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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * 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 */
Alexey Dobriyan129f6942005-06-23 00:08:33 -07008#include <linux/module.h>
Roland McGrath44210112008-01-30 13:31:50 +01009#include <linux/regset.h>
Ingo Molnarf6689642008-03-05 15:37:32 +010010#include <linux/sched.h>
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <asm/sigcontext.h>
Ingo Molnarf6689642008-03-05 15:37:32 +010013#include <asm/processor.h>
14#include <asm/math_emu.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <asm/uaccess.h>
Ingo Molnarf6689642008-03-05 15:37:32 +010016#include <asm/ptrace.h>
17#include <asm/i387.h>
18#include <asm/user.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
Roland McGrath44210112008-01-30 13:31:50 +010020#ifdef CONFIG_X86_64
Ingo Molnarf6689642008-03-05 15:37:32 +010021# include <asm/sigcontext32.h>
22# include <asm/user32.h>
Roland McGrath44210112008-01-30 13:31:50 +010023#else
Suresh Siddhaab513702008-07-29 10:29:22 -070024# define save_i387_xstate_ia32 save_i387_xstate
25# define restore_i387_xstate_ia32 restore_i387_xstate
Ingo Molnarf6689642008-03-05 15:37:32 +010026# define _fpstate_ia32 _fpstate
Suresh Siddhaab513702008-07-29 10:29:22 -070027# define _xstate_ia32 _xstate
Suresh Siddha3c1c7f12008-07-29 10:29:21 -070028# define sig_xstate_ia32_size sig_xstate_size
Suresh Siddhac37b5ef2008-07-29 10:29:25 -070029# define fx_sw_reserved_ia32 fx_sw_reserved
Ingo Molnarf6689642008-03-05 15:37:32 +010030# define user_i387_ia32_struct user_i387_struct
31# define user32_fxsr_struct user_fxsr_struct
Roland McGrath44210112008-01-30 13:31:50 +010032#endif
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#ifdef CONFIG_MATH_EMULATION
Ingo Molnarf6689642008-03-05 15:37:32 +010035# define HAVE_HWFP (boot_cpu_data.hard_math)
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#else
Ingo Molnarf6689642008-03-05 15:37:32 +010037# define HAVE_HWFP 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#endif
39
Ingo Molnarf6689642008-03-05 15:37:32 +010040static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
Suresh Siddha61c46282008-03-10 15:28:04 -070041unsigned int xstate_size;
Suresh Siddha3c1c7f12008-07-29 10:29:21 -070042unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
Suresh Siddha61c46282008-03-10 15:28:04 -070043static struct i387_fxsave_struct fx_scratch __cpuinitdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
Suresh Siddha61c46282008-03-10 15:28:04 -070045void __cpuinit mxcsr_feature_mask_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070046{
47 unsigned long mask = 0;
Ingo Molnarf6689642008-03-05 15:37:32 +010048
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 clts();
50 if (cpu_has_fxsr) {
Suresh Siddha61c46282008-03-10 15:28:04 -070051 memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
52 asm volatile("fxsave %0" : : "m" (fx_scratch));
53 mask = fx_scratch.mxcsr_mask;
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +010054 if (mask == 0)
55 mask = 0x0000ffbf;
56 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 mxcsr_feature_mask &= mask;
58 stts();
59}
60
Rakib Mullick9bc646f2008-11-20 19:08:45 +060061void __cpuinit init_thread_xstate(void)
Suresh Siddha61c46282008-03-10 15:28:04 -070062{
Suresh Siddhae8a496a2008-05-23 16:26:37 -070063 if (!HAVE_HWFP) {
64 xstate_size = sizeof(struct i387_soft_struct);
65 return;
66 }
67
Suresh Siddhadc1e35c2008-07-29 10:29:19 -070068 if (cpu_has_xsave) {
69 xsave_cntxt_init();
70 return;
71 }
72
Suresh Siddha61c46282008-03-10 15:28:04 -070073 if (cpu_has_fxsr)
74 xstate_size = sizeof(struct i387_fxsave_struct);
75#ifdef CONFIG_X86_32
76 else
77 xstate_size = sizeof(struct i387_fsave_struct);
78#endif
Suresh Siddha61c46282008-03-10 15:28:04 -070079}
80
Roland McGrath44210112008-01-30 13:31:50 +010081#ifdef CONFIG_X86_64
82/*
83 * Called at bootup to set up the initial FPU state that is later cloned
84 * into all processes.
