/* 
       * User address space access functions.
       * The non inlined parts of asm-i386/uaccess.h are here.
       *
       * Copyright 1997 Andi Kleen <ak@muc.de>
       * Copyright 1997 Linus Torvalds
       */
      #include <linux/config.h>
      #include <asm/uaccess.h>
      #include <asm/mmx.h>
      
      #ifdef CONFIG_X86_USE_3DNOW_AND_WORKS
      
      unsigned long
      __generic_copy_to_user(void *to, const void *from, unsigned long n)
      {
      	if (access_ok(VERIFY_WRITE, to, n))
      	{
      		if(n<512)
      			__copy_user(to,from,n);
      		else
      			mmx_copy_user(to,from,n);
      	}
      	return n;
      }
      
      unsigned long
      __generic_copy_from_user(void *to, const void *from, unsigned long n)
      {
      	if (access_ok(VERIFY_READ, from, n))
      	{
      		if(n<512)
      			__copy_user_zeroing(to,from,n);
      		else
      			mmx_copy_user_zeroing(to, from, n);
      	}
      	return n;
      }
      
      #else
      
      unsigned long
  43  __generic_copy_to_user(void *to, const void *from, unsigned long n)
      {
  45  	if (access_ok(VERIFY_WRITE, to, n))
  46  		__copy_user(to,from,n);
  47  	return n;
      }
      
      unsigned long
  51  __generic_copy_from_user(void *to, const void *from, unsigned long n)
      {
  53  	if (access_ok(VERIFY_READ, from, n))
  54  		__copy_user_zeroing(to,from,n);
  55  	return n;
      }
      
      #endif
      
      /*
       * Copy a null terminated string from userspace.
       */
      
      #define __do_strncpy_from_user(dst,src,count,res)			   \
      do {									   \
      	int __d0, __d1, __d2;						   \
      	__asm__ __volatile__(						   \
      		"	testl %1,%1\n"					   \
      		"	jz 2f\n"					   \
      		"0:	lodsb\n"					   \
      		"	stosb\n"					   \
      		"	testb %%al,%%al\n"				   \
      		"	jz 1f\n"					   \
      		"	decl %1\n"					   \
      		"	jnz 0b\n"					   \
      		"1:	subl %1,%0\n"					   \
      		"2:\n"							   \
      		".section .fixup,\"ax\"\n"				   \
      		"3:	movl %5,%0\n"					   \
      		"	jmp 2b\n"					   \
      		".previous\n"						   \
      		".section __ex_table,\"a\"\n"				   \
      		"	.align 4\n"					   \
      		"	.long 0b,3b\n"					   \
      		".previous"						   \
      		: "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1),	   \
      		  "=&D" (__d2)						   \
      		: "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
      		: "memory");						   \
      } while (0)
      
      long
  93  __strncpy_from_user(char *dst, const char *src, long count)
      {
      	long res;
  96  	__do_strncpy_from_user(dst, src, count, res);
  97  	return res;
      }
      
      long
 101  strncpy_from_user(char *dst, const char *src, long count)
      {
      	long res = -EFAULT;
 104  	if (access_ok(VERIFY_READ, src, 1))
 105  		__do_strncpy_from_user(dst, src, count, res);
 106  	return res;
      }
      
      
      /*
       * Zero Userspace
       */
      
      #define __do_clear_user(addr,size)					\
      do {									\
      	int __d0;							\
        	__asm__ __volatile__(						\
      		"0:	rep; stosl\n"					\
      		"	movl %2,%0\n"					\
      		"1:	rep; stosb\n"					\
      		"2:\n"							\
      		".section .fixup,\"ax\"\n"				\
      		"3:	lea 0(%2,%0,4),%0\n"				\
      		"	jmp 2b\n"					\
      		".previous\n"						\
      		".section __ex_table,\"a\"\n"				\
      		"	.align 4\n"					\
      		"	.long 0b,3b\n"					\
      		"	.long 1b,2b\n"					\
      		".previous"						\
      		: "=&c"(size), "=&D" (__d0)				\
      		: "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0));	\
      } while (0)
      
      unsigned long
 136  clear_user(void *to, unsigned long n)
      {
 138  	if (access_ok(VERIFY_WRITE, to, n))
 139  		__do_clear_user(to, n);
 140  	return n;
      }
      
      unsigned long
 144  __clear_user(void *to, unsigned long n)
      {
 146  	__do_clear_user(to, n);
 147  	return n;
      }
      
      /*
       * Return the size of a string (including the ending 0)
       *
       * Return 0 on exception, a value greater than N if too long
       */
      
 156  long strnlen_user(const char *s, long n)
      {
      	unsigned long mask = -__addr_ok(s);
      	unsigned long res, tmp;
      
      	__asm__ __volatile__(
      		"	andl %0,%%ecx\n"
      		"0:	repne; scasb\n"
      		"	setne %%al\n"
      		"	subl %%ecx,%0\n"
      		"	addl %0,%%eax\n"
      		"1:\n"
      		".section .fixup,\"ax\"\n"
      		"2:	xorl %%eax,%%eax\n"
      		"	jmp 1b\n"
      		".previous\n"
      		".section __ex_table,\"a\"\n"
      		"	.align 4\n"
      		"	.long 0b,2b\n"
      		".previous"
      		:"=r" (n), "=D" (s), "=a" (res), "=c" (tmp)
      		:"0" (n), "1" (s), "2" (0), "3" (mask)
      		:"cc");
 179  	return res & mask;
      }