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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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090011#include <linux/slab.h>
Ingo Molnarf6689642008-03-05 15:37:32 +010012
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <asm/sigcontext.h>
Ingo Molnarf6689642008-03-05 15:37:32 +010014#include <asm/processor.h>
15#include <asm/math_emu.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <asm/uaccess.h>
Ingo Molnarf6689642008-03-05 15:37:32 +010017#include <asm/ptrace.h>
18#include <asm/i387.h>
19#include <asm/user.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Roland McGrath44210112008-01-30 13:31:50 +010021#ifdef CONFIG_X86_64
Ingo Molnarf6689642008-03-05 15:37:32 +010022# include <asm/sigcontext32.h>
23# include <asm/user32.h>
Roland McGrath44210112008-01-30 13:31:50 +010024#else
Suresh Siddhaab513702008-07-29 10:29:22 -070025# define save_i387_xstate_ia32 save_i387_xstate
26# define restore_i387_xstate_ia32 restore_i387_xstate
Ingo Molnarf6689642008-03-05 15:37:32 +010027# define _fpstate_ia32 _fpstate
Suresh Siddhaab513702008-07-29 10:29:22 -070028# define _xstate_ia32 _xstate
Suresh Siddha3c1c7f12008-07-29 10:29:21 -070029# define sig_xstate_ia32_size sig_xstate_size
Suresh Siddhac37b5ef2008-07-29 10:29:25 -070030# define fx_sw_reserved_ia32 fx_sw_reserved
Ingo Molnarf6689642008-03-05 15:37:32 +010031# define user_i387_ia32_struct user_i387_struct
32# define user32_fxsr_struct user_fxsr_struct
Roland McGrath44210112008-01-30 13:31:50 +010033#endif
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#ifdef CONFIG_MATH_EMULATION
Ingo Molnarf6689642008-03-05 15:37:32 +010036# define HAVE_HWFP (boot_cpu_data.hard_math)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#else
Ingo Molnarf6689642008-03-05 15:37:32 +010038# define HAVE_HWFP 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#endif
40
Ingo Molnarf6689642008-03-05 15:37:32 +010041static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
Suresh Siddha61c46282008-03-10 15:28:04 -070042unsigned int xstate_size;
Suresh Siddha3c1c7f12008-07-29 10:29:21 -070043unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
Suresh Siddha61c46282008-03-10 15:28:04 -070044static struct i387_fxsave_struct fx_scratch __cpuinitdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Suresh Siddha61c46282008-03-10 15:28:04 -070046void __cpuinit mxcsr_feature_mask_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070047{
48 unsigned long mask = 0;
Ingo Molnarf6689642008-03-05 15:37:32 +010049
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 clts();
51 if (cpu_has_fxsr) {
Suresh Siddha61c46282008-03-10 15:28:04 -070052 memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
53 asm volatile("fxsave %0" : : "m" (fx_scratch));
54 mask = fx_scratch.mxcsr_mask;
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +010055 if (mask == 0)
56 mask = 0x0000ffbf;
57 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 mxcsr_feature_mask &= mask;
59 stts();
60}
61
Rakib Mullick9bc646f2008-11-20 19:08:45 +060062void __cpuinit init_thread_xstate(void)
Suresh Siddha61c46282008-03-10 15:28:04 -070063{
Suresh Siddhae8a496a2008-05-23 16:26:37 -070064 if (!HAVE_HWFP) {
65 xstate_size = sizeof(struct i387_soft_struct);
66 return;
67 }
68
Suresh Siddhadc1e35c2008-07-29 10:29:19 -070069 if (cpu_has_xsave) {
70 xsave_cntxt_init();
71 return;
72 }
73
Suresh Siddha61c46282008-03-10 15:28:04 -070074 if (cpu_has_fxsr)
75 xstate_size = sizeof(struct i387_fxsave_struct);
76#ifdef CONFIG_X86_32
77 else
78 xstate_size = sizeof(struct i387_fsave_struct);
79#endif
Suresh Siddha61c46282008-03-10 15:28:04 -070080}
81
Roland McGrath44210112008-01-30 13:31:50 +010082#ifdef CONFIG_X86_64
83/*
84 * Called at bootup to set up the initial FPU state that is later cloned
85 * into all processes.
