[Qemu-devel] [PATCH v2 0/7] remove useless muldiv64()

[Laurent Vivier <lvivier@redhat.com>]

Originally, timers were ticks based, and it made sense to
add ticks to current time to know when to trigger an alarm.

But since commit:

7447545 change all other clock references to use nanosecond resolution accessors

All timers use nanoseconds and we need to convert ticks to nanoseconds, by
doing something like:

     y = muldiv64(x, get_ticks_per_sec(), TIMER_FREQ)

where x is the number of device ticks and y the number of system ticks.

y is used as nanoseconds in timer functions,
it works because 1 tick is 1 nanosecond.
(get_ticks_per_sec() is 10^9)

But if get_ticks_per_sec() / TIMER_FREQ is an integer, we can do:

    y = x * TIMER_PERIOD;

v2:
4/4 For target-arm, don't remove muldiv64() but clarify
    the use of the values.
7/7 Replace qemu_clock_get_ns()/1000 by qemu_clock_get_us()

Laurent Vivier (7):
  PCI: remove muldiv64()
  mips: remove muldiv64()
  openrisc: remove muldiv64()
  arm: clarify the use of muldiv64()
  hpet: remove muldiv64()
  bt: remove muldiv64()
  net: remove muldiv64()

 hw/bt/hci.c                |  4 ++--
 hw/mips/cputimer.c         | 19 ++++++++-----------
 hw/net/pcnet.c             |  3 +--
 hw/net/rtl8139.c           | 14 ++++++--------
 hw/openrisc/cputimer.c     |  7 +++----
 hw/timer/hpet.c            |  6 +++---
 hw/watchdog/wdt_i6300esb.c | 11 +++--------
 include/hw/timer/hpet.h    |  4 ++--
 net/dump.c                 |  2 +-
 target-arm/helper.c        | 14 ++++++++------
 tests/rtl8139-test.c       |  2 +-
 11 files changed, 38 insertions(+), 48 deletions(-)

-- 
2.1.0