linux/arch/arm/include/asm/mmu.h
Nathan Lynch 1713ce7c43 ARM: 8329/1: miscellaneous vdso infrastructure, preparation
Define the layout of the data structure shared between kernel and
userspace.

Track the vdso address in the mm_context; needed for communicating
AT_SYSINFO_EHDR to the ELF loader.

Add declarations for arm_install_vdso; implementation is in a
following patch.

Define AT_SYSINFO_EHDR, and, if CONFIG_VDSO=y, report the vdso shared
object address via the ELF auxiliary vector.

Note - this adds the AT_SYSINFO_EHDR in a new user-visible header
asm/auxvec.h; this is consistent with other architectures.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-27 22:20:45 +00:00

41 lines
694 B
C

#ifndef __ARM_MMU_H
#define __ARM_MMU_H
#ifdef CONFIG_MMU
typedef struct {
#ifdef CONFIG_CPU_HAS_ASID
atomic64_t id;
#else
int switch_pending;
#endif
unsigned int vmalloc_seq;
unsigned long sigpage;
#ifdef CONFIG_VDSO
unsigned long vdso;
#endif
} mm_context_t;
#ifdef CONFIG_CPU_HAS_ASID
#define ASID_BITS 8
#define ASID_MASK ((~0ULL) << ASID_BITS)
#define ASID(mm) ((unsigned int)((mm)->context.id.counter & ~ASID_MASK))
#else
#define ASID(mm) (0)
#endif
#else
/*
* From nommu.h:
* Copyright (C) 2002, David McCullough <davidm@snapgear.com>
* modified for 2.6 by Hyok S. Choi <hyok.choi@samsung.com>
*/
typedef struct {
unsigned long end_brk;
} mm_context_t;
#endif
#endif