1 files changed, 253 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
new file mode 100644
index 000000000000..943515f0ef87
--- /dev/null
+++ b/arch/mips/include/asm/pgtable-64.h
@@ -0,0 +1,253 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
+ * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_PGTABLE_64_H
+#define _ASM_PGTABLE_64_H
+
+#include <linux/linkage.h>
+
+#include <asm/addrspace.h>
+#include <asm/page.h>
+#include <asm/cachectl.h>
+#include <asm/fixmap.h>
+
+#include <asm-generic/pgtable-nopud.h>
+
+/*
+ * Each address space has 2 4K pages as its page directory, giving 1024
+ * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a
+ * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page
+ * tables. Each page table is also a single 4K page, giving 512 (==
+ * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to
+ * invalid_pmd_table, each pmd entry is initialized to point to
+ * invalid_pte_table, each pte is initialized to 0. When memory is low,
+ * and a pmd table or a page table allocation fails, empty_bad_pmd_table
+ * and empty_bad_page_table is returned back to higher layer code, so
+ * that the failure is recognized later on. Linux does not seem to
+ * handle these failures very well though. The empty_bad_page_table has
+ * invalid pte entries in it, to force page faults.
+ *
+ * Kernel mappings: kernel mappings are held in the swapper_pg_table.
+ * The layout is identical to userspace except it's indexed with the
+ * fault address - VMALLOC_START.
+ */
+
+/* PMD_SHIFT determines the size of the area a second-level page table can map */
+#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+
+/* PGDIR_SHIFT determines what a third-level page table entry can map */
+#define PGDIR_SHIFT	(PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+/*
+ * For 4kB page size we use a 3 level page tree and an 8kB pud, 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 8kB page size we use a 3 level page tree which permits a total of
+ * 8TB of address space.  Alternatively a 33-bit / 8GB organization using
+ * two levels would be easy to implement.
+ *
+ * For 16kB page size we use a 2 level page tree which permits a total of
+ * 36 bits of virtual address space.  We could add a third level 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 PUD_ORDER		aieeee_attempt_to_allocate_pud
+#define PMD_ORDER		0
+#define PTE_ORDER		0
+#endif
+#ifdef CONFIG_PAGE_SIZE_8KB
+#define PGD_ORDER		0
+#define PUD_ORDER		aieeee_attempt_to_allocate_pud
+#define PMD_ORDER		0
+#define PTE_ORDER		0
+#endif
+#ifdef CONFIG_PAGE_SIZE_16KB
+#define PGD_ORDER		0
+#define PUD_ORDER		aieeee_attempt_to_allocate_pud
+#define PMD_ORDER		0
+#define PTE_ORDER		0
+#endif
+#ifdef CONFIG_PAGE_SIZE_64KB
+#define PGD_ORDER		0
+#define PUD_ORDER		aieeee_attempt_to_allocate_pud
+#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))
+
+#if PGDIR_SIZE >= TASK_SIZE
+#define USER_PTRS_PER_PGD       (1)
+#else
+#define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
+#endif
+#define FIRST_USER_ADDRESS	0UL
+
+#define VMALLOC_START		MAP_BASE
+#define VMALLOC_END	\
+	(VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE)
+#if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
+	VMALLOC_START != CKSSEG
+/* Load modules into 32bit-compatible segment. */
+#define MODULE_START	CKSSEG
+#define MODULE_END	(FIXADDR_START-2*PAGE_SIZE)
+extern pgd_t module_pg_dir[PTRS_PER_PGD];
+#endif
+
+#define pte_ERROR(e) \
+	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
+#define pmd_ERROR(e) \
+	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
+#define pgd_ERROR(e) \
+	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+extern pte_t invalid_pte_table[PTRS_PER_PTE];
+extern pte_t empty_bad_page_table[PTRS_PER_PTE];
+extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
+extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD];
+
+/*
+ * Empty pgd/pmd entries point to the invalid_pte_table.
