timekeeping: Introduce struct timekeeper

Add struct timekeeper to keep the internal values timekeeping.c needs
in regard to the currently selected clock source. This moves the
timekeeping intervals, xtime_nsec and the ntp error value from struct
clocksource to struct timekeeper. The raw_time is removed from the
clocksource as well. It gets treated like xtime as a global variable.
Eventually xtime raw_time should be moved to struct timekeeper.

[ tglx: minor cleanup ]

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
LKML-Reference: <20090814134809.613209842@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 4 insertions, 50 deletions

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 19ad43af62d..e12e3095e2f 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -155,8 +155,6 @@ extern u64 timecounter_cyc2time(struct timecounter *tc,
  * @flags:              flags describing special properties
  * @vread:              vsyscall based read
  * @resume:             resume function for the clocksource, if necessary
- * @cycle_interval:     Used internally by timekeeping core, please ignore.
- * @xtime_interval:     Used internally by timekeeping core, please ignore.
  */
 struct clocksource {
         /*
@@ -182,19 +180,12 @@ struct clocksource {
 #define CLKSRC_FSYS_MMIO_SET(mmio, addr)      do { } while (0)
 #endif
 
-        /* timekeeping specific data, ignore */
-        cycle_t cycle_interval;
-        u64     xtime_interval;
-        u32     raw_interval;
         /*
          * Second part is written at each timer interrupt
          * Keep it in a different cache line to dirty no
          * more than one cache line.
          */
         cycle_t cycle_last ____cacheline_aligned_in_smp;
-        u64 xtime_nsec;
-        s64 error;
-        struct timespec raw_time;
 
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
         /* Watchdog related data, used by the framework */
@@ -203,8 +194,6 @@ struct clocksource {
 #endif
 };
 
-extern struct clocksource *clock;       /* current clocksource */
-
 /*
  * Clock source flags bits::
  */
@@ -270,50 +259,15 @@ static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant)
 }
 
 /**
- * cyc2ns - converts clocksource cycles to nanoseconds
- * @cs:         Pointer to clocksource
- * @cycles:     Cycles
+ * clocksource_cyc2ns - converts clocksource cycles to nanoseconds
  *
- * Uses the clocksource and ntp ajdustment to convert cycle_ts to nanoseconds.
+ * Converts cycles to nanoseconds, using the given mult and shift.
  *
  * XXX - This could use some mult_lxl_ll() asm optimization
  */
-static inline s64 cyc2ns(struct clocksource *cs, cycle_t cycles)
+static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
 {
-        u64 ret = (u64)cycles;
-        ret = (ret * cs->mult) >> cs->shift;
-        return ret;
-}
-
-/**
- * clocksource_calculate_interval - Calculates a clocksource interval struct
- *
- * @c:          Pointer to clocksource.
- * @length_nsec: Desired interval length in nanoseconds.
- *
- * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
- * pair and interval request.
- *
- * Unless you're the timekeeping code, you should not be using this!
- */
-static inline void clocksource_calculate_interval(struct clocksource *c,
-                                                  unsigned long length_nsec)
-{
-        u64 tmp;
-
-        /* Do the ns -> cycle conversion first, using original mult */
-        tmp = length_nsec;
-        tmp <<= c->shift;
-        tmp += c->mult_orig/2;
-        do_div(tmp, c->mult_orig);
-
-        c->cycle_interval = (cycle_t)tmp;
-        if (c->cycle_interval == 0)
-                c->cycle_interval = 1;
-
-        /* Go back from cycles -> shifted ns, this time use ntp adjused mult */
-        c->xtime_interval = (u64)c->cycle_interval * c->mult;
-        c->raw_interval = ((u64)c->cycle_interval * c->mult_orig) >> c->shift;
+        return ((u64) cycles * mult) >> shift;
 }