[S390] rework idle code

Whenever the cpu loads an enabled wait PSW it will appear as idle to the
underlying host system. The code in default_idle calls vtime_stop_cpu
which does the necessary voodoo to get the cpu time accounting right.
The udelay code just loads an enabled wait PSW. To correct this rework
the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts
to entry[64].S, vtime_stop_cpu can now be called from anywhere and
vtime_start_cpu is gone. The correction of the cpu time during wakeup
from an enabled wait PSW is done with a critical section in entry[64].S.
As vtime_start_cpu is gone, s390_idle_check can be removed as well.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index 92b1617d0c9..4984785e307 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -4,7 +4,8 @@
 #include <linux/types.h>
 #include <linux/signal.h>
 #include <asm/ptrace.h>
-
+#include <asm/cputime.h>
+#include <asm/timer.h>
 
 extern void (*pgm_check_table[128])(struct pt_regs *);
 extern void *restart_stack;
@@ -16,6 +17,8 @@ void io_int_handler(void);
 void mcck_int_handler(void);
 void restart_int_handler(void);
 void restart_call_handler(void);
+void psw_idle(struct s390_idle_data *, struct vtimer_queue *,
+	      unsigned long, int);
 
 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs);
 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs);