added an arbitrary delay to our readings, causing us to use the ACPI-safe
read method when not necessary. Submitted by: bde
Old:
ACPI timer looks GOOD min = 3, max = 5, width = 2
ACPI timer looks BAD min = 3, max = 19, width = 16
ACPI timer looks GOOD min = 3, max = 5, width = 2
ACPI timer looks GOOD min = 3, max = 5, width = 2
ACPI timer looks GOOD min = 3, max = 5, width = 2
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 5, width = 2
ACPI timer looks BAD min = 3, max = 19, width = 16
ACPI timer looks GOOD min = 3, max = 5, width = 2
ACPI timer looks GOOD min = 3, max = 4, width = 1
Timecounter "ACPI-safe" frequency 3579545 Hz quality 1000
New:
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
ACPI timer looks GOOD min = 3, max = 4, width = 1
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
Also, reduce unnecesary overhead in ACPI-fast by remove the barrier for
reads. The timer in the ACPI-fast case is known to increase monotonically
so there is no need to serialize access to it.
workaround was for hardware where the clock was not latched, not for
hardware that was too slow. Also, make variable names more specific for ddb
printing.
what the ACPI-safe workaround is intended to fix. Requested by phk.
Set the bushandle and tag when attaching the timer, don't do it each time
in read_counter(). Pointed out by bde.
Move test_counter() to the end. Staticize acpi_timer_reg.
supported. Symptoms of this bug included unnecessary use of ACPI-safe
and a dmesg that has deltas of about 2^24:
ACPI timer looks BAD min = 2, max = 16777206, width = 16777204
ACPI timer looks BAD min = 2, max = 7, width = 5
ACPI timer looks GOOD min = 4, max = 5, width = 1
ACPI timer looks BAD min = 2, max = 16777206, width = 16777204
ACPI timer looks BAD min = 2, max = 7, width = 5
ACPI timer looks BAD min = 2, max = 16777210, width = 16777208
ACPI timer looks BAD min = 4, max = 16777189, width = 16777185
ACPI timer looks GOOD min = 4, max = 5, width = 1
ACPI timer looks BAD min = 2, max = 7, width = 5
ACPI timer looks BAD min = 4, max = 16777189, width = 16777185
To fix this:
* Use a 32 bit timecounter mask when the timer is 32 bits.
* In test_counter(), use the acpi_TimerDelta function which handles 24/32
bit timers and wraparound.
Miscellaneous fixes:
* Use C99 initializers for timecounter struct.
* Use u_int and uint32_t where appropriate instead of unsigned.
* Remove whitespace-only lines
* Remove the old PIIX4 PCI workaround. The timecounter testing code has
been in use for long enough to prove it's functional.
Sort acpi debug values. Change "disable" to "disabled" to match rest of
the kernel. Remove debugging from acpi_toshiba since it was only used for
probe/attach.
A timecounter will be selected when registered if its quality is
not negative and no less than the current timecounters.
Add a sysctl to report all available timecounters and their qualities.
Give the dummy timecounter a solid negative quality of minus a million.
Give the i8254 zero and the ACPI 1000.
The TSC gets 800, unless APM or SMP forces it negative.
Other timecounters default to zero quality and thereby retain current
selection behaviour.
at all (ie reads yield constant values). Display the width as the
difference between max and min so that constant timers have width
zero.
o Get the address of the timer from the XPmTmrBlk field instead of
the V1_PmTmrBlk field. The former is a generic address and can
specify a memory mapped I/O address. Remove <machine/bus_pio.h>
to account for this. The timer is now properly configured on
machines with ACPI v2 tables, whether PIO or MEMIO. Note that
the acpica code converts v1 tables into v2 tables so the address
is always present in XPmTmrBlk.
o Replace the TIMER_READ macro with a call to the read_counter()
function and add a barrier to make sure that we observe proper
ordering of the reads.
timecounter will be used starting at the next second, which is
good enough for sysctl purposes. If better adjustment is needed
the NTP PLL should be used.
environment needed at boot time to a dynamic subsystem when VM is
up. The dynamic kernel environment is protected by an sx lock.
This adds some new functions to manipulate the kernel environment :
freeenv(), setenv(), unsetenv() and testenv(). freeenv() has to be
called after every getenv() when you have finished using the string.
testenv() only tests if an environment variable is present, and
doesn't require a freeenv() call. setenv() and unsetenv() are self
explanatory.
The kenv(2) syscall exports these new functionalities to userland,
mainly for kenv(1).
