x86: consolidate header guards
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / asm-x86 / i387.h
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1/*
2 * Copyright (C) 1994 Linus Torvalds
3 *
4 * Pentium III FXSR, SSE support
5 * General FPU state handling cleanups
6 * Gareth Hughes <gareth@valinux.com>, May 2000
7 * x86-64 work by Andi Kleen 2002
8 */
9
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10#ifndef ASM_X86__I387_H
11#define ASM_X86__I387_H
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12
13#include <linux/sched.h>
14#include <linux/kernel_stat.h>
15#include <linux/regset.h>
92c37fa3 16#include <asm/asm.h>
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17#include <asm/processor.h>
18#include <asm/sigcontext.h>
19#include <asm/user.h>
20#include <asm/uaccess.h>
21
22extern void fpu_init(void);
1eeaed76 23extern void mxcsr_feature_mask_init(void);
aa283f49 24extern int init_fpu(struct task_struct *child);
1eeaed76 25extern asmlinkage void math_state_restore(void);
61c4628b 26extern void init_thread_xstate(void);
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27
28extern user_regset_active_fn fpregs_active, xfpregs_active;
29extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get;
30extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set;
31
32#ifdef CONFIG_IA32_EMULATION
33struct _fpstate_ia32;
34extern int save_i387_ia32(struct _fpstate_ia32 __user *buf);
35extern int restore_i387_ia32(struct _fpstate_ia32 __user *buf);
36#endif
37
38#ifdef CONFIG_X86_64
39
40/* Ignore delayed exceptions from user space */
41static inline void tolerant_fwait(void)
42{
43 asm volatile("1: fwait\n"
44 "2:\n"
affe6637 45 _ASM_EXTABLE(1b, 2b));
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46}
47
48static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
49{
50 int err;
51
52 asm volatile("1: rex64/fxrstor (%[fx])\n\t"
53 "2:\n"
54 ".section .fixup,\"ax\"\n"
55 "3: movl $-1,%[err]\n"
56 " jmp 2b\n"
57 ".previous\n"
affe6637 58 _ASM_EXTABLE(1b, 3b)
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59 : [err] "=r" (err)
60#if 0 /* See comment in __save_init_fpu() below. */
61 : [fx] "r" (fx), "m" (*fx), "0" (0));
62#else
63 : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
64#endif
65 if (unlikely(err))
66 init_fpu(current);
67 return err;
68}
69
70#define X87_FSW_ES (1 << 7) /* Exception Summary */
71
72/* AMD CPUs don't save/restore FDP/FIP/FOP unless an exception
73 is pending. Clear the x87 state here by setting it to fixed
74 values. The kernel data segment can be sometimes 0 and sometimes
75 new user value. Both should be ok.
76 Use the PDA as safe address because it should be already in L1. */
77static inline void clear_fpu_state(struct i387_fxsave_struct *fx)
78{
79 if (unlikely(fx->swd & X87_FSW_ES))
affe6637 80 asm volatile("fnclex");
1eeaed76 81 alternative_input(ASM_NOP8 ASM_NOP2,
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82 " emms\n" /* clear stack tags */
83 " fildl %%gs:0", /* load to clear state */
84 X86_FEATURE_FXSAVE_LEAK);
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85}
86
87static inline int save_i387_checking(struct i387_fxsave_struct __user *fx)
88{
89 int err;
90
91 asm volatile("1: rex64/fxsave (%[fx])\n\t"
92 "2:\n"
93 ".section .fixup,\"ax\"\n"
94 "3: movl $-1,%[err]\n"
95 " jmp 2b\n"
96 ".previous\n"
affe6637 97 _ASM_EXTABLE(1b, 3b)
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98 : [err] "=r" (err), "=m" (*fx)
99#if 0 /* See comment in __fxsave_clear() below. */
100 : [fx] "r" (fx), "0" (0));
101#else
102 : [fx] "cdaSDb" (fx), "0" (0));
103#endif
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104 if (unlikely(err) &&
105 __clear_user(fx, sizeof(struct i387_fxsave_struct)))
