arch/unicore32/include/asm/pgtable.h - linux - Git at Google

 /*
  * linux/arch/unicore32/include/asm/pgtable.h
  *
  * Code specific to PKUnity SoC and UniCore ISA
  *
  * Copyright (C) 2001-2010 GUAN Xue-tao
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #ifndef __UNICORE_PGTABLE_H__
 #define __UNICORE_PGTABLE_H__

 #define __ARCH_USE_5LEVEL_HACK
 #include <asm-generic/pgtable-nopmd.h>
 #include <asm/cpu-single.h>

 #include <asm/memory.h>
 #include <asm/pgtable-hwdef.h>

 /*
  * Just any arbitrary offset to the start of the vmalloc VM area: the
  * current 8MB value just means that there will be a 8MB "hole" after the
  * physical memory until the kernel virtual memory starts.  That means that
  * any out-of-bounds memory accesses will hopefully be caught.
  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  * area for the same reason. ;)
  *
  * Note that platforms may override VMALLOC_START, but they must provide
  * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
  * which may not overlap IO space.
  */
 #ifndef VMALLOC_START
 #define VMALLOC_OFFSET		SZ_8M
 #define VMALLOC_START		(((unsigned long)high_memory + VMALLOC_OFFSET) \
 					& ~(VMALLOC_OFFSET-1))
 #define VMALLOC_END		(0xff000000UL)
 #endif

 #define PTRS_PER_PTE		1024
 #define PTRS_PER_PGD		1024

 /*
  * PGDIR_SHIFT determines what a third-level page table entry can map
  */
 #define PGDIR_SHIFT		22

 #ifndef __ASSEMBLY__
 extern void __pte_error(const char *file, int line, unsigned long val);
 extern void __pgd_error(const char *file, int line, unsigned long val);

 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
 #endif /* !__ASSEMBLY__ */

 #define PGDIR_SIZE		(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK		(~(PGDIR_SIZE-1))

 /*
  * This is the lowest virtual address we can permit any user space
  * mapping to be mapped at.  This is particularly important for
  * non-high vector CPUs.
  */
 #define FIRST_USER_ADDRESS	PAGE_SIZE

 #define FIRST_USER_PGD_NR	1
 #define USER_PTRS_PER_PGD	((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)

 /*
  * section address mask and size definitions.
  */
 #define SECTION_SHIFT		22
 #define SECTION_SIZE		(1UL << SECTION_SHIFT)
 #define SECTION_MASK		(~(SECTION_SIZE-1))

 #ifndef __ASSEMBLY__

 /*
  * The pgprot_* and protection_map entries will be fixed up in runtime
  * to include the cachable bits based on memory policy, as well as any
  * architecture dependent bits.
  */
 #define _PTE_DEFAULT		(PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE)

 extern pgprot_t pgprot_user;
 extern pgprot_t pgprot_kernel;

 #define PAGE_NONE		pgprot_user
 #define PAGE_SHARED		__pgprot(pgprot_val(pgprot_user | PTE_READ \
 								| PTE_WRITE))
 #define PAGE_SHARED_EXEC	__pgprot(pgprot_val(pgprot_user | PTE_READ \
 								| PTE_WRITE \
 								| PTE_EXEC))
 #define PAGE_COPY		__pgprot(pgprot_val(pgprot_user | PTE_READ)
 #define PAGE_COPY_EXEC		__pgprot(pgprot_val(pgprot_user | PTE_READ \
 								| PTE_EXEC))
 #define PAGE_READONLY		__pgprot(pgprot_val(pgprot_user | PTE_READ))
 #define PAGE_READONLY_EXEC	__pgprot(pgprot_val(pgprot_user | PTE_READ \
 								| PTE_EXEC))
 #define PAGE_KERNEL		pgprot_kernel
 #define PAGE_KERNEL_EXEC	__pgprot(pgprot_val(pgprot_kernel | PTE_EXEC))

 #define __PAGE_NONE		__pgprot(_PTE_DEFAULT)
 #define __PAGE_SHARED		__pgprot(_PTE_DEFAULT | PTE_READ \
 							| PTE_WRITE)
 #define __PAGE_SHARED_EXEC	__pgprot(_PTE_DEFAULT | PTE_READ \
 							| PTE_WRITE \
 							| PTE_EXEC)
 #define __PAGE_COPY		__pgprot(_PTE_DEFAULT | PTE_READ)
 #define __PAGE_COPY_EXEC	__pgprot(_PTE_DEFAULT | PTE_READ \
 							| PTE_EXEC)
 #define __PAGE_READONLY		__pgprot(_PTE_DEFAULT | PTE_READ)
 #define __PAGE_READONLY_EXEC	__pgprot(_PTE_DEFAULT | PTE_READ \
 							| PTE_EXEC)

