#define PTE_MAGNITUDE	2	/* 32-bit PTEs */
+
+#define PTE_SHIFT	PAGE_SHIFT
+#define PTE_BITS	(PTE_SHIFT - PTE_MAGNITUDE)
+
+/* PGD bits */
+#define PGDIR_SHIFT	(PTE_SHIFT + PTE_BITS)
+
+#define PTRS_PER_PGD	(PAGE_SIZE / (1 << PTE_MAGNITUDE))
+#define USER_PTRS_PER_PGD	(TASK_SIZE/PGDIR_SIZE)
+
+#endif /* __ASM_SH_PGTABLE_NOPMD_H */