arch/mips/include/asm/pgtable-32.h - linux - Git at Google

 /*
  * 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_32_H
 #define _ASM_PGTABLE_32_H

 #include <asm/addrspace.h>
 #include <asm/page.h>

 #include <linux/linkage.h>
 #include <asm/cachectl.h>
 #include <asm/fixmap.h>

 #include <asm-generic/pgtable-nopmd.h>

 #ifdef CONFIG_HIGHMEM
 #include <asm/highmem.h>
 #endif

 /*
  * Regarding 32-bit MIPS huge page support (and the tradeoff it entails):
  *
  *  We use the same huge page sizes as 64-bit MIPS. Assuming a 4KB page size,
  * our 2-level table layout would normally have a PGD entry cover a contiguous
  * 4MB virtual address region (pointing to a 4KB PTE page of 1,024 32-bit pte_t
  * pointers, each pointing to a 4KB physical page). The problem is that 4MB,
  * spanning both halves of a TLB EntryLo0,1 pair, requires 2MB hardware page
  * support, not one of the standard supported sizes (1MB,4MB,16MB,...).
  *  To correct for this, when huge pages are enabled, we halve the number of
  * pointers a PTE page holds, making its last half go to waste. Correspondingly,
  * we double the number of PGD pages. Overall, page table memory overhead
  * increases to match 64-bit MIPS, but PTE lookups remain CPU cache-friendly.
  *
  * NOTE: We don't yet support huge pages if extended-addressing is enabled
  *       (i.e. EVA, XPA, 36-bit Alchemy/Netlogic).
  */

 extern int temp_tlb_entry;

 /*
  * - add_temporary_entry() add a temporary TLB entry. We use TLB entries
  *	starting at the top and working down. This is for populating the
  *	TLB before trap_init() puts the TLB miss handler in place. It
  *	should be used only for entries matching the actual page tables,
  *	to prevent inconsistencies.
  */
 extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
 			       unsigned long entryhi, unsigned long pagemask);

 /*
  * Basically we have the same two-level (which is the logical three level
  * Linux page table layout folded) page tables as the i386.  Some day
  * when we have proper page coloring support we can have a 1% quicker
  * tlb refill handling mechanism, but for now it is a bit slower but
  * works even with the cache aliasing problem the R4k and above have.
  */

 /* PGDIR_SHIFT determines what a third-level page table entry can map */
 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
 # define PGDIR_SHIFT	(2 * PAGE_SHIFT - PTE_T_LOG2 - 1)
 #else
 # define PGDIR_SHIFT	(2 * PAGE_SHIFT - PTE_T_LOG2)
 #endif

 #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 PUD/PMD directory physically.
  */
 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
 # define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2 + 1)
 #else
 # define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
 #endif

 #define PGD_TABLE_ORDER	(__PGD_TABLE_ORDER >= 0 ? __PGD_TABLE_ORDER : 0)
 #define PUD_TABLE_ORDER	aieeee_attempt_to_allocate_pud
 #define PMD_TABLE_ORDER	aieeee_attempt_to_allocate_pmd

 #define PTRS_PER_PGD	(USER_PTRS_PER_PGD * 2)
 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
 # define PTRS_PER_PTE	(PAGE_SIZE / sizeof(pte_t) / 2)
 #else
 # define PTRS_PER_PTE	(PAGE_SIZE / sizeof(pte_t))
 #endif

 #define USER_PTRS_PER_PGD	(0x80000000UL/PGDIR_SIZE)

 #define VMALLOC_START	  MAP_BASE

 #define PKMAP_END	((FIXADDR_START) & ~((LAST_PKMAP << PAGE_SHIFT)-1))
 #define PKMAP_BASE	(PKMAP_END - PAGE_SIZE * LAST_PKMAP)

 #ifdef CONFIG_HIGHMEM
 # define VMALLOC_END	(PKMAP_BASE-2*PAGE_SIZE)
 #else
 # define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
 #endif

 #ifdef CONFIG_PHYS_ADDR_T_64BIT
 #define pte_ERROR(e) \
 	printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
 #else
 #define pte_ERROR(e) \
 	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
 #endif
 #define pgd_ERROR(e) \
 	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))

 extern void load_pgd(unsigned long pg_dir);

 extern pte_t invalid_pte_table[PTRS_PER_PTE];

 /*
  * 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;
 }

 static inline int pmd_bad(pmd_t pmd)
 {
 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 	/* pmd_leaf(pmd) but inline */
 	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
 		return 0;
 #endif

 	if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
 		return 1;

 	return 0;
 }

 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);
 }

 #if defined(CONFIG_XPA)

