From b7b71725fb9584454bfe5f231223bd63421798fb Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:31:50 +0100 Subject: x86: i387 renaming This renames arch/x86/kernel/{i387_32.c => i387.c}. This is a pure renaming, but paves the way for merging the 32-bit and 64-bit versions of this code. Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/i387.c | 551 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 551 insertions(+) create mode 100644 arch/x86/kernel/i387.c (limited to 'arch/x86/kernel/i387.c') diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c new file mode 100644 index 000000000000..bebe03463461 --- /dev/null +++ b/arch/x86/kernel/i387.c @@ -0,0 +1,551 @@ +/* + * Copyright (C) 1994 Linus Torvalds + * + * Pentium III FXSR, SSE support + * General FPU state handling cleanups + * Gareth Hughes , May 2000 + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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(¤t->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(¤t->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(¤t->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; +} -- cgit v1.2.3