LXR linux/arch/x86/math-emu/fpu

   1/*---------------------------------------------------------------------------+
   2 |  fpu_system.h                                                             |
   3 |                                                                           |
   4 | Copyright (C) 1992,1994,1997                                              |
   5 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
   6 |                       Australia.  E-mail   billm@suburbia.net             |
   7 |                                                                           |
   8 +---------------------------------------------------------------------------*/
   9
  10#ifndef _FPU_SYSTEM_H
  11#define _FPU_SYSTEM_H
  12
  13/* system dependent definitions */
  14
  15#include <linux/sched.h>
  16#include <linux/kernel.h>
  17#include <linux/mm.h>
  18
  19/* s is always from a cpu register, and the cpu does bounds checking
  20 * during register load --> no further bounds checks needed */
  21#define LDT_DESCRIPTOR(s)       (((struct desc_struct *)current->mm->context.ldt)[(s) >> 3])
  22#define SEG_D_SIZE(x)           ((x).b & (3 << 21))
  23#define SEG_G_BIT(x)            ((x).b & (1 << 23))
  24#define SEG_GRANULARITY(x)      (((x).b & (1 << 23)) ? 4096 : 1)
  25#define SEG_286_MODE(x)         ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
  26#define SEG_BASE_ADDR(s)        (((s).b & 0xff000000) \
  27                                 | (((s).b & 0xff) << 16) | ((s).a >> 16))
  28#define SEG_LIMIT(s)            (((s).b & 0xff0000) | ((s).a & 0xffff))
  29#define SEG_EXECUTE_ONLY(s)     (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
  30#define SEG_WRITE_PERM(s)       (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
  31#define SEG_EXPAND_DOWN(s)      (((s).b & ((1 << 11) | (1 << 10))) \
  32                                 == (1 << 10))
  33
  34#define I387                    (current->thread.fpu.state)
  35#define FPU_info                (I387->soft.info)
  36
  37#define FPU_CS                  (*(unsigned short *) &(FPU_info->regs->cs))
  38#define FPU_SS                  (*(unsigned short *) &(FPU_info->regs->ss))
  39#define FPU_DS                  (*(unsigned short *) &(FPU_info->regs->ds))
  40#define FPU_EAX                 (FPU_info->regs->ax)
  41#define FPU_EFLAGS              (FPU_info->regs->flags)
  42#define FPU_EIP                 (FPU_info->regs->ip)
  43#define FPU_ORIG_EIP            (FPU_info->___orig_eip)
  44
  45#define FPU_lookahead           (I387->soft.lookahead)
  46
  47/* nz if ip_offset and cs_selector are not to be set for the current
  48   instruction. */
  49#define no_ip_update            (*(u_char *)&(I387->soft.no_update))
  50#define FPU_rm                  (*(u_char *)&(I387->soft.rm))
  51
  52/* Number of bytes of data which can be legally accessed by the current
  53   instruction. This only needs to hold a number <= 108, so a byte will do. */
  54#define access_limit            (*(u_char *)&(I387->soft.alimit))
  55
  56#define partial_status          (I387->soft.swd)
  57#define control_word            (I387->soft.cwd)
  58#define fpu_tag_word            (I387->soft.twd)
  59#define registers               (I387->soft.st_space)
  60#define top                     (I387->soft.ftop)
  61
  62#define instruction_address     (*(struct address *)&I387->soft.fip)
  63#define operand_address         (*(struct address *)&I387->soft.foo)
  64
  65#define FPU_access_ok(x,y,z)    if ( !access_ok(x,y,z) ) \
  66                                math_abort(FPU_info,SIGSEGV)
  67#define FPU_abort               math_abort(FPU_info, SIGSEGV)
  68
  69#undef FPU_IGNORE_CODE_SEGV
  70#ifdef FPU_IGNORE_CODE_SEGV
  71/* access_ok() is very expensive, and causes the emulator to run
  72   about 20% slower if applied to the code. Anyway, errors due to bad
  73   code addresses should be much rarer than errors due to bad data
  74   addresses. */
  75#define FPU_code_access_ok(z)
  76#else
  77/* A simpler test than access_ok() can probably be done for
  78   FPU_code_access_ok() because the only possible error is to step
  79   past the upper boundary of a legal code area. */
  80#define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z)
  81#endif
  82
  83#define FPU_get_user(x,y)       get_user((x),(y))
  84#define FPU_put_user(x,y)       put_user((x),(y))
  85
  86#endif
  87