src/patches/suse-2.6.27.39/patches.arch/s390-17-perf-12-get_clock_monotonic.patch

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: [PATCH] introduce get_clock_monotonic
   3 References: bnc#532063,LTC#55526
   4
   5 From: Heiko Carstens <heiko.carstens@de.ibm.com>
   6
   7 Introduce get_clock_monotonic() function which can be used to get a
   8 (fast) timestamp. Resolution is the same as for get_clock(). The
   9 only difference is that the timestamps are monotonic and don't jump
  10 backward or forward.
  11
  12 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
  13 Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
  14
  15 Acked-by: John Jolly <jjolly@suse.de>
  16 ---
  17
  18  arch/s390/include/asm/timex.h |   16 ++++++++++++++++
  19  arch/s390/kernel/time.c       |    3 ++-
  20  2 files changed, 18 insertions(+), 1 deletion(-)
  21
  22 Index: linux-sles11/arch/s390/include/asm/timex.h
  23 ===================================================================
  24 --- linux-sles11.orig/arch/s390/include/asm/timex.h
  25 +++ linux-sles11/arch/s390/include/asm/timex.h
  26 @@ -85,4 +85,20 @@ int get_sync_clock(unsigned long long *c
  27  void init_cpu_timer(void);
  28  unsigned long long monotonic_clock(void);
  29
  30 +extern u64 jiffies_timer_cc;
  31 +
  32 +/**
  33 + * get_clock_monotonic - returns current time in clock rate units
  34 + *
  35 + * The caller must ensure that preemption is disabled.
  36 + * The clock and sched_clock_base get changed via stop_machine.
  37 + * Therefore preemption must be disabled when calling this
  38 + * function, otherwise the returned value is not guaranteed to
  39 + * be monotonic.
  40 + */
  41 +static inline unsigned long long get_clock_monotonic(void)
  42 +{
  43 +       return get_clock_xt() - jiffies_timer_cc;
  44 +}
  45 +
  46  #endif
  47 Index: linux-sles11/arch/s390/kernel/time.c
  48 ===================================================================
  49 --- linux-sles11.orig/arch/s390/kernel/time.c
  50 +++ linux-sles11/arch/s390/kernel/time.c
  51 @@ -63,7 +63,8 @@
  52
  53  static ext_int_info_t ext_int_info_cc;
  54  static ext_int_info_t ext_int_etr_cc;
  55 -static u64 jiffies_timer_cc;
  56 +u64 jiffies_timer_cc;
  57 +EXPORT_SYMBOL(jiffies_timer_cc);
  58
  59  static DEFINE_PER_CPU(struct clock_event_device, comparators);
  60