85 */
86void __cpuinit fpu_init(void)
87{
88 unsigned long oldcr0 = read_cr0();
Ingo Molnarf6689642008-03-05 15:37:32 +010089
Roland McGrath44210112008-01-30 13:31:50 +010090 set_in_cr4(X86_CR4_OSFXSR);
91 set_in_cr4(X86_CR4_OSXMMEXCPT);
92
Ingo Molnarf6689642008-03-05 15:37:32 +010093 write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
Roland McGrath44210112008-01-30 13:31:50 +010094
Suresh Siddhadc1e35c2008-07-29 10:29:19 -070095 /*
96 * Boot processor to setup the FP and extended state context info.
97 */
98 if (!smp_processor_id())
99 init_thread_xstate();
100 xsave_init();
101
Roland McGrath44210112008-01-30 13:31:50 +0100102 mxcsr_feature_mask_init();
103 /* clean state in init */
Suresh Siddhab359e8a2008-07-29 10:29:20 -0700104 if (cpu_has_xsave)
105 current_thread_info()->status = TS_XSAVE;
106 else
107 current_thread_info()->status = 0;
Roland McGrath44210112008-01-30 13:31:50 +0100108 clear_used_math();
109}
110#endif /* CONFIG_X86_64 */
111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112/*
113 * The _current_ task is using the FPU for the first time
114 * so initialize it and set the mxcsr to its default
115 * value at reset if we support XMM instructions and then
116 * remeber the current task has used the FPU.
117 */
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700118int init_fpu(struct task_struct *tsk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
Roland McGrath44210112008-01-30 13:31:50 +0100120 if (tsk_used_math(tsk)) {
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700121 if (HAVE_HWFP && tsk == current)
Roland McGrath44210112008-01-30 13:31:50 +0100122 unlazy_fpu(tsk);
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700123 return 0;
124 }
125
126 /*
127 * Memory allocation at the first usage of the FPU and other state.
128 */
129 if (!tsk->thread.xstate) {
130 tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
131 GFP_KERNEL);
132 if (!tsk->thread.xstate)
133 return -ENOMEM;
Roland McGrath44210112008-01-30 13:31:50 +0100134 }
135
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700136#ifdef CONFIG_X86_32
137 if (!HAVE_HWFP) {
138 memset(tsk->thread.xstate, 0, xstate_size);
139 finit();
140 set_stopped_child_used_math(tsk);
141 return 0;
142 }
143#endif
144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 if (cpu_has_fxsr) {
Suresh Siddha61c46282008-03-10 15:28:04 -0700146 struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
147
148 memset(fx, 0, xstate_size);
149 fx->cwd = 0x37f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 if (cpu_has_xmm)
Suresh Siddha61c46282008-03-10 15:28:04 -0700151 fx->mxcsr = MXCSR_DEFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 } else {
Suresh Siddha61c46282008-03-10 15:28:04 -0700153 struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
154 memset(fp, 0, xstate_size);
155 fp->cwd = 0xffff037fu;
156 fp->swd = 0xffff0000u;
157 fp->twd = 0xffffffffu;
158 fp->fos = 0xffff0000u;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 }
Roland McGrath44210112008-01-30 13:31:50 +0100160 /*
161 * Only the device not available exception or ptrace can call init_fpu.