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106 err = -EFAULT;
107 /* No need to clear here because the caller clears USED_MATH */
108 return err;
109}
110
111static inline void __save_init_fpu(struct task_struct *tsk)
112{
113 /* Using "rex64; fxsave %0" is broken because, if the memory operand
114 uses any extended registers for addressing, a second REX prefix
115 will be generated (to the assembler, rex64 followed by semicolon
116 is a separate instruction), and hence the 64-bitness is lost. */
117#if 0
118 /* Using "fxsaveq %0" would be the ideal choice, but is only supported
119 starting with gas 2.16. */
120 __asm__ __volatile__("fxsaveq %0"
61c4628b 121 : "=m" (tsk->thread.xstate->fxsave));
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122#elif 0
123 /* Using, as a workaround, the properly prefixed form below isn't
124 accepted by any binutils version so far released, complaining that
125 the same type of prefix is used twice if an extended register is
126 needed for addressing (fix submitted to mainline 2005-11-21). */
127 __asm__ __volatile__("rex64/fxsave %0"
61c4628b 128 : "=m" (tsk->thread.xstate->fxsave));
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129#else
130 /* This, however, we can work around by forcing the compiler to select
131 an addressing mode that doesn't require extended registers. */
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132 __asm__ __volatile__("rex64/fxsave (%1)"
133 : "=m" (tsk->thread.xstate->fxsave)
134 : "cdaSDb" (&tsk->thread.xstate->fxsave));
1eeaed76 135#endif
61c4628b 136 clear_fpu_state(&tsk->thread.xstate->fxsave);
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137 task_thread_info(tsk)->status &= ~TS_USEDFPU;
138}
139
140/*
141 * Signal frame handlers.
142 */
143
144static inline int save_i387(struct _fpstate __user *buf)
145{
146 struct task_struct *tsk = current;
147 int err = 0;
148
149 BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
61c4628b 150 sizeof(tsk->thread.xstate->fxsave));
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151
152 if ((unsigned long)buf % 16)
153 printk("save_i387: bad fpstate %p\n", buf);
154
155 if (!used_math())
156 return 0;
157 clear_used_math(); /* trigger finit */
158 if (task_thread_info(tsk)->status & TS_USEDFPU) {
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159 err = save_i387_checking((struct i387_fxsave_struct __user *)
160 buf);
161 if (err)
162 return err;
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163 task_thread_info(tsk)->status &= ~TS_USEDFPU;
164 stts();
165 } else {
61c4628b 166 if (__copy_to_user(buf, &tsk->thread.xstate->fxsave,
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167 sizeof(struct i387_fxsave_struct)))
168 return -1;
169 }
170 return 1;
171}
172
173/*
174 * This restores directly out of user space. Exceptions are handled.
175 */
176static inline int restore_i387(struct _fpstate __user *buf)
177{
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178 struct task_struct *tsk = current;
179 int err;
180
181 if (!used_math()) {
182 err = init_fpu(tsk);
183 if (err)
184 return err;
185 }
186
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187 if (!(task_thread_info(current)->status & TS_USEDFPU)) {
188 clts();
189 task_thread_info(current)->status |= TS_USEDFPU;
190 }
191 return restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
192}
193
194#else /* CONFIG_X86_32 */
195
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196extern void finit(void);
197
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198static inline void tolerant_fwait(void)
199{
200 asm volatile("fnclex ; fwait");
201}
202
203static inline void restore_fpu(struct task_struct *tsk)
204{
205 /*
206 * The "nop" is needed to make the instructions the same
207 * length.
208 */
209 alternative_input(
210 "nop ; frstor %1",
211 "fxrstor %1",
212 X86_FEATURE_FXSR,
61c4628b 213 "m" (tsk->thread.xstate->fxsave));
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214}
215
216/* We need a safe address that is cheap to find and that is already
217 in L1 during context switch. The best choices are unfortunately
218 different for UP and SMP */
219#ifdef CONFIG_SMP
220#define safe_address (__per_cpu_offset[0])
221#else
222#define safe_address (kstat_cpu(0).cpustat.user)
223#endif
224
225/*
226 * These must be called with preempt disabled
227 */
228static inline void __save_init_fpu(struct task_struct *tsk)
229{
230 /* Use more nops than strictly needed in case the compiler
231 varies code */
232 alternative_input(
233 "fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4,
234 "fxsave %[fx]\n"
235 "bt $7,%[fsw] ; jnc 1f ; fnclex\n1:",
236 X86_FEATURE_FXSR,
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237 [fx] "m" (tsk->thread.xstate->fxsave),
238 [fsw] "m" (tsk->thread.xstate->fxsave.swd) : "memory");
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239 /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
240 is pending. Clear the x87 state here by setting it to fixed
241 values. safe_address is a random variable that should be in L1 */
242 alternative_input(
243 GENERIC_NOP8 GENERIC_NOP2,
244 "emms\n\t" /* clear stack tags */
245 "fildl %[addr]", /* set F?P to defined value */
246 X86_FEATURE_FXSAVE_LEAK,
247 [addr] "m" (safe_address));
248 task_thread_info(tsk)->status &= ~TS_USEDFPU;
249}
250
251/*
252 * Signal frame handlers...
253 */
254extern int save_i387(struct _fpstate __user *buf);
255extern int restore_i387(struct _fpstate __user *buf);
256
257#endif /* CONFIG_X86_64 */
258
259static inline void __unlazy_fpu(struct task_struct *tsk)
260{
261 if (task_thread_info(tsk)->status & TS_USEDFPU) {
262 __save_init_fpu(tsk);
263 stts();
264 } else
265 tsk->fpu_counter = 0;
266}
267
268static inline void __clear_fpu(struct task_struct *tsk)
269{
270 if (task_thread_info(tsk)->status & TS_USEDFPU) {
271 tolerant_fwait();
272 task_thread_info(tsk)->status &= ~TS_USEDFPU;
273 stts();
274 }
275}
276
277static inline void kernel_fpu_begin(void)
278{
279 struct thread_info *me = current_thread_info();
280 preempt_disable();
281 if (me->status & TS_USEDFPU)
282 __save_init_fpu(me->task);
283 else
284 clts();
285}
286
287static inline void kernel_fpu_end(void)
288{
289 stts();
290 preempt_enable();
291}
292
293#ifdef CONFIG_X86_64
294
295static inline void save_init_fpu(struct task_struct *tsk)
296{
297 __save_init_fpu(tsk);
298 stts();
299}
300
301#define unlazy_fpu __unlazy_fpu
302#define clear_fpu __clear_fpu
303
304#else /* CONFIG_X86_32 */
305
306/*
307 * These disable preemption on their own and are safe
308 */
309static inline void save_init_fpu(struct task_struct *tsk)
310{
311 preempt_disable();
312 __save_init_fpu(tsk);
313 stts();
314 preempt_enable();
315}
316
317static inline void unlazy_fpu(struct task_struct *tsk)
318{
319 preempt_disable();
320 __unlazy_fpu(tsk);
321 preempt_enable();
322}
323
324static inline void clear_fpu(struct task_struct *tsk)
325{
326 preempt_disable();
327 __clear_fpu(tsk);
328 preempt_enable();
329}
330
331#endif /* CONFIG_X86_64 */
332
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333/*
334 * i387 state interaction
335 */
336static inline unsigned short get_fpu_cwd(struct task_struct *tsk)
337{
338 if (cpu_has_fxsr) {
61c4628b 339 return tsk->thread.xstate->fxsave.cwd;
1eeaed76 340 } else {
1679f271 341 return (unsigned short)tsk->thread.xstate->fsave.cwd;
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342 }
343}
344
345static inline unsigned short get_fpu_swd(struct task_struct *tsk)
346{
347 if (cpu_has_fxsr) {
61c4628b 348 return tsk->thread.xstate->fxsave.swd;
1eeaed76 349 } else {
1679f271 350 return (unsigned short)tsk->thread.xstate->fsave.swd;
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351 }
352}
353
354static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
355{
356 if (cpu_has_xmm) {
61c4628b 357 return tsk->thread.xstate->fxsave.mxcsr;
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358 } else {
359 return MXCSR_DEFAULT;
360 }
361}
362
77ef50a5 363#endif /* ASM_X86__I387_H */