86 */
87void __cpuinit fpu_init(void)
88{
89 unsigned long oldcr0 = read_cr0();
Ingo Molnarf6689642008-03-05 15:37:32 +010090
Roland McGrath44210112008-01-30 13:31:50 +010091 set_in_cr4(X86_CR4_OSFXSR);
92 set_in_cr4(X86_CR4_OSXMMEXCPT);
93
Ingo Molnarf6689642008-03-05 15:37:32 +010094 write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
Roland McGrath44210112008-01-30 13:31:50 +010095
Suresh Siddhadc1e35c2008-07-29 10:29:19 -070096 /*
97 * Boot processor to setup the FP and extended state context info.
98 */
99 if (!smp_processor_id())
100 init_thread_xstate();
101 xsave_init();
102
Roland McGrath44210112008-01-30 13:31:50 +0100103 mxcsr_feature_mask_init();
104 /* clean state in init */
Avi Kivityc9ad4882010-05-06 11:45:45 +0300105 current_thread_info()->status = 0;
Roland McGrath44210112008-01-30 13:31:50 +0100106 clear_used_math();
107}
108#endif /* CONFIG_X86_64 */
109
Avi Kivity86603282010-05-06 11:45:46 +0300110static void fpu_finit(struct fpu *fpu)
111{
112#ifdef CONFIG_X86_32
113 if (!HAVE_HWFP) {
114 finit_soft_fpu(&fpu->state->soft);
115 return;
116 }
117#endif
118
119 if (cpu_has_fxsr) {
120 struct i387_fxsave_struct *fx = &fpu->state->fxsave;
121
122 memset(fx, 0, xstate_size);
123 fx->cwd = 0x37f;
124 if (cpu_has_xmm)
125 fx->mxcsr = MXCSR_DEFAULT;
126 } else {
127 struct i387_fsave_struct *fp = &fpu->state->fsave;
128 memset(fp, 0, xstate_size);
129 fp->cwd = 0xffff037fu;
130 fp->swd = 0xffff0000u;
131 fp->twd = 0xffffffffu;
132 fp->fos = 0xffff0000u;
133 }
134}
135
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136/*
137 * The _current_ task is using the FPU for the first time
138 * so initialize it and set the mxcsr to its default
139 * value at reset if we support XMM instructions and then
140 * remeber the current task has used the FPU.
141 */
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700142int init_fpu(struct task_struct *tsk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
Avi Kivity86603282010-05-06 11:45:46 +0300144 int ret;
145
Roland McGrath44210112008-01-30 13:31:50 +0100146 if (tsk_used_math(tsk)) {
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700147 if (HAVE_HWFP && tsk == current)
Roland McGrath44210112008-01-30 13:31:50 +0100148 unlazy_fpu(tsk);
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700149 return 0;
150 }
151
152 /*
153 * Memory allocation at the first usage of the FPU and other state.
154 */
Avi Kivity86603282010-05-06 11:45:46 +0300155 ret = fpu_alloc(&tsk->thread.fpu);
156 if (ret)
157 return ret;
Roland McGrath44210112008-01-30 13:31:50 +0100158
Avi Kivity86603282010-05-06 11:45:46 +0300159 fpu_finit(&tsk->thread.fpu);
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700160
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 set_stopped_child_used_math(tsk);
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700162 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}
164
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800165/*
166 * The xstateregs_active() routine is the same as the fpregs_active() routine,
167 * as the "regset->n" for the xstate regset will be updated based on the feature
168 * capabilites supported by the xsave.
