[mirror_ubuntu-artful-kernel.git] / include / asm-arm / pgtable.h

/*
 *  linux/include/asm-arm/pgtable.h
 *
 *  Copyright (C) 1995-2002 Russell King
 *
 * 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 _ASMARM_PGTABLE_H
#define _ASMARM_PGTABLE_H

#include <asm-generic/4level-fixup.h>

#include <asm/memory.h>
#include <asm/proc-fns.h>
#include <asm/arch/vmalloc.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		(8*1024*1024)
#define VMALLOC_START		(((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
#endif

/*
 * Hardware-wise, we have a two level page table structure, where the first
 * level has 4096 entries, and the second level has 256 entries.  Each entry
 * is one 32-bit word.  Most of the bits in the second level entry are used
 * by hardware, and there aren't any "accessed" and "dirty" bits.
 *
 * Linux on the other hand has a three level page table structure, which can
 * be wrapped to fit a two level page table structure easily - using the PGD
 * and PTE only.  However, Linux also expects one "PTE" table per page, and
 * at least a "dirty" bit.
 *
 * Therefore, we tweak the implementation slightly - we tell Linux that we
 * have 2048 entries in the first level, each of which is 8 bytes (iow, two
 * hardware pointers to the second level.)  The second level contains two
 * hardware PTE tables arranged contiguously, followed by Linux versions
 * which contain the state information Linux needs.  We, therefore, end up
 * with 512 entries in the "PTE" level.
 *
 * This leads to the page tables having the following layout:
 *
 *    pgd             pte
 * |        |
 * +--------+ +0
 * |        |-----> +------------+ +0
 * +- - - - + +4    |  h/w pt 0  |
 * |        |-----> +------------+ +1024
 * +--------+ +8    |  h/w pt 1  |
 * |        |       +------------+ +2048
 * +- - - - +       | Linux pt 0 |
 * |        |       +------------+ +3072
 * +--------+       | Linux pt 1 |
 * |        |       +------------+ +4096
 *
 * See L_PTE_xxx below for definitions of bits in the "Linux pt", and
 * PTE_xxx for definitions of bits appearing in the "h/w pt".
 *
 * PMD_xxx definitions refer to bits in the first level page table.
 *
 * The "dirty" bit is emulated by only granting hardware write permission
 * iff the page is marked "writable" and "dirty" in the Linux PTE.  This
 * means that a write to a clean page will cause a permission fault, and
 * the Linux MM layer will mark the page dirty via handle_pte_fault().
 * For the hardware to notice the permission change, the TLB entry must
 * be flushed, and ptep_establish() does that for us.
 *
 * The "accessed" or "young" bit is emulated by a similar method; we only
 * allow accesses to the page if the "young" bit is set.  Accesses to the
 * page will cause a fault, and handle_pte_fault() will set the young bit
 * for us as long as the page is marked present in the corresponding Linux
 * PTE entry.  Again, ptep_establish() will ensure that the TLB is up to
 * date.
 *
 * However, when the "young" bit is cleared, we deny access to the page
 * by clearing the hardware PTE.  Currently Linux does not flush the TLB
 * for us in this case, which means the TLB will retain the transation
 * until either the TLB entry is evicted under pressure, or a context
 * switch which changes the user space mapping occurs.
 */
#define PTRS_PER_PTE		512
#define PTRS_PER_PMD		1
#define PTRS_PER_PGD		2048

/*
 * PMD_SHIFT determines the size of the area a second-level page table can map
 * PGDIR_SHIFT determines what a third-level page table entry can map
 */
#define PMD_SHIFT		21
#define PGDIR_SHIFT		21

#define LIBRARY_TEXT_START	0x0c000000

#ifndef __ASSEMBLY__
extern void __pte_error(const char *file, int line, unsigned long val);
extern void __pmd_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 pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
#define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
#endif /* !__ASSEMBLY__ */

#define PMD_SIZE		(1UL << PMD_SHIFT)
#define PMD_MASK		(~(PMD_SIZE-1))
#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)

/*
 * ARMv6 supersection address mask and size definitions.
 */
#define SUPERSECTION_SHIFT	24
#define SUPERSECTION_SIZE	(1UL << SUPERSECTION_SHIFT)
#define SUPERSECTION_MASK	(~(SUPERSECTION_SIZE-1))