 #endif /* __ASSEMBLY__ */

 /*
  * The table below defines the page protection levels that we insert into our
  * Linux page table version.  These get translated into the best that the
  * architecture can perform.  Note that on UniCore hardware:
  *  1) We cannot do execute protection
  *  2) If we could do execute protection, then read is implied
  *  3) write implies read permissions
  */
 #define __P000  __PAGE_NONE
 #define __P001  __PAGE_READONLY
 #define __P010  __PAGE_COPY
 #define __P011  __PAGE_COPY
 #define __P100  __PAGE_READONLY_EXEC
 #define __P101  __PAGE_READONLY_EXEC
 #define __P110  __PAGE_COPY_EXEC
 #define __P111  __PAGE_COPY_EXEC

 #define __S000  __PAGE_NONE
 #define __S001  __PAGE_READONLY
 #define __S010  __PAGE_SHARED
 #define __S011  __PAGE_SHARED
 #define __S100  __PAGE_READONLY_EXEC
 #define __S101  __PAGE_READONLY_EXEC
 #define __S110  __PAGE_SHARED_EXEC
 #define __S111  __PAGE_SHARED_EXEC

 #ifndef __ASSEMBLY__
 /*
  * ZERO_PAGE is a global shared page that is always zero: used
  * for zero-mapped memory areas etc..
  */
 extern struct page *empty_zero_page;
 #define ZERO_PAGE(vaddr)		(empty_zero_page)

 #define pte_pfn(pte)			(pte_val(pte) >> PAGE_SHIFT)
 #define pfn_pte(pfn, prot)		(__pte(((pfn) << PAGE_SHIFT) \
 						| pgprot_val(prot)))

 #define pte_none(pte)			(!pte_val(pte))
 #define pte_clear(mm, addr, ptep)	set_pte(ptep, __pte(0))
 #define pte_page(pte)			(pfn_to_page(pte_pfn(pte)))
 #define pte_offset_kernel(dir, addr)	(pmd_page_vaddr(*(dir)) \
 						+ __pte_index(addr))

 #define pte_offset_map(dir, addr)	(pmd_page_vaddr(*(dir)) \
 						+ __pte_index(addr))
 #define pte_unmap(pte)			do { } while (0)

 #define set_pte(ptep, pte)	cpu_set_pte(ptep, pte)

 #define set_pte_at(mm, addr, ptep, pteval)	\
 	do {					\
 		set_pte(ptep, pteval);          \
 	} while (0)

 /*
  * The following only work if pte_present() is true.
  * Undefined behaviour if not..
  */
 #define pte_present(pte)	(pte_val(pte) & PTE_PRESENT)
 #define pte_write(pte)		(pte_val(pte) & PTE_WRITE)
 #define pte_dirty(pte)		(pte_val(pte) & PTE_DIRTY)
 #define pte_young(pte)		(pte_val(pte) & PTE_YOUNG)
 #define pte_exec(pte)		(pte_val(pte) & PTE_EXEC)
 #define pte_special(pte)	(0)

 #define PTE_BIT_FUNC(fn, op) \
 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }

 PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
 PTE_BIT_FUNC(mkwrite,   |= PTE_WRITE);
 PTE_BIT_FUNC(mkclean,   &= ~PTE_DIRTY);
 PTE_BIT_FUNC(mkdirty,   |= PTE_DIRTY);
 PTE_BIT_FUNC(mkold,     &= ~PTE_YOUNG);
 PTE_BIT_FUNC(mkyoung,   |= PTE_YOUNG);

 static inline pte_t pte_mkspecial(pte_t pte) { return pte; }

 /*
  * Mark the prot value as uncacheable.
  */
 #define pgprot_noncached(prot)		\
 	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 #define pgprot_writecombine(prot)	\
 	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 #define pgprot_dmacoherent(prot)	\
 	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)