+ */
+static inline int pmd_none(pmd_t pmd)
+{
+	return pmd_val(pmd) == (unsigned long) invalid_pte_table;
+}
+
+#define pmd_bad(pmd)		(pmd_val(pmd) & ~PAGE_MASK)
+
+static inline int pmd_present(pmd_t pmd)
+{
+	return pmd_val(pmd) != (unsigned long) invalid_pte_table;
+}
+
+static inline void pmd_clear(pmd_t *pmdp)
+{
+	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
+}
+
+/*
+ * Empty pud entries point to the invalid_pmd_table.
+ */
+static inline int pud_none(pud_t pud)
+{
+	return pud_val(pud) == (unsigned long) invalid_pmd_table;
+}
+
+static inline int pud_bad(pud_t pud)
+{
+	return pud_val(pud) & ~PAGE_MASK;
+}
+
+static inline int pud_present(pud_t pud)
+{
+	return pud_val(pud) != (unsigned long) invalid_pmd_table;
+}
+
+static inline void pud_clear(pud_t *pudp)
+{
+	pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
+}
+
+#define pte_page(x)		pfn_to_page(pte_pfn(x))
+
+#ifdef CONFIG_CPU_VR41XX
+#define pte_pfn(x)		((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
+#define pfn_pte(pfn, prot)	__pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
+#else
+#define pte_pfn(x)		((unsigned long)((x).pte >> PAGE_SHIFT))
+#define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
+#endif
+
+#define __pgd_offset(address)	pgd_index(address)
+#define __pud_offset(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
+#define __pmd_offset(address)	pmd_index(address)
+
+/* to find an entry in a kernel page-table-directory */
+#ifdef MODULE_START
+#define pgd_offset_k(address) \
+	((address) >= MODULE_START ? module_pg_dir : pgd_offset(&init_mm, 0UL))
+#else
+#define pgd_offset_k(address) pgd_offset(&init_mm, 0UL)
+#endif
+
+#define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
+#define pmd_index(address)	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+
+/* to find an entry in a page-table-directory */
+#define pgd_offset(mm, addr)	((mm)->pgd + pgd_index(addr))
+
+static inline unsigned long pud_page_vaddr(pud_t pud)
+{
+	return pud_val(pud);
+}
+#define pud_phys(pud)		virt_to_phys((void *)pud_val(pud))
+#define pud_page(pud)		(pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
+
+/* Find an entry in the second-level page table.. */
+static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address)
+{
+	return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address);
+}
+
+/* Find an entry in the third-level page table.. */
+#define __pte_offset(address)						\
+	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+#define pte_offset(dir, address)					\
+	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
+#define pte_offset_kernel(dir, address)					\
+	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
+#define pte_offset_map(dir, address)					\
+	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
+#define pte_offset_map_nested(dir, address)				\
+	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
+#define pte_unmap(pte) ((void)(pte))
+#define pte_unmap_nested(pte) ((void)(pte))
+
+/*
+ * Initialize a new pgd / pmd table with invalid pointers.
+ */
+extern void pgd_init(unsigned long page);
+extern void pmd_init(unsigned long page, unsigned long pagetable);
+
+/*
+ * Non-present pages:  high 24 bits are offset, next 8 bits type,
+ * low 32 bits zero.
+ */
+static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
+{ pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; }
+
+#define __swp_type(x)		(((x).val >> 32) & 0xff)
+#define __swp_offset(x)		((x).val >> 40)
+#define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
+#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)	((pte_t) { (x).val })
+
+/*
+ * Bits 0, 4, 6, and 7 are taken. Let's leave bits 1, 2, 3, and 5 alone to
+ * make things easier, and only use the upper 56 bits for the page offset...
+ */
+#define PTE_FILE_MAX_BITS	56
+
+#define pte_to_pgoff(_pte)	((_pte).pte >> 8)
+#define pgoff_to_pte(off)	((pte_t) { ((off) << 8) | _PAGE_FILE })
+
+#endif /* _ASM_PGTABLE_64_H */