/*
 * Hardware page table definitions.
 *
 * + Level 1 descriptor (PMD)
 *   - common
 */
#define PMD_TYPE_MASK		(3 << 0)
#define PMD_TYPE_FAULT		(0 << 0)
#define PMD_TYPE_TABLE		(1 << 0)
#define PMD_TYPE_SECT		(2 << 0)
#define PMD_BIT4		(1 << 4)
#define PMD_DOMAIN(x)		((x) << 5)
#define PMD_PROTECTION		(1 << 9)	/* v5 */
/*
 *   - section
 */
#define PMD_SECT_BUFFERABLE	(1 << 2)
#define PMD_SECT_CACHEABLE	(1 << 3)
#define PMD_SECT_AP_WRITE	(1 << 10)
#define PMD_SECT_AP_READ	(1 << 11)
#define PMD_SECT_TEX(x)		((x) << 12)	/* v5 */
#define PMD_SECT_APX		(1 << 15)	/* v6 */
#define PMD_SECT_S		(1 << 16)	/* v6 */
#define PMD_SECT_nG		(1 << 17)	/* v6 */
#define PMD_SECT_SUPER		(1 << 18)	/* v6 */

#define PMD_SECT_UNCACHED	(0)
#define PMD_SECT_BUFFERED	(PMD_SECT_BUFFERABLE)
#define PMD_SECT_WT		(PMD_SECT_CACHEABLE)
#define PMD_SECT_WB		(PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
#define PMD_SECT_MINICACHE	(PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE)
#define PMD_SECT_WBWA		(PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
#define PMD_SECT_NONSHARED_DEV	(PMD_SECT_TEX(2))

/*
 *   - coarse table (not used)
 */

/*
 * + Level 2 descriptor (PTE)
 *   - common
 */
#define PTE_TYPE_MASK		(3 << 0)
#define PTE_TYPE_FAULT		(0 << 0)
#define PTE_TYPE_LARGE		(1 << 0)
#define PTE_TYPE_SMALL		(2 << 0)
#define PTE_TYPE_EXT		(3 << 0)	/* v5 */
#define PTE_BUFFERABLE		(1 << 2)
#define PTE_CACHEABLE		(1 << 3)

/*
 *   - extended small page/tiny page
 */
#define PTE_EXT_XN		(1 << 0)	/* v6 */
#define PTE_EXT_AP_MASK		(3 << 4)
#define PTE_EXT_AP0		(1 << 4)
#define PTE_EXT_AP1		(2 << 4)
#define PTE_EXT_AP_UNO_SRO	(0 << 4)
#define PTE_EXT_AP_UNO_SRW	(PTE_EXT_AP0)
#define PTE_EXT_AP_URO_SRW	(PTE_EXT_AP1)
#define PTE_EXT_AP_URW_SRW	(PTE_EXT_AP1|PTE_EXT_AP0)
#define PTE_EXT_TEX(x)		((x) << 6)	/* v5 */
#define PTE_EXT_APX		(1 << 9)	/* v6 */
#define PTE_EXT_SHARED		(1 << 10)	/* v6 */
#define PTE_EXT_NG		(1 << 11)	/* v6 */

/*
 *   - small page
 */
#define PTE_SMALL_AP_MASK	(0xff << 4)
#define PTE_SMALL_AP_UNO_SRO	(0x00 << 4)
#define PTE_SMALL_AP_UNO_SRW	(0x55 << 4)
#define PTE_SMALL_AP_URO_SRW	(0xaa << 4)
#define PTE_SMALL_AP_URW_SRW	(0xff << 4)

/*
 * "Linux" PTE definitions.
 *
 * We keep two sets of PTEs - the hardware and the linux version.
 * This allows greater flexibility in the way we map the Linux bits
 * onto the hardware tables, and allows us to have YOUNG and DIRTY
 * bits.
 *
 * The PTE table pointer refers to the hardware entries; the "Linux"
 * entries are stored 1024 bytes below.
 */
#define L_PTE_PRESENT		(1 << 0)
#define L_PTE_FILE		(1 << 1)	/* only when !PRESENT */
#define L_PTE_YOUNG		(1 << 1)
#define L_PTE_BUFFERABLE	(1 << 2)	/* matches PTE */
#define L_PTE_CACHEABLE		(1 << 3)	/* matches PTE */
#define L_PTE_USER		(1 << 4)
#define L_PTE_WRITE		(1 << 5)
#define L_PTE_EXEC		(1 << 6)
#define L_PTE_DIRTY		(1 << 7)
#define L_PTE_SHARED		(1 << 10)	/* shared between CPUs (v6) */
#define L_PTE_ASID		(1 << 11)	/* non-global (use ASID, v6) */

#ifndef __ASSEMBLY__

#include <asm/domain.h>

#define _PAGE_USER_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
#define _PAGE_KERNEL_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))

/*
 * The following macros handle the cache and bufferable bits...
 */
#define _L_PTE_DEFAULT	L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_CACHEABLE | L_PTE_BUFFERABLE
#define _L_PTE_READ	L_PTE_USER | L_PTE_EXEC

extern pgprot_t		pgprot_kernel;