162 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 set_stopped_child_used_math(tsk);
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700164 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165}
166
Roland McGrath44210112008-01-30 13:31:50 +0100167int fpregs_active(struct task_struct *target, const struct user_regset *regset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168{
Roland McGrath44210112008-01-30 13:31:50 +0100169 return tsk_used_math(target) ? regset->n : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170}
Roland McGrath44210112008-01-30 13:31:50 +0100171
172int xfpregs_active(struct task_struct *target, const struct user_regset *regset)
173{
174 return (cpu_has_fxsr && tsk_used_math(target)) ? regset->n : 0;
175}
176
177int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
178 unsigned int pos, unsigned int count,
179 void *kbuf, void __user *ubuf)
180{
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700181 int ret;
182
Roland McGrath44210112008-01-30 13:31:50 +0100183 if (!cpu_has_fxsr)
184 return -ENODEV;
185
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700186 ret = init_fpu(target);
187 if (ret)
188 return ret;
Roland McGrath44210112008-01-30 13:31:50 +0100189
190 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
Suresh Siddha61c46282008-03-10 15:28:04 -0700191 &target->thread.xstate->fxsave, 0, -1);
Roland McGrath44210112008-01-30 13:31:50 +0100192}
193
194int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
195 unsigned int pos, unsigned int count,
196 const void *kbuf, const void __user *ubuf)
197{
198 int ret;
199
200 if (!cpu_has_fxsr)
201 return -ENODEV;
202
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700203 ret = init_fpu(target);
204 if (ret)
205 return ret;
206
Roland McGrath44210112008-01-30 13:31:50 +0100207 set_stopped_child_used_math(target);
208
209 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
Suresh Siddha61c46282008-03-10 15:28:04 -0700210 &target->thread.xstate->fxsave, 0, -1);
Roland McGrath44210112008-01-30 13:31:50 +0100211
212 /*
213 * mxcsr reserved bits must be masked to zero for security reasons.
214 */
Suresh Siddha61c46282008-03-10 15:28:04 -0700215 target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
Roland McGrath44210112008-01-30 13:31:50 +0100216
Suresh Siddha42deec62008-07-29 10:29:26 -0700217 /*
218 * update the header bits in the xsave header, indicating the
219 * presence of FP and SSE state.
220 */
221 if (cpu_has_xsave)
222 target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
223
Roland McGrath44210112008-01-30 13:31:50 +0100224 return ret;
225}
226
227#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229/*
230 * FPU tag word conversions.
231 */
232
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100233static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234{
235 unsigned int tmp; /* to avoid 16 bit prefixes in the code */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100236
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 /* Transform each pair of bits into 01 (valid) or 00 (empty) */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100238 tmp = ~twd;
Roland McGrath44210112008-01-30 13:31:50 +0100239 tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100240 /* and move the valid bits to the lower byte. */
241 tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
242 tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
243 tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
Ingo Molnarf6689642008-03-05 15:37:32 +0100244
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100245 return tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
Roland McGrath44210112008-01-30 13:31:50 +0100248#define FPREG_ADDR(f, n) ((void *)&(f)->st_space + (n) * 16);
249#define FP_EXP_TAG_VALID 0
250#define FP_EXP_TAG_ZERO 1
251#define FP_EXP_TAG_SPECIAL 2
252#define FP_EXP_TAG_EMPTY 3
253
254static inline u32 twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255{
Roland McGrath44210112008-01-30 13:31:50 +0100256 struct _fpxreg *st;
257 u32 tos = (fxsave->swd >> 11) & 7;
258 u32 twd = (unsigned long) fxsave->twd;
259 u32 tag;
260 u32 ret = 0xffff0000u;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 int i;
262
Roland McGrath44210112008-01-30 13:31:50 +0100263 for (i = 0; i < 8; i++, twd >>= 1) {
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100264 if (twd & 0x1) {
265 st = FPREG_ADDR(fxsave, (i - tos) & 7);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100267 switch (st->exponent & 0x7fff) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 case 0x7fff:
Roland McGrath44210112008-01-30 13:31:50 +0100269 tag = FP_EXP_TAG_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 break;
271 case 0x0000:
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100272 if (!st->significand[0] &&
273 !st->significand[1] &&
274 !st->significand[2] &&
Roland McGrath44210112008-01-30 13:31:50 +0100275 !st->significand[3])
276 tag = FP_EXP_TAG_ZERO;
277 else
278 tag = FP_EXP_TAG_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 break;
280 default:
Roland McGrath44210112008-01-30 13:31:50 +0100281 if (st->significand[3] & 0x8000)
282 tag = FP_EXP_TAG_VALID;
283 else
284 tag = FP_EXP_TAG_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 break;
286 }
287 } else {
Roland McGrath44210112008-01-30 13:31:50 +0100288 tag = FP_EXP_TAG_EMPTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 }
Roland McGrath44210112008-01-30 13:31:50 +0100290 ret |= tag << (2 * i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 }
292 return ret;
293}
294
295/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 * FXSR floating point environment conversions.
297 */
298
Ingo Molnarf6689642008-03-05 15:37:32 +0100299static void
300convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
Suresh Siddha61c46282008-03-10 15:28:04 -0700302 struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
Roland McGrath44210112008-01-30 13:31:50 +0100303 struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
304 struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 int i;
306
Roland McGrath44210112008-01-30 13:31:50 +0100307 env->cwd = fxsave->cwd | 0xffff0000u;
308 env->swd = fxsave->swd | 0xffff0000u;
309 env->twd = twd_fxsr_to_i387(fxsave);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310
Roland McGrath44210112008-01-30 13:31:50 +0100311#ifdef CONFIG_X86_64
312 env->fip = fxsave->rip;
313 env->foo = fxsave->rdp;
314 if (tsk == current) {
315 /*
316 * should be actually ds/cs at fpu exception time, but
317 * that information is not available in 64bit mode.
318 */
Ingo Molnarf6689642008-03-05 15:37:32 +0100319 asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
320 asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
Roland McGrath44210112008-01-30 13:31:50 +0100321 } else {
322 struct pt_regs *regs = task_pt_regs(tsk);
Ingo Molnarf6689642008-03-05 15:37:32 +0100323
Roland McGrath44210112008-01-30 13:31:50 +0100324 env->fos = 0xffff0000 | tsk->thread.ds;
325 env->fcs = regs->cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 }
Roland McGrath44210112008-01-30 13:31:50 +0100327#else
328 env->fip = fxsave->fip;
Jan Beulich609b5292008-03-05 08:35:14 +0000329 env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
Roland McGrath44210112008-01-30 13:31:50 +0100330 env->foo = fxsave->foo;
331 env->fos = fxsave->fos;
332#endif
333
334 for (i = 0; i < 8; ++i)
335 memcpy(&to[i], &from[i], sizeof(to[0]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336}
337
Roland McGrath44210112008-01-30 13:31:50 +0100338static void convert_to_fxsr(struct task_struct *tsk,
339 const struct user_i387_ia32_struct *env)
340
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341{
Suresh Siddha61c46282008-03-10 15:28:04 -0700342 struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
Roland McGrath44210112008-01-30 13:31:50 +0100343 struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
344 struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 int i;
346
Roland McGrath44210112008-01-30 13:31:50 +0100347 fxsave->cwd = env->cwd;
348 fxsave->swd = env->swd;
349 fxsave->twd = twd_i387_to_fxsr(env->twd);
350 fxsave->fop = (u16) ((u32) env->fcs >> 16);
351#ifdef CONFIG_X86_64
352 fxsave->rip = env->fip;
353 fxsave->rdp = env->foo;
354 /* cs and ds ignored */
355#else
356 fxsave->fip = env->fip;
357 fxsave->fcs = (env->fcs & 0xffff);
358 fxsave->foo = env->foo;
359 fxsave->fos = env->fos;
360#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
Roland McGrath44210112008-01-30 13:31:50 +0100362 for (i = 0; i < 8; ++i)
363 memcpy(&to[i], &from[i], sizeof(from[0]));
364}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365
Roland McGrath44210112008-01-30 13:31:50 +0100366int fpregs_get(struct task_struct *target, const struct user_regset *regset,
367 unsigned int pos, unsigned int count,
368 void *kbuf, void __user *ubuf)
369{
370 struct user_i387_ia32_struct env;
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700371 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700373 ret = init_fpu(target);
374 if (ret)
375 return ret;
Roland McGrath44210112008-01-30 13:31:50 +0100376
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700377 if (!HAVE_HWFP)
378 return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
379
Ingo Molnarf6689642008-03-05 15:37:32 +0100380 if (!cpu_has_fxsr) {
Roland McGrath44210112008-01-30 13:31:50 +0100381 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
Suresh Siddha61c46282008-03-10 15:28:04 -0700382 &target->thread.xstate->fsave, 0,
383 -1);
Ingo Molnarf6689642008-03-05 15:37:32 +0100384 }
