[mirror_ubuntu-bionic-kernel.git] / arch / x86 / kernel / i387.c

/*
 *  Copyright (C) 1994 Linus Torvalds
 *
 *  Pentium III FXSR, SSE support
 *  General FPU state handling cleanups
 *	Gareth Hughes <gareth@valinux.com>, May 2000
 */

#include <linux/sched.h>
#include <linux/module.h>
#include <asm/processor.h>
#include <asm/i387.h>
#include <asm/math_emu.h>
#include <asm/sigcontext.h>
#include <asm/user.h>
#include <asm/ptrace.h>
#include <asm/uaccess.h>

#ifdef CONFIG_MATH_EMULATION
#define HAVE_HWFP (boot_cpu_data.hard_math)
#else
#define HAVE_HWFP 1
#endif

static unsigned long mxcsr_feature_mask __read_mostly = 0xffffffff;

void mxcsr_feature_mask_init(void)
{
	unsigned long mask = 0;
	clts();
	if (cpu_has_fxsr) {
		memset(&current->thread.i387.fxsave, 0,
		       sizeof(struct i387_fxsave_struct));
		asm volatile("fxsave %0" : : "m" (current->thread.i387.fxsave));
		mask = current->thread.i387.fxsave.mxcsr_mask;
		if (mask == 0)
			mask = 0x0000ffbf;
	}
	mxcsr_feature_mask &= mask;
	stts();
}

/*
 * The _current_ task is using the FPU for the first time
 * so initialize it and set the mxcsr to its default
 * value at reset if we support XMM instructions and then
 * remeber the current task has used the FPU.
 */
void init_fpu(struct task_struct *tsk)
{
	if (cpu_has_fxsr) {
		memset(&tsk->thread.i387.fxsave, 0,
		       sizeof(struct i387_fxsave_struct));
		tsk->thread.i387.fxsave.cwd = 0x37f;
		if (cpu_has_xmm)
			tsk->thread.i387.fxsave.mxcsr = 0x1f80;
	} else {
		memset(&tsk->thread.i387.fsave, 0,
		       sizeof(struct i387_fsave_struct));
		tsk->thread.i387.fsave.cwd = 0xffff037fu;
		tsk->thread.i387.fsave.swd = 0xffff0000u;
		tsk->thread.i387.fsave.twd = 0xffffffffu;
		tsk->thread.i387.fsave.fos = 0xffff0000u;
	}
	/* only the device not available exception
	 * or ptrace can call init_fpu */
	set_stopped_child_used_math(tsk);
}

/*
 * FPU lazy state save handling.
 */

void kernel_fpu_begin(void)
{
	struct thread_info *thread = current_thread_info();

	preempt_disable();
	if (thread->status & TS_USEDFPU) {
		__save_init_fpu(thread->task);
		return;
	}
	clts();
}
EXPORT_SYMBOL_GPL(kernel_fpu_begin);

/*
 * FPU tag word conversions.
 */

static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
{
	unsigned int tmp; /* to avoid 16 bit prefixes in the code */

	/* Transform each pair of bits into 01 (valid) or 00 (empty) */
	tmp = ~twd;
	tmp = (tmp | (tmp >> 1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
	/* and move the valid bits to the lower byte. */
	tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
	tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
	tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */

	return tmp;
}

static inline unsigned long twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
{
	struct _fpxreg *st = NULL;
	unsigned long tos = (fxsave->swd >> 11) & 7;
	unsigned long twd = (unsigned long) fxsave->twd;
	unsigned long tag;
	unsigned long ret = 0xffff0000u;
	int i;

#define FPREG_ADDR(f, n)	((void *)&(f)->st_space + (n) * 16);

	for (i = 0; i < 8; i++) {
		if (twd & 0x1) {
			st = FPREG_ADDR(fxsave, (i - tos) & 7);

			switch (st->exponent & 0x7fff) {
			case 0x7fff:
				tag = 2;		/* Special */
				break;
			case 0x0000:
				if (!st->significand[0] &&
				    !st->significand[1] &&
				    !st->significand[2] &&
				    !st->significand[3]) {
					tag = 1;	/* Zero */
				} else {
					tag = 2;	/* Special */
				}
				break;
			default:
				if (st->significand[3] & 0x8000) {
					tag = 0;	/* Valid */
				} else {
					tag = 2;	/* Special */
				}
				break;
			}
		} else {
			tag = 3;			/* Empty */
		}
		ret |= (tag << (2 * i));
		twd = twd >> 1;
	}
	return ret;
}

/*
 * FPU state interaction.
 */

unsigned short get_fpu_cwd(struct task_struct *tsk)
{
	if (cpu_has_fxsr) {
		return tsk->thread.i387.fxsave.cwd;
	} else {
		return (unsigned short)tsk->thread.i387.fsave.cwd;
	}
}

unsigned short get_fpu_swd(struct task_struct *tsk)
{
	if (cpu_has_fxsr) {
		return tsk->thread.i387.fxsave.swd;
	} else {
		return (unsigned short)tsk->thread.i387.fsave.swd;
	}
}