#define PAGE_NONE       __pgprot(_L_PTE_DEFAULT)
#define PAGE_COPY       __pgprot(_L_PTE_DEFAULT | _L_PTE_READ)
#define PAGE_SHARED     __pgprot(_L_PTE_DEFAULT | _L_PTE_READ | L_PTE_WRITE)
#define PAGE_READONLY   __pgprot(_L_PTE_DEFAULT | _L_PTE_READ)
#define PAGE_KERNEL	pgprot_kernel

#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 most ARM 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
#define __P101  PAGE_READONLY
#define __P110  PAGE_COPY
#define __P111  PAGE_COPY

#define __S000  PAGE_NONE
#define __S001  PAGE_READONLY
#define __S010  PAGE_SHARED
#define __S011  PAGE_SHARED
#define __S100  PAGE_READONLY
#define __S101  PAGE_READONLY
#define __S110  PAGE_SHARED
#define __S111  PAGE_SHARED

#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_at((mm),(addr),(ptep), __pte(0))
#define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
#define pte_offset_kernel(dir,addr)	(pmd_page_kernel(*(dir)) + __pte_index(addr))
#define pte_offset_map(dir,addr)	(pmd_page_kernel(*(dir)) + __pte_index(addr))
#define pte_offset_map_nested(dir,addr)	(pmd_page_kernel(*(dir)) + __pte_index(addr))
#define pte_unmap(pte)		do { } while (0)
#define pte_unmap_nested(pte)	do { } while (0)

#define set_pte(ptep, pte)	cpu_set_pte(ptep,pte)
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
#define pte_present(pte)	(pte_val(pte) & L_PTE_PRESENT)
#define pte_read(pte)		(pte_val(pte) & L_PTE_USER)
#define pte_write(pte)		(pte_val(pte) & L_PTE_WRITE)
#define pte_exec(pte)		(pte_val(pte) & L_PTE_EXEC)
#define pte_dirty(pte)		(pte_val(pte) & L_PTE_DIRTY)
#define pte_young(pte)		(pte_val(pte) & L_PTE_YOUNG)

/*
 * The following only works if pte_present() is not true.
 */
#define pte_file(pte)		(pte_val(pte) & L_PTE_FILE)
#define pte_to_pgoff(x)		(pte_val(x) >> 2)
#define pgoff_to_pte(x)		__pte(((x) << 2) | L_PTE_FILE)

#define PTE_FILE_MAX_BITS	30

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

/*PTE_BIT_FUNC(rdprotect, &= ~L_PTE_USER);*/
/*PTE_BIT_FUNC(mkread,    |= L_PTE_USER);*/
PTE_BIT_FUNC(wrprotect, &= ~L_PTE_WRITE);
PTE_BIT_FUNC(mkwrite,   |= L_PTE_WRITE);
PTE_BIT_FUNC(exprotect, &= ~L_PTE_EXEC);
PTE_BIT_FUNC(mkexec,    |= L_PTE_EXEC);
PTE_BIT_FUNC(mkclean,   &= ~L_PTE_DIRTY);
PTE_BIT_FUNC(mkdirty,   |= L_PTE_DIRTY);
PTE_BIT_FUNC(mkold,     &= ~L_PTE_YOUNG);
PTE_BIT_FUNC(mkyoung,   |= L_PTE_YOUNG);

/*
 * Mark the prot value as uncacheable and unbufferable.
 */
#define pgprot_noncached(prot)	__pgprot(pgprot_val(prot) & ~(L_PTE_CACHEABLE | L_PTE_BUFFERABLE))
#define pgprot_writecombine(prot) __pgprot(pgprot_val(prot) & ~L_PTE_CACHEABLE)

#define pmd_none(pmd)		(!pmd_val(pmd))
#define pmd_present(pmd)	(pmd_val(pmd))
#define pmd_bad(pmd)		(pmd_val(pmd) & 2)

#define copy_pmd(pmdpd,pmdps)		\
	do {				\
		pmdpd[0] = pmdps[0];	\
		pmdpd[1] = pmdps[1];	\
		flush_pmd_entry(pmdpd);	\
	} while (0)

#define pmd_clear(pmdp)			\
	do {				\
		pmdp[0] = __pmd(0);	\
		pmdp[1] = __pmd(0);	\
		clean_pmd_entry(pmdp);	\
	} while (0)

static inline pte_t *pmd_page_kernel(pmd_t pmd)
{
	unsigned long ptr;

	ptr = pmd_val(pmd) & ~(PTRS_PER_PTE * sizeof(void *) - 1);
	ptr += PTRS_PER_PTE * sizeof(void *);

	return __va(ptr);
}

#define pmd_page(pmd) virt_to_page(__va(pmd_val(pmd)))

