linux/include/asm-arm/page.h
Nicolas Pitre da2b1cd619 [ARM] 3101/1: ARM EABI: slab memory must be 64-bit aligned
Patch from Nicolas Pitre

Although ARM is still using 32-bit pointers, version 5 and later
versions of the ARM architecture introduced the ldrd and strd
instructions to move 64-bit data which must be 64-bit aligned in memory,
and the EABI includes new constraints on structure data alignment to
allow for the compiler to use those instructions. This means that any
slab allocation must start on a 64-bit boundary which is not equivalent
to BYTES_PER_WORD, especially on those architecture versions that
implements the ldrd/strd instructions.

Overriding the default alignment disables some slab debug features. If
those debug features are really needed then the kernel will have to be
compiled for version 4 of the ARM architecture.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-14 16:18:07 +00:00

185 lines
4.1 KiB
C

/*
* linux/include/asm-arm/page.h
*
* Copyright (C) 1995-2003 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_PAGE_H
#define _ASMARM_PAGE_H
#include <linux/config.h>
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT 12
#define PAGE_SIZE (1UL << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#ifdef __KERNEL__
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)
#ifndef __ASSEMBLY__
#include <asm/glue.h>
/*
* User Space Model
* ================
*
* This section selects the correct set of functions for dealing with
* page-based copying and clearing for user space for the particular
* processor(s) we're building for.
*
* We have the following to choose from:
* v3 - ARMv3
* v4wt - ARMv4 with writethrough cache, without minicache
* v4wb - ARMv4 with writeback cache, without minicache
* v4_mc - ARMv4 with minicache
* xscale - Xscale
*/
#undef _USER
#undef MULTI_USER
#ifdef CONFIG_CPU_COPY_V3
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER v3
# endif
#endif
#ifdef CONFIG_CPU_COPY_V4WT
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER v4wt
# endif
#endif
#ifdef CONFIG_CPU_COPY_V4WB
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER v4wb
# endif
#endif
#ifdef CONFIG_CPU_SA1100
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER v4_mc
# endif
#endif
#ifdef CONFIG_CPU_XSCALE
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER xscale_mc
# endif
#endif
#ifdef CONFIG_CPU_COPY_V6
# define MULTI_USER 1
#endif
#if !defined(_USER) && !defined(MULTI_USER)
#error Unknown user operations model
#endif
struct cpu_user_fns {
void (*cpu_clear_user_page)(void *p, unsigned long user);
void (*cpu_copy_user_page)(void *to, const void *from,
unsigned long user);
};
#ifdef MULTI_USER
extern struct cpu_user_fns cpu_user;
#define __cpu_clear_user_page cpu_user.cpu_clear_user_page
#define __cpu_copy_user_page cpu_user.cpu_copy_user_page
#else
#define __cpu_clear_user_page __glue(_USER,_clear_user_page)
#define __cpu_copy_user_page __glue(_USER,_copy_user_page)
extern void __cpu_clear_user_page(void *p, unsigned long user);
extern void __cpu_copy_user_page(void *to, const void *from,
unsigned long user);
#endif
#define clear_user_page(addr,vaddr,pg) __cpu_clear_user_page(addr, vaddr)
#define copy_user_page(to,from,vaddr,pg) __cpu_copy_user_page(to, from, vaddr)
#define clear_page(page) memzero((void *)(page), PAGE_SIZE)
extern void copy_page(void *to, const void *from);
#undef STRICT_MM_TYPECHECKS
#ifdef STRICT_MM_TYPECHECKS
/*
* These are used to make use of C type-checking..
*/
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pgd[2]; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;
#define pte_val(x) ((x).pte)
#define pmd_val(x) ((x).pmd)
#define pgd_val(x) ((x).pgd[0])
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
#else
/*
* .. while these make it easier on the compiler
*/
typedef unsigned long pte_t;
typedef unsigned long pmd_t;
typedef unsigned long pgd_t[2];
typedef unsigned long pgprot_t;
#define pte_val(x) (x)
#define pmd_val(x) (x)
#define pgd_val(x) ((x)[0])
#define pgprot_val(x) (x)
#define __pte(x) (x)
#define __pmd(x) (x)
#define __pgprot(x) (x)
#endif /* STRICT_MM_TYPECHECKS */
/* the upper-most page table pointer */
extern pmd_t *top_pmd;
#include <asm/memory.h>
#endif /* !__ASSEMBLY__ */
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
/*
* With EABI on ARMv5 and above we must have 64-bit aligned slab pointers.
*/
#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
#define ARCH_SLAB_MINALIGN 8
#endif
#endif /* __KERNEL__ */
#include <asm-generic/page.h>
#endif