[PATCH 06/35] m68k: modify user space access functions to support ColdFire CPUs

[<gerg@snapgear.com>]

From: Greg Ungerer <gerg@uclinux.org>

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>
---
 arch/m68k/Kconfig                  |    3 ++
 arch/m68k/Kconfig.cpu              |    4 +++
 arch/m68k/include/asm/segment.h    |    4 +-
 arch/m68k/include/asm/uaccess_mm.h |   42 ++++++++++++++++++++++++-----------
 arch/m68k/lib/uaccess.c            |   22 +++++++++---------
 5 files changed, 49 insertions(+), 26 deletions(-)

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 32fd364..5f860cf 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -66,6 +66,9 @@ config CPU_HAS_NO_BITFIELDS
 config CPU_HAS_NO_MULDIV64
 	bool
 
+config CPU_HAS_ADDRESS_SPACES
+	bool
+
 config HZ
 	int
 	default 1000 if CLEOPATRA
diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index 017f4fc..5ae1d63 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -38,6 +38,7 @@ config M68020
 	bool "68020 support"
 	depends on MMU
 	select GENERIC_ATOMIC64
+	select CPU_HAS_ADDRESS_SPACES
 	help
 	  If you anticipate running this kernel on a computer with a MC68020
 	  processor, say Y. Otherwise, say N. Note that the 68020 requires a
@@ -48,6 +49,7 @@ config M68030
 	bool "68030 support"
 	depends on MMU && !MMU_SUN3
 	select GENERIC_ATOMIC64
+	select CPU_HAS_ADDRESS_SPACES
 	help
 	  If you anticipate running this kernel on a computer with a MC68030
 	  processor, say Y. Otherwise, say N. Note that a MC68EC030 will not
@@ -57,6 +59,7 @@ config M68040
 	bool "68040 support"
 	depends on MMU && !MMU_SUN3
 	select GENERIC_ATOMIC64
+	select CPU_HAS_ADDRESS_SPACES
 	help
 	  If you anticipate running this kernel on a computer with a MC68LC040
 	  or MC68040 processor, say Y. Otherwise, say N. Note that an
@@ -67,6 +70,7 @@ config M68060
 	bool "68060 support"
 	depends on MMU && !MMU_SUN3
 	select GENERIC_ATOMIC64
+	select CPU_HAS_ADDRESS_SPACES
 	help
 	  If you anticipate running this kernel on a computer with a MC68060
 	  processor, say Y. Otherwise, say N.
diff --git a/arch/m68k/include/asm/segment.h b/arch/m68k/include/asm/segment.h
index ee95921..1a142e9 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 7107f3f..9c80cd5 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"							\
diff --git a/arch/m68k/lib/uaccess.c b/arch/m68k/lib/uaccess.c
index 13854ed..5664386 100644
--- a/arch/m68k/lib/uaccess.c
+++ b/arch/m68k/lib/uaccess.c
@@ -15,17 +15,17 @@ unsigned long __generic_copy_from_user(void *to, const void __user *from,
 	asm volatile ("\n"
 		"	tst.l	%0\n"
 		"	jeq	2f\n"
-		"1:	moves.l	(%1)+,%3\n"
+		"1:	"MOVES".l	(%1)+,%3\n"
 		"	move.l	%3,(%2)+\n"
 		"	subq.l	#1,%0\n"
 		"	jne	1b\n"
 		"2:	btst	#1,%5\n"
 		"	jeq	4f\n"
-		"3:	moves.w	(%1)+,%3\n"
+		"3:	"MOVES".w	(%1)+,%3\n"
 		"	move.w	%3,(%2)+\n"
 		"4:	btst	#0,%5\n"
 		"	jeq	6f\n"
-		"5:	moves.b	(%1)+,%3\n"
+		"5:	"MOVES".b	(%1)+,%3\n"
 		"	move.b  %3,(%2)+\n"
 		"6:\n"
 		"	.section .fixup,\"ax\"\n"
@@ -68,17 +68,17 @@ unsigned long __generic_copy_to_user(void __user *to, const void *from,
 		"	tst.l	%0\n"
 		"	jeq	4f\n"
 		"1:	move.l	(%1)+,%3\n"
-		"2:	moves.l	%3,(%2)+\n"
+		"2:	"MOVES".l	%3,(%2)+\n"
 		"3:	subq.l	#1,%0\n"
 		"	jne	1b\n"
 		"4:	btst	#1,%5\n"
 		"	jeq	6f\n"
 		"	move.w	(%1)+,%3\n"
-		"5:	moves.w	%3,(%2)+\n"
+		"5:	"MOVES".w	%3,(%2)+\n"
 		"6:	btst	#0,%5\n"
 		"	jeq	8f\n"
 		"	move.b	(%1)+,%3\n"
-		"7:	moves.b  %3,(%2)+\n"
+		"7:	"MOVES".b  %3,(%2)+\n"
 		"8:\n"
 		"	.section .fixup,\"ax\"\n"
 		"	.even\n"
@@ -115,7 +115,7 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
 		return count;
 
 	asm volatile ("\n"
-		"1:	moves.b	(%2)+,%4\n"
+		"1:	"MOVES".b	(%2)+,%4\n"
 		"	move.b	%4,(%1)+\n"
 		"	jeq	2f\n"
 		"	subq.l	#1,%3\n"
@@ -152,7 +152,7 @@ long strnlen_user(const char __user *src, long n)
 	asm volatile ("\n"
 		"1:	subq.l	#1,%1\n"
 		"	jmi	3f\n"
-		"2:	moves.b	(%0)+,%2\n"
+		"2:	"MOVES".b	(%0)+,%2\n"
 		"	tst.b	%2\n"
 		"	jne	1b\n"
 		"	jra	4f\n"
@@ -188,15 +188,15 @@ unsigned long __clear_user(void __user *to, unsigned long n)
 	asm volatile ("\n"
 		"	tst.l	%0\n"
 		"	jeq	3f\n"
-		"1:	moves.l	%2,(%1)+\n"
+		"1:	"MOVES".l	%2,(%1)+\n"
 		"2:	subq.l	#1,%0\n"
 		"	jne	1b\n"
 		"3:	btst	#1,%4\n"
 		"	jeq	5f\n"
-		"4:	moves.w	%2,(%1)+\n"
+		"4:	"MOVES".w	%2,(%1)+\n"
 		"5:	btst	#0,%4\n"
 		"	jeq	7f\n"
-		"6:	moves.b	%2,(%1)\n"
+		"6:	"MOVES".b	%2,(%1)\n"
 		"7:\n"
 		"	.section .fixup,\"ax\"\n"
 		"	.even\n"
-- 
1.7.0.4