linux-stable/arch/m68k/include/asm/segment.h
Greg Ungerer feb1ee7595 m68k: use addr_limit checking for m68k CPUs that do no support address spaces
The ColdFire CPU family, and the original 68000, do not support separate
address spaces like the other 680x0 CPU types. Modify the set_fs()/get_fs()
functions and macros to use a thread_info addr_limit for address space
checking. This is pretty much what all other architectures that do not
support separate setable address spaces do.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>
2011-12-30 10:20:22 +10:00

65 lines
1.4 KiB
C

#ifndef _M68K_SEGMENT_H
#define _M68K_SEGMENT_H
/* define constants */
/* Address spaces (FC0-FC2) */
#define USER_DATA (1)
#ifndef __USER_DS
#define __USER_DS (USER_DATA)
#endif
#define USER_PROGRAM (2)
#define SUPER_DATA (5)
#ifndef __KERNEL_DS
#define __KERNEL_DS (SUPER_DATA)
#endif
#define SUPER_PROGRAM (6)
#define CPU_SPACE (7)
#ifndef __ASSEMBLY__
typedef struct {
unsigned long seg;
} mm_segment_t;
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
/*
* Get/set the SFC/DFC registers for MOVES instructions
*/
#define USER_DS MAKE_MM_SEG(__USER_DS)
#define KERNEL_DS MAKE_MM_SEG(__KERNEL_DS)
static inline mm_segment_t get_fs(void)
{
mm_segment_t _v;
__asm__ ("movec %/dfc,%0":"=r" (_v.seg):);
return _v;
}
static inline void set_fs(mm_segment_t val)
{
__asm__ __volatile__ ("movec %0,%/sfc\n\t"
"movec %0,%/dfc\n\t"
: /* no outputs */ : "r" (val.seg) : "memory");
}
static inline mm_segment_t get_ds(void)
{
/* return the supervisor data space code */
return KERNEL_DS;
}
#else
#define USER_DS MAKE_MM_SEG(TASK_SIZE)
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#endif
#define segment_eq(a,b) ((a).seg == (b).seg)
#endif /* __ASSEMBLY__ */
#endif /* _M68K_SEGMENT_H */