#if 0
unsigned short get_fpu_twd(struct task_struct *tsk)
{
	if (cpu_has_fxsr) {
		return tsk->thread.i387.fxsave.twd;
	} else {
		return (unsigned short)tsk->thread.i387.fsave.twd;
	}
}
#endif  /*  0  */

unsigned short get_fpu_mxcsr(struct task_struct *tsk)
{
	if (cpu_has_xmm) {
		return tsk->thread.i387.fxsave.mxcsr;
	} else {
		return 0x1f80;
	}
}

#if 0

void set_fpu_cwd(struct task_struct *tsk, unsigned short cwd)
{
	if (cpu_has_fxsr) {
		tsk->thread.i387.fxsave.cwd = cwd;
	} else {
		tsk->thread.i387.fsave.cwd = ((long)cwd | 0xffff0000u);
	}
}

void set_fpu_swd(struct task_struct *tsk, unsigned short swd)
{
	if (cpu_has_fxsr) {
		tsk->thread.i387.fxsave.swd = swd;
	} else {
		tsk->thread.i387.fsave.swd = ((long)swd | 0xffff0000u);
	}
}

void set_fpu_twd(struct task_struct *tsk, unsigned short twd)
{
	if (cpu_has_fxsr) {
		tsk->thread.i387.fxsave.twd = twd_i387_to_fxsr(twd);
	} else {
		tsk->thread.i387.fsave.twd = ((long)twd | 0xffff0000u);
	}
}

#endif  /*  0  */

/*
 * FXSR floating point environment conversions.
 */

static int convert_fxsr_to_user(struct _fpstate __user *buf,
				struct i387_fxsave_struct *fxsave)
{
	unsigned long env[7];
	struct _fpreg __user *to;
	struct _fpxreg *from;
	int i;

	env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
	env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
	env[2] = twd_fxsr_to_i387(fxsave);
	env[3] = fxsave->fip;
	env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
	env[5] = fxsave->foo;
	env[6] = fxsave->fos;

	if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
		return 1;

	to = &buf->_st[0];
	from = (struct _fpxreg *) &fxsave->st_space[0];
	for (i = 0; i < 8; i++, to++, from++) {
		unsigned long __user *t = (unsigned long __user *)to;
		unsigned long *f = (unsigned long *)from;

		if (__put_user(*f, t) ||
		    __put_user(*(f + 1), t + 1) ||
		    __put_user(from->exponent, &to->exponent))
			return 1;
	}
	return 0;
}

static int convert_fxsr_from_user(struct i387_fxsave_struct *fxsave,
				  struct _fpstate __user *buf)
{
	unsigned long env[7];
	struct _fpxreg *to;
	struct _fpreg __user *from;
	int i;

	if (__copy_from_user(env, buf, 7 * sizeof(long)))
		return 1;

	fxsave->cwd = (unsigned short)(env[0] & 0xffff);
	fxsave->swd = (unsigned short)(env[1] & 0xffff);
	fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
	fxsave->fip = env[3];
	fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
	fxsave->fcs = (env[4] & 0xffff);
	fxsave->foo = env[5];
	fxsave->fos = env[6];

	to = (struct _fpxreg *) &fxsave->st_space[0];
	from = &buf->_st[0];
	for (i = 0; i < 8; i++, to++, from++) {
		unsigned long *t = (unsigned long *)to;
		unsigned long __user *f = (unsigned long __user *)from;

		if (__get_user(*t, f) ||
		    __get_user(*(t + 1), f + 1) ||
		    __get_user(to->exponent, &from->exponent))
			return 1;
	}
	return 0;
}

/*
 * Signal frame handlers.
 */

static inline int save_i387_fsave(struct _fpstate __user *buf)
{
	struct task_struct *tsk = current;

	unlazy_fpu(tsk);
	tsk->thread.i387.fsave.status = tsk->thread.i387.fsave.swd;
	if (__copy_to_user(buf, &tsk->thread.i387.fsave,
			   sizeof(struct i387_fsave_struct)))
		return -1;
	return 1;
}

static int save_i387_fxsave(struct _fpstate __user *buf)
{
	struct task_struct *tsk = current;
	int err = 0;

	unlazy_fpu(tsk);

	if (convert_fxsr_to_user(buf, &tsk->thread.i387.fxsave))
		return -1;

	err |= __put_user(tsk->thread.i387.fxsave.swd, &buf->status);
	err |= __put_user(X86_FXSR_MAGIC, &buf->magic);
	if (err)
		return -1;

	if (__copy_to_user(&buf->_fxsr_env[0], &tsk->thread.i387.fxsave,
			   sizeof(struct i387_fxsave_struct)))
		return -1;
	return 1;
}

int save_i387(struct _fpstate __user *buf)
{
	if (!used_math())
		return 0;

	/* This will cause a "finit" to be triggered by the next
	 * attempted FPU operation by the 'current' process.
	 */
	clear_used_math();

	if (HAVE_HWFP) {
		if (cpu_has_fxsr) {
			return save_i387_fxsave(buf);
		} else {
			return save_i387_fsave(buf);
		}
	} else {
		return save_i387_soft(&current->thread.i387.soft, buf);
	}
}

static inline int restore_i387_fsave(struct _fpstate __user *buf)
{
	struct task_struct *tsk = current;
	clear_fpu(tsk);
	return __copy_from_user(&tsk->thread.i387.fsave, buf,
				sizeof(struct i387_fsave_struct));
}

static int restore_i387_fxsave(struct _fpstate __user *buf)
{
	int err;
	struct task_struct *tsk = current;
	clear_fpu(tsk);
	err = __copy_from_user(&tsk->thread.i387.fxsave, &buf->_fxsr_env[0],
			       sizeof(struct i387_fxsave_struct));
	/* mxcsr reserved bits must be masked to zero for security reasons */
	tsk->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
	return err ? 1 : convert_fxsr_from_user(&tsk->thread.i387.fxsave, buf);
}

int restore_i387(struct _fpstate __user *buf)
{
	int err;

	if (HAVE_HWFP) {
		if (cpu_has_fxsr) {
			err = restore_i387_fxsave(buf);
		} else {
			err = restore_i387_fsave(buf);
		}
	} else {
		err = restore_i387_soft(&current->thread.i387.soft, buf);
	}
	set_used_math();
	return err;
}

/*
 * ptrace request handlers.
 */

static inline int get_fpregs_fsave(struct user_i387_struct __user *buf,
				   struct task_struct *tsk)
{
	return __copy_to_user(buf, &tsk->thread.i387.fsave,
			      sizeof(struct user_i387_struct));
}

static inline int get_fpregs_fxsave(struct user_i387_struct __user *buf,
				    struct task_struct *tsk)
{
	return convert_fxsr_to_user((struct _fpstate __user *)buf,
				    &tsk->thread.i387.fxsave);
}

int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *tsk)
{
	if (HAVE_HWFP) {
		if (cpu_has_fxsr) {
			return get_fpregs_fxsave(buf, tsk);
		} else {
			return get_fpregs_fsave(buf, tsk);
		}
	} else {
		return save_i387_soft(&tsk->thread.i387.soft,
				      (struct _fpstate __user *)buf);
	}
}

static inline int set_fpregs_fsave(struct task_struct *tsk,
				   struct user_i387_struct __user *buf)
{
	return __copy_from_user(&tsk->thread.i387.fsave, buf,
				sizeof(struct user_i387_struct));
}

static inline int set_fpregs_fxsave(struct task_struct *tsk,
				    struct user_i387_struct __user *buf)
{
	return convert_fxsr_from_user(&tsk->thread.i387.fxsave,
				      (struct _fpstate __user *)buf);
}

int set_fpregs(struct task_struct *tsk, struct user_i387_struct __user *buf)
{
	if (HAVE_HWFP) {
		if (cpu_has_fxsr) {
			return set_fpregs_fxsave(tsk, buf);
		} else {
			return set_fpregs_fsave(tsk, buf);
		}
	} else {
		return restore_i387_soft(&tsk->thread.i387.soft,
					 (struct _fpstate __user *)buf);
	}
}

int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *tsk)
{
	if (cpu_has_fxsr) {
		if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
				   sizeof(struct user_fxsr_struct)))
			return -EFAULT;
		return 0;
	} else {
		return -EIO;
	}
}

int set_fpxregs(struct task_struct *tsk, struct user_fxsr_struct __user *buf)
{
	int ret = 0;

	if (cpu_has_fxsr) {
		if (__copy_from_user(&tsk->thread.i387.fxsave, buf,
				     sizeof(struct user_fxsr_struct)))
			ret = -EFAULT;
		/* mxcsr reserved bits must be masked to zero
		 * for security reasons */
		tsk->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
	} else {
		ret = -EIO;
	}
	return ret;
}

/*
 * FPU state for core dumps.
 */

static inline void copy_fpu_fsave(struct task_struct *tsk,
				  struct user_i387_struct *fpu)
{
	memcpy(fpu, &tsk->thread.i387.fsave,
	       sizeof(struct user_i387_struct));
}

static inline void copy_fpu_fxsave(struct task_struct *tsk,
				   struct user_i387_struct *fpu)
{
	unsigned short *to;
	unsigned short *from;
	int i;

	memcpy(fpu, &tsk->thread.i387.fxsave, 7 * sizeof(long));

	to = (unsigned short *)&fpu->st_space[0];
	from = (unsigned short *)&tsk->thread.i387.fxsave.st_space[0];
	for (i = 0; i < 8; i++, to += 5, from += 8)
		memcpy(to, from, 5 * sizeof(unsigned short));
}

