x86, fpu: lazy allocation of FPU area - v5
[linux-2.6.git] / arch / x86 / kernel / i387.c
index bebe034..db6839b 100644 (file)
@@ -5,34 +5,48 @@
  *  General FPU state handling cleanups
  *     Gareth Hughes <gareth@valinux.com>, May 2000
  */
-
-#include <linux/sched.h>
 #include <linux/module.h>
+#include <linux/regset.h>
+#include <linux/sched.h>
+
+#include <asm/sigcontext.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>
+#include <asm/ptrace.h>
+#include <asm/i387.h>
+#include <asm/user.h>
+
+#ifdef CONFIG_X86_64
+# include <asm/sigcontext32.h>
+# include <asm/user32.h>
+#else
+# define save_i387_ia32                save_i387
+# define restore_i387_ia32     restore_i387
+# define _fpstate_ia32         _fpstate
+# define user_i387_ia32_struct user_i387_struct
+# define user32_fxsr_struct    user_fxsr_struct
+#endif
 
 #ifdef CONFIG_MATH_EMULATION
-#define HAVE_HWFP (boot_cpu_data.hard_math)
+# define HAVE_HWFP             (boot_cpu_data.hard_math)
 #else
-#define HAVE_HWFP 1
+# define HAVE_HWFP             1
 #endif
 
-static unsigned long mxcsr_feature_mask __read_mostly = 0xffffffff;
+static unsigned int            mxcsr_feature_mask __read_mostly = 0xffffffffu;
+unsigned int xstate_size;
+static struct i387_fxsave_struct fx_scratch __cpuinitdata;
 
-void mxcsr_feature_mask_init(void)
+void __cpuinit 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;
+               memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
+               asm volatile("fxsave %0" : : "m" (fx_scratch));
+               mask = fx_scratch.mxcsr_mask;
                if (mask == 0)
                        mask = 0x0000ffbf;
        }
@@ -40,49 +54,137 @@ void mxcsr_feature_mask_init(void)
        stts();
 }
 
+void __init init_thread_xstate(void)
+{
+       if (cpu_has_fxsr)
+               xstate_size = sizeof(struct i387_fxsave_struct);
+#ifdef CONFIG_X86_32
+       else
+               xstate_size = sizeof(struct i387_fsave_struct);
+#endif
+}
+
+#ifdef CONFIG_X86_64
+/*
+ * Called at bootup to set up the initial FPU state that is later cloned
+ * into all processes.
+ */
+void __cpuinit fpu_init(void)
+{
+       unsigned long oldcr0 = read_cr0();
+
+       set_in_cr4(X86_CR4_OSFXSR);
+       set_in_cr4(X86_CR4_OSXMMEXCPT);
+
+       write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
+
+       mxcsr_feature_mask_init();
+       /* clean state in init */
+       current_thread_info()->status = 0;
+       clear_used_math();
+}
+#endif /* CONFIG_X86_64 */
+
 /*
  * 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)
+int init_fpu(struct task_struct *tsk)
 {
+       if (tsk_used_math(tsk)) {
+               if (tsk == current)
+                       unlazy_fpu(tsk);
+               return 0;
+       }
+
+       /*
+        * Memory allocation at the first usage of the FPU and other state.
+        */
+       if (!tsk->thread.xstate) {
+               tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
+                                                     GFP_KERNEL);
+               if (!tsk->thread.xstate)
+                       return -ENOMEM;
+       }
+
        if (cpu_has_fxsr) {
-               memset(&tsk->thread.i387.fxsave, 0,
-                      sizeof(struct i387_fxsave_struct));
-               tsk->thread.i387.fxsave.cwd = 0x37f;
+               struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
+
+               memset(fx, 0, xstate_size);
+               fx->cwd = 0x37f;
                if (cpu_has_xmm)
-                       tsk->thread.i387.fxsave.mxcsr = 0x1f80;
+                       fx->mxcsr = MXCSR_DEFAULT;
        } 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;
+               struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
+               memset(fp, 0, xstate_size);
+               fp->cwd = 0xffff037fu;
+               fp->swd = 0xffff0000u;
+               fp->twd = 0xffffffffu;
+               fp->fos = 0xffff0000u;
        }
-       /* only the device not available exception
-        * or ptrace can call init_fpu */
+       /*
+        * Only the device not available exception or ptrace can call init_fpu.
+        */
        set_stopped_child_used_math(tsk);
+       return 0;
 }
 
