arch/arm/include/asm/pgtable.h

Source file repositories/reference/linux-study-clean/arch/arm/include/asm/pgtable.h

File Facts

System
Linux kernel
Corpus path
arch/arm/include/asm/pgtable.h
Extension
.h
Size
10088 bytes
Lines
328
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ASMARM_PGTABLE_H
#define _ASMARM_PGTABLE_H

#include <linux/const.h>
#include <asm/proc-fns.h>

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

#ifndef CONFIG_MMU
#include <asm/pgtable-nommu.h>

#else

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


#include <asm/tlbflush.h>

#ifdef CONFIG_ARM_LPAE
#include <asm/pgtable-3level.h>
#else
#include <asm/pgtable-2level.h>
#endif

/*
 * 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. ;)
 */
#define VMALLOC_OFFSET		(8*1024*1024)
#define VMALLOC_START		(((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
#define VMALLOC_END		0xff800000UL

#define LIBRARY_TEXT_START	0x0c000000

#ifndef __ASSEMBLY__
extern void __pte_error(const char *file, int line, pte_t);
extern void __pmd_error(const char *file, int line, pmd_t);
extern void __pgd_error(const char *file, int line, pgd_t);

#define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte)
#define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd)
#define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd)

/*
 * 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 * 2)

/*
 * Use TASK_SIZE as the ceiling argument for free_pgtables() and
 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
 * page shared between user and kernel).
 */
#ifdef CONFIG_ARM_LPAE
#define USER_PGTABLES_CEILING	TASK_SIZE
#endif

/*
 * The pgprot_* and protection_map entries will be fixed up in runtime
 * to include the cachable and bufferable bits based on memory policy,
 * as well as any architecture dependent bits like global/ASID and SMP
 * shared mapping bits.
 */
#define _L_PTE_DEFAULT	L_PTE_PRESENT | L_PTE_YOUNG

extern pgprot_t		pgprot_user;
extern pgprot_t		pgprot_kernel;

#define _MOD_PROT(p, b)	__pgprot(pgprot_val(p) | (b))

#define PAGE_NONE		_MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE)
#define PAGE_SHARED		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
#define PAGE_SHARED_EXEC	_MOD_PROT(pgprot_user, L_PTE_USER)
#define PAGE_COPY		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
#define PAGE_COPY_EXEC		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
#define PAGE_READONLY		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
#define PAGE_READONLY_EXEC	_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
#define PAGE_KERNEL		_MOD_PROT(pgprot_kernel, L_PTE_XN)
#define PAGE_KERNEL_EXEC	pgprot_kernel

#define __PAGE_NONE		__pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
#define __PAGE_SHARED		__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
#define __PAGE_SHARED_EXEC	__pgprot(_L_PTE_DEFAULT | L_PTE_USER)

Annotation

Implementation Notes