patch-2.4.25 linux-2.4.25/include/asm-mips64/pgtable.h

• Lines: 58
• Date: 2004-02-18 05:36:32.000000000 -0800
• Orig file: linux-2.4.24/include/asm-mips64/pgtable.h
• Orig date: 2003-08-25 04:44:44.000000000 -0700

diff -urN linux-2.4.24/include/asm-mips64/pgtable.h linux-2.4.25/include/asm-mips64/pgtable.h
@@ -67,12 +67,43 @@
 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
 
-/* Entries per page directory level: we use two-level, so we don't really
-   have any PMD directory physically.  */
-#define PTRS_PER_PGD	1024
-#define PTRS_PER_PMD	1024
-#define PTRS_PER_PTE	512
+#define PGD_T_LOG2	ffz(~sizeof(pgd_t))
+#define PMD_T_LOG2	ffz(~sizeof(pmd_t))
+#define PTE_T_LOG2	ffz(~sizeof(pte_t))
+
+/*
+ * For 4kB page size we use a 3 level page tree and a 8kB pmd and pgds which
+ * permits us mapping 40 bits of virtual address space.
+ *
+ * We used to implement 41 bits by having an order 1 pmd level but that seemed
+ * rather pointless.
+ *
+ * For 16kB page size we use a 2 level page tree which permit a total of
+ * 36 bits of virtual address space.  We could add a third leve. but it seems
+ * like at the moment there's no need for this.
+ *
+ * For 64kB page size we use a 2 level page table tree for a total of 42 bits
+ * of virtual address space.
+ */
+#ifdef CONFIG_PAGE_SIZE_4KB
 #define PGD_ORDER		1
+#define PMD_ORDER		1
+#define PTE_ORDER		0
+#endif
+#ifdef CONFIG_PAGE_SIZE_16KB
+#define PGD_ORDER		0
+#define PMD_ORDER		0
+#define PTE_ORDER		0
+#endif
+#ifdef CONFIG_PAGE_SIZE_64KB
+#define PGD_ORDER		0
+#define PMD_ORDER		0
+#define PTE_ORDER		0
+#endif
+
+#define PTRS_PER_PGD		((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
+#define PTRS_PER_PMD		((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
+#define PTRS_PER_PTE		((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
 
 #define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
 #define FIRST_USER_PGD_NR	0
@@ -435,7 +466,7 @@
 extern void pgd_init(unsigned long page);
 extern void pmd_init(unsigned long page, unsigned long pagetable);
 
-extern pgd_t swapper_pg_dir[1024];
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 extern void paging_init(void);
 
 extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,