Roland McGrath44210112008-01-30 13:31:50 +0100385
386 if (kbuf && pos == 0 && count == sizeof(env)) {
387 convert_from_fxsr(kbuf, target);
388 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 }
Roland McGrath44210112008-01-30 13:31:50 +0100390
391 convert_from_fxsr(&env, target);
Ingo Molnarf6689642008-03-05 15:37:32 +0100392
Roland McGrath44210112008-01-30 13:31:50 +0100393 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
394}
395
396int fpregs_set(struct task_struct *target, const struct user_regset *regset,
397 unsigned int pos, unsigned int count,
398 const void *kbuf, const void __user *ubuf)
399{
400 struct user_i387_ia32_struct env;
401 int ret;
402
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700403 ret = init_fpu(target);
404 if (ret)
405 return ret;
406
Roland McGrath44210112008-01-30 13:31:50 +0100407 set_stopped_child_used_math(target);
408
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700409 if (!HAVE_HWFP)
410 return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
411
Ingo Molnarf6689642008-03-05 15:37:32 +0100412 if (!cpu_has_fxsr) {
Roland McGrath44210112008-01-30 13:31:50 +0100413 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
Suresh Siddha61c46282008-03-10 15:28:04 -0700414 &target->thread.xstate->fsave, 0, -1);
Ingo Molnarf6689642008-03-05 15:37:32 +0100415 }
Roland McGrath44210112008-01-30 13:31:50 +0100416
417 if (pos > 0 || count < sizeof(env))
418 convert_from_fxsr(&env, target);
419
420 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
421 if (!ret)
422 convert_to_fxsr(target, &env);
423
Suresh Siddha42deec62008-07-29 10:29:26 -0700424 /*
425 * update the header bit in the xsave header, indicating the
426 * presence of FP.
427 */
428 if (cpu_has_xsave)
429 target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
Roland McGrath44210112008-01-30 13:31:50 +0100430 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431}
432
433/*
434 * Signal frame handlers.
435 */
436
Roland McGrath44210112008-01-30 13:31:50 +0100437static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438{
439 struct task_struct *tsk = current;
Suresh Siddha61c46282008-03-10 15:28:04 -0700440 struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441
Suresh Siddha61c46282008-03-10 15:28:04 -0700442 fp->status = fp->swd;
443 if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 return -1;
445 return 1;
446}
447
Roland McGrath44210112008-01-30 13:31:50 +0100448static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449{
450 struct task_struct *tsk = current;
Suresh Siddha61c46282008-03-10 15:28:04 -0700451 struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
Roland McGrath44210112008-01-30 13:31:50 +0100452 struct user_i387_ia32_struct env;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 int err = 0;
454
Roland McGrath44210112008-01-30 13:31:50 +0100455 convert_from_fxsr(&env, tsk);
456 if (__copy_to_user(buf, &env, sizeof(env)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 return -1;
458
Suresh Siddha61c46282008-03-10 15:28:04 -0700459 err |= __put_user(fx->swd, &buf->status);
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100460 err |= __put_user(X86_FXSR_MAGIC, &buf->magic);
461 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 return -1;
463
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700464 if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 return -1;
466 return 1;
467}
468
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700469static int save_i387_xsave(void __user *buf)
470{
Suresh Siddha04944b72008-10-07 14:04:28 -0700471 struct task_struct *tsk = current;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700472 struct _fpstate_ia32 __user *fx = buf;
473 int err = 0;
474
Suresh Siddha04944b72008-10-07 14:04:28 -0700475 /*
476 * For legacy compatible, we always set FP/SSE bits in the bit
477 * vector while saving the state to the user context.