169 */
Roland McGrath44210112008-01-30 13:31:50 +0100170int fpregs_active(struct task_struct *target, const struct user_regset *regset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171{
Roland McGrath44210112008-01-30 13:31:50 +0100172 return tsk_used_math(target) ? regset->n : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173}
Roland McGrath44210112008-01-30 13:31:50 +0100174
175int xfpregs_active(struct task_struct *target, const struct user_regset *regset)
176{
177 return (cpu_has_fxsr && tsk_used_math(target)) ? regset->n : 0;
178}
179
180int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
181 unsigned int pos, unsigned int count,
182 void *kbuf, void __user *ubuf)
183{
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700184 int ret;
185
Roland McGrath44210112008-01-30 13:31:50 +0100186 if (!cpu_has_fxsr)
187 return -ENODEV;
188
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700189 ret = init_fpu(target);
190 if (ret)
191 return ret;
Roland McGrath44210112008-01-30 13:31:50 +0100192
Suresh Siddha29104e12010-07-19 16:05:49 -0700193 sanitize_i387_state(target);
194
Roland McGrath44210112008-01-30 13:31:50 +0100195 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
Avi Kivity86603282010-05-06 11:45:46 +0300196 &target->thread.fpu.state->fxsave, 0, -1);
Roland McGrath44210112008-01-30 13:31:50 +0100197}
198
199int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
200 unsigned int pos, unsigned int count,
201 const void *kbuf, const void __user *ubuf)
202{
203 int ret;
204
205 if (!cpu_has_fxsr)
206 return -ENODEV;
207
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700208 ret = init_fpu(target);
209 if (ret)
210 return ret;
211
Suresh Siddha29104e12010-07-19 16:05:49 -0700212 sanitize_i387_state(target);
213
Roland McGrath44210112008-01-30 13:31:50 +0100214 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
Avi Kivity86603282010-05-06 11:45:46 +0300215 &target->thread.fpu.state->fxsave, 0, -1);
Roland McGrath44210112008-01-30 13:31:50 +0100216
217 /*
218 * mxcsr reserved bits must be masked to zero for security reasons.
219 */
Avi Kivity86603282010-05-06 11:45:46 +0300220 target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
Roland McGrath44210112008-01-30 13:31:50 +0100221
Suresh Siddha42deec62008-07-29 10:29:26 -0700222 /*
223 * update the header bits in the xsave header, indicating the
224 * presence of FP and SSE state.
225 */
226 if (cpu_has_xsave)
Avi Kivity86603282010-05-06 11:45:46 +0300227 target->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
Suresh Siddha42deec62008-07-29 10:29:26 -0700228
Roland McGrath44210112008-01-30 13:31:50 +0100229 return ret;
230}
231
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800232int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
233 unsigned int pos, unsigned int count,
234 void *kbuf, void __user *ubuf)
235{
236 int ret;
237
238 if (!cpu_has_xsave)
239 return -ENODEV;
240
241 ret = init_fpu(target);
242 if (ret)
243 return ret;
244
245 /*
Suresh Siddhaff7fbc72010-02-22 14:51:33 -0800246 * Copy the 48bytes defined by the software first into the xstate
247 * memory layout in the thread struct, so that we can copy the entire
248 * xstateregs to the user using one user_regset_copyout().
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800249 */
Avi Kivity86603282010-05-06 11:45:46 +0300250 memcpy(&target->thread.fpu.state->fxsave.sw_reserved,
Suresh Siddhaff7fbc72010-02-22 14:51:33 -0800251 xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800252
253 /*
Suresh Siddhaff7fbc72010-02-22 14:51:33 -0800254 * Copy the xstate memory layout.
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800255 */
256 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
Avi Kivity86603282010-05-06 11:45:46 +0300257 &target->thread.fpu.state->xsave, 0, -1);
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800258 return ret;
259}
260
261int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
262 unsigned int pos, unsigned int count,
263 const void *kbuf, const void __user *ubuf)
264{
265 int ret;
266 struct xsave_hdr_struct *xsave_hdr;
267
268 if (!cpu_has_xsave)
269 return -ENODEV;
270
271 ret = init_fpu(target);
272 if (ret)
273 return ret;
274
275 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
Avi Kivity86603282010-05-06 11:45:46 +0300276 &target->thread.fpu.state->xsave, 0, -1);
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800277
278 /*
279 * mxcsr reserved bits must be masked to zero for security reasons.