/*
 * Permanent address of a page. We never have highmem, so this is trivial.
 */
#define pages_to_mb(x)		((x) >> (20 - PAGE_SHIFT))

/*
 * 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)

/*
 * The "pgd_xxx()" functions here are trivial for a folded two-level
 * setup: the pgd is never bad, and a pmd always exists (as it's folded
 * into the pgd entry)
 */
#define pgd_none(pgd)		(0)
#define pgd_bad(pgd)		(0)
#define pgd_present(pgd)	(1)
#define pgd_clear(pgdp)		do { } while (0)
#define set_pgd(pgd,pgdp)	do { } while (0)

/* 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 second-level page table.. */
#define pmd_offset(dir, addr)	((pmd_t *)(dir))

/* 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 = L_PTE_EXEC | L_PTE_WRITE | L_PTE_USER;
	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.
 *
 * We support up to 32GB of swap on 4k machines
 */
#define __swp_type(x)		(((x).val >> 2) & 0x7f)
#define __swp_offset(x)		((x).val >> 9)
#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 2) | ((offset) << 9) })
#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })

/* 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>

/*
 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
 */
#define HAVE_ARCH_UNMAPPED_AREA

/*
 * remap a physical page `pfn' of size `size' with page protection `prot'
 * into virtual address `from'
 */
#define io_remap_pfn_range(vma,from,pfn,size,prot) \
		remap_pfn_range(vma, from, pfn, size, prot)

#define MK_IOSPACE_PFN(space, pfn)	(pfn)
#define GET_IOSPACE(pfn)		0
#define GET_PFN(pfn)			(pfn)

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

#endif /* !__ASSEMBLY__ */

#endif /* _ASMARM_PGTABLE_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/include/asm-arm/pgtable.h
	3	*
	4	* Copyright (C) 1995-2002 Russell King
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10	#ifndef _ASMARM_PGTABLE_H
	11	#define _ASMARM_PGTABLE_H
	12
	13	#include <asm-generic/4level-fixup.h>
	14
	15	#include <asm/memory.h>
	16	#include <asm/proc-fns.h>
	17	#include <asm/arch/vmalloc.h>
	18
5c3073e6 RK	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 (810241024)
	33	#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
	34	#endif
	35
1da177e4 LT	36	/*
	37	* Hardware-wise, we have a two level page table structure, where the first
	38	* level has 4096 entries, and the second level has 256 entries. Each entry
	39	* is one 32-bit word. Most of the bits in the second level entry are used
	40	* by hardware, and there aren't any "accessed" and "dirty" bits.
	41	*
	42	* Linux on the other hand has a three level page table structure, which can
	43	* be wrapped to fit a two level page table structure easily - using the PGD
	44	* and PTE only. However, Linux also expects one "PTE" table per page, and
	45	* at least a "dirty" bit.
	46	*
	47	* Therefore, we tweak the implementation slightly - we tell Linux that we
	48	* have 2048 entries in the first level, each of which is 8 bytes (iow, two
	49	* hardware pointers to the second level.) The second level contains two
	50	* hardware PTE tables arranged contiguously, followed by Linux versions
	51	* which contain the state information Linux needs. We, therefore, end up
	52	* with 512 entries in the "PTE" level.
	53	*
	54	* This leads to the page tables having the following layout:
	55	*
	56	* pgd pte
	57	* \| \|
	58	* +--------+ +0
	59	* \| \|-----> +------------+ +0
	60	* +- - - - + +4 \| h/w pt 0 \|
	61	* \| \|-----> +------------+ +1024
	62	* +--------+ +8 \| h/w pt 1 \|
	63	* \| \| +------------+ +2048
	64	* +- - - - + \| Linux pt 0 \|
	65	* \| \| +------------+ +3072
	66	* +--------+ \| Linux pt 1 \|
	67	* \| \| +------------+ +4096
	68	*
	69	* See L_PTE_xxx below for definitions of bits in the "Linux pt", and
	70	* PTE_xxx for definitions of bits appearing in the "h/w pt".
	71	*
	72	* PMD_xxx definitions refer to bits in the first level page table.
	73	*
	74	* The "dirty" bit is emulated by only granting hardware write permission
	75	* iff the page is marked "writable" and "dirty" in the Linux PTE. This
	76	* means that a write to a clean page will cause a permission fault, and
	77	* the Linux MM layer will mark the page dirty via handle_pte_fault().
	78	* For the hardware to notice the permission change, the TLB entry must
	79	* be flushed, and ptep_establish() does that for us.
	80	*
	81	* The "accessed" or "young" bit is emulated by a similar method; we only
	82	* allow accesses to the page if the "young" bit is set. Accesses to the
	83	* page will cause a fault, and handle_pte_fault() will set the young bit
	84	* for us as long as the page is marked present in the corresponding Linux
	85	* PTE entry. Again, ptep_establish() will ensure that the TLB is up to
	86	* date.
	87	*
	88	* However, when the "young" bit is cleared, we deny access to the page
	89	* by clearing the hardware PTE. Currently Linux does not flush the TLB
	90	* for us in this case, which means the TLB will retain the transation
	91	* until either the TLB entry is evicted under pressure, or a context
	92	* switch which changes the user space mapping occurs.
	93	*/
	94	#define PTRS_PER_PTE 512
	95	#define PTRS_PER_PMD 1
	96	#define PTRS_PER_PGD 2048
	97
	98	/*
	99	* PMD_SHIFT determines the size of the area a second-level page table can map
100	* PGDIR_SHIFT determines what a third-level page table entry can map
101	*/
102	#define PMD_SHIFT 21
103	#define PGDIR_SHIFT 21
104
105	#define LIBRARY_TEXT_START 0x0c000000
106
107	#ifndef __ASSEMBLY__
108	extern void __pte_error(const char *file, int line, unsigned long val);
109	extern void __pmd_error(const char *file, int line, unsigned long val);
110	extern void __pgd_error(const char *file, int line, unsigned long val);
111
112	#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte_val(pte))
113	#define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd_val(pmd))
114	#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
115	#endif /* !__ASSEMBLY__ */
116
117	#define PMD_SIZE (1UL << PMD_SHIFT)
118	#define PMD_MASK (~(PMD_SIZE-1))
119	#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
120	#define PGDIR_MASK (~(PGDIR_SIZE-1))
121
6119be0b HD	122	/*
	123	* This is the lowest virtual address we can permit any user space
	124	* mapping to be mapped at. This is particularly important for
	125	* non-high vector CPUs.
	126	*/
	127	#define FIRST_USER_ADDRESS PAGE_SIZE
	128
1da177e4 LT	129	#define FIRST_USER_PGD_NR 1
	130	#define USER_PTRS_PER_PGD ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
	131
	132	/*
	133	* ARMv6 supersection address mask and size definitions.
	134	*/
	135	#define SUPERSECTION_SHIFT 24
	136	#define SUPERSECTION_SIZE (1UL << SUPERSECTION_SHIFT)
	137	#define SUPERSECTION_MASK (~(SUPERSECTION_SIZE-1))
	138
	139	/*
	140	* Hardware page table definitions.
	141	*
	142	* + Level 1 descriptor (PMD)
	143	* - common
	144	*/
	145	#define PMD_TYPE_MASK (3 << 0)
	146	#define PMD_TYPE_FAULT (0 << 0)
	147	#define PMD_TYPE_TABLE (1 << 0)
	148	#define PMD_TYPE_SECT (2 << 0)
	149	#define PMD_BIT4 (1 << 4)
	150	#define PMD_DOMAIN(x) ((x) << 5)
	151	#define PMD_PROTECTION (1 << 9) /* v5 */
	152	/*
	153	* - section
	154	*/
	155	#define PMD_SECT_BUFFERABLE (1 << 2)
	156	#define PMD_SECT_CACHEABLE (1 << 3)
	157	#define PMD_SECT_AP_WRITE (1 << 10)
	158	#define PMD_SECT_AP_READ (1 << 11)
	159	#define PMD_SECT_TEX(x) ((x) << 12) /* v5 */
	160	#define PMD_SECT_APX (1 << 15) /* v6 */
	161	#define PMD_SECT_S (1 << 16) /* v6 */
	162	#define PMD_SECT_nG (1 << 17) /* v6 */
	163	#define PMD_SECT_SUPER (1 << 18) /* v6 */
	164
	165	#define PMD_SECT_UNCACHED (0)
	166	#define PMD_SECT_BUFFERED (PMD_SECT_BUFFERABLE)
	167	#define PMD_SECT_WT (PMD_SECT_CACHEABLE)
	168	#define PMD_SECT_WB (PMD_SECT_CACHEABLE \| PMD_SECT_BUFFERABLE)
	169	#define PMD_SECT_MINICACHE (PMD_SECT_TEX(1) \| PMD_SECT_CACHEABLE)
	170	#define PMD_SECT_WBWA (PMD_SECT_TEX(1) \| PMD_SECT_CACHEABLE \| PMD_SECT_BUFFERABLE)
7efb8300	171	#define PMD_SECT_NONSHARED_DEV (PMD_SECT_TEX(2))
1da177e4 LT	172
	173	/*
	174	* - coarse table (not used)
	175	*/
	176
	177	/*
	178	* + Level 2 descriptor (PTE)
	179	* - common
	180	*/
	181	#define PTE_TYPE_MASK (3 << 0)
	182	#define PTE_TYPE_FAULT (0 << 0)
	183	#define PTE_TYPE_LARGE (1 << 0)
	184	#define PTE_TYPE_SMALL (2 << 0)
	185	#define PTE_TYPE_EXT (3 << 0) /* v5 */
	186	#define PTE_BUFFERABLE (1 << 2)
	187	#define PTE_CACHEABLE (1 << 3)
	188
	189	/*
	190	* - extended small page/tiny page
	191	*/
1b9749e7	192	#define PTE_EXT_XN (1 << 0) /* v6 */
1da177e4	193	#define PTE_EXT_AP_MASK (3 << 4)
1b9749e7 RK	194	#define PTE_EXT_AP0 (1 << 4)
1b9749e7 RK	195	#define PTE_EXT_AP1 (2 << 4)
1da177e4	196	#define PTE_EXT_AP_UNO_SRO (0 << 4)
1b9749e7 RK	197	#define PTE_EXT_AP_UNO_SRW (PTE_EXT_AP0)
	198	#define PTE_EXT_AP_URO_SRW (PTE_EXT_AP1)
	199	#define PTE_EXT_AP_URW_SRW (PTE_EXT_AP1\|PTE_EXT_AP0)
1da177e4	200	#define PTE_EXT_TEX(x) ((x) << 6) /* v5 */
1b9749e7 RK	201	#define PTE_EXT_APX (1 << 9) /* v6 */
	202	#define PTE_EXT_SHARED (1 << 10) /* v6 */
	203	#define PTE_EXT_NG (1 << 11) /* v6 */
1da177e4 LT	204
	205	/*
	206	* - small page
	207	*/
	208	#define PTE_SMALL_AP_MASK (0xff << 4)
	209	#define PTE_SMALL_AP_UNO_SRO (0x00 << 4)
	210	#define PTE_SMALL_AP_UNO_SRW (0x55 << 4)
	211	#define PTE_SMALL_AP_URO_SRW (0xaa << 4)
	212	#define PTE_SMALL_AP_URW_SRW (0xff << 4)
	213
	214	/*
	215	* "Linux" PTE definitions.
	216	*
	217	* We keep two sets of PTEs - the hardware and the linux version.
	218	* This allows greater flexibility in the way we map the Linux bits
	219	* onto the hardware tables, and allows us to have YOUNG and DIRTY
	220	* bits.
	221	*
	222	* The PTE table pointer refers to the hardware entries; the "Linux"
	223	* entries are stored 1024 bytes below.
	224	*/
	225	#define L_PTE_PRESENT (1 << 0)
	226	#define L_PTE_FILE (1 << 1) /* only when !PRESENT */
	227	#define L_PTE_YOUNG (1 << 1)
	228	#define L_PTE_BUFFERABLE (1 << 2) /* matches PTE */
