[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>
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index aeeaf89..ed8c913 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -8,6 +8,8 @@
 
 #include <linux/kbuild.h>
 #include <linux/sched.h>
+#include <asm/cputime.h>
+#include <asm/timer.h>
 #include <asm/vdso.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -70,6 +72,12 @@
 	DEFINE(__CLOCK_MONOTONIC, CLOCK_MONOTONIC);
 	DEFINE(__CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC);
 	BLANK();
+	/* idle data offsets */
+	DEFINE(__IDLE_ENTER, offsetof(struct s390_idle_data, idle_enter));
+	DEFINE(__IDLE_EXIT, offsetof(struct s390_idle_data, idle_exit));
+	/* vtimer queue offsets */
+	DEFINE(__VQ_IDLE_ENTER, offsetof(struct vtimer_queue, idle_enter));
+	DEFINE(__VQ_IDLE_EXIT, offsetof(struct vtimer_queue, idle_exit));
 	/* lowcore offsets */
 	DEFINE(__LC_EXT_PARAMS, offsetof(struct _lowcore, ext_params));
 	DEFINE(__LC_EXT_CPU_ADDR, offsetof(struct _lowcore, ext_cpu_addr));