* [M68KNOMMU]: simplify ColdFire resume code
@ 2007-07-25 12:07 Greg Ungerer
0 siblings, 0 replies; only message in thread
From: Greg Ungerer @ 2007-07-25 12:07 UTC (permalink / raw)
To: torvalds; +Cc: gerg, linux-kernel
It is useless to preserve THREAD_SR in `resume'. The real user's sr
is actually in the stack. We also don't need to disable interrupts :
we'll never be in an invalid state, the sp switch is atomic.
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
---
diff -Naur linux-2.6.22/arch/m68knommu/platform/5307/entry.S linux-2.6.22-uc0/arch/m68knommu/platform/5307/entry.S
--- linux-2.6.22/arch/m68knommu/platform/5307/entry.S 2007-07-12 15:23:02.000000000 +1000
+++ linux-2.6.22-uc0/arch/m68knommu/platform/5307/entry.S 2007-07-12 15:27:01.000000000 +1000
@@ -235,16 +216,12 @@
* Beware - when entering resume, prev (the current task) is
* in a0, next (the new task) is in a1,so don't change these
* registers until their contents are no longer needed.
+ * This is always called in supervisor mode, so don't bother to save
+ * and restore sr; user's process sr is actually in the stack.
*/
ENTRY(resume)
movel %a0, %d1 /* get prev thread in d1 */
- movew %sr,%d0 /* save thread status reg */
- movew %d0,%a0@(TASK_THREAD+THREAD_SR)
-
- oril #0x700,%d0 /* disable interrupts */
- move %d0,%sr
-
movel sw_usp,%d0 /* save usp */
movel %d0,%a0@(TASK_THREAD+THREAD_USP)
@@ -255,7 +232,4 @@
movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore thread user stack */
movel %a0, sw_usp
-
- movew %a1@(TASK_THREAD+THREAD_SR),%d0 /* restore thread status reg */
- movew %d0, %sr
rts
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2007-07-25 12:10 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-07-25 12:07 [M68KNOMMU]: simplify ColdFire resume code Greg Ungerer
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®