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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/x86_64/kernel/i387.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/kernel/i387.c')
-rw-r--r--arch/x86_64/kernel/i387.c155
1 files changed, 155 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/i387.c b/arch/x86_64/kernel/i387.c
new file mode 100644
index 000000000000..ba139cac57ce
--- /dev/null
+++ b/arch/x86_64/kernel/i387.c
@@ -0,0 +1,155 @@
1/*
2 * linux/arch/x86_64/kernel/i387.c
3 *
4 * Copyright (C) 1994 Linus Torvalds
5 * Copyright (C) 2002 Andi Kleen, SuSE Labs
6 *
7 * Pentium III FXSR, SSE support
8 * General FPU state handling cleanups
9 * Gareth Hughes <gareth@valinux.com>, May 2000
10 *
11 * x86-64 rework 2002 Andi Kleen.
12 * Does direct fxsave in and out of user space now for signal handlers.
13 * All the FSAVE<->FXSAVE conversion code has been moved to the 32bit emulation,
14 * the 64bit user space sees a FXSAVE frame directly.
15 */
16
17#include <linux/config.h>
18#include <linux/sched.h>
19#include <linux/init.h>
20#include <asm/processor.h>
21#include <asm/i387.h>
22#include <asm/sigcontext.h>
23#include <asm/user.h>
24#include <asm/ptrace.h>
25#include <asm/uaccess.h>
26
27unsigned int mxcsr_feature_mask = 0xffffffff;
28
29void mxcsr_feature_mask_init(void)
30{
31 unsigned int mask;
32 clts();
33 memset(&current->thread.i387.fxsave, 0, sizeof(struct i387_fxsave_struct));
34 asm volatile("fxsave %0" : : "m" (current->thread.i387.fxsave));
35 mask = current->thread.i387.fxsave.mxcsr_mask;
36 if (mask == 0) mask = 0x0000ffbf;
37 mxcsr_feature_mask &= mask;
38 stts();
39}
40
41/*
42 * Called at bootup to set up the initial FPU state that is later cloned
43 * into all processes.
44 */
45void __init fpu_init(void)
46{
47 unsigned long oldcr0 = read_cr0();
48 extern void __bad_fxsave_alignment(void);
49
50 if (offsetof(struct task_struct, thread.i387.fxsave) & 15)
51 __bad_fxsave_alignment();
52 set_in_cr4(X86_CR4_OSFXSR);
53 set_in_cr4(X86_CR4_OSXMMEXCPT);
54
55 write_cr0(oldcr0 & ~((1UL<<3)|(1UL<<2))); /* clear TS and EM */
56
57 mxcsr_feature_mask_init();
58 /* clean state in init */
59 current_thread_info()->status = 0;
60 clear_used_math();
61}
62
63void init_fpu(struct task_struct *child)
64{
65 if (tsk_used_math(child)) {
66 if (child == current)
67 unlazy_fpu(child);
68 return;
69 }
70 memset(&child->thread.i387.fxsave, 0, sizeof(struct i387_fxsave_struct));
71 child->thread.i387.fxsave.cwd = 0x37f;
72 child->thread.i387.fxsave.mxcsr = 0x1f80;
73 /* only the device not available exception or ptrace can call init_fpu */
74 set_stopped_child_used_math(child);
75}
76
77/*
78 * Signal frame handlers.
79 */
80
81int save_i387(struct _fpstate __user *buf)
82{
83 struct task_struct *tsk = current;
84 int err = 0;
85
86 {
87 extern void bad_user_i387_struct(void);
88 if (sizeof(struct user_i387_struct) != sizeof(tsk->thread.i387.fxsave))
89 bad_user_i387_struct();
90 }
91
92 if ((unsigned long)buf % 16)
93 printk("save_i387: bad fpstate %p\n",buf);
94
95 if (!used_math())
96 return 0;
97 clear_used_math(); /* trigger finit */
98 if (tsk->thread_info->status & TS_USEDFPU) {
99 err = save_i387_checking((struct i387_fxsave_struct __user *)buf);
100 if (err) return err;
101 stts();
102 } else {
103 if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
104 sizeof(struct i387_fxsave_struct)))
105 return -1;
106 }
107 return 1;
108}
109
110/*
111 * ptrace request handlers.
112 */
113
114int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *tsk)
115{
116 init_fpu(tsk);
117 return __copy_to_user(buf, &tsk->thread.i387.fxsave,
118 sizeof(struct user_i387_struct)) ? -EFAULT : 0;
119}
120
121int set_fpregs(struct task_struct *tsk, struct user_i387_struct __user *buf)
122{
123 if (__copy_from_user(&tsk->thread.i387.fxsave, buf,
124 sizeof(struct user_i387_struct)))
125 return -EFAULT;
126 return 0;
127}
128
129/*
130 * FPU state for core dumps.
131 */
132
133int dump_fpu( struct pt_regs *regs, struct user_i387_struct *fpu )
134{
135 struct task_struct *tsk = current;
136
137 if (!used_math())
138 return 0;
139
140 unlazy_fpu(tsk);
141 memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(struct user_i387_struct));
142 return 1;
143}
144
145int dump_task_fpu(struct task_struct *tsk, struct user_i387_struct *fpu)
146{
147 int fpvalid = !!tsk_used_math(tsk);
148
149 if (fpvalid) {
150 if (tsk == current)
151 unlazy_fpu(tsk);
152 memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(struct user_i387_struct));
153}
154 return fpvalid;
155}