 #define pmd_none(pmd)		(!pmd_val(pmd))
 #define pmd_present(pmd)	(pmd_val(pmd) & PMD_PRESENT)
 #define pmd_bad(pmd)		(((pmd_val(pmd) &		\
 				(PMD_PRESENT | PMD_TYPE_MASK))	\
 				!= (PMD_PRESENT | PMD_TYPE_TABLE)))

 #define set_pmd(pmdpd, pmdval)		\
 	do {				\
 		*(pmdpd) = pmdval;	\
 	} while (0)

 #define pmd_clear(pmdp)			\
 	do {				\
 		set_pmd(pmdp, __pmd(0));\
 		clean_pmd_entry(pmdp);	\
 	} while (0)

 #define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd)))

 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
  */
 #define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)

 /* to find an entry in a page-table-directory */
 #define pgd_index(addr)		((addr) >> PGDIR_SHIFT)

 #define pgd_offset(mm, addr)	((mm)->pgd+pgd_index(addr))

 /* to find an entry in a kernel page-table-directory */
 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)

 /* Find an entry in the third-level page table.. */
 #define __pte_index(addr)	(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))

 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ;
 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 	return pte;
 }

 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

 /*
  * Encode and decode a swap entry.  Swap entries are stored in the Linux
  * page tables as follows:
  *
  *   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
  *
  * This gives us up to 127 swap files and 32GB per swap file.  Note that
  * the offset field is always non-zero.
  */
 #define __SWP_TYPE_SHIFT	5
 #define __SWP_TYPE_BITS		7
 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)

 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT)		\
 				& __SWP_TYPE_MASK)
 #define __swp_offset(x)		((x).val >> __SWP_OFFSET_SHIFT)
 #define __swp_entry(type, offset) ((swp_entry_t) {			\
 				((type) << __SWP_TYPE_SHIFT) |		\
 				((offset) << __SWP_OFFSET_SHIFT) })

 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })

 /*
  * It is an error for the kernel to have more swap files than we can
  * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
  * is increased beyond what we presently support.
  */
 #define MAX_SWAPFILES_CHECK()	\
 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)

 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 /* FIXME: this is not correct */
 #define kern_addr_valid(addr)	(1)

 #include <asm-generic/pgtable.h>

 #define pgtable_cache_init() do { } while (0)

 #endif /* !__ASSEMBLY__ */

 #endif /* __UNICORE_PGTABLE_H__ */
	/*
	* linux/arch/unicore32/include/asm/pgtable.h
	*
	* Code specific to PKUnity SoC and UniCore ISA
	*
	* Copyright (C) 2001-2010 GUAN Xue-tao
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#ifndef __UNICORE_PGTABLE_H__
	#define __UNICORE_PGTABLE_H__

	#define __ARCH_USE_5LEVEL_HACK
	#include <asm-generic/pgtable-nopmd.h>
	#include <asm/cpu-single.h>

	#include <asm/memory.h>
	#include <asm/pgtable-hwdef.h>

	/*
	* Just any arbitrary offset to the start of the vmalloc VM area: the
	* current 8MB value just means that there will be a 8MB "hole" after the
	* physical memory until the kernel virtual memory starts. That means that
	* any out-of-bounds memory accesses will hopefully be caught.
	* The vmalloc() routines leaves a hole of 4kB between each vmalloced
	* area for the same reason. ;)
	*
	* Note that platforms may override VMALLOC_START, but they must provide
	* VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space,
	* which may not overlap IO space.
	*/
	#ifndef VMALLOC_START
	#define VMALLOC_OFFSET SZ_8M
	#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) \
	& ~(VMALLOC_OFFSET-1))
	#define VMALLOC_END (0xff000000UL)
	#endif

	#define PTRS_PER_PTE 1024
	#define PTRS_PER_PGD 1024

	/*
	* PGDIR_SHIFT determines what a third-level page table entry can map
	*/
	#define PGDIR_SHIFT 22

	#ifndef __ASSEMBLY__
	extern void __pte_error(const char *file, int line, unsigned long val);
	extern void __pgd_error(const char *file, int line, unsigned long val);

	#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte_val(pte))
	#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
	#endif /* !__ASSEMBLY__ */

	#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
	#define PGDIR_MASK (~(PGDIR_SIZE-1))

	/*
	* This is the lowest virtual address we can permit any user space
	* mapping to be mapped at. This is particularly important for
	* non-high vector CPUs.
	*/
	#define FIRST_USER_ADDRESS PAGE_SIZE

