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(¤t->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(¤t->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 (¤t->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