int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
{
	int fpvalid;
	struct task_struct *tsk = current;

	fpvalid = !!used_math();
	if (fpvalid) {
		unlazy_fpu(tsk);
		if (cpu_has_fxsr) {
			copy_fpu_fxsave(tsk, fpu);
		} else {
			copy_fpu_fsave(tsk, fpu);
		}
	}

	return fpvalid;
}
EXPORT_SYMBOL(dump_fpu);

int dump_task_fpu(struct task_struct *tsk, struct user_i387_struct *fpu)
{
	int fpvalid = !!tsk_used_math(tsk);

	if (fpvalid) {
		if (tsk == current)
			unlazy_fpu(tsk);
		if (cpu_has_fxsr)
			copy_fpu_fxsave(tsk, fpu);
		else
			copy_fpu_fsave(tsk, fpu);
	}
	return fpvalid;
}

int dump_task_extended_fpu(struct task_struct *tsk,
			   struct user_fxsr_struct *fpu)
{
	int fpvalid = tsk_used_math(tsk) && cpu_has_fxsr;

	if (fpvalid) {
		if (tsk == current)
		       unlazy_fpu(tsk);
		memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(*fpu));
	}
	return fpvalid;
}
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	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	*/
	8
1da177e4	9	#include <linux/sched.h>
129f6946	10	#include <linux/module.h>
1da177e4 LT	11	#include <asm/processor.h>
	12	#include <asm/i387.h>
	13	#include <asm/math_emu.h>
	14	#include <asm/sigcontext.h>
	15	#include <asm/user.h>
	16	#include <asm/ptrace.h>
	17	#include <asm/uaccess.h>
	18
	19	#ifdef CONFIG_MATH_EMULATION
	20	#define HAVE_HWFP (boot_cpu_data.hard_math)
	21	#else
	22	#define HAVE_HWFP 1
	23	#endif
	24
7b0c2d92	25	static unsigned long mxcsr_feature_mask __read_mostly = 0xffffffff;
1da177e4 LT	26
	27	void mxcsr_feature_mask_init(void)
	28	{
	29	unsigned long mask = 0;
	30	clts();
	31	if (cpu_has_fxsr) {
3b095a04 CG	32	memset(&current->thread.i387.fxsave, 0,
	33	sizeof(struct i387_fxsave_struct));
	34	asm volatile("fxsave %0" : : "m" (current->thread.i387.fxsave));
1da177e4	35	mask = current->thread.i387.fxsave.mxcsr_mask;
3b095a04 CG	36	if (mask == 0)
	37	mask = 0x0000ffbf;
	38	}
1da177e4 LT	39	mxcsr_feature_mask &= mask;
	40	stts();
	41	}
	42
	43	/*
	44	* The _current_ task is using the FPU for the first time
	45	* so initialize it and set the mxcsr to its default
	46	* value at reset if we support XMM instructions and then
	47	* remeber the current task has used the FPU.
	48	*/
	49	void init_fpu(struct task_struct *tsk)
	50	{
	51	if (cpu_has_fxsr) {
3b095a04 CG	52	memset(&tsk->thread.i387.fxsave, 0,
3b095a04 CG	53	sizeof(struct i387_fxsave_struct));
1da177e4 LT	54	tsk->thread.i387.fxsave.cwd = 0x37f;
	55	if (cpu_has_xmm)
	56	tsk->thread.i387.fxsave.mxcsr = 0x1f80;
	57	} else {
3b095a04 CG	58	memset(&tsk->thread.i387.fsave, 0,
3b095a04 CG	59	sizeof(struct i387_fsave_struct));
1da177e4 LT	60	tsk->thread.i387.fsave.cwd = 0xffff037fu;
	61	tsk->thread.i387.fsave.swd = 0xffff0000u;
	62	tsk->thread.i387.fsave.twd = 0xffffffffu;
	63	tsk->thread.i387.fsave.fos = 0xffff0000u;
	64	}
3b095a04 CG	65	/* only the device not available exception
3b095a04 CG	66	* or ptrace can call init_fpu */
1da177e4 LT	67	set_stopped_child_used_math(tsk);
	68	}
	69
	70	/*
	71	* FPU lazy state save handling.
	72	*/
	73
	74	void kernel_fpu_begin(void)
	75	{
	76	struct thread_info *thread = current_thread_info();
	77
	78	preempt_disable();
	79	if (thread->status & TS_USEDFPU) {
	80	__save_init_fpu(thread->task);
	81	return;
	82	}
	83	clts();
	84	}
129f6946	85	EXPORT_SYMBOL_GPL(kernel_fpu_begin);
1da177e4	86
1da177e4 LT	87	/*
	88	* FPU tag word conversions.
	89	*/
	90
3b095a04	91	static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
1da177e4 LT	92	{
1da177e4 LT	93	unsigned int tmp; /* to avoid 16 bit prefixes in the code */
3b095a04	94
1da177e4	95	/* Transform each pair of bits into 01 (valid) or 00 (empty) */
3b095a04 CG	96	tmp = ~twd;
	97	tmp = (tmp \| (tmp >> 1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
	98	/* and move the valid bits to the lower byte. */
	99	tmp = (tmp \| (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
	100	tmp = (tmp \| (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
	101	tmp = (tmp \| (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
	102
	103	return tmp;
1da177e4 LT	104	}
1da177e4 LT	105
3b095a04	106	static inline unsigned long twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
1da177e4 LT	107	{
	108	struct _fpxreg *st = NULL;
	109	unsigned long tos = (fxsave->swd >> 11) & 7;
	110	unsigned long twd = (unsigned long) fxsave->twd;
	111	unsigned long tag;
	112	unsigned long ret = 0xffff0000u;
	113	int i;
	114
	115	#define FPREG_ADDR(f, n) ((void )&(f)->st_space + (n) 16);
	116
3b095a04 CG	117	for (i = 0; i < 8; i++) {
	118	if (twd & 0x1) {
	119	st = FPREG_ADDR(fxsave, (i - tos) & 7);
1da177e4	120
3b095a04	121	switch (st->exponent & 0x7fff) {
1da177e4 LT	122	case 0x7fff:
	123	tag = 2; /* Special */
	124	break;
	125	case 0x0000:
3b095a04 CG	126	if (!st->significand[0] &&
	127	!st->significand[1] &&
	128	!st->significand[2] &&
	129	!st->significand[3]) {
1da177e4 LT	130	tag = 1; /* Zero */
	131	} else {
	132	tag = 2; /* Special */
	133	}
	134	break;
	135	default:
3b095a04	136	if (st->significand[3] & 0x8000) {
1da177e4 LT	137	tag = 0; /* Valid */
	138	} else {
	139	tag = 2; /* Special */
	140	}
	141	break;
	142	}
	143	} else {
	144	tag = 3; /* Empty */
	145	}
	146	ret \|= (tag << (2 * i));
	147	twd = twd >> 1;
	148	}
	149	return ret;
	150	}
	151
	152	/*
	153	* FPU state interaction.
	154	*/
	155
3b095a04	156	unsigned short get_fpu_cwd(struct task_struct *tsk)
1da177e4	157	{
3b095a04	158	if (cpu_has_fxsr) {
1da177e4 LT	159	return tsk->thread.i387.fxsave.cwd;
	160	} else {
	161	return (unsigned short)tsk->thread.i387.fsave.cwd;
	162	}
	163	}
	164
3b095a04	165	unsigned short get_fpu_swd(struct task_struct *tsk)
1da177e4	166	{
3b095a04	167	if (cpu_has_fxsr) {
1da177e4 LT	168	return tsk->thread.i387.fxsave.swd;
	169	} else {
	170	return (unsigned short)tsk->thread.i387.fsave.swd;
	171	}
	172	}
	173
	174	#if 0
3b095a04	175	unsigned short get_fpu_twd(struct task_struct *tsk)
1da177e4	176	{
3b095a04	177	if (cpu_has_fxsr) {
1da177e4 LT	178	return tsk->thread.i387.fxsave.twd;
	179	} else {
	180	return (unsigned short)tsk->thread.i387.fsave.twd;
	181	}
	182	}
	183	#endif /* 0 */
	184
3b095a04	185	unsigned short get_fpu_mxcsr(struct task_struct *tsk)
1da177e4	186	{
3b095a04	187	if (cpu_has_xmm) {
1da177e4 LT	188	return tsk->thread.i387.fxsave.mxcsr;
	189	} else {
	190	return 0x1f80;
	191	}
	192	}
	193
	194	#if 0
	195
3b095a04	196	void set_fpu_cwd(struct task_struct *tsk, unsigned short cwd)
1da177e4	197	{
3b095a04	198	if (cpu_has_fxsr) {
1da177e4 LT	199	tsk->thread.i387.fxsave.cwd = cwd;
	200	} else {
	201	tsk->thread.i387.fsave.cwd = ((long)cwd \| 0xffff0000u);
	202	}
	203	}
	204
3b095a04	205	void set_fpu_swd(struct task_struct *tsk, unsigned short swd)
1da177e4	206	{
3b095a04	207	if (cpu_has_fxsr) {
1da177e4 LT	208	tsk->thread.i387.fxsave.swd = swd;
	209	} else {
	210	tsk->thread.i387.fsave.swd = ((long)swd \| 0xffff0000u);
	211	}
	212	}
	213
3b095a04	214	void set_fpu_twd(struct task_struct *tsk, unsigned short twd)
1da177e4	215	{
3b095a04	216	if (cpu_has_fxsr) {
1da177e4 LT	217	tsk->thread.i387.fxsave.twd = twd_i387_to_fxsr(twd);
	218	} else {
	219	tsk->thread.i387.fsave.twd = ((long)twd \| 0xffff0000u);
	220	}
	221	}
	222
	223	#endif /* 0 */
	224
	225	/*
	226	* FXSR floating point environment conversions.
	227	*/
	228
3b095a04 CG	229	static int convert_fxsr_to_user(struct _fpstate __user *buf,
3b095a04 CG	230	struct i387_fxsave_struct *fxsave)
1da177e4 LT	231	{
	232	unsigned long env[7];
	233	struct _fpreg __user *to;
	234	struct _fpxreg *from;
	235	int i;
	236
	237	env[0] = (unsigned long)fxsave->cwd \| 0xffff0000ul;
	238	env[1] = (unsigned long)fxsave->swd \| 0xffff0000ul;
	239	env[2] = twd_fxsr_to_i387(fxsave);
	240	env[3] = fxsave->fip;
	241	env[4] = fxsave->fcs \| ((unsigned long)fxsave->fop << 16);
	242	env[5] = fxsave->foo;
	243	env[6] = fxsave->fos;
	244
3b095a04	245	if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
1da177e4 LT	246	return 1;
	247
	248	to = &buf->_st[0];
	249	from = (struct _fpxreg *) &fxsave->st_space[0];
3b095a04	250	for (i = 0; i < 8; i++, to++, from++) {
1da177e4 LT	251	unsigned long __user t = (unsigned long __user )to;
	252	unsigned long f = (unsigned long )from;
	253
	254	if (__put_user(*f, t) \|\|
3b095a04 CG	255	__put_user(*(f + 1), t + 1) \|\|
3b095a04 CG	256	__put_user(from->exponent, &to->exponent))
1da177e4 LT	257	return 1;
	258	}
	259	return 0;
	260	}
	261
3b095a04 CG	262	static int convert_fxsr_from_user(struct i387_fxsave_struct *fxsave,
3b095a04 CG	263	struct _fpstate __user *buf)
1da177e4 LT	264	{
	265	unsigned long env[7];
	266	struct _fpxreg *to;
	267	struct _fpreg __user *from;
	268	int i;
	269
3b095a04	270	if (__copy_from_user(env, buf, 7 * sizeof(long)))
1da177e4 LT	271	return 1;
	272
	273	fxsave->cwd = (unsigned short)(env[0] & 0xffff);
	274	fxsave->swd = (unsigned short)(env[1] & 0xffff);
	275	fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
	276	fxsave->fip = env[3];
	277	fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
	278	fxsave->fcs = (env[4] & 0xffff);
	279	fxsave->foo = env[5];
	280	fxsave->fos = env[6];
	281
	282	to = (struct _fpxreg *) &fxsave->st_space[0];
	283	from = &buf->_st[0];
3b095a04	284	for (i = 0; i < 8; i++, to++, from++) {
1da177e4 LT	285	unsigned long t = (unsigned long )to;
	286	unsigned long __user f = (unsigned long __user )from;
	287
	288	if (__get_user(*t, f) \|\|
3b095a04 CG	289	__get_user(*(t + 1), f + 1) \|\|
3b095a04 CG	290	__get_user(to->exponent, &from->exponent))
1da177e4 LT	291	return 1;
	292	}
	293	return 0;
	294	}
	295
	296	/*
	297	* Signal frame handlers.
	298	*/
	299
3b095a04	300	static inline int save_i387_fsave(struct _fpstate __user *buf)
1da177e4 LT	301	{
	302	struct task_struct *tsk = current;
	303
3b095a04	304	unlazy_fpu(tsk);
1da177e4	305	tsk->thread.i387.fsave.status = tsk->thread.i387.fsave.swd;
3b095a04 CG	306	if (__copy_to_user(buf, &tsk->thread.i387.fsave,
3b095a04 CG	307	sizeof(struct i387_fsave_struct)))
1da177e4 LT	308	return -1;
	309	return 1;
	310	}
	311
3b095a04	312	static int save_i387_fxsave(struct _fpstate __user *buf)
1da177e4 LT	313	{
	314	struct task_struct *tsk = current;
	315	int err = 0;
	316
3b095a04	317	unlazy_fpu(tsk);
1da177e4	318
3b095a04	319	if (convert_fxsr_to_user(buf, &tsk->thread.i387.fxsave))
1da177e4 LT	320	return -1;
1da177e4 LT	321
3b095a04 CG	322	err \|= __put_user(tsk->thread.i387.fxsave.swd, &buf->status);
	323	err \|= __put_user(X86_FXSR_MAGIC, &buf->magic);
	324	if (err)
1da177e4 LT	325	return -1;
1da177e4 LT	326
3b095a04 CG	327	if (__copy_to_user(&buf->_fxsr_env[0], &tsk->thread.i387.fxsave,
3b095a04 CG	328	sizeof(struct i387_fxsave_struct)))
