Commit Graph

16 Commits

Author SHA1 Message Date
Alexander Motin
875b8844be Implement new event timers infrastructure. It provides unified APIs for
writing event timer drivers, for choosing best possible drivers by machine
independent code and for operating them to supply kernel with hardclock(),
statclock() and profclock() events in unified fashion on various hardware.

Infrastructure provides support for both per-CPU (independent for every CPU
core) and global timers in periodic and one-shot modes. MI management code
at this moment uses only periodic mode, but one-shot mode use planned for
later, as part of tickless kernel project.

For this moment infrastructure used on i386 and amd64 architectures. Other
archs are welcome to follow, while their current operation should not be
affected.

This patch updates existing drivers (i8254, RTC and LAPIC) for the new
order, and adds event timers support into the HPET driver. These drivers
have different capabilities:
 LAPIC - per-CPU timer, supports periodic and one-shot operation, may
freeze in C3 state, calibrated on first use, so may be not exactly precise.
 HPET - depending on hardware can work as per-CPU or global, supports
periodic and one-shot operation, usually provides several event timers.
 i8254 - global, limited to periodic mode, because same hardware used also
as time counter.
 RTC - global, supports only periodic mode, set of frequencies in Hz
limited by powers of 2.

Depending on hardware capabilities, drivers preferred in following orders,
either LAPIC, HPETs, i8254, RTC or HPETs, LAPIC, i8254, RTC.
User may explicitly specify wanted timers via loader tunables or sysctls:
kern.eventtimer.timer1 and kern.eventtimer.timer2.
If requested driver is unavailable or unoperational, system will try to
replace it. If no more timers available or "NONE" specified for second,
system will operate using only one timer, multiplying it's frequency by few
times and uing respective dividers to honor hz, stathz and profhz values,
set during initial setup.
2010-06-20 21:33:29 +00:00
Alexander Motin
1703f2b424 Rename statclock_disable variable to atrtcclock_disable that it actually is,
and hide it inside of atrtc driver. Add new tunable hint.atrtc.0.clock
controlling it. Setting it to 0 disables using RTC clock as stat-/
profclock sources.

Teach i386 and amd64 SMP platforms to emulate stat-/profclocks using i8254
hardclock, when LAPIC and RTC clocks are disabled.

This allows to reduce global interrupt rate of idle system down to about
100 interrupts per core, permitting C3 and deeper C-states provide maximum
CPU power efficiency.
2009-05-03 17:47:21 +00:00
Poul-Henning Kamp
7e82012aff atrtc.c is a repocopy of the RTC device driver from i386/isa/clock.c
In addition to the device driver functionality, it exposes a number of
functions which various other bits of code use to fondle the RTC chip.
2008-04-14 07:57:15 +00:00
Warner Losh
f36cfd49ad Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson
2004-04-07 20:46:16 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Poul-Henning Kamp
3bc7e56592 Improve a couple of comment.
PR:		7242
Reviewed by:	phk
Submitted by:	Peter Jeremy <peter.jeremyp@alcatel.com.au>
1998-07-11 08:01:18 +00:00
Peter Wemm
6875d25465 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Joerg Wunsch
86a727d96d BIOS manufacturers don't seem to have a unique idea about 2.88 MB
floppy drive types in the CMOS; add 0x50 as an alias for 2.88 MB.
1995-10-09 15:00:39 +00:00
Joerg Wunsch
290dd077ef Here is a minor patch for FreeBSD 2.0R to allow it to recognize
2.88MB floppy drives.  All it does is set the type to 1.44MB if
it finds the 2.88MB drive.

Submitted by:	Andrew Gillham <gillham@andrews.edu>
1994-12-04 20:22:20 +00:00
Andrey A. Chernov
7b915aa631 resettodr() implemented, inittodr() fixed
Submitted by: me & chris@gnome.co.uk
1994-09-20 00:31:07 +00:00
Garrett Wollman
8ea838500f Enable use of the RTC chip for the statistical clock. While this does
not provide the full accuracy of a randomized statistical clock, it does
provide greater accuracy than the previous method, while not significantly
increasing overhead.  It also provides profiling support at 1024 Hz.

You must re-compile config before making a new kernel, or you will end
up with unresolved symbols.

Reviewed uy:	Bruce evans said it worked for him.
1994-08-15 03:15:20 +00:00
Andrey A. Chernov
159569a418 RTCFDT_720K (physical drive 720K) added. 1993-12-18 01:12:47 +00:00
Garrett Wollman
13c0dce671 Made all header files idempotent and moved incorrect common data from
headers into a related source file.  Also fixed a bug in ed_probe() where
it was possible to fall off the end of the function
1993-11-07 17:44:34 +00:00
Rodney W. Grimes
6f78ca6026 Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup.  Added $Id$ to files that did not have any version info, etc
1993-10-16 13:48:52 +00:00
Rodney W. Grimes
5b81b6b301 Initial import, 0.1 + pk 0.2.4-B1 1993-06-12 14:58:17 +00:00