tile: Reorganize _switch_to()

Move the simulator bits into finish_arch_post_lock_switch() and
properly call __switch_to() from _switch_to().

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: <efault@gmx.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438783412-10990-1-git-send-email-cmetcalf@ezchip.com
[ Made it a delta to: fe363adb9225 ("sched, tile: Remove finish_arch_switch"). ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 6 insertions, 12 deletions

diff --git a/arch/tile/include/asm/switch_to.h b/arch/tile/include/asm/switch_to.h
index 422842a56a3d..34ee72705521 100644
--- a/arch/tile/include/asm/switch_to.h
+++ b/arch/tile/include/asm/switch_to.h
@@ -56,6 +56,8 @@ extern unsigned long get_switch_to_pc(void);
  * We defer homecache migration until the runqueue lock is released.
  */
 #define finish_arch_post_lock_switch() do {                               \
+        __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_SWITCH |             \
+                (current->pid << _SIM_CONTROL_OPERATOR_BITS));            \
         if (current->mm == NULL && !kstack_hash &&                        \
             current_thread_info()->homecache_cpu != raw_smp_processor_id()) \
                 homecache_migrate_kthread();                              \
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index 1087375cd57c..7d5769310bef 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -446,26 +446,18 @@ struct task_struct *__sched _switch_to(struct task_struct *prev,
         hardwall_switch_tasks(prev, next);
 #endif
 
-        /*
-         * Switch kernel SP, PC, and callee-saved registers.
-         * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp.
-         * Once we return from this function we will have changed stacks
-         * and be running with current == next.
-         */
-        __switch_to(prev, next, next_current_ksp0(next));
-
-        /* Notify the simulator of task switch and task exit. */
+        /* Notify the simulator of task exit. */
         if (unlikely(prev->state == TASK_DEAD))
                 __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_EXIT |
                              (prev->pid << _SIM_CONTROL_OPERATOR_BITS));
-        __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_SWITCH |
-                (next->pid << _SIM_CONTROL_OPERATOR_BITS));
 
         /*
+         * Switch kernel SP, PC, and callee-saved registers.
          * In the context of the new task, return the old task pointer
          * (i.e. the task that actually called __switch_to).
+         * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp.
          */
-        return prev;
+        return __switch_to(prev, next, next_current_ksp0(next));
 }
 
 /*