Reviewed by: peter
The conclusion is that this method really can tell the perfect from the
less than perfect ACPI counters.
It is in fact probably a bit more discriminative than that, but we
will rather condemn some otherwise perfect counters to the slightly
slower "-safe" version, than certify a counter as perfect which
will let us down later.
Many thanks to all the people who sent email reports!
the inter-value histogram for 2000 samples. If the width is 3 or less
for 10 consequtive samples, we trust the counter to be good, otherwise
we use the *_safe() method.
This method may be too strict, but the worst which can happen is that
we take the performance hit of the *_safe() method when we should not.
Make the *_safe() method more discriminating by mandating that the three
samples do not span more than 15 ticks on the counter.
Disable the PCI-ident based probing as a means to recognize good
counters.
Inspiration from: dillon and msmith
latch the acpi timer, resulting in weird deltas. The problem is severe
enough to adversely effect the timecounter code.
Default to the 'safe' version of the get-timecount function. The probe
will override it if a known-good chipset is found. This is temporary
until a more complete solution is found.
Reviewed by: phk
- Remove the beer-ware license (reqested by phk)
- Reorganise so that the PIIX4 workaround code is kept together, and
switch the workaround function via the timecounter struct, saving
a compare in the read-timecounter codepath. Also indicate that
the workaround is active by changing the timecounter hardware string.
This code is based on the mp_clock code by phk. It attempts to
detect the PIIX4 (see comments for details) and use a workaround
for its problems.
This code is experimental, and could use some testing and review by a
timekeeping enthusiast.
- Use __func__ instead of __FUNCTION.
- Support power-off to S3 or S5 (takawata)
- Enable ACPI debugging earlier (with a sysinit)
- Fix a deadlock in the EC code (takawata)
- Improve arithmetic and reduce the risk of spurious wakeup in
AcpiOsSleep.
- Add AcpiOsGetThreadId.
- Simplify mutex code (still disabled).
acpi_EvaluateInteger.
Use acpi_EvaluateInteger instead of doing things the hard way where
possible.
AcpiSetSystemSleepState (unofficial) becomes AcpiEnterSleepState.
Use the AcpiGbl_FADT pointer rather than searching for the FADT.
infrastructure. It's not perfect, but it's a lot better than what
we've been using so far. The following rules apply to this:
o BSD component names should be capitalised
o Layer names should be taken from the non-CA set for now. We
may elect to add some new BSD-specific layers later.
- Make it possible to turn off selective debugging flags or layers
by listing them in debug.acpi.layer or debug.acpi.level prefixed
with !.
- Fully implement support for avoiding nodes in the ACPI namespace.
Nodes may be listed in the debug.acpi.avoid environment variable;
these nodes and all their children will be ignored (although still
scanned over) by ACPI functions which scan the namespace. Multiple
nodes can be specified, separated by whitespace.
- Implement support for selectively disabling ACPI subsystem components
via the debug.acpi.disable environment variable. The following
components can be disabled:
o bus creation/scanning of the ACPI 'bus'
o children attachment of children to the ACPI 'bus'
o button the acpi_button control-method button driver
o ec the acpi_ec embedded-controller driver
o isa acpi replacement of PnP BIOS for ISA device discovery
o lid the control-method lid switch driver
o pci pci root-bus discovery
o processor CPU power/speed management
o thermal system temperature detection and control
o timer ACPI timecounter
Multiple components may be disabled by specifying their name(s)
separated by whitespace.
- Add support for ioctl registration. ACPI subsystem components may
register ioctl handlers with the /dev/acpi generic ioctl handler,
allowing us to avoid the need for a multitude of /dev/acpi* control
devices, etc.
- Use ACPI_PHYSICAL_ADDRESS
- RSDT -> XSDT
- FACP -> FADT
- No APIC table support
- Don't install a global EC handler; this has bad side-effects
(it invokes _REG in *all* EC spaces in the namespace!)
- Check for PCI bus instances already existing before adding them
ACPICA. Most of these are still works in progress. Support exists for:
- Fixed feature and control method power, lid and sleep buttons.
- Detection of ISA PnP devices using ACPI namespace.
- Detection of PCI root busses using ACPI namespace.
- CPU throttling and sleep states (incomplete)
- Thermal monitoring and cooling control (incomplete)
- Interface to platform embedded controllers (mostly complete)
- ACPI timer (incomplete)
- Simple userland control of sleep states.
- Shutdown and poweroff.
