bitkeeper revision 1.952 (40c8935a3XSRdQfnx5RoO7XgaggvOQ)

Towards x86_64 support. Merged a bunch of the existing x86_64 stuff
back into a generic 'x86' architecture. Aim is to share as much
as possible between 32- and 64-bit worlds.

1 files changed, 190 insertions, 0 deletions

diff --git a/xen/arch/x86/usercopy.c b/xen/arch/x86/usercopy.c
new file mode 100644
index 0000000000..dc2d34cb90
--- /dev/null
+++ b/xen/arch/x86/usercopy.c
@@ -0,0 +1,190 @@
+/* 
+ * 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 <xen/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);
+	}
+	else
+		memset(to, 0, n);
+	return n;
+}
+
+#else
+
+unsigned long
+__generic_copy_to_user(void *to, const void *from, unsigned long n)
+{
+	prefetch(from);
+	if (access_ok(VERIFY_WRITE, to, n))
+		__copy_user(to,from,n);
+	return n;
+}
+
+unsigned long
+__generic_copy_from_user(void *to, const void *from, unsigned long n)
+{
+	prefetchw(to);
+	if (access_ok(VERIFY_READ, from, n))
+		__copy_user_zeroing(to,from,n);
+	else
+		memset(to, 0, n);
+	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
+__strncpy_from_user(char *dst, const char *src, long count)
+{
+	long res;
+	__do_strncpy_from_user(dst, src, count, res);
+	return res;
+}
+
+long
+strncpy_from_user(char *dst, const char *src, long count)
+{
+	long res = -EFAULT;
+	if (access_ok(VERIFY_READ, src, 1))
+		__do_strncpy_from_user(dst, src, count, res);
+	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
+clear_user(void *to, unsigned long n)
+{
+	if (access_ok(VERIFY_WRITE, to, n))
+		__do_clear_user(to, n);
+	return n;
+}
+
+unsigned long
+__clear_user(void *to, unsigned long n)
+{
+	__do_clear_user(to, n);
+	return n;
+}
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 on exception, a value greater than N if too long
+ */
+
+long strnlen_user(const char *s, long n)
+{
+	unsigned long mask = -__addr_ok(s);
+	unsigned long res, tmp;
+
+	__asm__ __volatile__(
+		"	testl %0, %0\n"
+		"	jz 3f\n"
+		"	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"
+		"3:	movb $1,%%al\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");
+	return res & mask;
+}