• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
FPU_get_ldt_descriptor(unsigned seg)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->size)
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
102