[ARM] 3707/1: iwmmxt: use the generic thread notifier infrastructure

Patch from Lennert Buytenhek

This patch makes the iWMMXt context switch hook use the generic
thread notifier infrastructure that was recently merged in commit
d6551e884cf66de072b81f8b6d23259462c40baf.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 12 insertions, 15 deletions

diff --git a/arch/arm/kernel/iwmmxt.S b/arch/arm/kernel/iwmmxt.S
index a3bae95e536c..b63b528f22a6 100644
--- a/arch/arm/kernel/iwmmxt.S
+++ b/arch/arm/kernel/iwmmxt.S
@@ -271,30 +271,27 @@ ENTRY(iwmmxt_task_restore)
 /*
  * Concan handling on task switch
  *
- * r0 = previous task_struct pointer (must be preserved)
- * r1 = previous thread_info pointer
- * r2 = next thread_info pointer (must be preserved)
+ * r0 = next thread_info pointer
  *
- * Called only from __switch_to with task preemption disabled.
- * No need to care about preserving r4 and above.
+ * Called only from the iwmmxt notifier with task preemption disabled.
  */
 ENTRY(iwmmxt_task_switch)
 
-        mrc     p15, 0, r4, c15, c1, 0
-        tst     r4, #0x3                        @ CP0 and CP1 accessible?
+        mrc     p15, 0, r1, c15, c1, 0
+        tst     r1, #0x3                        @ CP0 and CP1 accessible?
         bne     1f                              @ yes: block them for next task
 
-        ldr     r5, =concan_owner
-        add     r6, r2, #TI_IWMMXT_STATE        @ get next task Concan save area
-        ldr     r5, [r5]                        @ get current Concan owner
-        teq     r5, r6                          @ next task owns it?
+        ldr     r2, =concan_owner
+        add     r3, r0, #TI_IWMMXT_STATE        @ get next task Concan save area
+        ldr     r2, [r2]                        @ get current Concan owner
+        teq     r2, r3                          @ next task owns it?
         movne   pc, lr                          @ no: leave Concan disabled
 
-1:      eor     r4, r4, #3                      @ flip Concan access
-        mcr     p15, 0, r4, c15, c1, 0
+1:      eor     r1, r1, #3                      @ flip Concan access
+        mcr     p15, 0, r1, c15, c1, 0
 
-        mrc     p15, 0, r4, c2, c0, 0
-        sub     pc, lr, r4, lsr #32             @ cpwait and return
+        mrc     p15, 0, r1, c2, c0, 0
+        sub     pc, lr, r1, lsr #32             @ cpwait and return
 
 /*
  * Remove Concan ownership of given task