m68k/uaccess: Fix asm constraints for userspace access

When compiling a MMU kernel with CPU_HAS_ADDRESS_SPACES=n (e.g. "MMU=y
allnoconfig": "echo CONFIG_MMU=y > allno.config && make KCONFIG_ALLCONFIG=1
allnoconfig"), we use plain "move" instead of "moves", and I got:

  CC      arch/m68k/lib/uaccess.o
{standard input}: Assembler messages:
{standard input}:47: Error: operands mismatch -- statement `move.b %a0,(%a1)' ignored

This happens because plain "move" doesn't support byte transfers between
memory and address registers, while "moves" does.

Fix the asm constraints for __generic_copy_from_user(),
__generic_copy_to_user(), and __clear_user() to only use data registers
when accessing userspace.

Also, relax the asm constraints for 16-bit userspace accesses in
__put_user() and __get_user(), as both "move" and "moves" do support
such transfers between memory and address registers.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

2 files changed, 7 insertions, 7 deletions

diff --git a/arch/m68k/include/asm/uaccess_mm.h b/arch/m68k/include/asm/uaccess_mm.h
index 472c891a4aee..15901db435b9 100644
--- a/arch/m68k/include/asm/uaccess_mm.h
+++ b/arch/m68k/include/asm/uaccess_mm.h
@@ -90,7 +90,7 @@ asm volatile ("\n"					\
                 __put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \
                 break;                                                  \
         case 2:                                                         \
-                __put_user_asm(__pu_err, __pu_val, ptr, w, d, -EFAULT); \
+                __put_user_asm(__pu_err, __pu_val, ptr, w, r, -EFAULT); \
                 break;                                                  \
         case 4:                                                         \
                 __put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \
@@ -158,7 +158,7 @@ asm volatile ("\n"					\
                 __get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT);    \
                 break;                                                  \
         case 2:                                                         \
-                __get_user_asm(__gu_err, x, ptr, u16, w, d, -EFAULT);   \
+                __get_user_asm(__gu_err, x, ptr, u16, w, r, -EFAULT);   \
                 break;                                                  \
         case 4:                                                         \
                 __get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT);   \
@@ -245,7 +245,7 @@ __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
                 __get_user_asm(res, *(u8 *)to, (u8 __user *)from, u8, b, d, 1);
                 break;
         case 2:
-                __get_user_asm(res, *(u16 *)to, (u16 __user *)from, u16, w, d, 2);
+                __get_user_asm(res, *(u16 *)to, (u16 __user *)from, u16, w, r, 2);
                 break;
         case 3:
                 __constant_copy_from_user_asm(res, to, from, tmp, 3, w, b,);
@@ -326,7 +326,7 @@ __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
                 __put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
                 break;
         case 2:
-                __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, d, 2);
+                __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2);
                 break;
         case 3:
                 __constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);
diff --git a/arch/m68k/lib/uaccess.c b/arch/m68k/lib/uaccess.c
index 5e97f2ee7c11..35d1442dee89 100644
--- a/arch/m68k/lib/uaccess.c
+++ b/arch/m68k/lib/uaccess.c
@@ -52,7 +52,7 @@ unsigned long __generic_copy_from_user(void *to, const void __user *from,
                 "       .long   3b,30b\n"
                 "       .long   5b,50b\n"
                 "       .previous"
-                : "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
+                : "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
                 : "0" (n / 4), "d" (n & 3));
 
         return res;
@@ -96,7 +96,7 @@ unsigned long __generic_copy_to_user(void __user *to, const void *from,
                 "       .long   7b,50b\n"
                 "       .long   8b,50b\n"
                 "       .previous"
-                : "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
+                : "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
                 : "0" (n / 4), "d" (n & 3));
 
         return res;
@@ -141,7 +141,7 @@ unsigned long __clear_user(void __user *to, unsigned long n)
                 "       .long   7b,40b\n"
                 "       .previous"
                 : "=d" (res), "+a" (to)
-                : "r" (0), "0" (n / 4), "d" (n & 3));
+                : "d" (0), "0" (n / 4), "d" (n & 3));
 
     return res;
 }