/*---------------------------------------------------------------------------+
 |  fpu_system.h                                                             |
 |                                                                           |
 | Copyright (C) 1992,1994                                                   |
 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
 |                       Australia.  E-mail   billm@vaxc.cc.monash.edu.au    |
 |                                                                           |
 +---------------------------------------------------------------------------*/

#ifndef _FPU_SYSTEM_H
#define _FPU_SYSTEM_H

/* system dependent definitions */

#include <linux/sched.h>
#include <linux/kernel.h>

/* This sets the pointer FPU_info to point to the argument part
   of the stack frame of math_emulate() */
#define SETUP_DATA_AREA(arg)    FPU_info = (struct info *) &arg

#define LDT_DESCRIPTOR(s)       (current->ldt[(s) >> 3])
#define SEG_D_SIZE(x)           ((x).b & (3 << 21))
#define SEG_G_BIT(x)            ((x).b & (1 << 23))
#define SEG_GRANULARITY(x)      (((x).b & (1 << 23)) ? 4096 : 1)
#define SEG_286_MODE(x)         ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
#define SEG_BASE_ADDR(s)        (((s).b & 0xff000000) \
				 | (((s).b & 0xff) << 16) | ((s).a >> 16))
#define SEG_LIMIT(s)            (((s).b & 0xff0000) | ((s).a & 0xffff))
#define SEG_EXECUTE_ONLY(s)     (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
#define SEG_WRITE_PERM(s)       (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
#define SEG_EXPAND_DOWN(s)      (((s).b & ((1 << 11) | (1 << 10))) \
				 == (1 << 10))

#define I387			(current->tss.i387)
#define FPU_info		(I387.soft.info)

#define FPU_CS			(*(unsigned short *) &(FPU_info->___cs))
#define FPU_SS			(*(unsigned short *) &(FPU_info->___ss))
#define FPU_DS			(*(unsigned short *) &(FPU_info->___ds))
#define FPU_EAX			(FPU_info->___eax)
#define FPU_EFLAGS		(FPU_info->___eflags)
#define FPU_EIP			(FPU_info->___eip)
#define FPU_ORIG_EIP		(FPU_info->___orig_eip)

#define FPU_lookahead           (I387.soft.lookahead)

/* nz if ip_offset and cs_selector are not to be set for the current
   instruction. */
#define no_ip_update            (((char *)&(I387.soft.twd))[0])
#define FPU_rm                  (((unsigned char *)&(I387.soft.twd))[1])

/* Number of bytes of data which can be legally accessed by the current
   instruction. This only needs to hold a number <= 108, so a byte will do. */
#define access_limit            (((unsigned char *)&(I387.soft.twd))[2])

#define partial_status       	(I387.soft.swd)
#define control_word		(I387.soft.cwd)
#define regs			(I387.soft.regs)
#define top			(I387.soft.top)

#define instruction_address     (*(struct address *)&I387.soft.fip)
#define operand_address         (*(struct address *)&I387.soft.foo)

#define FPU_verify_area(x,y,z)  if ( verify_area(x,y,z) ) \
                                math_abort(FPU_info,SIGSEGV)

#undef FPU_IGNORE_CODE_SEGV
#ifdef FPU_IGNORE_CODE_SEGV
/* verify_area() is very expensive, and causes the emulator to run
   about 20% slower if applied to the code. Anyway, errors due to bad
   code addresses should be much rarer than errors due to bad data
   addresses. */
#define	FPU_code_verify_area(z)
#else
/* A simpler test than verify_area() can probably be done for
   FPU_code_verify_area() because the only possible error is to step
   past the upper boundary of a legal code area. */
#define	FPU_code_verify_area(z) FPU_verify_area(VERIFY_READ,(void *)FPU_EIP,z)
#endif

#endif