 #define MAX_POSSIBLE_PHYSMEM_BITS 40
 #define pte_pfn(x)		(((unsigned long)((x).pte_high >> PFN_PTE_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
 static inline pte_t
 pfn_pte(unsigned long pfn, pgprot_t prot)
 {
 	pte_t pte;

 	pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) |
 				(pgprot_val(prot) & ~_PFNX_MASK);
 	pte.pte_high = (pfn << PFN_PTE_SHIFT) |
 				(pgprot_val(prot) & ~_PFN_MASK);
 	return pte;
 }

 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)

 #define MAX_POSSIBLE_PHYSMEM_BITS 36
 #define pte_pfn(x)		((unsigned long)((x).pte_high >> 6))

 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
 {
 	pte_t pte;

 	pte.pte_high = (pfn << 6) | (pgprot_val(prot) & 0x3f);
 	pte.pte_low = pgprot_val(prot);

 	return pte;
 }

 #else

 #define MAX_POSSIBLE_PHYSMEM_BITS 32
 #define pte_pfn(x)		((unsigned long)((x).pte >> PFN_PTE_SHIFT))
 #define pfn_pte(pfn, prot)	__pte(((unsigned long long)(pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
 #define pfn_pmd(pfn, prot)	__pmd(((unsigned long long)(pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
 #endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */

 #define pte_page(x)		pfn_to_page(pte_pfn(x))

 /*
  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
  * are !pte_none() && !pte_present().
  */
 #if defined(CONFIG_CPU_R3K_TLB)

 /*
  * Format of swap PTEs:
  *
  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
  *   <----------- offset ------------> < type -> V G E 0 0 0 0 0 0 P
  *
  *   E is the exclusive marker that is not stored in swap entries.
  *   _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
  *   unused.
  */
 #define __swp_type(x)			(((x).val >> 10) & 0x1f)
 #define __swp_offset(x)			((x).val >> 15)
 #define __swp_entry(type, offset)	((swp_entry_t) { (((type) & 0x1f) << 10) | ((offset) << 15) })
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })

 /* We borrow bit 7 to store the exclusive marker in swap PTEs. */
 #define _PAGE_SWP_EXCLUSIVE	(1 << 7)

 #else

 #if defined(CONFIG_XPA)

 /*
  * Format of swap PTEs:
  *
  *   6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3
  *   3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
  *   0 0 0 0 0 0 E P <------------------ zeroes ------------------->
  *
  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
  *   <----------------- offset ------------------> < type -> V G 0 0
  *
  *   E is the exclusive marker that is not stored in swap entries.
  *   _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
  *   unused.
  */
 #define __swp_type(x)			(((x).val >> 4) & 0x1f)
 #define __swp_offset(x)			 ((x).val >> 9)
 #define __swp_entry(type, offset)	((swp_entry_t)  { (((type) & 0x1f) << 4) | ((offset) << 9) })
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_high })
 #define __swp_entry_to_pte(x)		((pte_t) { 0, (x).val })

 /*
  * We borrow bit 57 (bit 25 in the low PTE) to store the exclusive marker in
  * swap PTEs.
  */
 #define _PAGE_SWP_EXCLUSIVE	(1 << 25)

 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)

 /*
  * Format of swap PTEs:
  *
  *   6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3
  *   3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
  *   <------------------ zeroes -------------------> E P 0 0 0 0 0 0
  *
  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
  *   <------------------- offset --------------------> < type -> V G
  *
  *   E is the exclusive marker that is not stored in swap entries.
  *   _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
  *   unused.
  */
 #define __swp_type(x)			(((x).val >> 2) & 0x1f)
 #define __swp_offset(x)			 ((x).val >> 7)
 #define __swp_entry(type, offset)	((swp_entry_t)  { (((type) & 0x1f) << 2) | ((offset) << 7) })
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_high })
 #define __swp_entry_to_pte(x)		((pte_t) { 0, (x).val })

 /*
  * We borrow bit 39 (bit 7 in the low PTE) to store the exclusive marker in swap
  * PTEs.
  */
 #define _PAGE_SWP_EXCLUSIVE	(1 << 7)

 #else
 /*
  * Format of swap PTEs:
  *
  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
  *   <------------- offset --------------> < type -> 0 0 0 0 0 0 E P
  *
  *   E is the exclusive marker that is not stored in swap entries.
  *   _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
  *   unused. The location of V and G varies.
  */
 #define __swp_type(x)			(((x).val >> 8) & 0x1f)
 #define __swp_offset(x)			 ((x).val >> 13)
 #define __swp_entry(type, offset)	((swp_entry_t)	{ ((type) << 8) | ((offset) << 13) })
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })

 /* We borrow bit 1 to store the exclusive marker in swap PTEs. */
 #define _PAGE_SWP_EXCLUSIVE	(1 << 1)

 #endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */

 #endif /* defined(CONFIG_CPU_R3K_TLB) */

 #endif /* _ASM_PGTABLE_32_H */
	/*
	* 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_32_H
	#define _ASM_PGTABLE_32_H

	#include <asm/addrspace.h>
	#include <asm/page.h>

	#include <linux/linkage.h>
	#include <asm/cachectl.h>
	#include <asm/fixmap.h>

	#include <asm-generic/pgtable-nopmd.h>

	#ifdef CONFIG_HIGHMEM
	#include <asm/highmem.h>
	#endif

	/*
	* Regarding 32-bit MIPS huge page support (and the tradeoff it entails):
	*
	* We use the same huge page sizes as 64-bit MIPS. Assuming a 4KB page size,
	* our 2-level table layout would normally have a PGD entry cover a contiguous
	* 4MB virtual address region (pointing to a 4KB PTE page of 1,024 32-bit pte_t
	* pointers, each pointing to a 4KB physical page). The problem is that 4MB,
	* spanning both halves of a TLB EntryLo0,1 pair, requires 2MB hardware page
	* support, not one of the standard supported sizes (1MB,4MB,16MB,...).
	* To correct for this, when huge pages are enabled, we halve the number of
	* pointers a PTE page holds, making its last half go to waste. Correspondingly,
	* we double the number of PGD pages. Overall, page table memory overhead
	* increases to match 64-bit MIPS, but PTE lookups remain CPU cache-friendly.
	*
	* NOTE: We don't yet support huge pages if extended-addressing is enabled
	* (i.e. EVA, XPA, 36-bit Alchemy/Netlogic).
	*/

	extern int temp_tlb_entry;

	/*
	* - add_temporary_entry() add a temporary TLB entry. We use TLB entries
	* starting at the top and working down. This is for populating the
	* TLB before trap_init() puts the TLB miss handler in place. It
	* should be used only for entries matching the actual page tables,
	* to prevent inconsistencies.
	*/
	extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
	unsigned long entryhi, unsigned long pagemask);

	/*
	* Basically we have the same two-level (which is the logical three level
	* Linux page table layout folded) page tables as the i386. Some day
	* when we have proper page coloring support we can have a 1% quicker
	* tlb refill handling mechanism, but for now it is a bit slower but
	* works even with the cache aliasing problem the R4k and above have.
	*/

	/* PGDIR_SHIFT determines what a third-level page table entry can map */
	#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
	# define PGDIR_SHIFT (2 * PAGE_SHIFT - PTE_T_LOG2 - 1)
	#else
	# define PGDIR_SHIFT (2 * PAGE_SHIFT - PTE_T_LOG2)
	#endif

	#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 PUD/PMD directory physically.
	*/
	#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
	# define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2 + 1)
	#else
	# define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
	#endif

	#define PGD_TABLE_ORDER (__PGD_TABLE_ORDER >= 0 ? __PGD_TABLE_ORDER : 0)
	#define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud
	#define PMD_TABLE_ORDER aieeee_attempt_to_allocate_pmd

	#define PTRS_PER_PGD (USER_PTRS_PER_PGD * 2)
	#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
	# define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t) / 2)
	#else
	# define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t))
	#endif

	#define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE)

	#define VMALLOC_START MAP_BASE

	#define PKMAP_END ((FIXADDR_START) & ~((LAST_PKMAP << PAGE_SHIFT)-1))
	#define PKMAP_BASE (PKMAP_END - PAGE_SIZE * LAST_PKMAP)

	#ifdef CONFIG_HIGHMEM
	# define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE)
	#else
	# define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
	#endif

	#ifdef CONFIG_PHYS_ADDR_T_64BIT
	#define pte_ERROR(e) \
	printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
	#else
	#define pte_ERROR(e) \
	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
	#endif
	#define pgd_ERROR(e) \
	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))

	extern void load_pgd(unsigned long pg_dir);

	extern pte_t invalid_pte_table[PTRS_PER_PTE];

	/*
	* 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;
	}

	static inline int pmd_bad(pmd_t pmd)
	{
	#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
	/* pmd_leaf(pmd) but inline */
	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
	return 0;
	#endif

	if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
	return 1;

	return 0;
	}

	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);
	}

	#if defined(CONFIG_XPA)