	#define FIRST_USER_PGD_NR 1
	#define USER_PTRS_PER_PGD ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)

	/*
	* section address mask and size definitions.
	*/
	#define SECTION_SHIFT 22
	#define SECTION_SIZE (1UL << SECTION_SHIFT)
	#define SECTION_MASK (~(SECTION_SIZE-1))

	#ifndef __ASSEMBLY__

	/*
	* The pgprot_* and protection_map entries will be fixed up in runtime
	* to include the cachable bits based on memory policy, as well as any
	* architecture dependent bits.
	*/
	#define _PTE_DEFAULT (PTE_PRESENT \| PTE_YOUNG \| PTE_CACHEABLE)

	extern pgprot_t pgprot_user;
	extern pgprot_t pgprot_kernel;

	#define PAGE_NONE pgprot_user
	#define PAGE_SHARED __pgprot(pgprot_val(pgprot_user \| PTE_READ \
	\| PTE_WRITE))
	#define PAGE_SHARED_EXEC __pgprot(pgprot_val(pgprot_user \| PTE_READ \
	\| PTE_WRITE \
	\| PTE_EXEC))
	#define PAGE_COPY __pgprot(pgprot_val(pgprot_user \| PTE_READ)
	#define PAGE_COPY_EXEC __pgprot(pgprot_val(pgprot_user \| PTE_READ \
	\| PTE_EXEC))
	#define PAGE_READONLY __pgprot(pgprot_val(pgprot_user \| PTE_READ))
	#define PAGE_READONLY_EXEC __pgprot(pgprot_val(pgprot_user \| PTE_READ \
	\| PTE_EXEC))
	#define PAGE_KERNEL pgprot_kernel
	#define PAGE_KERNEL_EXEC __pgprot(pgprot_val(pgprot_kernel \| PTE_EXEC))

	#define __PAGE_NONE __pgprot(_PTE_DEFAULT)
	#define __PAGE_SHARED __pgprot(_PTE_DEFAULT \| PTE_READ \
	\| PTE_WRITE)
	#define __PAGE_SHARED_EXEC __pgprot(_PTE_DEFAULT \| PTE_READ \
	\| PTE_WRITE \
	\| PTE_EXEC)
	#define __PAGE_COPY __pgprot(_PTE_DEFAULT \| PTE_READ)
	#define __PAGE_COPY_EXEC __pgprot(_PTE_DEFAULT \| PTE_READ \
	\| PTE_EXEC)
	#define __PAGE_READONLY __pgprot(_PTE_DEFAULT \| PTE_READ)
	#define __PAGE_READONLY_EXEC __pgprot(_PTE_DEFAULT \| PTE_READ \
	\| PTE_EXEC)

	#endif /* __ASSEMBLY__ */

	/*
	* The table below defines the page protection levels that we insert into our
	* Linux page table version. These get translated into the best that the
	* architecture can perform. Note that on UniCore hardware:
	* 1) We cannot do execute protection
	* 2) If we could do execute protection, then read is implied
	* 3) write implies read permissions
	*/
	#define __P000 __PAGE_NONE
	#define __P001 __PAGE_READONLY
	#define __P010 __PAGE_COPY
	#define __P011 __PAGE_COPY
	#define __P100 __PAGE_READONLY_EXEC
	#define __P101 __PAGE_READONLY_EXEC
	#define __P110 __PAGE_COPY_EXEC
	#define __P111 __PAGE_COPY_EXEC

	#define __S000 __PAGE_NONE
	#define __S001 __PAGE_READONLY
	#define __S010 __PAGE_SHARED
	#define __S011 __PAGE_SHARED
	#define __S100 __PAGE_READONLY_EXEC
	#define __S101 __PAGE_READONLY_EXEC
	#define __S110 __PAGE_SHARED_EXEC
	#define __S111 __PAGE_SHARED_EXEC

	#ifndef __ASSEMBLY__
	/*
	* ZERO_PAGE is a global shared page that is always zero: used
	* for zero-mapped memory areas etc..
	*/
	extern struct page *empty_zero_page;
	#define ZERO_PAGE(vaddr) (empty_zero_page)

	#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
	#define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) \
	\| pgprot_val(prot)))

	#define pte_none(pte) (!pte_val(pte))
	#define pte_clear(mm, addr, ptep) set_pte(ptep, __pte(0))
	#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
	#define pte_offset_kernel(dir, addr) (pmd_page_vaddr(*(dir)) \
	+ __pte_index(addr))

	#define pte_offset_map(dir, addr) (pmd_page_vaddr(*(dir)) \
	+ __pte_index(addr))
	#define pte_unmap(pte) do { } while (0)

	#define set_pte(ptep, pte) cpu_set_pte(ptep, pte)

	#define set_pte_at(mm, addr, ptep, pteval) \
	do { \
	set_pte(ptep, pteval); \
	} while (0)

	/*
	* The following only work if pte_present() is true.
	* Undefined behaviour if not..
	*/
	#define pte_present(pte) (pte_val(pte) & PTE_PRESENT)
	#define pte_write(pte) (pte_val(pte) & PTE_WRITE)
	#define pte_dirty(pte) (pte_val(pte) & PTE_DIRTY)
	#define pte_young(pte) (pte_val(pte) & PTE_YOUNG)
	#define pte_exec(pte) (pte_val(pte) & PTE_EXEC)
	#define pte_special(pte) (0)

	#define PTE_BIT_FUNC(fn, op) \
	static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }

	PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
	PTE_BIT_FUNC(mkwrite, \|= PTE_WRITE);
	PTE_BIT_FUNC(mkclean, &= ~PTE_DIRTY);
	PTE_BIT_FUNC(mkdirty, \|= PTE_DIRTY);
	PTE_BIT_FUNC(mkold, &= ~PTE_YOUNG);
	PTE_BIT_FUNC(mkyoung, \|= PTE_YOUNG);

	static inline pte_t pte_mkspecial(pte_t pte) { return pte; }

	/*
	* Mark the prot value as uncacheable.
	*/
	#define pgprot_noncached(prot) \
	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
	#define pgprot_writecombine(prot) \
	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
	#define pgprot_dmacoherent(prot) \
	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)

	#define pmd_none(pmd) (!pmd_val(pmd))
	#define pmd_present(pmd) (pmd_val(pmd) & PMD_PRESENT)
	#define pmd_bad(pmd) (((pmd_val(pmd) & \
	(PMD_PRESENT \| PMD_TYPE_MASK)) \
	!= (PMD_PRESENT \| PMD_TYPE_TABLE)))

	#define set_pmd(pmdpd, pmdval) \
	do { \
	*(pmdpd) = pmdval; \
	} while (0)

	#define pmd_clear(pmdp) \
	do { \
	set_pmd(pmdp, __pmd(0));\
	clean_pmd_entry(pmdp); \
	} while (0)

	#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
	#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd)))

	/*
	* Conversion functions: convert a page and protection to a page entry,
	* and a page entry and page directory to the page they refer to.
	*/
	#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)

	/* to find an entry in a page-table-directory */
	#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)

	#define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr))

	/* to find an entry in a kernel page-table-directory */
	#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)

	/* Find an entry in the third-level page table.. */
	#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))

	static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
	{
	const unsigned long mask = PTE_EXEC \| PTE_WRITE \| PTE_READ;
	pte_val(pte) = (pte_val(pte) & ~mask) \| (pgprot_val(newprot) & mask);
	return pte;
	}

	extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

	/*
	* Encode and decode a swap entry. Swap entries are stored in the Linux
	* page tables as follows:
	*
	* 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
	*
	* This gives us up to 127 swap files and 32GB per swap file. Note that
	* the offset field is always non-zero.
	*/
	#define __SWP_TYPE_SHIFT 5
	#define __SWP_TYPE_BITS 7
	#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
	#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)

	#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) \
	& __SWP_TYPE_MASK)
	#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
	#define __swp_entry(type, offset) ((swp_entry_t) { \
	((type) << __SWP_TYPE_SHIFT) \| \
	((offset) << __SWP_OFFSET_SHIFT) })

	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
	#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })

	/*
	* It is an error for the kernel to have more swap files than we can
	* encode in the PTEs. This ensures that we know when MAX_SWAPFILES
	* is increased beyond what we presently support.
	*/
	#define MAX_SWAPFILES_CHECK() \
	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)

	/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
	/* FIXME: this is not correct */
	#define kern_addr_valid(addr) (1)

	#include <asm-generic/pgtable.h>

	#define pgtable_cache_init() do { } while (0)

	#endif /* !__ASSEMBLY__ */

	#endif /* __UNICORE_PGTABLE_H__ */