478 * This will enable us capturing any changes(during sigreturn) to
479 * the FP/SSE bits by the legacy applications which don't touch
480 * xstate_bv in the xsave header.
481 *
482 * xsave aware applications can change the xstate_bv in the xsave
483 * header as well as change any contents in the memory layout.
484 * xrestore as part of sigreturn will capture all the changes.
485 */
486 tsk->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
487
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700488 if (save_i387_fxsave(fx) < 0)
489 return -1;
490
491 err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32,
492 sizeof(struct _fpx_sw_bytes));
493 err |= __put_user(FP_XSTATE_MAGIC2,
494 (__u32 __user *) (buf + sig_xstate_ia32_size
495 - FP_XSTATE_MAGIC2_SIZE));
496 if (err)
497 return -1;
498
499 return 1;
500}
501
Suresh Siddhaab513702008-07-29 10:29:22 -0700502int save_i387_xstate_ia32(void __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503{
Suresh Siddhaab513702008-07-29 10:29:22 -0700504 struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
505 struct task_struct *tsk = current;
506
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100507 if (!used_math())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 return 0;
Suresh Siddhaab513702008-07-29 10:29:22 -0700509
510 if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size))
511 return -EACCES;
Ingo Molnarf6689642008-03-05 15:37:32 +0100512 /*
513 * This will cause a "finit" to be triggered by the next
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 * attempted FPU operation by the 'current' process.
515 */
516 clear_used_math();
517
Ingo Molnarf6689642008-03-05 15:37:32 +0100518 if (!HAVE_HWFP) {
Roland McGrath44210112008-01-30 13:31:50 +0100519 return fpregs_soft_get(current, NULL,
520 0, sizeof(struct user_i387_ia32_struct),
Suresh Siddhaab513702008-07-29 10:29:22 -0700521 NULL, fp) ? -1 : 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 }
Ingo Molnarf6689642008-03-05 15:37:32 +0100523
Suresh Siddhaab513702008-07-29 10:29:22 -0700524 unlazy_fpu(tsk);
525
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700526 if (cpu_has_xsave)
527 return save_i387_xsave(fp);
Ingo Molnarf6689642008-03-05 15:37:32 +0100528 if (cpu_has_fxsr)
Suresh Siddhaab513702008-07-29 10:29:22 -0700529 return save_i387_fxsave(fp);
Ingo Molnarf6689642008-03-05 15:37:32 +0100530 else
Suresh Siddhaab513702008-07-29 10:29:22 -0700531 return save_i387_fsave(fp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532}
533
Roland McGrath44210112008-01-30 13:31:50 +0100534static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535{
536 struct task_struct *tsk = current;
Ingo Molnarf6689642008-03-05 15:37:32 +0100537
Suresh Siddha61c46282008-03-10 15:28:04 -0700538 return __copy_from_user(&tsk->thread.xstate->fsave, buf,
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100539 sizeof(struct i387_fsave_struct));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540}
541
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700542static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf,
543 unsigned int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 struct task_struct *tsk = current;
Roland McGrath44210112008-01-30 13:31:50 +0100546 struct user_i387_ia32_struct env;
Ingo Molnarf6689642008-03-05 15:37:32 +0100547 int err;
548
Suresh Siddha61c46282008-03-10 15:28:04 -0700549 err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0],
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700550 size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 /* mxcsr reserved bits must be masked to zero for security reasons */
Suresh Siddha61c46282008-03-10 15:28:04 -0700552 tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
Roland McGrath44210112008-01-30 13:31:50 +0100553 if (err || __copy_from_user(&env, buf, sizeof(env)))
554 return 1;
555 convert_to_fxsr(tsk, &env);
Ingo Molnarf6689642008-03-05 15:37:32 +0100556
Roland McGrath44210112008-01-30 13:31:50 +0100557 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558}
559
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700560static int restore_i387_xsave(void __user *buf)
561{
562 struct _fpx_sw_bytes fx_sw_user;
563 struct _fpstate_ia32 __user *fx_user =
564 ((struct _fpstate_ia32 __user *) buf);
565 struct i387_fxsave_struct __user *fx =
566 (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
567 struct xsave_hdr_struct *xsave_hdr =
568 &current->thread.xstate->xsave.xsave_hdr;
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700569 u64 mask;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700570 int err;
571
572 if (check_for_xstate(fx, buf, &fx_sw_user))
573 goto fx_only;
574
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700575 mask = fx_sw_user.xstate_bv;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700576
577 err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
578
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700579 xsave_hdr->xstate_bv &= pcntxt_mask;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700580 /*
581 * These bits must be zero.