	#define MAX_POSSIBLE_PHYSMEM_BITS 40
	#define pte_pfn(x) (((unsigned long)((x).pte_high >> PFN_PTE_SHIFT)) \| (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
	static inline pte_t
	pfn_pte(unsigned long pfn, pgprot_t prot)
	{
	pte_t pte;

	pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) \|
	(pgprot_val(prot) & ~_PFNX_MASK);
	pte.pte_high = (pfn << PFN_PTE_SHIFT) \|
	(pgprot_val(prot) & ~_PFN_MASK);
	return pte;
	}

	#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)

	#define MAX_POSSIBLE_PHYSMEM_BITS 36
	#define pte_pfn(x) ((unsigned long)((x).pte_high >> 6))

	static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
	{
	pte_t pte;

	pte.pte_high = (pfn << 6) \| (pgprot_val(prot) & 0x3f);
	pte.pte_low = pgprot_val(prot);

	return pte;
	}

	#else

	#define MAX_POSSIBLE_PHYSMEM_BITS 32
	#define pte_pfn(x) ((unsigned long)((x).pte >> PFN_PTE_SHIFT))
	#define pfn_pte(pfn, prot) __pte(((unsigned long long)(pfn) << PFN_PTE_SHIFT) \| pgprot_val(prot))
	#define pfn_pmd(pfn, prot) __pmd(((unsigned long long)(pfn) << PFN_PTE_SHIFT) \| pgprot_val(prot))
	#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */

	#define pte_page(x) pfn_to_page(pte_pfn(x))

	/*
	* Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
	* are !pte_none() && !pte_present().
	*/
	#if defined(CONFIG_CPU_R3K_TLB)

	/*
	* Format of swap PTEs:
	*
	* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
	* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
	* <----------- offset ------------> < type -> V G E 0 0 0 0 0 0 P
	*
	* E is the exclusive marker that is not stored in swap entries.
	* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
	* unused.
	*/
	#define __swp_type(x) (((x).val >> 10) & 0x1f)
	#define __swp_offset(x) ((x).val >> 15)
	#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x1f) << 10) \| ((offset) << 15) })
	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
	#define __swp_entry_to_pte(x) ((pte_t) { (x).val })

	/* We borrow bit 7 to store the exclusive marker in swap PTEs. */
	#define _PAGE_SWP_EXCLUSIVE (1 << 7)

	#else

	#if defined(CONFIG_XPA)

	/*
	* Format of swap PTEs:
	*
	* 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3
	* 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
	* 0 0 0 0 0 0 E P <------------------ zeroes ------------------->
	*
	* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
	* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
	* <----------------- offset ------------------> < type -> V G 0 0
	*
	* E is the exclusive marker that is not stored in swap entries.
	* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
	* unused.
	*/
	#define __swp_type(x) (((x).val >> 4) & 0x1f)
	#define __swp_offset(x) ((x).val >> 9)
	#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x1f) << 4) \| ((offset) << 9) })
	#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
	#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })

	/*
	* We borrow bit 57 (bit 25 in the low PTE) to store the exclusive marker in
	* swap PTEs.
	*/
	#define _PAGE_SWP_EXCLUSIVE (1 << 25)

	#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)

	/*
	* Format of swap PTEs:
	*
	* 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3
	* 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
	* <------------------ zeroes -------------------> E P 0 0 0 0 0 0
	*
	* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
	* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
	* <------------------- offset --------------------> < type -> V G
	*
	* E is the exclusive marker that is not stored in swap entries.
	* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
	* unused.
	*/
	#define __swp_type(x) (((x).val >> 2) & 0x1f)
	#define __swp_offset(x) ((x).val >> 7)
	#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x1f) << 2) \| ((offset) << 7) })
	#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
	#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })

	/*
	* We borrow bit 39 (bit 7 in the low PTE) to store the exclusive marker in swap
	* PTEs.
	*/
	#define _PAGE_SWP_EXCLUSIVE (1 << 7)

	#else
	/*
	* Format of swap PTEs:
	*
	* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
	* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
	* <------------- offset --------------> < type -> 0 0 0 0 0 0 E P
	*
	* E is the exclusive marker that is not stored in swap entries.
	* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
	* unused. The location of V and G varies.
	*/
	#define __swp_type(x) (((x).val >> 8) & 0x1f)
	#define __swp_offset(x) ((x).val >> 13)
	#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 8) \| ((offset) << 13) })
	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
	#define __swp_entry_to_pte(x) ((pte_t) { (x).val })

	/* We borrow bit 1 to store the exclusive marker in swap PTEs. */
	#define _PAGE_SWP_EXCLUSIVE (1 << 1)

	#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */

	#endif /* defined(CONFIG_CPU_R3K_TLB) */

	#endif /* _ASM_PGTABLE_32_H */