arch/x86/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 #include <asm/desc.h>
  20 #include <asm/mmu_context.h>
  21
  22 static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg)
  23 {
  24         static struct desc_struct zero_desc;
  25         struct desc_struct ret = zero_desc;
  26
  27 #ifdef CONFIG_MODIFY_LDT_SYSCALL
  28         seg >>= 3;
  29         mutex_lock(&current->mm->context.lock);
  30         if (current->mm->context.ldt && seg < current->mm->context.ldt->nr_entries)
  31                 ret = current->mm->context.ldt->entries[seg];
  32         mutex_unlock(&current->mm->context.lock);
  33 #endif
  34         return ret;
  35 }
  36
  37 #define SEG_D_SIZE(x)           ((x).b & (3 << 21))
  38 #define SEG_G_BIT(x)            ((x).b & (1 << 23))
  39 #define SEG_GRANULARITY(x)      (((x).b & (1 << 23)) ? 4096 : 1)
  40 #define SEG_286_MODE(x)         ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
  41 #define SEG_BASE_ADDR(s)        (((s).b & 0xff000000) \
  42                                  | (((s).b & 0xff) << 16) | ((s).a >> 16))
  43 #define SEG_LIMIT(s)            (((s).b & 0xff0000) | ((s).a & 0xffff))
  44 #define SEG_EXECUTE_ONLY(s)     (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
  45 #define SEG_WRITE_PERM(s)       (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
  46 #define SEG_EXPAND_DOWN(s)      (((s).b & ((1 << 11) | (1 << 10))) \
  47                                  == (1 << 10))
  48
  49 #define I387                    (&current->thread.fpu.state)
  50 #define FPU_info                (I387->soft.info)
  51
  52 #define FPU_CS                  (*(unsigned short *) &(FPU_info->regs->cs))
  53 #define FPU_SS                  (*(unsigned short *) &(FPU_info->regs->ss))
  54 #define FPU_DS                  (*(unsigned short *) &(FPU_info->regs->ds))
  55 #define FPU_EAX                 (FPU_info->regs->ax)
  56 #define FPU_EFLAGS              (FPU_info->regs->flags)
  57 #define FPU_EIP                 (FPU_info->regs->ip)
  58 #define FPU_ORIG_EIP            (FPU_info->___orig_eip)
  59
  60 #define FPU_lookahead           (I387->soft.lookahead)
  61
  62 /* nz if ip_offset and cs_selector are not to be set for the current
  63    instruction. */
  64 #define no_ip_update            (*(u_char *)&(I387->soft.no_update))
  65 #define FPU_rm                  (*(u_char *)&(I387->soft.rm))
  66
  67 /* Number of bytes of data which can be legally accessed by the current
  68    instruction. This only needs to hold a number <= 108, so a byte will do. */
  69 #define access_limit            (*(u_char *)&(I387->soft.alimit))
  70
  71 #define partial_status          (I387->soft.swd)
  72 #define control_word            (I387->soft.cwd)
  73 #define fpu_tag_word            (I387->soft.twd)
  74 #define registers               (I387->soft.st_space)
  75 #define top                     (I387->soft.ftop)
  76
  77 #define instruction_address     (*(struct address *)&I387->soft.fip)
  78 #define operand_address         (*(struct address *)&I387->soft.foo)
  79
  80 #define FPU_access_ok(x,y,z)    if ( !access_ok(x,y,z) ) \
  81                                 math_abort(FPU_info,SIGSEGV)
  82 #define FPU_abort               math_abort(FPU_info, SIGSEGV)
  83
  84 #undef FPU_IGNORE_CODE_SEGV
  85 #ifdef FPU_IGNORE_CODE_SEGV
  86 /* access_ok() is very expensive, and causes the emulator to run
  87    about 20% slower if applied to the code. Anyway, errors due to bad
  88    code addresses should be much rarer than errors due to bad data
  89    addresses. */
  90 #define FPU_code_access_ok(z)
  91 #else
  92 /* A simpler test than access_ok() can probably be done for
  93    FPU_code_access_ok() because the only possible error is to step
  94    past the upper boundary of a legal code area. */
  95 #define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z)
  96 #endif
  97
  98 #define FPU_get_user(x,y)       get_user((x),(y))
  99 #define FPU_put_user(x,y)       put_user((x),(y))
 100
 101 #endif