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>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/m68k/platform/coldfire/entry.S b/arch/m68k/platform/coldfire/entry.S
index f567a163bc4..863889fc31c 100644
--- a/arch/m68k/platform/coldfire/entry.S
+++ b/arch/m68k/platform/coldfire/entry.S
@@ -62,6 +62,7 @@ enosys:
 ENTRY(system_call)
         SAVE_ALL_SYS
         move    #0x2000,%sr             /* enable intrs again */
+        GET_CURRENT(%d2)
 
         cmpl    #NR_syscalls,%d0
         jcc     enosys
@@ -165,6 +166,7 @@ Lsignal_return:
  */
 ENTRY(inthandler)
         SAVE_ALL_INT
+        GET_CURRENT(%d2)
 
         movew   %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */
         andl    #0x03fc,%d0             /* mask out vector only */
@@ -190,7 +192,9 @@ ENTRY(resume)
         movel   %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
         RDUSP                                    /* movel %usp,%a3 */
         movel   %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */
-
+#ifdef CONFIG_MMU
+        movel   %a1,%a2                          /* set new current */
+#endif
         movel   %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */
         WRUSP                                    /* movel %a3,%usp */
         movel   %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */