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