aboutsummaryrefslogtreecommitdiff
path: root/drivers/idle/Makefile
diff options
context:
space:
mode:
authorPatrick Ohly <patrick.ohly@intel.com>2009-02-12 05:03:34 +0000
committerDavid S. Miller <davem@davemloft.net>2009-02-15 22:43:31 -0800
commita038a353c3de4040d8445ec568acebdac144436f (patch)
tree2fac74d812b47fa2d9fabfa55261d544813b66f6 /drivers/idle/Makefile
parent0a834a36ac92375cd82d9e4fe4f571e257997d6a (diff)
clocksource: allow usage independent of timekeeping.c
So far struct clocksource acted as the interface between time/timekeeping.c and hardware. This patch generalizes the concept so that a similar interface can also be used in other contexts. For that it introduces new structures and related functions *without* touching the existing struct clocksource. The reasons for adding these new structures to clocksource.[ch] are * the APIs are clearly related * struct clocksource could be cleaned up to use the new structs * avoids proliferation of files with similar names (timesource.h? timecounter.h?) As outlined in the discussion with John Stultz, this patch adds * struct cyclecounter: stateless API to hardware which counts clock cycles * struct timecounter: stateful utility code built on a cyclecounter which provides a nanosecond counter * only the function to read the nanosecond counter; deltas are used internally and not exposed to users of timecounter The code does no locking of the shared state. It must be called at least as often as the cycle counter wraps around to detect these wrap arounds. Both is the responsibility of the timecounter user. Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/idle/Makefile')
0 files changed, 0 insertions, 0 deletions