280 */
Avi Kivity86603282010-05-06 11:45:46 +0300281 target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800282
Avi Kivity86603282010-05-06 11:45:46 +0300283 xsave_hdr = &target->thread.fpu.state->xsave.xsave_hdr;
Suresh Siddha5b3efd52010-02-11 11:50:59 -0800284
285 xsave_hdr->xstate_bv &= pcntxt_mask;
286 /*
287 * These bits must be zero.
288 */
289 xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
290
291 return ret;
292}
293
Roland McGrath44210112008-01-30 13:31:50 +0100294#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296/*
297 * FPU tag word conversions.
298 */
299
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100300static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
302 unsigned int tmp; /* to avoid 16 bit prefixes in the code */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100303
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 /* Transform each pair of bits into 01 (valid) or 00 (empty) */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100305 tmp = ~twd;
Roland McGrath44210112008-01-30 13:31:50 +0100306 tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100307 /* and move the valid bits to the lower byte. */
308 tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
309 tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
310 tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
Ingo Molnarf6689642008-03-05 15:37:32 +0100311
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100312 return tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313}
314
Roland McGrath44210112008-01-30 13:31:50 +0100315#define FPREG_ADDR(f, n) ((void *)&(f)->st_space + (n) * 16);
316#define FP_EXP_TAG_VALID 0
317#define FP_EXP_TAG_ZERO 1
318#define FP_EXP_TAG_SPECIAL 2
319#define FP_EXP_TAG_EMPTY 3
320
321static inline u32 twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322{
Roland McGrath44210112008-01-30 13:31:50 +0100323 struct _fpxreg *st;
324 u32 tos = (fxsave->swd >> 11) & 7;
325 u32 twd = (unsigned long) fxsave->twd;
326 u32 tag;
327 u32 ret = 0xffff0000u;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 int i;
329
Roland McGrath44210112008-01-30 13:31:50 +0100330 for (i = 0; i < 8; i++, twd >>= 1) {
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100331 if (twd & 0x1) {
332 st = FPREG_ADDR(fxsave, (i - tos) & 7);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100334 switch (st->exponent & 0x7fff) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 case 0x7fff:
Roland McGrath44210112008-01-30 13:31:50 +0100336 tag = FP_EXP_TAG_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 break;
338 case 0x0000:
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100339 if (!st->significand[0] &&
340 !st->significand[1] &&
341 !st->significand[2] &&
Roland McGrath44210112008-01-30 13:31:50 +0100342 !st->significand[3])
343 tag = FP_EXP_TAG_ZERO;
344 else
345 tag = FP_EXP_TAG_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 break;
347 default:
Roland McGrath44210112008-01-30 13:31:50 +0100348 if (st->significand[3] & 0x8000)
349 tag = FP_EXP_TAG_VALID;
350 else
351 tag = FP_EXP_TAG_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 break;
353 }
354 } else {
Roland McGrath44210112008-01-30 13:31:50 +0100355 tag = FP_EXP_TAG_EMPTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 }
Roland McGrath44210112008-01-30 13:31:50 +0100357 ret |= tag << (2 * i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 }
359 return ret;
360}
361
362/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 * FXSR floating point environment conversions.
364 */
365
Ingo Molnarf6689642008-03-05 15:37:32 +0100366static void
367convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368{
Avi Kivity86603282010-05-06 11:45:46 +0300369 struct i387_fxsave_struct *fxsave = &tsk->thread.fpu.state->fxsave;
Roland McGrath44210112008-01-30 13:31:50 +0100370 struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
371 struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 int i;
373
Roland McGrath44210112008-01-30 13:31:50 +0100374 env->cwd = fxsave->cwd | 0xffff0000u;
375 env->swd = fxsave->swd | 0xffff0000u;
376 env->twd = twd_fxsr_to_i387(fxsave);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
Roland McGrath44210112008-01-30 13:31:50 +0100378#ifdef CONFIG_X86_64
379 env->fip = fxsave->rip;
380 env->foo = fxsave->rdp;
381 if (tsk == current) {
382 /*
383 * should be actually ds/cs at fpu exception time, but
384 * that information is not available in 64bit mode.
385 */
Ingo Molnarf6689642008-03-05 15:37:32 +0100386 asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
387 asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
Roland McGrath44210112008-01-30 13:31:50 +0100388 } else {
389 struct pt_regs *regs = task_pt_regs(tsk);
Ingo Molnarf6689642008-03-05 15:37:32 +0100390
Roland McGrath44210112008-01-30 13:31:50 +0100391 env->fos = 0xffff0000 | tsk->thread.ds;
392 env->fcs = regs->cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 }
Roland McGrath44210112008-01-30 13:31:50 +0100394#else
395 env->fip = fxsave->fip;
Jan Beulich609b5292008-03-05 08:35:14 +0000396 env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
Roland McGrath44210112008-01-30 13:31:50 +0100397 env->foo = fxsave->foo;
398 env->fos = fxsave->fos;
399#endif
400
401 for (i = 0; i < 8; ++i)
402 memcpy(&to[i], &from[i], sizeof(to[0]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403}
404
Roland McGrath44210112008-01-30 13:31:50 +0100405static void convert_to_fxsr(struct task_struct *tsk,
406 const struct user_i387_ia32_struct *env)
407
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408{
Avi Kivity86603282010-05-06 11:45:46 +0300409 struct i387_fxsave_struct *fxsave = &tsk->thread.fpu.state->fxsave;
Roland McGrath44210112008-01-30 13:31:50 +0100410 struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
411 struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 int i;
413
Roland McGrath44210112008-01-30 13:31:50 +0100414 fxsave->cwd = env->cwd;
415 fxsave->swd = env->swd;
416 fxsave->twd = twd_i387_to_fxsr(env->twd);
417 fxsave->fop = (u16) ((u32) env->fcs >> 16);
418#ifdef CONFIG_X86_64
419 fxsave->rip = env->fip;
420 fxsave->rdp = env->foo;
421 /* cs and ds ignored */
422#else
423 fxsave->fip = env->fip;
424 fxsave->fcs = (env->fcs & 0xffff);
425 fxsave->foo = env->foo;
426 fxsave->fos = env->fos;
427#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
Roland McGrath44210112008-01-30 13:31:50 +0100429 for (i = 0; i < 8; ++i)
430 memcpy(&to[i], &from[i], sizeof(from[0]));
431}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
Roland McGrath44210112008-01-30 13:31:50 +0100433int fpregs_get(struct task_struct *target, const struct user_regset *regset,
434 unsigned int pos, unsigned int count,
435 void *kbuf, void __user *ubuf)
436{
437 struct user_i387_ia32_struct env;
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700438 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700440 ret = init_fpu(target);
441 if (ret)
442 return ret;
Roland McGrath44210112008-01-30 13:31:50 +0100443
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700444 if (!HAVE_HWFP)
445 return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
446
Ingo Molnarf6689642008-03-05 15:37:32 +0100447 if (!cpu_has_fxsr) {
Roland McGrath44210112008-01-30 13:31:50 +0100448 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
Avi Kivity86603282010-05-06 11:45:46 +0300449 &target->thread.fpu.state->fsave, 0,
Suresh Siddha61c46282008-03-10 15:28:04 -0700450 -1);
Ingo Molnarf6689642008-03-05 15:37:32 +0100451 }
Roland McGrath44210112008-01-30 13:31:50 +0100452
Suresh Siddha29104e12010-07-19 16:05:49 -0700453 sanitize_i387_state(target);
454
Roland McGrath44210112008-01-30 13:31:50 +0100455 if (kbuf && pos == 0 && count == sizeof(env)) {
456 convert_from_fxsr(kbuf, target);
457 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 }
Roland McGrath44210112008-01-30 13:31:50 +0100459
460 convert_from_fxsr(&env, target);
Ingo Molnarf6689642008-03-05 15:37:32 +0100461
Roland McGrath44210112008-01-30 13:31:50 +0100462 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
463}
464
465int fpregs_set(struct task_struct *target, const struct user_regset *regset,
466 unsigned int pos, unsigned int count,
467 const void *kbuf, const void __user *ubuf)
468{
469 struct user_i387_ia32_struct env;
470 int ret;
471
Suresh Siddhaaa283f42008-03-10 15:28:05 -0700472 ret = init_fpu(target);
473 if (ret)
474 return ret;
475
Suresh Siddha29104e12010-07-19 16:05:49 -0700476 sanitize_i387_state(target);
477
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700478 if (!HAVE_HWFP)
479 return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
480
Ingo Molnarf6689642008-03-05 15:37:32 +0100481 if (!cpu_has_fxsr) {
Roland McGrath44210112008-01-30 13:31:50 +0100482 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
Avi Kivity86603282010-05-06 11:45:46 +0300483 &target->thread.fpu.state->fsave, 0, -1);
Ingo Molnarf6689642008-03-05 15:37:32 +0100484 }
Roland McGrath44210112008-01-30 13:31:50 +0100485
486 if (pos > 0 || count < sizeof(env))
487 convert_from_fxsr(&env, target);
488
489 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
490 if (!ret)
491 convert_to_fxsr(target, &env);
492
Suresh Siddha42deec62008-07-29 10:29:26 -0700493 /*
494 * update the header bit in the xsave header, indicating the
495 * presence of FP.
496 */
497 if (cpu_has_xsave)
Avi Kivity86603282010-05-06 11:45:46 +0300498 target->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
Roland McGrath44210112008-01-30 13:31:50 +0100499 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500}
501
502/*
503 * Signal frame handlers.
504 */
505
Roland McGrath44210112008-01-30 13:31:50 +0100506static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507{
508 struct task_struct *tsk = current;
Avi Kivity86603282010-05-06 11:45:46 +0300509 struct i387_fsave_struct *fp = &tsk->thread.fpu.state->fsave;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
Suresh Siddha61c46282008-03-10 15:28:04 -0700511 fp->status = fp->swd;
512 if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 return -1;
514 return 1;
515}
516
Roland McGrath44210112008-01-30 13:31:50 +0100517static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518{
519 struct task_struct *tsk = current;
Avi Kivity86603282010-05-06 11:45:46 +0300520 struct i387_fxsave_struct *fx = &tsk->thread.fpu.state->fxsave;
Roland McGrath44210112008-01-30 13:31:50 +0100521 struct user_i387_ia32_struct env;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 int err = 0;
523
Roland McGrath44210112008-01-30 13:31:50 +0100524 convert_from_fxsr(&env, tsk);
525 if (__copy_to_user(buf, &env, sizeof(env)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 return -1;
527
Suresh Siddha61c46282008-03-10 15:28:04 -0700528 err |= __put_user(fx->swd, &buf->status);
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100529 err |= __put_user(X86_FXSR_MAGIC, &buf->magic);
530 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 return -1;
532
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700533 if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 return -1;
535 return 1;
536}
537
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700538static int save_i387_xsave(void __user *buf)
539{
Suresh Siddha04944b72008-10-07 14:04:28 -0700540 struct task_struct *tsk = current;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700541 struct _fpstate_ia32 __user *fx = buf;
542 int err = 0;
543
Suresh Siddha29104e12010-07-19 16:05:49 -0700544
545 sanitize_i387_state(tsk);
546
Suresh Siddha04944b72008-10-07 14:04:28 -0700547 /*
548 * For legacy compatible, we always set FP/SSE bits in the bit
549 * vector while saving the state to the user context.
550 * This will enable us capturing any changes(during sigreturn) to
551 * the FP/SSE bits by the legacy applications which don't touch
552 * xstate_bv in the xsave header.
553 *
554 * xsave aware applications can change the xstate_bv in the xsave
555 * header as well as change any contents in the memory layout.
556 * xrestore as part of sigreturn will capture all the changes.
557 */
Avi Kivity86603282010-05-06 11:45:46 +0300558 tsk->thread.fpu.state->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
Suresh Siddha04944b72008-10-07 14:04:28 -0700559
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700560 if (save_i387_fxsave(fx) < 0)
561 return -1;
562
563 err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32,
564 sizeof(struct _fpx_sw_bytes));
565 err |= __put_user(FP_XSTATE_MAGIC2,
566 (__u32 __user *) (buf + sig_xstate_ia32_size
567 - FP_XSTATE_MAGIC2_SIZE));
568 if (err)
569 return -1;
570
571 return 1;
572}
573
Suresh Siddhaab513702008-07-29 10:29:22 -0700574int save_i387_xstate_ia32(void __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575{
Suresh Siddhaab513702008-07-29 10:29:22 -0700576 struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
577 struct task_struct *tsk = current;
578
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100579 if (!used_math())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 return 0;
Suresh Siddhaab513702008-07-29 10:29:22 -0700581
582 if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size))
583 return -EACCES;
Ingo Molnarf6689642008-03-05 15:37:32 +0100584 /*
585 * This will cause a "finit" to be triggered by the next
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 * attempted FPU operation by the 'current' process.
587 */
588 clear_used_math();
589
Ingo Molnarf6689642008-03-05 15:37:32 +0100590 if (!HAVE_HWFP) {
Roland McGrath44210112008-01-30 13:31:50 +0100591 return fpregs_soft_get(current, NULL,
592 0, sizeof(struct user_i387_ia32_struct),
Suresh Siddhaab513702008-07-29 10:29:22 -0700593 NULL, fp) ? -1 : 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 }
Ingo Molnarf6689642008-03-05 15:37:32 +0100595
Suresh Siddhaab513702008-07-29 10:29:22 -0700596 unlazy_fpu(tsk);
597
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700598 if (cpu_has_xsave)
599 return save_i387_xsave(fp);
Ingo Molnarf6689642008-03-05 15:37:32 +0100600 if (cpu_has_fxsr)
Suresh Siddhaab513702008-07-29 10:29:22 -0700601 return save_i387_fxsave(fp);
Ingo Molnarf6689642008-03-05 15:37:32 +0100602 else
Suresh Siddhaab513702008-07-29 10:29:22 -0700603 return save_i387_fsave(fp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604}
605
Roland McGrath44210112008-01-30 13:31:50 +0100606static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607{
608 struct task_struct *tsk = current;
Ingo Molnarf6689642008-03-05 15:37:32 +0100609
Avi Kivity86603282010-05-06 11:45:46 +0300610 return __copy_from_user(&tsk->thread.fpu.state->fsave, buf,
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100611 sizeof(struct i387_fsave_struct));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612}
613
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700614static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf,
615 unsigned int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 struct task_struct *tsk = current;
Roland McGrath44210112008-01-30 13:31:50 +0100618 struct user_i387_ia32_struct env;
Ingo Molnarf6689642008-03-05 15:37:32 +0100619 int err;
620
Avi Kivity86603282010-05-06 11:45:46 +0300621 err = __copy_from_user(&tsk->thread.fpu.state->fxsave, &buf->_fxsr_env[0],
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700622 size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 /* mxcsr reserved bits must be masked to zero for security reasons */
Avi Kivity86603282010-05-06 11:45:46 +0300624 tsk->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
Roland McGrath44210112008-01-30 13:31:50 +0100625 if (err || __copy_from_user(&env, buf, sizeof(env)))
626 return 1;
627 convert_to_fxsr(tsk, &env);
Ingo Molnarf6689642008-03-05 15:37:32 +0100628
Roland McGrath44210112008-01-30 13:31:50 +0100629 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630}
631
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700632static int restore_i387_xsave(void __user *buf)
633{
634 struct _fpx_sw_bytes fx_sw_user;
635 struct _fpstate_ia32 __user *fx_user =
636 ((struct _fpstate_ia32 __user *) buf);
637 struct i387_fxsave_struct __user *fx =
638 (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
639 struct xsave_hdr_struct *xsave_hdr =
Avi Kivity86603282010-05-06 11:45:46 +0300640 &current->thread.fpu.state->xsave.xsave_hdr;
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700641 u64 mask;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700642 int err;
643
644 if (check_for_xstate(fx, buf, &fx_sw_user))
645 goto fx_only;
646
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700647 mask = fx_sw_user.xstate_bv;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700648
649 err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
650
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700651 xsave_hdr->xstate_bv &= pcntxt_mask;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700652 /*
653 * These bits must be zero.
