arch/i386/math-emu/fpu_system.h

   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 /* This sets the pointer FPU_info to point to the argument part
  20    of the stack frame of math_emulate() */
  21 #define SETUP_DATA_AREA(arg)    FPU_info = (struct info *) &arg
  22
  23 /* s is always from a cpu register, and the cpu does bounds checking
  24  * during register load --> no further bounds checks needed */
  25 #define LDT_DESCRIPTOR(s)       (((struct desc_struct *)current->mm->context.ldt)[(s) >> 3])
  26 #define SEG_D_SIZE(x)           ((x).b & (3 << 21))
  27 #define SEG_G_BIT(x)            ((x).b & (1 << 23))
  28 #define SEG_GRANULARITY(x)      (((x).b & (1 << 23)) ? 4096 : 1)
  29 #define SEG_286_MODE(x)         ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
  30 #define SEG_BASE_ADDR(s)        (((s).b & 0xff000000) \
  31                                  | (((s).b & 0xff) << 16) | ((s).a >> 16))
  32 #define SEG_LIMIT(s)            (((s).b & 0xff0000) | ((s).a & 0xffff))
  33 #define SEG_EXECUTE_ONLY(s)     (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
  34 #define SEG_WRITE_PERM(s)       (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
  35 #define SEG_EXPAND_DOWN(s)      (((s).b & ((1 << 11) | (1 << 10))) \
  36                                  == (1 << 10))
  37
  38 #define I387                    (current->thread.i387)
  39 #define FPU_info                (I387.soft.info)
  40
  41 #define FPU_CS                  (*(unsigned short *) &(FPU_info->___cs))
  42 #define FPU_SS                  (*(unsigned short *) &(FPU_info->___ss))
  43 #define FPU_DS                  (*(unsigned short *) &(FPU_info->___ds))
  44 #define FPU_EAX                 (FPU_info->___eax)
  45 #define FPU_EFLAGS              (FPU_info->___eflags)
  46 #define FPU_EIP                 (FPU_info->___eip)
  47 #define FPU_ORIG_EIP            (FPU_info->___orig_eip)
  48
  49 #define FPU_lookahead           (I387.soft.lookahead)
  50
  51 /* nz if ip_offset and cs_selector are not to be set for the current
  52    instruction. */
  53 #define no_ip_update            (*(u_char *)&(I387.soft.no_update))
  54 #define FPU_rm                  (*(u_char *)&(I387.soft.rm))
  55
  56 /* Number of bytes of data which can be legally accessed by the current
  57    instruction. This only needs to hold a number <= 108, so a byte will do. */
  58 #define access_limit            (*(u_char *)&(I387.soft.alimit))
  59
  60 #define partial_status          (I387.soft.swd)
  61 #define control_word            (I387.soft.cwd)
  62 #define fpu_tag_word            (I387.soft.twd)
  63 #define registers               (I387.soft.st_space)
  64 #define top                     (I387.soft.ftop)
  65
  66 #define instruction_address     (*(struct address *)&I387.soft.fip)
  67 #define operand_address         (*(struct address *)&I387.soft.foo)
  68
  69 #define FPU_access_ok(x,y,z)    if ( !access_ok(x,y,z) ) \
  70                                 math_abort(FPU_info,SIGSEGV)
  71 #define FPU_abort               math_abort(FPU_info, SIGSEGV)
  72
  73 #undef FPU_IGNORE_CODE_SEGV
  74 #ifdef FPU_IGNORE_CODE_SEGV
  75 /* access_ok() is very expensive, and causes the emulator to run
  76    about 20% slower if applied to the code. Anyway, errors due to bad
  77    code addresses should be much rarer than errors due to bad data
  78    addresses. */
  79 #define FPU_code_access_ok(z)
  80 #else
  81 /* A simpler test than access_ok() can probably be done for
  82    FPU_code_access_ok() because the only possible error is to step
  83    past the upper boundary of a legal code area. */
  84 #define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z)
  85 #endif
  86
  87 #define FPU_get_user(x,y)       get_user((x),(y))
  88 #define FPU_put_user(x,y)       put_user((x),(y))
  89
  90 #endif