m68k: modify user space access functions to support ColdFire CPUs

Modify the user space access functions to support the ColdFire V4e cores
running with MMU enabled.

The ColdFire processors do not support the "moves" instruction used by
the traditional 680x0 processors for moving data into and out of another
address space. They only support the notion of a single address space,
and you use the usual "move" instruction to access that.

Create a new config symbol (CONFIG_CPU_HAS_ADDRESS_SPACES) to mark the
CPU types that support separate address spaces, and thus also support
the sfc/dfc registers and the "moves" instruction that go along with that.

The code is almost identical for user space access, so lets just use a
define to choose either the "move" or "moves" in the assembler code.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

2 files changed, 31 insertions, 15 deletions

diff --git a/arch/m68k/include/asm/segment.h b/arch/m68k/include/asm/segment.h
index ee959219fdf..1a142e9ceaa 100644
--- a/arch/m68k/include/asm/segment.h
+++ b/arch/m68k/include/asm/segment.h
@@ -31,7 +31,7 @@ typedef struct {
 
 static inline mm_segment_t get_fs(void)
 {
-#ifdef CONFIG_MMU
+#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
 	mm_segment_t _v;
 	__asm__ ("movec %/dfc,%0":"=r" (_v.seg):);
 
@@ -49,7 +49,7 @@ static inline mm_segment_t get_ds(void)
 
 static inline void set_fs(mm_segment_t val)
 {
-#ifdef CONFIG_MMU
+#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
 	__asm__ __volatile__ ("movec %0,%/sfc\n\t"
 			      "movec %0,%/dfc\n\t"
 			      : /* no outputs */ : "r" (val.seg) : "memory");
diff --git a/arch/m68k/include/asm/uaccess_mm.h b/arch/m68k/include/asm/uaccess_mm.h
index 7107f3fbdbb..9c80cd515b2 100644
--- a/arch/m68k/include/asm/uaccess_mm.h
+++ b/arch/m68k/include/asm/uaccess_mm.h
@@ -21,6 +21,22 @@ static inline int access_ok(int type, const void __user *addr,
 }
 
 /*
+ * Not all varients of the 68k family support the notion of address spaces.
+ * The traditional 680x0 parts do, and they use the sfc/dfc registers and
+ * the "moves" instruction to access user space from kernel space. Other
+ * family members like ColdFire don't support this, and only have a single
+ * address space, and use the usual "move" instruction for user space access.
+ *
+ * Outside of this difference the user space access functions are the same.
+ * So lets keep the code simple and just define in what we need to use.
+ */
+#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
+#define	MOVES	"moves"
+#else
+#define	MOVES	"move"
+#endif
+
+/*
  * The exception table consists of pairs of addresses: the first is the
  * address of an instruction that is allowed to fault, and the second is
  * the address at which the program should continue.  No registers are
@@ -43,7 +59,7 @@ extern int __get_user_bad(void);
 
 #define __put_user_asm(res, x, ptr, bwl, reg, err)	\
 asm volatile ("\n"					\
-	"1:	moves."#bwl"	%2,%1\n"		\
+	"1:	"MOVES"."#bwl"	%2,%1\n"		\
 	"2:\n"						\
 	"	.section .fixup,\"ax\"\n"		\
 	"	.even\n"				\
@@ -83,8 +99,8 @@ asm volatile ("\n"					\
  	    {								\
  		const void __user *__pu_ptr = (ptr);			\
 		asm volatile ("\n"					\
-			"1:	moves.l	%2,(%1)+\n"			\
-			"2:	moves.l	%R2,(%1)\n"			\
+			"1:	"MOVES".l	%2,(%1)+\n"		\
+			"2:	"MOVES".l	%R2,(%1)\n"		\
 			"3:\n"						\
 			"	.section .fixup,\"ax\"\n"		\
 			"	.even\n"				\
@@ -115,12 +131,12 @@ asm volatile ("\n"					\
 #define __get_user_asm(res, x, ptr, type, bwl, reg, err) ({	\
 	type __gu_val;						\
 	asm volatile ("\n"					\
-		"1:	moves."#bwl"	%2,%1\n"		\
+		"1:	"MOVES"."#bwl"	%2,%1\n"		\
 		"2:\n"						\
 		"	.section .fixup,\"ax\"\n"		\
 		"	.even\n"				\
 		"10:	move.l	%3,%0\n"			\
-		"	sub."#bwl"	%1,%1\n"		\
+		"	sub.l	%1,%1\n"			\
 		"	jra	2b\n"				\
 		"	.previous\n"				\
 		"\n"						\
@@ -152,8 +168,8 @@ asm volatile ("\n"					\
  		const void *__gu_ptr = (ptr);				\
  		u64 __gu_val;						\
 		asm volatile ("\n"					\
-			"1:	moves.l	(%2)+,%1\n"			\
-			"2:	moves.l	(%2),%R1\n"			\
+			"1:	"MOVES".l	(%2)+,%1\n"		\
+			"2:	"MOVES".l	(%2),%R1\n"		\
 			"3:\n"						\
 			"	.section .fixup,\"ax\"\n"		\
 			"	.even\n"				\
@@ -188,12 +204,12 @@ unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned
 
 #define __constant_copy_from_user_asm(res, to, from, tmp, n, s1, s2, s3)\
 	asm volatile ("\n"						\
-		"1:	moves."#s1"	(%2)+,%3\n"			\
+		"1:	"MOVES"."#s1"	(%2)+,%3\n"			\
 		"	move."#s1"	%3,(%1)+\n"			\
-		"2:	moves."#s2"	(%2)+,%3\n"			\
+		"2:	"MOVES"."#s2"	(%2)+,%3\n"			\
 		"	move."#s2"	%3,(%1)+\n"			\
 		"	.ifnc	\""#s3"\",\"\"\n"			\
-		"3:	moves."#s3"	(%2)+,%3\n"			\
+		"3:	"MOVES"."#s3"	(%2)+,%3\n"			\
 		"	move."#s3"	%3,(%1)+\n"			\
 		"	.endif\n"					\
 		"4:\n"							\
@@ -269,13 +285,13 @@ __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
 #define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3)	\
 	asm volatile ("\n"						\
 		"	move."#s1"	(%2)+,%3\n"			\
-		"11:	moves."#s1"	%3,(%1)+\n"			\
+		"11:	"MOVES"."#s1"	%3,(%1)+\n"			\
 		"12:	move."#s2"	(%2)+,%3\n"			\
-		"21:	moves."#s2"	%3,(%1)+\n"			\
+		"21:	"MOVES"."#s2"	%3,(%1)+\n"			\
 		"22:\n"							\
 		"	.ifnc	\""#s3"\",\"\"\n"			\
 		"	move."#s3"	(%2)+,%3\n"			\
-		"31:	moves."#s3"	%3,(%1)+\n"			\
+		"31:	"MOVES"."#s3"	%3,(%1)+\n"			\
 		"32:\n"							\
 		"	.endif\n"					\
 		"4:\n"							\