diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/x86_64/ia32/fpu32.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/x86_64/ia32/fpu32.c')
-rw-r--r-- | arch/x86_64/ia32/fpu32.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/arch/x86_64/ia32/fpu32.c b/arch/x86_64/ia32/fpu32.c new file mode 100644 index 000000000000..1c23095f1813 --- /dev/null +++ b/arch/x86_64/ia32/fpu32.c | |||
@@ -0,0 +1,184 @@ | |||
1 | /* | ||
2 | * Copyright 2002 Andi Kleen, SuSE Labs. | ||
3 | * FXSAVE<->i387 conversion support. Based on code by Gareth Hughes. | ||
4 | * This is used for ptrace, signals and coredumps in 32bit emulation. | ||
5 | * $Id: fpu32.c,v 1.1 2002/03/21 14:16:32 ak Exp $ | ||
6 | */ | ||
7 | |||
8 | #include <linux/sched.h> | ||
9 | #include <asm/sigcontext32.h> | ||
10 | #include <asm/processor.h> | ||
11 | #include <asm/uaccess.h> | ||
12 | #include <asm/i387.h> | ||
13 | |||
14 | static inline unsigned short twd_i387_to_fxsr(unsigned short twd) | ||
15 | { | ||
16 | unsigned int tmp; /* to avoid 16 bit prefixes in the code */ | ||
17 | |||
18 | /* Transform each pair of bits into 01 (valid) or 00 (empty) */ | ||
19 | tmp = ~twd; | ||
20 | tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */ | ||
21 | /* and move the valid bits to the lower byte. */ | ||
22 | tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */ | ||
23 | tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */ | ||
24 | tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */ | ||
25 | return tmp; | ||
26 | } | ||
27 | |||
28 | static inline unsigned long twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave) | ||
29 | { | ||
30 | struct _fpxreg *st = NULL; | ||
31 | unsigned long tos = (fxsave->swd >> 11) & 7; | ||
32 | unsigned long twd = (unsigned long) fxsave->twd; | ||
33 | unsigned long tag; | ||
34 | unsigned long ret = 0xffff0000; | ||
35 | int i; | ||
36 | |||
37 | #define FPREG_ADDR(f, n) ((void *)&(f)->st_space + (n) * 16); | ||
38 | |||
39 | for (i = 0 ; i < 8 ; i++) { | ||
40 | if (twd & 0x1) { | ||
41 | st = FPREG_ADDR( fxsave, (i - tos) & 7 ); | ||
42 | |||
43 | switch (st->exponent & 0x7fff) { | ||
44 | case 0x7fff: | ||
45 | tag = 2; /* Special */ | ||
46 | break; | ||
47 | case 0x0000: | ||
48 | if ( !st->significand[0] && | ||
49 | !st->significand[1] && | ||
50 | !st->significand[2] && | ||
51 | !st->significand[3] ) { | ||
52 | tag = 1; /* Zero */ | ||
53 | } else { | ||
54 | tag = 2; /* Special */ | ||
55 | } | ||
56 | break; | ||
57 | default: | ||
58 | if (st->significand[3] & 0x8000) { | ||
59 | tag = 0; /* Valid */ | ||
60 | } else { | ||
61 | tag = 2; /* Special */ | ||
62 | } | ||
63 | break; | ||
64 | } | ||
65 | } else { | ||
66 | tag = 3; /* Empty */ | ||
67 | } | ||
68 | ret |= (tag << (2 * i)); | ||
69 | twd = twd >> 1; | ||
70 | } | ||
71 | return ret; | ||
72 | } | ||
73 | |||
74 | |||
75 | static inline int convert_fxsr_from_user(struct i387_fxsave_struct *fxsave, | ||
76 | struct _fpstate_ia32 __user *buf) | ||
77 | { | ||
78 | struct _fpxreg *to; | ||
79 | struct _fpreg __user *from; | ||
80 | int i; | ||
81 | u32 v; | ||
82 | int err = 0; | ||
83 | |||
84 | #define G(num,val) err |= __get_user(val, num + (u32 __user *)buf) | ||
85 | G(0, fxsave->cwd); | ||
86 | G(1, fxsave->swd); | ||
87 | G(2, fxsave->twd); | ||
88 | fxsave->twd = twd_i387_to_fxsr(fxsave->twd); | ||
89 | G(3, fxsave->rip); | ||
90 | G(4, v); | ||
91 | fxsave->fop = v>>16; /* cs ignored */ | ||
92 | G(5, fxsave->rdp); | ||
93 | /* 6: ds ignored */ | ||
94 | #undef G | ||
95 | if (err) | ||
96 | return -1; | ||
97 | |||
98 | to = (struct _fpxreg *)&fxsave->st_space[0]; | ||
99 | from = &buf->_st[0]; | ||
100 | for (i = 0 ; i < 8 ; i++, to++, from++) { | ||
101 | if (__copy_from_user(to, from, sizeof(*from))) | ||
102 | return -1; | ||
103 | } | ||
104 | return 0; | ||
105 | } | ||
106 | |||
107 | |||
108 | static inline int convert_fxsr_to_user(struct _fpstate_ia32 __user *buf, | ||
109 | struct i387_fxsave_struct *fxsave, | ||
110 | struct pt_regs *regs, | ||
111 | struct task_struct *tsk) | ||
112 | { | ||
113 | struct _fpreg __user *to; | ||
114 | struct _fpxreg *from; | ||
115 | int i; | ||
116 | u16 cs,ds; | ||
117 | int err = 0; | ||
118 | |||
119 | if (tsk == current) { | ||
120 | /* should be actually ds/cs at fpu exception time, | ||
121 | but that information is not available in 64bit mode. */ | ||
122 | asm("movw %%ds,%0 " : "=r" (ds)); | ||
123 | asm("movw %%cs,%0 " : "=r" (cs)); | ||
124 | } else { /* ptrace. task has stopped. */ | ||
125 | ds = tsk->thread.ds; | ||
126 | cs = regs->cs; | ||
127 | } | ||
128 | |||
129 | #define P(num,val) err |= __put_user(val, num + (u32 __user *)buf) | ||
130 | P(0, (u32)fxsave->cwd | 0xffff0000); | ||
131 | P(1, (u32)fxsave->swd | 0xffff0000); | ||
132 | P(2, twd_fxsr_to_i387(fxsave)); | ||
133 | P(3, (u32)fxsave->rip); | ||
134 | P(4, cs | ((u32)fxsave->fop) << 16); | ||
135 | P(5, fxsave->rdp); | ||
136 | P(6, 0xffff0000 | ds); | ||
137 | #undef P | ||
138 | |||
139 | if (err) | ||
140 | return -1; | ||
141 | |||
142 | to = &buf->_st[0]; | ||
143 | from = (struct _fpxreg *) &fxsave->st_space[0]; | ||
144 | for ( i = 0 ; i < 8 ; i++, to++, from++ ) { | ||
145 | if (__copy_to_user(to, from, sizeof(*to))) | ||
146 | return -1; | ||
147 | } | ||
148 | return 0; | ||
149 | } | ||
150 | |||
151 | int restore_i387_ia32(struct task_struct *tsk, struct _fpstate_ia32 __user *buf, int fsave) | ||
152 | { | ||
153 | clear_fpu(tsk); | ||
154 | if (!fsave) { | ||
155 | if (__copy_from_user(&tsk->thread.i387.fxsave, | ||
156 | &buf->_fxsr_env[0], | ||
157 | sizeof(struct i387_fxsave_struct))) | ||
158 | return -1; | ||
159 | tsk->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask; | ||
160 | set_stopped_child_used_math(tsk); | ||
161 | } | ||
162 | return convert_fxsr_from_user(&tsk->thread.i387.fxsave, buf); | ||
163 | } | ||
164 | |||
165 | int save_i387_ia32(struct task_struct *tsk, | ||
166 | struct _fpstate_ia32 __user *buf, | ||
167 | struct pt_regs *regs, | ||
168 | int fsave) | ||
169 | { | ||
170 | int err = 0; | ||
171 | |||
172 | init_fpu(tsk); | ||
173 | if (convert_fxsr_to_user(buf, &tsk->thread.i387.fxsave, regs, tsk)) | ||
174 | return -1; | ||
175 | if (fsave) | ||
176 | return 0; | ||
177 | err |= __put_user(tsk->thread.i387.fxsave.swd, &buf->status); | ||
178 | if (fsave) | ||
179 | return err ? -1 : 1; | ||
180 | err |= __put_user(X86_FXSR_MAGIC, &buf->magic); | ||
181 | err |= __copy_to_user(&buf->_fxsr_env[0], &tsk->thread.i387.fxsave, | ||
182 | sizeof(struct i387_fxsave_struct)); | ||
183 | return err ? -1 : 1; | ||
184 | } | ||