1da177e4 LT	329	return -1;
	330	return 1;
	331	}
	332
3b095a04	333	int save_i387(struct _fpstate __user *buf)
1da177e4	334	{
3b095a04	335	if (!used_math())
1da177e4 LT	336	return 0;
	337
	338	/* This will cause a "finit" to be triggered by the next
	339	* attempted FPU operation by the 'current' process.
	340	*/
	341	clear_used_math();
	342
3b095a04 CG	343	if (HAVE_HWFP) {
	344	if (cpu_has_fxsr) {
	345	return save_i387_fxsave(buf);
1da177e4	346	} else {
3b095a04	347	return save_i387_fsave(buf);
1da177e4 LT	348	}
1da177e4 LT	349	} else {
3b095a04	350	return save_i387_soft(&current->thread.i387.soft, buf);
1da177e4 LT	351	}
	352	}
	353
3b095a04	354	static inline int restore_i387_fsave(struct _fpstate __user *buf)
1da177e4 LT	355	{
1da177e4 LT	356	struct task_struct *tsk = current;
3b095a04 CG	357	clear_fpu(tsk);
	358	return __copy_from_user(&tsk->thread.i387.fsave, buf,
	359	sizeof(struct i387_fsave_struct));
1da177e4 LT	360	}
1da177e4 LT	361
3b095a04	362	static int restore_i387_fxsave(struct _fpstate __user *buf)
1da177e4 LT	363	{
	364	int err;
	365	struct task_struct *tsk = current;
3b095a04 CG	366	clear_fpu(tsk);
	367	err = __copy_from_user(&tsk->thread.i387.fxsave, &buf->_fxsr_env[0],
	368	sizeof(struct i387_fxsave_struct));
1da177e4 LT	369	/* mxcsr reserved bits must be masked to zero for security reasons */
1da177e4 LT	370	tsk->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
3b095a04	371	return err ? 1 : convert_fxsr_from_user(&tsk->thread.i387.fxsave, buf);
1da177e4 LT	372	}
1da177e4 LT	373
3b095a04	374	int restore_i387(struct _fpstate __user *buf)
1da177e4 LT	375	{
	376	int err;
	377
3b095a04 CG	378	if (HAVE_HWFP) {
	379	if (cpu_has_fxsr) {
	380	err = restore_i387_fxsave(buf);
1da177e4	381	} else {
3b095a04	382	err = restore_i387_fsave(buf);
1da177e4 LT	383	}
1da177e4 LT	384	} else {
3b095a04	385	err = restore_i387_soft(&current->thread.i387.soft, buf);
1da177e4 LT	386	}
	387	set_used_math();
	388	return err;
	389	}
	390
	391	/*
	392	* ptrace request handlers.
	393	*/
	394
3b095a04 CG	395	static inline int get_fpregs_fsave(struct user_i387_struct __user *buf,
3b095a04 CG	396	struct task_struct *tsk)
1da177e4	397	{
3b095a04 CG	398	return __copy_to_user(buf, &tsk->thread.i387.fsave,
3b095a04 CG	399	sizeof(struct user_i387_struct));
1da177e4 LT	400	}
1da177e4 LT	401
3b095a04 CG	402	static inline int get_fpregs_fxsave(struct user_i387_struct __user *buf,
3b095a04 CG	403	struct task_struct *tsk)
1da177e4	404	{
3b095a04 CG	405	return convert_fxsr_to_user((struct _fpstate __user *)buf,
3b095a04 CG	406	&tsk->thread.i387.fxsave);
1da177e4 LT	407	}
1da177e4 LT	408
3b095a04	409	int get_fpregs(struct user_i387_struct __user buf, struct task_struct tsk)
1da177e4	410	{
3b095a04 CG	411	if (HAVE_HWFP) {
	412	if (cpu_has_fxsr) {
	413	return get_fpregs_fxsave(buf, tsk);
1da177e4	414	} else {
3b095a04	415	return get_fpregs_fsave(buf, tsk);
1da177e4 LT	416	}
1da177e4 LT	417	} else {
3b095a04 CG	418	return save_i387_soft(&tsk->thread.i387.soft,
3b095a04 CG	419	(struct _fpstate __user *)buf);
1da177e4 LT	420	}
	421	}
	422
3b095a04 CG	423	static inline int set_fpregs_fsave(struct task_struct *tsk,
3b095a04 CG	424	struct user_i387_struct __user *buf)
1da177e4	425	{
3b095a04 CG	426	return __copy_from_user(&tsk->thread.i387.fsave, buf,
3b095a04 CG	427	sizeof(struct user_i387_struct));
1da177e4 LT	428	}
1da177e4 LT	429
3b095a04 CG	430	static inline int set_fpregs_fxsave(struct task_struct *tsk,
3b095a04 CG	431	struct user_i387_struct __user *buf)
1da177e4	432	{