654 */
655 xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
656
657 /*
658 * Init the state that is not present in the memory layout
659 * and enabled by the OS.
660 */
H. Peter Anvin6152e4b2008-07-29 17:23:16 -0700661 mask = ~(pcntxt_mask & ~mask);
662 xsave_hdr->xstate_bv &= mask;
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700663
664 return err;
665fx_only:
666 /*
667 * Couldn't find the extended state information in the memory
668 * layout. Restore the FP/SSE and init the other extended state
669 * enabled by the OS.
670 */
671 xsave_hdr->xstate_bv = XSTATE_FPSSE;
672 return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct));
673}
674
Suresh Siddhaab513702008-07-29 10:29:22 -0700675int restore_i387_xstate_ia32(void __user *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676{
677 int err;
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700678 struct task_struct *tsk = current;
Suresh Siddhaab513702008-07-29 10:29:22 -0700679 struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700681 if (HAVE_HWFP)
Suresh Siddhafd3c3ed2008-05-07 12:09:52 -0700682 clear_fpu(tsk);
683
Suresh Siddhaab513702008-07-29 10:29:22 -0700684 if (!buf) {
685 if (used_math()) {
686 clear_fpu(tsk);
687 clear_used_math();
688 }
689
690 return 0;
691 } else
692 if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size))
693 return -EACCES;
694
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700695 if (!used_math()) {
696 err = init_fpu(tsk);
697 if (err)
698 return err;
699 }
Suresh Siddhafd3c3ed2008-05-07 12:09:52 -0700700
Suresh Siddhae8a496a2008-05-23 16:26:37 -0700701 if (HAVE_HWFP) {
Suresh Siddhac37b5ef2008-07-29 10:29:25 -0700702 if (cpu_has_xsave)
703 err = restore_i387_xsave(buf);
704 else if (cpu_has_fxsr)
705 err = restore_i387_fxsave(fp, sizeof(struct
706 i387_fxsave_struct));
Ingo Molnarf6689642008-03-05 15:37:32 +0100707 else
Suresh Siddhaab513702008-07-29 10:29:22 -0700708 err = restore_i387_fsave(fp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 } else {
Roland McGrath44210112008-01-30 13:31:50 +0100710 err = fpregs_soft_set(current, NULL,
711 0, sizeof(struct user_i387_ia32_struct),
Suresh Siddhaab513702008-07-29 10:29:22 -0700712 NULL, fp) != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 }
714 set_used_math();
Ingo Molnarf6689642008-03-05 15:37:32 +0100715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 return err;
717}
718
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719/*
720 * FPU state for core dumps.
Roland McGrath60b3b9a2008-01-30 13:31:55 +0100721 * This is only used for a.out dumps now.
722 * It is declared generically using elf_fpregset_t (which is
723 * struct user_i387_struct) but is in fact only used for 32-bit
724 * dumps, so on 64-bit it is really struct user_i387_ia32_struct.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 */
Cyrill Gorcunov3b095a02008-01-30 13:31:26 +0100726int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 struct task_struct *tsk = current;
Ingo Molnarf6689642008-03-05 15:37:32 +0100729 int fpvalid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730
731 fpvalid = !!used_math();
Roland McGrath60b3b9a2008-01-30 13:31:55 +0100732 if (fpvalid)
733 fpvalid = !fpregs_get(tsk, NULL,
734 0, sizeof(struct user_i387_ia32_struct),
735 fpu, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 return fpvalid;
738}
Alexey Dobriyan129f6942005-06-23 00:08:33 -0700739EXPORT_SYMBOL(dump_fpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740
Roland McGrath60b3b9a2008-01-30 13:31:55 +0100741#endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */