m68k: get rid of zeroing

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/m68k/include/asm/uaccess_mm.h

@@ -179,39 +179,55 @@ asm volatile ("\n"					\
 unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n);
 unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n);
 
-#define __constant_copy_from_user_asm(res, to, from, tmp, n, s1, s2, s3)\
+#define __suffix0
+#define __suffix1 b
+#define __suffix2 w
+#define __suffix4 l
+
+#define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
 	asm volatile ("\n"						\
 		"1:	"MOVES"."#s1"	(%2)+,%3\n"			\
 		"	move."#s1"	%3,(%1)+\n"			\
+		"	.ifnc	\""#s2"\",\"\"\n"			\
 		"2:	"MOVES"."#s2"	(%2)+,%3\n"			\
 		"	move."#s2"	%3,(%1)+\n"			\
 		"	.ifnc	\""#s3"\",\"\"\n"			\
 		"3:	"MOVES"."#s3"	(%2)+,%3\n"			\
 		"	move."#s3"	%3,(%1)+\n"			\
 		"	.endif\n"					\
+		"	.endif\n"					\
 		"4:\n"							\
 		"	.section __ex_table,\"a\"\n"			\
 		"	.align	4\n"					\
 		"	.long	1b,10f\n"				\
+		"	.ifnc	\""#s2"\",\"\"\n"			\
 		"	.long	2b,20f\n"				\
 		"	.ifnc	\""#s3"\",\"\"\n"			\
 		"	.long	3b,30f\n"				\
 		"	.endif\n"					\
+		"	.endif\n"					\
 		"	.previous\n"					\
 		"\n"							\
 		"	.section .fixup,\"ax\"\n"			\
 		"	.even\n"					\
-		"10:	clr."#s1"	(%1)+\n"			\
-		"20:	clr."#s2"	(%1)+\n"			\
+		"10:	addq.l #"#n1",%0\n"				\
+		"	.ifnc	\""#s2"\",\"\"\n"			\
+		"20:	addq.l #"#n2",%0\n"				\
 		"	.ifnc	\""#s3"\",\"\"\n"			\
-		"30:	clr."#s3"	(%1)+\n"			\
+		"30:	addq.l #"#n3",%0\n"				\
+		"	.endif\n"					\
 		"	.endif\n"					\
-		"	moveq.l	#"#n",%0\n"				\
 		"	jra	4b\n"					\
 		"	.previous\n"					\
 		: "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp)	\
 		: : "memory")
 
+#define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
+	____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)
+#define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3)	\
+	___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3,  \
+					__suffix##n1, __suffix##n2, __suffix##n3)
+
 static __always_inline unsigned long
 __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
@@ -219,37 +235,37 @@ __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
 
 	switch (n) {
 	case 1:
-		__get_user_asm(res, *(u8 *)to, (u8 __user *)from, u8, b, d, 1);
+		__constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0);
 		break;
 	case 2:
-		__get_user_asm(res, *(u16 *)to, (u16 __user *)from, u16, w, r, 2);
+		__constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0);
 		break;
 	case 3:
-		__constant_copy_from_user_asm(res, to, from, tmp, 3, w, b,);
+		__constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0);
 		break;
 	case 4:
-		__get_user_asm(res, *(u32 *)to, (u32 __user *)from, u32, l, r, 4);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0);
 		break;
 	case 5:
-		__constant_copy_from_user_asm(res, to, from, tmp, 5, l, b,);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0);
 		break;
 	case 6:
-		__constant_copy_from_user_asm(res, to, from, tmp, 6, l, w,);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0);
 		break;
 	case 7:
-		__constant_copy_from_user_asm(res, to, from, tmp, 7, l, w, b);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1);
 		break;
 	case 8:
-		__constant_copy_from_user_asm(res, to, from, tmp, 8, l, l,);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0);
 		break;
 	case 9:
-		__constant_copy_from_user_asm(res, to, from, tmp, 9, l, l, b);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1);
 		break;
 	case 10:
-		__constant_copy_from_user_asm(res, to, from, tmp, 10, l, l, w);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2);
 		break;
 	case 12:
-		__constant_copy_from_user_asm(res, to, from, tmp, 12, l, l, l);
+		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4);
 		break;
 	default:
 		/* we limit the inlined version to 3 moves */
@@ -353,7 +369,14 @@ __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
 #define __copy_to_user_inatomic		__copy_to_user
 #define __copy_from_user_inatomic	__copy_from_user
 
-#define copy_from_user(to, from, n)	__copy_from_user(to, from, n)
+static inline unsigned long
+copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	unsigned long res = __copy_from_user_inatomic(to, from, n);
+	if (unlikely(res))
+		memset(to + (n - res), 0, res);
+	return res;
+}
 #define copy_to_user(to, from, n)	__copy_to_user(to, from, n)
 
 #define user_addr_max() \

arch/m68k/lib/uaccess.c

@@ -30,19 +30,13 @@ unsigned long __generic_copy_from_user(void *to, const void __user *from,
 		"6:\n"
 		"	.section .fixup,\"ax\"\n"
 		"	.even\n"
-		"10:	move.l	%0,%3\n"
-		"7:	clr.l	(%2)+\n"
-		"	subq.l	#1,%3\n"
-		"	jne	7b\n"
-		"	lsl.l	#2,%0\n"
+		"10:	lsl.l	#2,%0\n"
 		"	btst	#1,%5\n"
 		"	jeq	8f\n"
-		"30:	clr.w	(%2)+\n"
-		"	addq.l	#2,%0\n"
+		"30:	addq.l	#2,%0\n"
 		"8:	btst	#0,%5\n"
 		"	jeq	6b\n"
-		"50:	clr.b	(%2)+\n"
-		"	addq.l	#1,%0\n"
+		"50:	addq.l	#1,%0\n"
 		"	jra	6b\n"
 		"	.previous\n"
 		"\n"