-/*
- * FPU lazy state save handling.
- */
+int fpregs_active(struct task_struct *target, const struct user_regset *regset)
+{
+       return tsk_used_math(target) ? regset->n : 0;
+}
 
-void kernel_fpu_begin(void)
+int xfpregs_active(struct task_struct *target, const struct user_regset *regset)
 {
-       struct thread_info *thread = current_thread_info();
+       return (cpu_has_fxsr && tsk_used_math(target)) ? regset->n : 0;
+}
 
-       preempt_disable();
-       if (thread->status & TS_USEDFPU) {
-               __save_init_fpu(thread->task);
-               return;
-       }
-       clts();
+int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
+               unsigned int pos, unsigned int count,
+               void *kbuf, void __user *ubuf)
+{
+       int ret;
+
+       if (!cpu_has_fxsr)
+               return -ENODEV;
+
+       ret = init_fpu(target);
+       if (ret)
+               return ret;
+
+       return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  &target->thread.xstate->fxsave, 0, -1);
 }
-EXPORT_SYMBOL_GPL(kernel_fpu_begin);
+
+int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
+               unsigned int pos, unsigned int count,
+               const void *kbuf, const void __user *ubuf)
+{
+       int ret;
+
+       if (!cpu_has_fxsr)
+               return -ENODEV;
+
+       ret = init_fpu(target);
+       if (ret)
+               return ret;
+
+       set_stopped_child_used_math(target);
+
+       ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                &target->thread.xstate->fxsave, 0, -1);
+
+       /*
+        * mxcsr reserved bits must be masked to zero for security reasons.
+        */
+       target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
+
+       return ret;
+}
+
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 
 /*
  * FPU tag word conversions.
@@ -94,7 +196,7 @@ static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
 
        /* Transform each pair of bits into 01 (valid) or 00 (empty) */
        tmp = ~twd;
-       tmp = (tmp | (tmp >> 1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
+       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 */
@@ -103,449 +205,313 @@ static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
        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);
+#define FP_EXP_TAG_VALID       0
+#define FP_EXP_TAG_ZERO                1
+#define FP_EXP_TAG_SPECIAL     2
+#define FP_EXP_TAG_EMPTY       3
+
+static inline u32 twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
+{
+       struct _fpxreg *st;
+       u32 tos = (fxsave->swd >> 11) & 7;
+       u32 twd = (unsigned long) fxsave->twd;
+       u32 tag;
+       u32 ret = 0xffff0000u;
+       int i;
 
-       for (i = 0; i < 8; i++) {
+       for (i = 0; i < 8; i++, twd >>= 1) {
                if (twd & 0x1) {
                        st = FPREG_ADDR(fxsave, (i - tos) & 7);
 
                        switch (st->exponent & 0x7fff) {
                        case 0x7fff:
-                               tag = 2;                /* Special */
+                               tag = FP_EXP_TAG_SPECIAL;
                                break;
                        case 0x0000:
                                if (!st->significand[0] &&
                                    !st->significand[1] &&
                                    !st->significand[2] &&
-                                   !st->significand[3]) {
-                                       tag = 1;        /* Zero */
-                               } else {
-                                       tag = 2;        /* Special */
-                               }
+                                   !st->significand[3])
+                                       tag = FP_EXP_TAG_ZERO;
+                               else
+                                       tag = FP_EXP_TAG_SPECIAL;
                                break;
                        default:
-                               if (st->significand[3] & 0x8000) {
-                                       tag = 0;        /* Valid */
-                               } else {
-                                       tag = 2;        /* Special */
-                               }
+                               if (st->significand[3] & 0x8000)
+                                       tag = FP_EXP_TAG_VALID;
+                               else
+                                       tag = FP_EXP_TAG_SPECIAL;
                                break;
                        }
                } else {
-                       tag = 3;                        /* Empty */
+                       tag = FP_EXP_TAG_EMPTY;
                }
-               ret |= (tag << (2 * i));
-               twd = twd >> 1;
+               ret |= tag << (2 * i);
        }
        return ret;
 }
 
 /*
- * FPU state interaction.
+ * FXSR floating point environment conversions.
  */
 
-unsigned short get_fpu_cwd(struct task_struct *tsk)
+static void
+convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
 {
-       if (cpu_has_fxsr) {
-               return tsk->thread.i387.fxsave.cwd;
-       } else {
-               return (unsigned short)tsk->thread.i387.fsave.cwd;
-       }
-}
+       struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
+       struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
+       struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
+       int i;
 
-unsigned short get_fpu_swd(struct task_struct *tsk)
-{
-       if (cpu_has_fxsr) {
-               return tsk->thread.i387.fxsave.swd;
+       env->cwd = fxsave->cwd | 0xffff0000u;
+       env->swd = fxsave->swd | 0xffff0000u;
+       env->twd = twd_fxsr_to_i387(fxsave);
+
+#ifdef CONFIG_X86_64
+       env->fip = fxsave->rip;
+       env->foo = fxsave->rdp;
+       if (tsk == current) {
+               /*
+                * should be actually ds/cs at fpu exception time, but
+                * that information is not available in 64bit mode.
+                */
+               asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
+               asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
        } else {
-               return (unsigned short)tsk->thread.i387.fsave.swd;
-       }
-}
+               struct pt_regs *regs = task_pt_regs(tsk);
 
-#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;
+               env->fos = 0xffff0000 | tsk->thread.ds;
+               env->fcs = regs->cs;
        }
-}
-#endif  /*  0  */
+#else
+       env->fip = fxsave->fip;
+       env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
+       env->foo = fxsave->foo;
+       env->fos = fxsave->fos;
+#endif
 
-unsigned short get_fpu_mxcsr(struct task_struct *tsk)
-{
-       if (cpu_has_xmm) {
-               return tsk->thread.i387.fxsave.mxcsr;
-       } else {
-               return 0x1f80;
-       }
+       for (i = 0; i < 8; ++i)
+               memcpy(&to[i], &from[i], sizeof(to[0]));
 }
 
-#if 0
+static void convert_to_fxsr(struct task_struct *tsk,
+                           const struct user_i387_ia32_struct *env)
 
-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);
-       }
+       struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
+       struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
+       struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
+       int i;
+
+       fxsave->cwd = env->cwd;
+       fxsave->swd = env->swd;
+       fxsave->twd = twd_i387_to_fxsr(env->twd);
+       fxsave->fop = (u16) ((u32) env->fcs >> 16);
+#ifdef CONFIG_X86_64
+       fxsave->rip = env->fip;
+       fxsave->rdp = env->foo;
+       /* cs and ds ignored */
+#else
+       fxsave->fip = env->fip;
+       fxsave->fcs = (env->fcs & 0xffff);
+       fxsave->foo = env->foo;
+       fxsave->fos = env->fos;
+#endif
+
+       for (i = 0; i < 8; ++i)
+               memcpy(&to[i], &from[i], sizeof(from[0]));
 }
 
-void set_fpu_swd(struct task_struct *tsk, unsigned short swd)
+int fpregs_get(struct task_struct *target, const struct user_regset *regset,
+              unsigned int pos, unsigned int count,
+              void *kbuf, void __user *ubuf)
 {
-       if (cpu_has_fxsr) {
-               tsk->thread.i387.fxsave.swd = swd;
-       } else {
-               tsk->thread.i387.fsave.swd = ((long)swd | 0xffff0000u);
+       struct user_i387_ia32_struct env;
+       int ret;
+
+       if (!HAVE_HWFP)
+               return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
+
+       ret = init_fpu(target);
+       if (ret)
+               return ret;
+
+       if (!cpu_has_fxsr) {
+               return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                          &target->thread.xstate->fsave, 0,
+                                          -1);
        }
-}
 
-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);
+       if (kbuf && pos == 0 && count == sizeof(env)) {
+               convert_from_fxsr(kbuf, target);
+               return 0;
        }
-}
 
-#endif  /*  0  */
+       convert_from_fxsr(&env, target);
 
-/*
- * FXSR floating point environment conversions.
- */
+       return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
+}
 
-static int convert_fxsr_to_user(struct _fpstate __user *buf,
-                               struct i387_fxsave_struct *fxsave)
+int fpregs_set(struct task_struct *target, const struct user_regset *regset,
+              unsigned int pos, unsigned int count,
+              const void *kbuf, const void __user *ubuf)
 {
-       unsigned long env[7];
-       struct _fpreg __user *to;
-       struct _fpxreg *from;
-       int i;
+       struct user_i387_ia32_struct env;
+       int ret;
 
-       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 (!HAVE_HWFP)
+               return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
 
-       if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
-               return 1;
+       ret = init_fpu(target);
+       if (ret)
+               return ret;
 
-       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;
+       set_stopped_child_used_math(target);
 
-               if (__put_user(*f, t) ||
-                   __put_user(*(f + 1), t + 1) ||
-                   __put_user(from->exponent, &to->exponent))
-                       return 1;
+       if (!cpu_has_fxsr) {
+               return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                         &target->thread.xstate->fsave, 0, -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 (pos > 0 || count < sizeof(env))
+               convert_from_fxsr(&env, target);
 
-       if (__copy_from_user(env, buf, 7 * sizeof(long)))
-               return 1;
+       ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
+       if (!ret)
+               convert_to_fxsr(target, &env);
 
-       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;
+       return ret;
 }
 
 /*
  * Signal frame handlers.
  */
 
-static inline int save_i387_fsave(struct _fpstate __user *buf)
+static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
 {
        struct task_struct *tsk = current;
+       struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
 
        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)))
+       fp->status = fp->swd;
+       if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
                return -1;
        return 1;
 }
 
-static int save_i387_fxsave(struct _fpstate __user *buf)
+static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
 {
        struct task_struct *tsk = current;
+       struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
+       struct user_i387_ia32_struct env;
        int err = 0;
 
        unlazy_fpu(tsk);
 
-       if (convert_fxsr_to_user(buf, &tsk->thread.i387.fxsave))
+       convert_from_fxsr(&env, tsk);
+       if (__copy_to_user(buf, &env, sizeof(env)))
                return -1;
 
-       err |= __put_user(tsk->thread.i387.fxsave.swd, &buf->status);
+       err |= __put_user(fx->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,
+       if (__copy_to_user(&buf->_fxsr_env[0], fx,
                           sizeof(struct i387_fxsave_struct)))
                return -1;
        return 1;
 }
 
-int save_i387(struct _fpstate __user *buf)
+int save_i387_ia32(struct _fpstate_ia32 __user *buf)
 {
        if (!used_math())
                return 0;
-
-       /* This will cause a "finit" to be triggered by the next
+       /*
+        * 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);
+       if (!HAVE_HWFP) {
+               return fpregs_soft_get(current, NULL,
+                                      0, sizeof(struct user_i387_ia32_struct),
+                                      NULL, buf) ? -1 : 1;
        }
+
+       if (cpu_has_fxsr)
+               return save_i387_fxsave(buf);
+       else
+               return save_i387_fsave(buf);
 }
 
-static inline int restore_i387_fsave(struct _fpstate __user *buf)
+static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
 {
        struct task_struct *tsk = current;
+
        clear_fpu(tsk);
-       return __copy_from_user(&tsk->thread.i387.fsave, buf,
+       return __copy_from_user(&tsk->thread.xstate->fsave, buf,
                                sizeof(struct i387_fsave_struct));
 }
 
-static int restore_i387_fxsave(struct _fpstate __user *buf)
+static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
 {
-       int err;
        struct task_struct *tsk = current;
+       struct user_i387_ia32_struct env;
+       int err;
+
        clear_fpu(tsk);
-       err = __copy_from_user(&tsk->thread.i387.fxsave, &buf->_fxsr_env[0],
+       err = __copy_from_user(&tsk->thread.xstate->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);
+       tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
+       if (err || __copy_from_user(&env, buf, sizeof(env)))
+               return 1;
+       convert_to_fxsr(tsk, &env);
+
+       return 0;
 }
 
-int restore_i387(struct _fpstate __user *buf)
+int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
 {
        int err;
 
        if (HAVE_HWFP) {
-               if (cpu_has_fxsr) {
+               if (cpu_has_fxsr)
                        err = restore_i387_fxsave(buf);
-               } else {
+               else
                        err = restore_i387_fsave(buf);
-               }
        } else {
-               err = restore_i387_soft(&current->thread.i387.soft, buf);
+               err = fpregs_soft_set(current, NULL,
+                                     0, sizeof(struct user_i387_ia32_struct),
+                                     NULL, buf) != 0;
        }
        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;
+       return err;
 }
 
 /*
  * FPU state for core dumps.
+ * This is only used for a.out dumps now.
+ * It is declared generically using elf_fpregset_t (which is
+ * struct user_i387_struct) but is in fact only used for 32-bit
+ * dumps, so on 64-bit it is really struct user_i387_ia32_struct.
  */
-
-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;
+       int fpvalid;
 
        fpvalid = !!used_math();
-       if (fpvalid) {
-               unlazy_fpu(tsk);
-               if (cpu_has_fxsr) {
-                       copy_fpu_fxsave(tsk, fpu);
-               } else {
-                       copy_fpu_fsave(tsk, fpu);
-               }
-       }
+       if (fpvalid)
+               fpvalid = !fpregs_get(tsk, NULL,
+                                     0, sizeof(struct user_i387_ia32_struct),
+                                     fpu, NULL);
 
        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;
-}
+#endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */