Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 555 insertions, 0 deletions

diff --git a/arch/i386/kernel/i387.c b/arch/i386/kernel/i387.c
new file mode 100644
index 00000000000..c55e037f08f
--- /dev/null
+++ b/arch/i386/kernel/i387.c
@@ -0,0 +1,555 @@
+/*
+ *  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>
+
+#ifdef CONFIG_MATH_EMULATION
+#define HAVE_HWFP (boot_cpu_data.hard_math)
+#else
+#define HAVE_HWFP 1
+#endif
+
+static unsigned long mxcsr_feature_mask = 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();
+}
+
+void restore_fpu( struct task_struct *tsk )
+{
+	if ( cpu_has_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 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;
+}
+
+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;
+}