	229	#define L_PTE_CACHEABLE (1 << 3) /* matches PTE */
	230	#define L_PTE_USER (1 << 4)
	231	#define L_PTE_WRITE (1 << 5)
	232	#define L_PTE_EXEC (1 << 6)
	233	#define L_PTE_DIRTY (1 << 7)
6626a707 RK	234	#define L_PTE_SHARED (1 << 10) /* shared between CPUs (v6) */
6626a707 RK	235	#define L_PTE_ASID (1 << 11) /* non-global (use ASID, v6) */
1da177e4 LT	236
	237	#ifndef __ASSEMBLY__
	238
	239	#include <asm/domain.h>
	240
	241	#define _PAGE_USER_TABLE (PMD_TYPE_TABLE \| PMD_BIT4 \| PMD_DOMAIN(DOMAIN_USER))
	242	#define _PAGE_KERNEL_TABLE (PMD_TYPE_TABLE \| PMD_BIT4 \| PMD_DOMAIN(DOMAIN_KERNEL))
	243
	244	/*
	245	* The following macros handle the cache and bufferable bits...
	246	*/
	247	#define _L_PTE_DEFAULT L_PTE_PRESENT \| L_PTE_YOUNG \| L_PTE_CACHEABLE \| L_PTE_BUFFERABLE
	248	#define _L_PTE_READ L_PTE_USER \| L_PTE_EXEC
	249
	250	extern pgprot_t pgprot_kernel;
	251
	252	#define PAGE_NONE __pgprot(_L_PTE_DEFAULT)
	253	#define PAGE_COPY __pgprot(_L_PTE_DEFAULT \| _L_PTE_READ)
	254	#define PAGE_SHARED __pgprot(_L_PTE_DEFAULT \| _L_PTE_READ \| L_PTE_WRITE)
	255	#define PAGE_READONLY __pgprot(_L_PTE_DEFAULT \| _L_PTE_READ)
	256	#define PAGE_KERNEL pgprot_kernel
	257
	258	#endif /* __ASSEMBLY__ */
	259
	260	/*
	261	* The table below defines the page protection levels that we insert into our
	262	* Linux page table version. These get translated into the best that the
	263	* architecture can perform. Note that on most ARM hardware:
	264	* 1) We cannot do execute protection
	265	* 2) If we could do execute protection, then read is implied
	266	* 3) write implies read permissions
	267	*/
	268	#define __P000 PAGE_NONE
	269	#define __P001 PAGE_READONLY
	270	#define __P010 PAGE_COPY
	271	#define __P011 PAGE_COPY
	272	#define __P100 PAGE_READONLY
	273	#define __P101 PAGE_READONLY
	274	#define __P110 PAGE_COPY
	275	#define __P111 PAGE_COPY
	276
	277	#define __S000 PAGE_NONE
	278	#define __S001 PAGE_READONLY
	279	#define __S010 PAGE_SHARED
	280	#define __S011 PAGE_SHARED
	281	#define __S100 PAGE_READONLY
	282	#define __S101 PAGE_READONLY
	283	#define __S110 PAGE_SHARED
	284	#define __S111 PAGE_SHARED
	285
	286	#ifndef __ASSEMBLY__
	287	/*
	288	* ZERO_PAGE is a global shared page that is always zero: used
	289	* for zero-mapped memory areas etc..
	290	*/
	291	extern struct page *empty_zero_page;
	292	#define ZERO_PAGE(vaddr) (empty_zero_page)
	293
	294	#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
	295	#define pfn_pte(pfn,prot) (__pte(((pfn) << PAGE_SHIFT) \| pgprot_val(prot)))
	296
	297	#define pte_none(pte) (!pte_val(pte))
	298	#define pte_clear(mm,addr,ptep) set_pte_at((mm),(addr),(ptep), __pte(0))
	299	#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
300	#define pte_offset_kernel(dir,addr) (pmd_page_kernel(*(dir)) + __pte_index(addr))
301	#define pte_offset_map(dir,addr) (pmd_page_kernel(*(dir)) + __pte_index(addr))
302	#define pte_offset_map_nested(dir,addr) (pmd_page_kernel(*(dir)) + __pte_index(addr))
303	#define pte_unmap(pte) do { } while (0)
304	#define pte_unmap_nested(pte) do { } while (0)
305
306	#define set_pte(ptep, pte) cpu_set_pte(ptep,pte)
307	#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
308
309	/*
310	* The following only work if pte_present() is true.
311	* Undefined behaviour if not..
312	*/
313	#define pte_present(pte) (pte_val(pte) & L_PTE_PRESENT)
314	#define pte_read(pte) (pte_val(pte) & L_PTE_USER)
315	#define pte_write(pte) (pte_val(pte) & L_PTE_WRITE)
316	#define pte_exec(pte) (pte_val(pte) & L_PTE_EXEC)
317	#define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY)
318	#define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG)
319
320	/*
321	* The following only works if pte_present() is not true.
322	*/
323	#define pte_file(pte) (pte_val(pte) & L_PTE_FILE)
324	#define pte_to_pgoff(x) (pte_val(x) >> 2)
325	#define pgoff_to_pte(x) __pte(((x) << 2) \| L_PTE_FILE)
326
327	#define PTE_FILE_MAX_BITS 30
328
329	#define PTE_BIT_FUNC(fn,op) \
330	static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
331
332	/PTE_BIT_FUNC(rdprotect, &= ~L_PTE_USER);/
333	/PTE_BIT_FUNC(mkread, \|= L_PTE_USER);/
334	PTE_BIT_FUNC(wrprotect, &= ~L_PTE_WRITE);
335	PTE_BIT_FUNC(mkwrite, \|= L_PTE_WRITE);
336	PTE_BIT_FUNC(exprotect, &= ~L_PTE_EXEC);
337	PTE_BIT_FUNC(mkexec, \|= L_PTE_EXEC);
338	PTE_BIT_FUNC(mkclean, &= ~L_PTE_DIRTY);
339	PTE_BIT_FUNC(mkdirty, \|= L_PTE_DIRTY);
340	PTE_BIT_FUNC(mkold, &= ~L_PTE_YOUNG);
341	PTE_BIT_FUNC(mkyoung, \|= L_PTE_YOUNG);
342
343	/*
344	* Mark the prot value as uncacheable and unbufferable.
345	*/
346	#define pgprot_noncached(prot) __pgprot(pgprot_val(prot) & ~(L_PTE_CACHEABLE \| L_PTE_BUFFERABLE))
347	#define pgprot_writecombine(prot) __pgprot(pgprot_val(prot) & ~L_PTE_CACHEABLE)
348
349	#define pmd_none(pmd) (!pmd_val(pmd))
350	#define pmd_present(pmd) (pmd_val(pmd))
351	#define pmd_bad(pmd) (pmd_val(pmd) & 2)
352
353	#define copy_pmd(pmdpd,pmdps) \
354	do { \
355	pmdpd[0] = pmdps[0]; \
356	pmdpd[1] = pmdps[1]; \
357	flush_pmd_entry(pmdpd); \
358	} while (0)
359
360	#define pmd_clear(pmdp) \
361	do { \
362	pmdp[0] = __pmd(0); \
363	pmdp[1] = __pmd(0); \
364	clean_pmd_entry(pmdp); \
365	} while (0)
366
367	static inline pte_t *pmd_page_kernel(pmd_t pmd)
368	{
369	unsigned long ptr;
370
371	ptr = pmd_val(pmd) & ~(PTRS_PER_PTE * sizeof(void *) - 1);
372	ptr += PTRS_PER_PTE * sizeof(void *);
373
374	return __va(ptr);
375	}
376
377	#define pmd_page(pmd) virt_to_page(__va(pmd_val(pmd)))
378
379	/*
380	* Permanent address of a page. We never have highmem, so this is trivial.
381	*/
382	#define pages_to_mb(x) ((x) >> (20 - PAGE_SHIFT))
383
384	/*
385	* Conversion functions: convert a page and protection to a page entry,
386	* and a page entry and page directory to the page they refer to.
387	*/
388	#define mk_pte(page,prot) pfn_pte(page_to_pfn(page),prot)
389
390	/*
391	* The "pgd_xxx()" functions here are trivial for a folded two-level
392	* setup: the pgd is never bad, and a pmd always exists (as it's folded
393	* into the pgd entry)
394	*/
395	#define pgd_none(pgd) (0)
396	#define pgd_bad(pgd) (0)
397	#define pgd_present(pgd) (1)
398	#define pgd_clear(pgdp) do { } while (0)
399	#define set_pgd(pgd,pgdp) do { } while (0)
400
1da177e4 LT	401	/* to find an entry in a page-table-directory */
	402	#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
	403
	404	#define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr))
	405
	406	/* to find an entry in a kernel page-table-directory */
	407	#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
	408
	409	/* Find an entry in the second-level page table.. */
	410	#define pmd_offset(dir, addr) ((pmd_t *)(dir))
	411
	412	/* Find an entry in the third-level page table.. */
	413	#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
	414
	415	static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
	416	{
	417	const unsigned long mask = L_PTE_EXEC \| L_PTE_WRITE \| L_PTE_USER;
	418	pte_val(pte) = (pte_val(pte) & ~mask) \| (pgprot_val(newprot) & mask);
	419	return pte;
	420	}
	421
	422	extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
	423
	424	/* Encode and decode a swap entry.
	425	*
	426	* We support up to 32GB of swap on 4k machines
	427	*/
	428	#define __swp_type(x) (((x).val >> 2) & 0x7f)
	429	#define __swp_offset(x) ((x).val >> 9)
	430	#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 2) \| ((offset) << 9) })
	431	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
	432	#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
	433
	434	/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
	435	/* FIXME: this is not correct */
	436	#define kern_addr_valid(addr) (1)
	437
	438	#include <asm-generic/pgtable.h>
	439
	440	/*
	441	* We provide our own arch_get_unmapped_area to cope with VIPT caches.
	442	*/
	443	#define HAVE_ARCH_UNMAPPED_AREA
	444
	445	/*
33bf5610	446	* remap a physical page `pfn' of size `size' with page protection `prot'
1da177e4 LT	447	* into virtual address `from'
1da177e4 LT	448	*/
1da177e4 LT	449	#define io_remap_pfn_range(vma,from,pfn,size,prot) \
	450	remap_pfn_range(vma, from, pfn, size, prot)
	451
	452	#define MK_IOSPACE_PFN(space, pfn) (pfn)
	453	#define GET_IOSPACE(pfn) 0
	454	#define GET_PFN(pfn) (pfn)
	455
	456	#define pgtable_cache_init() do { } while (0)
	457
	458	#endif /* !__ASSEMBLY__ */
	459
	460	#endif /* _ASMARM_PGTABLE_H */