patch-2.4.0-test2 linux/arch/i386/kernel/i387.c

• Lines: 508
• Date: Wed Jun 21 20:59:38 2000
• Orig file: v2.4.0-test1/linux/arch/i386/kernel/i387.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test1/linux/arch/i386/kernel/i387.c linux/arch/i386/kernel/i387.c
@@ -0,0 +1,507 @@
+/*
+ *  linux/arch/i386/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/config.h>
+#include <linux/sched.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>
+
+#if defined(CONFIG_X86_FXSR)
+#define HAVE_FXSR 1
+#elif defined(CONFIG_X86_RUNTIME_FXSR)
+#define HAVE_FXSR (cpu_has_fxsr)
+#else
+#define HAVE_FXSR 0
+#endif
+
+#ifdef CONFIG_MATH_EMULATION
+#define HAVE_HWFP (boot_cpu_data.hard_math)
+#else
+#define HAVE_HWFP 1
+#endif
+
+/*
+ * FPU lazy state save handling.
+ */
+
+void save_fpu( struct task_struct *tsk )
+{
+	if ( HAVE_FXSR ) {
+		asm volatile( "fxsave %0 ; fwait"
+			      : "=m" (tsk->thread.i387.fxsave) );
+	} else {
+		asm volatile( "fnsave %0 ; fwait"
+			      : "=m" (tsk->thread.i387.fsave) );
+	}
+	tsk->flags &= ~PF_USEDFPU;
+	stts();
+}
+
+void save_init_fpu( struct task_struct *tsk )
+{
+	if ( HAVE_FXSR ) {
+		asm volatile( "fxsave %0 ; fnclex"
+			      : "=m" (tsk->thread.i387.fxsave) );
+	} else {
+		asm volatile( "fnsave %0 ; fwait"
+			      : "=m" (tsk->thread.i387.fsave) );
+	}
+	tsk->flags &= ~PF_USEDFPU;
+	stts();
+}
+
+void restore_fpu( struct task_struct *tsk )
+{
+	if ( HAVE_FXSR ) {
+		asm volatile( "fxrstor %0"
+			      : : "m" (tsk->thread.i387.fxsave) );
+	} else {
+		asm volatile( "frstor %0"
+			      : : "m" (tsk->thread.i387.fsave) );
+	}
+}
+
+/*
+ * FPU tag word conversions.
+ */
+
+static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
+{
+	unsigned short ret = 0;
+	int i;
+
+	for ( i = 0 ; i < 8 ; i++ ) {
+		if ( (twd & 0x3) != 0x3 ) {
+			ret |= (1 << i);
+		}
+		twd = twd >> 2;
+	}
+	return ret;
+}
+
+static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
+{
+	struct _fpxreg *st = NULL;
+	unsigned long twd = (unsigned long) fxsave->twd;
+	unsigned long tag;
+	unsigned long ret = 0xffff0000;
+	int i;
+
+#define FPREG_ADDR(f, n)	((char *)&(f)->st_space + (n) * 16);
+
+	for ( i = 0 ; i < 8 ; i++ ) {
+		if ( twd & 0x1 ) {
+			st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
+
+			switch ( st->exponent ) {
+			case 0xffff:
+				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 ( HAVE_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 ( HAVE_FXSR ) {
+		return tsk->thread.i387.fxsave.swd;
+	} else {
+		return (unsigned short)tsk->thread.i387.fsave.swd;
+	}
+}
+
+unsigned short get_fpu_twd( struct task_struct *tsk )
+{
+	if ( HAVE_FXSR ) {
+		return tsk->thread.i387.fxsave.twd;
+	} else {
+		return (unsigned short)tsk->thread.i387.fsave.twd;
+	}
+}
+
+unsigned short get_fpu_mxcsr( struct task_struct *tsk )
+{
+	if ( HAVE_FXSR ) {
+		return tsk->thread.i387.fxsave.mxcsr;
+	} else {
+		return 0x1f80;
+	}
+}
+
+void set_fpu_cwd( struct task_struct *tsk, unsigned short cwd )
+{
+	if ( HAVE_FXSR ) {
+		tsk->thread.i387.fxsave.cwd = cwd;
+	} else {
+		tsk->thread.i387.fsave.cwd = ((long)cwd | 0xffff0000);
+	}
+}
+
+void set_fpu_swd( struct task_struct *tsk, unsigned short swd )
+{
+	if ( HAVE_FXSR ) {
+		tsk->thread.i387.fxsave.swd = swd;
+	} else {
+		tsk->thread.i387.fsave.swd = ((long)swd | 0xffff0000);
+	}
+}
+
+void set_fpu_twd( struct task_struct *tsk, unsigned short twd )
+{
+	if ( HAVE_FXSR ) {
+		tsk->thread.i387.fxsave.twd = twd_i387_to_fxsr(twd);
+	} else {
+		tsk->thread.i387.fsave.twd = ((long)twd | 0xffff0000);
+	}
+}
+
+void set_fpu_mxcsr( struct task_struct *tsk, unsigned short mxcsr )
+{
+	if ( HAVE_FXSR ) {
+		tsk->thread.i387.fxsave.mxcsr = mxcsr;
+	}
+}
+
+/*
+ * FXSR floating point environment conversions.
+ */
+
+static inline int convert_fxsr_to_user( struct _fpstate *buf,
+					struct i387_fxsave_struct *fxsave )
+{
+	unsigned long env[7];
+	struct _fpreg *to;
+	struct _fpxreg *from;
+	int i;
+
+	env[0] = (unsigned long)fxsave->cwd | 0xffff0000;
+	env[1] = (unsigned long)fxsave->swd | 0xffff0000;
+	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++ ) {
+		if ( __copy_to_user( to, from, sizeof(*to) ) )
+			return 1;
+	}
+	return 0;
+}
+
+static inline int convert_fxsr_from_user( struct i387_fxsave_struct *fxsave,
+					  struct _fpstate *buf )
+{
+	unsigned long env[7];
+	struct _fpxreg *to;
+	struct _fpreg *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] & 0xffff0000) >> 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++ ) {
+		if ( __copy_from_user( to, from, sizeof(*from) ) )
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * Signal frame handlers.
+ */
+
+static inline int save_i387_fsave( struct _fpstate *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 inline int save_i387_fxsave( struct _fpstate *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 *buf )
+{
+	if ( !current->used_math )
+		return 0;
+
+	/* This will cause a "finit" to be triggered by the next
+	 * attempted FPU operation by the 'current' process.
+	 */
+	current->used_math = 0;
+
+	if ( HAVE_HWFP ) {
+		if ( HAVE_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 *buf )
+{
+	struct task_struct *tsk = current;
+	clear_fpu( tsk );
+	return __copy_from_user( &tsk->thread.i387.fsave, buf,
+				 sizeof(struct i387_fsave_struct) );
+}
+
+static inline int restore_i387_fxsave( struct _fpstate *buf )
+{
+	struct task_struct *tsk = current;
+	clear_fpu( tsk );
+	if ( __copy_from_user( &tsk->thread.i387.fxsave, &buf->_fxsr_env[0],
+			       sizeof(struct i387_fxsave_struct) ) )
+		return 1;
+	return convert_fxsr_from_user( &tsk->thread.i387.fxsave, buf );
+}
+
+int restore_i387( struct _fpstate *buf )
+{
+	int err;
+
+	if ( HAVE_HWFP ) {
+		if ( HAVE_FXSR ) {
+			err =  restore_i387_fxsave( buf );
+		} else {
+			err = restore_i387_fsave( buf );
+		}
+	} else {
+		err = restore_i387_soft( &current->thread.i387.soft, buf );
+	}
+	current->used_math = 1;
+	return err;
+}
+
+/*
+ * ptrace request handlers.
+ */
+
+static inline int get_fpregs_fsave( struct user_i387_struct *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 *buf,
+				     struct task_struct *tsk )
+{
+	return convert_fxsr_to_user( (struct _fpstate *)buf,
+				     &tsk->thread.i387.fxsave );
+}
+
+int get_fpregs( struct user_i387_struct *buf, struct task_struct *tsk )
+{
+	if ( HAVE_HWFP ) {
+		if ( HAVE_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 *)buf );
+	}
+}
+
+static inline int set_fpregs_fsave( struct task_struct *tsk,
+				    struct user_i387_struct *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 *buf )
+{
+	return convert_fxsr_from_user( &tsk->thread.i387.fxsave,
+				       (struct _fpstate *)buf );
+}
+
+int set_fpregs( struct task_struct *tsk, struct user_i387_struct *buf )
+{
+	if ( HAVE_HWFP ) {
+		if ( HAVE_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 *)buf );
+	}
+}
+
+int get_fpxregs( struct user_fxsr_struct *buf, struct task_struct *tsk )
+{
+	if ( HAVE_FXSR ) {
+		__copy_to_user( (void *)buf, &tsk->thread.i387.fxsave,
+				sizeof(struct user_fxsr_struct) );
+		return 0;
+	} else {
+		return -EIO;
+	}
+}
+
+int set_fpxregs( struct task_struct *tsk, struct user_fxsr_struct *buf )
+{
+	if ( HAVE_FXSR ) {
+		__copy_from_user( &tsk->thread.i387.fxsave, (void *)buf,
+				  sizeof(struct user_fxsr_struct) );
+		return 0;
+	} else {
+		return -EIO;
+	}
+}
+
+/*
+ * 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 = tsk->used_math;
+	if ( fpvalid ) {
+		unlazy_fpu( tsk );
+		if ( HAVE_FXSR ) {
+			copy_fpu_fxsave( tsk, fpu );
+		} else {
+			copy_fpu_fsave( tsk, fpu );
+		}
+	}
+
+	return fpvalid;
+}
+
+int dump_extended_fpu( struct pt_regs *regs, struct user_fxsr_struct *fpu )
+{
+	int fpvalid;
+	struct task_struct *tsk = current;
+
+	fpvalid = tsk->used_math && HAVE_FXSR;
+	if ( fpvalid ) {
+		unlazy_fpu( tsk );
+		memcpy( fpu, &tsk->thread.i387.fxsave,
+			sizeof(struct user_fxsr_struct) );
+	}
+
+	return fpvalid;
+}