From: Greg Ungerer <[email protected]>

Virtual memory m68k systems build with register a2 dedicated to being the
current proc pointer. Add code to the ColdFire interrupt and exception
processing to set this on entry, and also at context switch time.

Signed-off-by: Greg Ungerer <[email protected]>
---
 arch/m68k/kernel/entry_no.S         |   24 ++++++++++++++++++------
 arch/m68k/platform/coldfire/entry.S |   18 +++++++++++++++++-
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/arch/m68k/kernel/entry_no.S b/arch/m68k/kernel/entry_no.S
index 1b42890..050d7ea 100644
--- a/arch/m68k/kernel/entry_no.S
+++ b/arch/m68k/kernel/entry_no.S
@@ -44,8 +44,12 @@
 
 ENTRY(buserr)
        SAVE_ALL_INT
-       moveq   #-1,%d0
-       movel   %d0,%sp@(PT_OFF_ORIG_D0)
+#ifdef CONFIG_MMU
+       movel   %sp,%d0                 /* get thread_info pointer */
+       andl    #-THREAD_SIZE,%d0       /* at start of kernel stack */
+       movel   %d0,%a2
+       movel   %a2@,%a2                /* current pointer into a2 */
+#endif
        movel   %sp,%sp@-               /* stack frame pointer argument */
        jsr     buserr_c
        addql   #4,%sp
@@ -53,8 +57,12 @@ ENTRY(buserr)
 
 ENTRY(trap)
        SAVE_ALL_INT
-       moveq   #-1,%d0
-       movel   %d0,%sp@(PT_OFF_ORIG_D0)
+#ifdef CONFIG_MMU
+       movel   %sp,%d0                 /* get thread_info pointer */
+       andl    #-THREAD_SIZE,%d0       /* at start of kernel stack */
+       movel   %d0,%a2
+       movel   %a2@,%a2                /* current pointer into a2 */
+#endif
        movel   %sp,%sp@-               /* stack frame pointer argument */
        jsr     trap_c
        addql   #4,%sp
@@ -65,8 +73,12 @@ ENTRY(trap)
 .globl dbginterrupt
 ENTRY(dbginterrupt)
        SAVE_ALL_INT
-       moveq   #-1,%d0
-       movel   %d0,%sp@(PT_OFF_ORIG_D0)
+#ifdef CONFIG_MMU
+       movel   %sp,%d0                 /* get thread_info pointer */
+       andl    #-THREAD_SIZE,%d0       /* at start of kernel stack */
+       movel   %d0,%a2
+       movel   %a2@,%a2                /* current pointer into a2 */
+#endif
        movel   %sp,%sp@-               /* stack frame pointer argument */
        jsr     dbginterrupt_c
        addql   #4,%sp
diff --git a/arch/m68k/platform/coldfire/entry.S 
b/arch/m68k/platform/coldfire/entry.S
index f567a16..5fc1f40 100644
--- a/arch/m68k/platform/coldfire/entry.S
+++ b/arch/m68k/platform/coldfire/entry.S
@@ -63,6 +63,13 @@ ENTRY(system_call)
        SAVE_ALL_SYS
        move    #0x2000,%sr             /* enable intrs again */
 
+#ifdef CONFIG_MMU
+       movel   %sp,%d2                 /* get thread_info pointer */
+       andl    #-THREAD_SIZE,%d2       /* at start of kernel stack */
+       movel   %d2,%a2
+       movel   %a2@,%a2                /* current pointer into a2 */
+#endif
+
        cmpl    #NR_syscalls,%d0
        jcc     enosys
        lea     sys_call_table,%a0
@@ -166,6 +173,13 @@ Lsignal_return:
 ENTRY(inthandler)
        SAVE_ALL_INT
 
+#ifdef CONFIG_MMU
+       movel   %sp,%d2                 /* get thread_info pointer */
+       andl    #-THREAD_SIZE,%d2       /* at start of kernel stack */
+       movel   %d2,%a2
+       movel   %a2@,%a2                /* current pointer into a2 */
+#endif
+
        movew   %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */
        andl    #0x03fc,%d0             /* mask out vector only */
 
@@ -190,7 +204,9 @@ 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 */
-- 
1.7.0.4

--
To unsubscribe from this list: send the line "unsubscribe linux-m68k" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to