[linux-2.6-block.git] / arch / unicore32 / include / asm / pgtable.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * linux/arch/unicore32/include/asm/pgtable.h
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 */
#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 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>

#endif /* !__ASSEMBLY__ */

#endif /* __UNICORE_PGTABLE_H__ */
Commit	Line	Data
d2912cb1	1	/* SPDX-License-Identifier: GPL-2.0-only */
56372b0b G	2	/*
	3	* linux/arch/unicore32/include/asm/pgtable.h
	4	*
	5	* Code specific to PKUnity SoC and UniCore ISA
	6	*
	7	* Copyright (C) 2001-2010 GUAN Xue-tao
56372b0b G	8	*/
	9	#ifndef __UNICORE_PGTABLE_H__
	10	#define __UNICORE_PGTABLE_H__
	11
9849a569	12	#define __ARCH_USE_5LEVEL_HACK
56372b0b G	13	#include <asm-generic/pgtable-nopmd.h>
	14	#include <asm/cpu-single.h>
	15
	16	#include <asm/memory.h>
	17	#include <asm/pgtable-hwdef.h>
	18
	19	/*
	20	* Just any arbitrary offset to the start of the vmalloc VM area: the
	21	* current 8MB value just means that there will be a 8MB "hole" after the
	22	* physical memory until the kernel virtual memory starts. That means that
	23	* any out-of-bounds memory accesses will hopefully be caught.
	24	* The vmalloc() routines leaves a hole of 4kB between each vmalloced
	25	* area for the same reason. ;)
	26	*
	27	* Note that platforms may override VMALLOC_START, but they must provide
	28	* VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space,
	29	* which may not overlap IO space.
	30	*/
	31	#ifndef VMALLOC_START
	32	#define VMALLOC_OFFSET SZ_8M
	33	#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) \
	34	& ~(VMALLOC_OFFSET-1))
	35	#define VMALLOC_END (0xff000000UL)
	36	#endif
	37
	38	#define PTRS_PER_PTE 1024
	39	#define PTRS_PER_PGD 1024
	40
	41	/*
	42	* PGDIR_SHIFT determines what a third-level page table entry can map
	43	*/
	44	#define PGDIR_SHIFT 22
	45
	46	#ifndef __ASSEMBLY__
	47	extern void __pte_error(const char *file, int line, unsigned long val);
	48	extern void __pgd_error(const char *file, int line, unsigned long val);
	49
	50	#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte_val(pte))
	51	#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
	52	#endif /* !__ASSEMBLY__ */
	53
	54	#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
	55	#define PGDIR_MASK (~(PGDIR_SIZE-1))
	56
	57	/*
	58	* This is the lowest virtual address we can permit any user space
	59	* mapping to be mapped at. This is particularly important for
	60	* non-high vector CPUs.
	61	*/
	62	#define FIRST_USER_ADDRESS PAGE_SIZE
	63
	64	#define FIRST_USER_PGD_NR 1
	65	#define USER_PTRS_PER_PGD ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
	66
	67	/*
	68	* section address mask and size definitions.
	69	*/
	70	#define SECTION_SHIFT 22
	71	#define SECTION_SIZE (1UL << SECTION_SHIFT)
	72	#define SECTION_MASK (~(SECTION_SIZE-1))
	73
	74	#ifndef __ASSEMBLY__
	75
	76	/*
77	* The pgprot_* and protection_map entries will be fixed up in runtime
78	* to include the cachable bits based on memory policy, as well as any
79	* architecture dependent bits.
80	*/
81	#define _PTE_DEFAULT (PTE_PRESENT \| PTE_YOUNG \| PTE_CACHEABLE)
82
83	extern pgprot_t pgprot_user;
84	extern pgprot_t pgprot_kernel;
85
86	#define PAGE_NONE pgprot_user
87	#define PAGE_SHARED __pgprot(pgprot_val(pgprot_user \| PTE_READ \
aaad6183	88	\| PTE_WRITE))
56372b0b G	89	#define PAGE_SHARED_EXEC __pgprot(pgprot_val(pgprot_user \| PTE_READ \
56372b0b G	90	\| PTE_WRITE \
aaad6183	91	\| PTE_EXEC))
56372b0b G	92	#define PAGE_COPY __pgprot(pgprot_val(pgprot_user \| PTE_READ)
56372b0b G	93	#define PAGE_COPY_EXEC __pgprot(pgprot_val(pgprot_user \| PTE_READ \
aaad6183 CG	94	\| PTE_EXEC))
aaad6183 CG	95	#define PAGE_READONLY __pgprot(pgprot_val(pgprot_user \| PTE_READ))
56372b0b	96	#define PAGE_READONLY_EXEC __pgprot(pgprot_val(pgprot_user \| PTE_READ \
aaad6183	97	\| PTE_EXEC))
56372b0b G	98	#define PAGE_KERNEL pgprot_kernel
	99	#define PAGE_KERNEL_EXEC __pgprot(pgprot_val(pgprot_kernel \| PTE_EXEC))
	100
	101	#define __PAGE_NONE __pgprot(_PTE_DEFAULT)
	102	#define __PAGE_SHARED __pgprot(_PTE_DEFAULT \| PTE_READ \
	103	\| PTE_WRITE)
	104	#define __PAGE_SHARED_EXEC __pgprot(_PTE_DEFAULT \| PTE_READ \
	105	\| PTE_WRITE \
	106	\| PTE_EXEC)
	107	#define __PAGE_COPY __pgprot(_PTE_DEFAULT \| PTE_READ)
	108	#define __PAGE_COPY_EXEC __pgprot(_PTE_DEFAULT \| PTE_READ \
	109	\| PTE_EXEC)
	110	#define __PAGE_READONLY __pgprot(_PTE_DEFAULT \| PTE_READ)
	111	#define __PAGE_READONLY_EXEC __pgprot(_PTE_DEFAULT \| PTE_READ \
	112	\| PTE_EXEC)
	113
	114	#endif /* __ASSEMBLY__ */
	115
	116	/*
	117	* The table below defines the page protection levels that we insert into our
	118	* Linux page table version. These get translated into the best that the
	119	* architecture can perform. Note that on UniCore hardware:
	120	* 1) We cannot do execute protection
	121	* 2) If we could do execute protection, then read is implied
	122	* 3) write implies read permissions
	123	*/
	124	#define __P000 __PAGE_NONE
	125	#define __P001 __PAGE_READONLY
	126	#define __P010 __PAGE_COPY
	127	#define __P011 __PAGE_COPY
	128	#define __P100 __PAGE_READONLY_EXEC
	129	#define __P101 __PAGE_READONLY_EXEC
	130	#define __P110 __PAGE_COPY_EXEC
	131	#define __P111 __PAGE_COPY_EXEC
	132
	133	#define __S000 __PAGE_NONE
	134	#define __S001 __PAGE_READONLY
	135	#define __S010 __PAGE_SHARED
	136	#define __S011 __PAGE_SHARED
	137	#define __S100 __PAGE_READONLY_EXEC
	138	#define __S101 __PAGE_READONLY_EXEC
	139	#define __S110 __PAGE_SHARED_EXEC
	140	#define __S111 __PAGE_SHARED_EXEC
	141
	142	#ifndef __ASSEMBLY__
	143	/*
	144	* ZERO_PAGE is a global shared page that is always zero: used
	145	* for zero-mapped memory areas etc..
	146	*/
	147	extern struct page *empty_zero_page;
	148	#define ZERO_PAGE(vaddr) (empty_zero_page)
	149
	150	#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
	151	#define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) \
	152	\| pgprot_val(prot)))
	153
	154	#define pte_none(pte) (!pte_val(pte))
	155	#define pte_clear(mm, addr, ptep) set_pte(ptep, __pte(0))
	156	#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
	157	#define pte_offset_kernel(dir, addr) (pmd_page_vaddr(*(dir)) \
	158	+ __pte_index(addr))
	159
	160	#define pte_offset_map(dir, addr) (pmd_page_vaddr(*(dir)) \
	161	+ __pte_index(addr))
162	#define pte_unmap(pte) do { } while (0)
163
164	#define set_pte(ptep, pte) cpu_set_pte(ptep, pte)
165
166	#define set_pte_at(mm, addr, ptep, pteval) \
167	do { \
168	set_pte(ptep, pteval); \
169	} while (0)
170
171	/*
172	* The following only work if pte_present() is true.
173	* Undefined behaviour if not..
174	*/
175	#define pte_present(pte) (pte_val(pte) & PTE_PRESENT)
176	#define pte_write(pte) (pte_val(pte) & PTE_WRITE)
177	#define pte_dirty(pte) (pte_val(pte) & PTE_DIRTY)
178	#define pte_young(pte) (pte_val(pte) & PTE_YOUNG)
179	#define pte_exec(pte) (pte_val(pte) & PTE_EXEC)
180	#define pte_special(pte) (0)
181
182	#define PTE_BIT_FUNC(fn, op) \
183	static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
184
185	PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
186	PTE_BIT_FUNC(mkwrite, \|= PTE_WRITE);
187	PTE_BIT_FUNC(mkclean, &= ~PTE_DIRTY);
188	PTE_BIT_FUNC(mkdirty, \|= PTE_DIRTY);
189	PTE_BIT_FUNC(mkold, &= ~PTE_YOUNG);
190	PTE_BIT_FUNC(mkyoung, \|= PTE_YOUNG);
191
192	static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
193
194	/*
195	* Mark the prot value as uncacheable.
196	*/
197	#define pgprot_noncached(prot) \
198	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
199	#define pgprot_writecombine(prot) \
200	__pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
56372b0b G	201
	202	#define pmd_none(pmd) (!pmd_val(pmd))
	203	#define pmd_present(pmd) (pmd_val(pmd) & PMD_PRESENT)
	204	#define pmd_bad(pmd) (((pmd_val(pmd) & \
	205	(PMD_PRESENT \| PMD_TYPE_MASK)) \
	206	!= (PMD_PRESENT \| PMD_TYPE_TABLE)))
	207
	208	#define set_pmd(pmdpd, pmdval) \
	209	do { \
	210	*(pmdpd) = pmdval; \
	211	} while (0)
	212
	213	#define pmd_clear(pmdp) \
	214	do { \
	215	set_pmd(pmdp, __pmd(0));\
	216	clean_pmd_entry(pmdp); \
	217	} while (0)
	218
	219	#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
	220	#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
	221
	222	/*
	223	* Conversion functions: convert a page and protection to a page entry,
	224	* and a page entry and page directory to the page they refer to.
	225	*/
	226	#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
	227
	228	/* to find an entry in a page-table-directory */
	229	#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
	230
	231	#define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr))
	232
	233	/* to find an entry in a kernel page-table-directory */
	234	#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
	235
	236	/* Find an entry in the third-level page table.. */
	237	#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
	238
	239	static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
	240	{
	241	const unsigned long mask = PTE_EXEC \| PTE_WRITE \| PTE_READ;
	242	pte_val(pte) = (pte_val(pte) & ~mask) \| (pgprot_val(newprot) & mask);
	243	return pte;
	244	}
	245
	246	extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
	247
	248	/*
	249	* Encode and decode a swap entry. Swap entries are stored in the Linux
	250	* page tables as follows:
	251	*
	252	* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
	253	* 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
	254	* <--------------- offset --------------> <--- type --> 0 0 0 0 0
	255	*
	256	* This gives us up to 127 swap files and 32GB per swap file. Note that
	257	* the offset field is always non-zero.
	258	*/
	259	#define __SWP_TYPE_SHIFT 5
	260	#define __SWP_TYPE_BITS 7
	261	#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
	262	#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
	263
	264	#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) \
265	& __SWP_TYPE_MASK)
266	#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
267	#define __swp_entry(type, offset) ((swp_entry_t) { \
268	((type) << __SWP_TYPE_SHIFT) \| \
269	((offset) << __SWP_OFFSET_SHIFT) })
270
271	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
272	#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
273
274	/*
275	* It is an error for the kernel to have more swap files than we can
276	* encode in the PTEs. This ensures that we know when MAX_SWAPFILES
277	* is increased beyond what we presently support.
278	*/
279	#define MAX_SWAPFILES_CHECK() \
280	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
281
56372b0b G	282	/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
	283	/* FIXME: this is not correct */
	284	#define kern_addr_valid(addr) (1)
	285
	286	#include <asm-generic/pgtable.h>
	287
56372b0b G	288	#endif /* !__ASSEMBLY__ */
	289
	290	#endif /* __UNICORE_PGTABLE_H__ */