m68k: set register a2 to current if MMU enabled on ColdFire

Virtual memory m68k systems build with register a2 dedicated to being the
current proc pointer (non-MMU don't do this). Add code to the ColdFire
interrupt and exception processing to set this on entry, and at context
switch time. We use the same GET_CURRENT() macro that MMU enabled code
uses - modifying it so that the assembler is ColdFire clean.

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>
diff --git a/arch/m68k/include/asm/entry.h b/arch/m68k/include/asm/entry.h
index c3c5a86..622138d 100644
--- a/arch/m68k/include/asm/entry.h
+++ b/arch/m68k/include/asm/entry.h
@@ -222,16 +222,24 @@
  * Non-MMU systems do not reserve %a2 in this way, and this definition is
  * not used for them.
  */
+#ifdef CONFIG_MMU
+
 #define curptr a2
 
 #define GET_CURRENT(tmp) get_current tmp
 .macro get_current reg=%d0
 	movel	%sp,\reg
-	andw	#-THREAD_SIZE,\reg
+	andl	#-THREAD_SIZE,\reg
 	movel	\reg,%curptr
 	movel	%curptr@,%curptr
 .endm
 
+#else
+
+#define GET_CURRENT(tmp)
+
+#endif /* CONFIG_MMU */
+
 #else /* C source */
 
 #define STR(X) STR1(X)