linux/arch/x86/include/asm/proto.h
H. Peter Anvin 4763ed4d45 x86, mm: Clean up and simplify NX enablement
The 32- and 64-bit code used very different mechanisms for enabling
NX, but even the 32-bit code was enabling NX in head_32.S if it is
available.  Furthermore, we had a bewildering collection of tests for
the available of NX.

This patch:

a) merges the 32-bit set_nx() and the 64-bit check_efer() function
   into a single x86_configure_nx() function.  EFER control is left
   to the head code.

b) eliminates the nx_enabled variable entirely.  Things that need to
   test for NX enablement can verify __supported_pte_mask directly,
   and cpu_has_nx gives the supported status of NX.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Chris Wright <chrisw@sous-sol.org>
LKML-Reference: <1258154897-6770-5-git-send-email-hpa@zytor.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
2009-11-16 13:44:59 -08:00

36 lines
919 B
C

#ifndef _ASM_X86_PROTO_H
#define _ASM_X86_PROTO_H
#include <asm/ldt.h>
/* misc architecture specific prototypes */
extern void early_idt_handler(void);
extern void system_call(void);
extern void syscall_init(void);
extern void ia32_syscall(void);
extern void ia32_cstar_target(void);
extern void ia32_sysenter_target(void);
extern void syscall32_cpu_init(void);
extern void x86_configure_nx(void);
extern int reboot_force;
long do_arch_prctl(struct task_struct *task, int code, unsigned long addr);
/*
* This looks more complex than it should be. But we need to
* get the type for the ~ right in round_down (it needs to be
* as wide as the result!), and we want to evaluate the macro
* arguments just once each.
*/
#define __round_mask(x,y) ((__typeof__(x))((y)-1))
#define round_up(x,y) ((((x)-1) | __round_mask(x,y))+1)
#define round_down(x,y) ((x) & ~__round_mask(x,y))
#endif /* _ASM_X86_PROTO_H */