3b095a04 CG	433	return convert_fxsr_from_user(&tsk->thread.i387.fxsave,
3b095a04 CG	434	(struct _fpstate __user *)buf);
1da177e4 LT	435	}
1da177e4 LT	436
3b095a04	437	int set_fpregs(struct task_struct tsk, struct user_i387_struct __user buf)
1da177e4	438	{
3b095a04 CG	439	if (HAVE_HWFP) {
	440	if (cpu_has_fxsr) {
	441	return set_fpregs_fxsave(tsk, buf);
1da177e4	442	} else {
3b095a04	443	return set_fpregs_fsave(tsk, buf);
1da177e4 LT	444	}
1da177e4 LT	445	} else {
3b095a04 CG	446	return restore_i387_soft(&tsk->thread.i387.soft,
3b095a04 CG	447	(struct _fpstate __user *)buf);
1da177e4 LT	448	}
	449	}
	450
3b095a04	451	int get_fpxregs(struct user_fxsr_struct __user buf, struct task_struct tsk)
1da177e4	452	{
3b095a04 CG	453	if (cpu_has_fxsr) {
	454	if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
	455	sizeof(struct user_fxsr_struct)))
1da177e4 LT	456	return -EFAULT;
	457	return 0;
	458	} else {
	459	return -EIO;
	460	}
	461	}
	462
3b095a04	463	int set_fpxregs(struct task_struct tsk, struct user_fxsr_struct __user buf)
1da177e4 LT	464	{
	465	int ret = 0;
	466
3b095a04 CG	467	if (cpu_has_fxsr) {
	468	if (__copy_from_user(&tsk->thread.i387.fxsave, buf,
	469	sizeof(struct user_fxsr_struct)))
1da177e4	470	ret = -EFAULT;
3b095a04 CG	471	/* mxcsr reserved bits must be masked to zero
3b095a04 CG	472	* for security reasons */
1da177e4 LT	473	tsk->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
	474	} else {
	475	ret = -EIO;
	476	}
	477	return ret;
	478	}
	479
	480	/*
	481	* FPU state for core dumps.
	482	*/
	483
3b095a04 CG	484	static inline void copy_fpu_fsave(struct task_struct *tsk,
3b095a04 CG	485	struct user_i387_struct *fpu)
1da177e4	486	{
3b095a04 CG	487	memcpy(fpu, &tsk->thread.i387.fsave,
3b095a04 CG	488	sizeof(struct user_i387_struct));
1da177e4 LT	489	}
1da177e4 LT	490
3b095a04 CG	491	static inline void copy_fpu_fxsave(struct task_struct *tsk,
3b095a04 CG	492	struct user_i387_struct *fpu)
1da177e4 LT	493	{
	494	unsigned short *to;
	495	unsigned short *from;
	496	int i;
	497
3b095a04	498	memcpy(fpu, &tsk->thread.i387.fxsave, 7 * sizeof(long));
1da177e4 LT	499
	500	to = (unsigned short *)&fpu->st_space[0];
	501	from = (unsigned short *)&tsk->thread.i387.fxsave.st_space[0];
3b095a04 CG	502	for (i = 0; i < 8; i++, to += 5, from += 8)
3b095a04 CG	503	memcpy(to, from, 5 * sizeof(unsigned short));
1da177e4 LT	504	}
1da177e4 LT	505
3b095a04	506	int dump_fpu(struct pt_regs regs, struct user_i387_struct fpu)
1da177e4 LT	507	{
	508	int fpvalid;
	509	struct task_struct *tsk = current;
	510
	511	fpvalid = !!used_math();
3b095a04 CG	512	if (fpvalid) {
	513	unlazy_fpu(tsk);
	514	if (cpu_has_fxsr) {
	515	copy_fpu_fxsave(tsk, fpu);
1da177e4	516	} else {
3b095a04	517	copy_fpu_fsave(tsk, fpu);
1da177e4 LT	518	}
	519	}
	520
	521	return fpvalid;
	522	}
129f6946	523	EXPORT_SYMBOL(dump_fpu);
1da177e4 LT	524
	525	int dump_task_fpu(struct task_struct tsk, struct user_i387_struct fpu)
	526	{
	527	int fpvalid = !!tsk_used_math(tsk);
	528
	529	if (fpvalid) {
	530	if (tsk == current)
	531	unlazy_fpu(tsk);
	532	if (cpu_has_fxsr)
	533	copy_fpu_fxsave(tsk, fpu);
	534	else
	535	copy_fpu_fsave(tsk, fpu);
	536	}
	537	return fpvalid;
	538	}
	539
3b095a04 CG	540	int dump_task_extended_fpu(struct task_struct *tsk,
3b095a04 CG	541	struct user_fxsr_struct *fpu)
1da177e4 LT	542	{
	543	int fpvalid = tsk_used_math(tsk) && cpu_has_fxsr;
	544
	545	if (fpvalid) {
	546	if (tsk == current)
	547	unlazy_fpu(tsk);
	548	memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(*fpu));
	549	}
	550	return fpvalid;
	551	}