582 */
583 xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
584
585 /*
586 * Init the state that is not present in the memory layout
587 * and enabled by the OS.
588 */
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700589 mask = ~(pcntxt_mask & ~mask);
590 xsave_hdr->xstate_bv &= mask;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700591
592 return err;
593fx_only:
594 /*
595 * Couldn't find the extended state information in the memory
596 * layout. Restore the FP/SSE and init the other extended state
597 * enabled by the OS.
598 */
599 xsave_hdr->xstate_bv = XSTATE_FPSSE;
600 return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct));
601}
602
Suresh Siddhaab513702008-07-29 10:29:22 -0700603int restore_i387_xstate_ia32(void __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604{
605 int err;
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700606 struct task_struct *tsk = current;
Suresh Siddhaab513702008-07-29 10:29:22 -0700607 struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700609 if (HAVE_HWFP)
Suresh Siddhafd3c3ed2008-05-07 12:09:52 -0700610 clear_fpu(tsk);
611
Suresh Siddhaab513702008-07-29 10:29:22 -0700612 if (!buf) {
613 if (used_math()) {
614 clear_fpu(tsk);
615 clear_used_math();
616 }
617
618 return 0;
619 } else
620 if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size))
621 return -EACCES;
622
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700623 if (!used_math()) {
624 err = init_fpu(tsk);
625 if (err)
626 return err;
627 }
Suresh Siddhafd3c3ed2008-05-07 12:09:52 -0700628
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700629 if (HAVE_HWFP) {
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700630 if (cpu_has_xsave)
631 err = restore_i387_xsave(buf);
632 else if (cpu_has_fxsr)
633 err = restore_i387_fxsave(fp, sizeof(struct
634 i387_fxsave_struct));
Ingo Molnarf6689642008-03-05 15:37:32 +0100635 else
Suresh Siddhaab513702008-07-29 10:29:22 -0700636 err = restore_i387_fsave(fp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 } else {
Roland McGrath44210112008-01-30 13:31:50 +0100638 err = fpregs_soft_set(current, NULL,
639 0, sizeof(struct user_i387_ia32_struct),
Suresh Siddhaab513702008-07-29 10:29:22 -0700640 NULL, fp) != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 }
642 set_used_math();
Ingo Molnarf6689642008-03-05 15:37:32 +0100643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 return err;
645}
646
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647/*
648 * FPU state for core dumps.
Roland McGrath60b3b9a2008-01-30 13:31:55 +0100649 * This is only used for a.out dumps now.
650 * It is declared generically using elf_fpregset_t (which is
651 * struct user_i387_struct) but is in fact only used for 32-bit
652 * dumps, so on 64-bit it is really struct user_i387_ia32_struct.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100654int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 struct task_struct *tsk = current;
Ingo Molnarf6689642008-03-05 15:37:32 +0100657 int fpvalid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658
659 fpvalid = !!used_math();
Roland McGrath60b3b9a2008-01-30 13:31:55 +0100660 if (fpvalid)
661 fpvalid = !fpregs_get(tsk, NULL,
662 0, sizeof(struct user_i387_ia32_struct),
663 fpu, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
665 return fpvalid;
666}
Alexey Dobriyan129f6942005-06-23 00:08:33 -0700667EXPORT_SYMBOL(dump_fpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Roland McGrath60b3b9a2008-01-30 13:31:55 +0100669#endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */