Now all the users of ptimers have converted to the transaction-based
API, we can remove ptimer_init_with_bh() and all the code paths
that are used only by bottom-half based ptimers, and tidy up the
documentation comments to consider the transaction-based API the
only possibility.
The code changes result from:
* s->bh no longer exists
* s->callback is now always non-NULL
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191025142411.17085-1-peter.maydell@linaro.org
Provide the new transaction-based API. If a ptimer is created
using ptimer_init() rather than ptimer_init_with_bh(), then
instead of providing a QEMUBH, it provides a pointer to the
callback function directly, and has opted into the transaction
API. All calls to functions which modify ptimer state:
- ptimer_set_period()
- ptimer_set_freq()
- ptimer_set_limit()
- ptimer_set_count()
- ptimer_run()
- ptimer_stop()
must be between matched calls to ptimer_transaction_begin()
and ptimer_transaction_commit(). When ptimer_transaction_commit()
is called it will evaluate the state of the timer after all the
changes in the transaction, and call the callback if necessary.
In the old API the individual update functions generally would
call ptimer_trigger() immediately, which would schedule the QEMUBH.
In the new API the update functions will instead defer the
"set s->next_event and call ptimer_reload()" work to
ptimer_transaction_commit().
Because ptimer_trigger() can now immediately call into the
device code which may then call other ptimer functions that
update ptimer_state fields, we must be more careful in
ptimer_reload() not to cache fields from ptimer_state across
the ptimer_trigger() call. (This was harmless with the QEMUBH
mechanism as the BH would not be invoked until much later.)
We use assertions to check that:
* the functions modifying ptimer state are not called outside
a transaction block
* ptimer_transaction_begin() and _commit() calls are paired
* the transaction API is not used with a QEMUBH ptimer
There is some slight repetition of code:
* most of the set functions have similar looking "if s->bh
call ptimer_reload, otherwise set s->need_reload" code
* ptimer_init() and ptimer_init_with_bh() have similar code
We deliberately don't try to avoid this repetition, because
it will all be deleted when the QEMUBH version of the API
is removed.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-3-peter.maydell@linaro.org
Currently the ptimer design uses a QEMU bottom-half as its
mechanism for calling back into the device model using the
ptimer when the timer has expired. Unfortunately this design
is fatally flawed, because it means that there is a lag
between the ptimer updating its own state and the device
callback function updating device state, and guest accesses
to device registers between the two can return inconsistent
device state.
We want to replace the bottom-half design with one where
the guest device's callback is called either immediately
(when the ptimer triggers by timeout) or when the device
model code closes a transaction-begin/end section (when the
ptimer triggers because the device model changed the
ptimer's count value or other state). As the first step,
rename ptimer_init() to ptimer_init_with_bh(), to free up
the ptimer_init() name for the new API. We can then convert
all the ptimer users away from ptimer_init_with_bh() before
removing it entirely.
(Commit created with
git grep -l ptimer_init | xargs sed -i -e 's/ptimer_init/ptimer_init_with_bh/'
and three overlong lines folded by hand.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-2-peter.maydell@linaro.org
In my "build everything" tree, changing hw/hw.h triggers a recompile
of some 2600 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).
The previous commits have left only the declaration of hw_error() in
hw/hw.h. This permits dropping most of its inclusions. Touching it
now recompiles less than 200 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In my "build everything" tree, changing migration/vmstate.h triggers a
recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
hw/hw.h supposedly includes it for convenience. Several other headers
include it just to get VMStateDescription. The previous commit made
that unnecessary.
Include migration/vmstate.h only where it's still needed. Touching it
now recompiles only some 1600 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-16-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
The CMSDK timer behaviour is that an interrupt is triggered when the
counter counts down from 1 to 0; however one is not triggered if the
counter is manually set to 0 by a guest write to the counter register.
Currently ptimer can't handle this; add a policy option to allow
a ptimer user to request this behaviour.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Message-id: 20180703171044.9503-2-peter.maydell@linaro.org
This dependency is the wrong way, and we will need util/qemu-timer.h from
sysemu/cpus.h in the next patch.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For most of the timers counter starts to decrement after first period
expires. Due to rounding down performed by the ptimer_get_count, it returns
counter - 1 for the running timer, so that for the ptimer user it looks
like counter gets decremented immediately after running the timer. Add "no
counter round down" policy that provides correct behaviour for those timers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: ef39622d0ebfdc32a0877e59ffdf6910dc3db688.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Immediate counter re-load on setting (or on starting to run with)
counter = 0 is a wrong behaviour for some of the timers. Add "no
immediate reload" policy that provides correct behaviour for such timers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: bf9385cd2550ca451d564fa46007688cee3f3d9d.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Performing trigger on setting (or starting to run with) counter = 0 could
be a wrong behaviour for some of the timers, provide "no immediate trigger"
policy to maintain correct behaviour for such timers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 72c0319cf2ec599f22397b7da280c06c34dc40dd.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Currently, periodic timer that has load = delta = 0 performs trigger
on timer reload and stops, printing a "period zero" error message.
Introduce new policy that makes periodic timer to continuously trigger
with a period interval in case of load = 0.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 632b23dd11055d9bd5e338d66b38fac0bd51462e.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Currently, periodic counter wraps around immediately once counter reaches
"0", this is wrong behaviour for some of the timers, resulting in one period
being lost. Add new ptimer policy that provides correct behaviour for such
timers, so that counter stays with "0" for a one period before wrapping
around.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: f22a670cf1f4be298b31640cb5f4be1df0f20ab6.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Under qtest ptimer emits lots of warning messages. The messages are caused
by the actual checking of the ptimer error conditions. Suppress those
messages, so they do not distract.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 44877fff4ff03205590698d3dc189ad6d091472f.1473252818.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Some of the timer devices may behave differently from what ptimer
provides. Introduce ptimer policy feature that allows ptimer users to
change default and wrong timer behaviour, for example to continuously
trigger periodic timer when load value is equal to "0".
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 994cd608ec392da6e58f0643800dda595edb9d97.1473252818.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Running with counter / period = 0 is treated as a error case, printing error
message claiming that timer has been disabled. However, timer is only marked
as disabled, keeping to tick till expired and triggering after being claimed
as disabled. Stop the QEMU timer to avoid confusion.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 1e9bae4fae3c36430d7c28b0f486a0c71aff7eb3.1473252818.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Software should see timer counter wraparound only after IRQ being triggered.
This fixes regression introduced by the commit 5a50307 ("hw/ptimer: Perform
counter wrap around if timer already expired"), resulting in monotonic timer
jumping backwards on SPARC emulated machine running NetBSD guest OS, as
reported by Mark Cave-Ayland.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 20160708132206.2080-1-digetx@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Currently ptimer users are used to store copy of the limit value, because
ptimer doesn't provide facility to retrieve the limit. Let's provide it.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: 8f1fa9f90d8dbf8086fb02f3b4835eaeb4089cf6.1464367869.git.digetx@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Allow switching between periodic <-> oneshot modes while timer is running.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: f030be6e28fbd219e1e8d22297aee367bd9af5bb.1464367869.git.digetx@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Delta value must be updated on period/freq change, otherwise running timer
would be restarted (counter reloaded with old delta). Only m68k/mcf520x
and arm/arm_timer devices are currently doing freq change correctly, i.e.
stopping the timer. Perform delta update to fix affected devices and
eliminate potential further mistakes.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: 4987ef5fdc128bb9a744fd794d3f609135c6a39c.1464367869.git.digetx@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
ptimer_get_count() might be called while QEMU timer already been expired.
In that case ptimer would return counter = 0, which might be undesirable
in case of polled timer. Do counter wrap around for periodic timer to keep
it distributed. In order to achieve more accurate emulation behaviour of
certain hardware, don't perform wrap around when in icount mode and return
counter = 0 in that case (that doesn't affect polled counter distribution).
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: 4ce381c7d24d85d165ff251d2875d16a4b6a5c04.1464367869.git.digetx@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Multiple issues here related to the timer with a adjusted .limit value:
1) ptimer_get_count() returns incorrect counter value for the disabled
timer after loading the counter with a small value, because adjusted limit
value is used instead of the original.
For instance:
1) ptimer_stop(t)
2) ptimer_set_period(t, 1)
3) ptimer_set_limit(t, 0, 1)
4) ptimer_get_count(t) <-- would return 10000 instead of 0
2) ptimer_get_count() might return incorrect value for the timer running
with a adjusted limit value.
For instance:
1) ptimer_stop(t)
2) ptimer_set_period(t, 1)
3) ptimer_set_limit(t, 10, 1)
4) ptimer_run(t)
5) ptimer_get_count(t) <-- might return value > 10
3) Neither ptimer_set_period() nor ptimer_set_freq() are adjusting the
limit value, so it is still possible to make timer timeout value
arbitrary small.
For instance:
1) ptimer_set_period(t, 10000)
2) ptimer_set_limit(t, 1, 0)
3) ptimer_set_period(t, 1) <-- bypass limit correction
Fix all of the above issues by adjusting timer period instead of the limit.
Perform the adjustment for periodic timer only. Use the delta value instead
of the limit to make decision whether adjustment is required, as limit could
be altered while timer is running, resulting in incorrect value returned by
ptimer_get_count.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: cd141f74f5737480ec586b9c7d18cce1d69884e2.1464367869.git.digetx@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-37-git-send-email-peter.maydell@linaro.org
This patch adds deterministic replay for hardware periodic countdown timers.
ptimer uses bottom halves layer to execute such an asynchronous callback.
We put this callback into the replay queue instead of bottom halves one.
When checkpoint is met by main loop thread, the replay queue is processed
and callback is executed. Binding callback moment to one of the checkpoints
makes it deterministic.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162456.8676.83366.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
After previous Peter patch, they are redundant. This way we don't
assign them except when needed. Once there, there were lots of case
where the ".fields" indentation was wrong:
.fields = (VMStateField []) {
and
.fields = (VMStateField []) {
Change all the combinations to:
.fields = (VMStateField[]){
The biggest problem (appart from aesthetics) was that checkpatch complained
when we copy&pasted the code from one place to another.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
This is an autogenerated patch using scripts/switch-timer-api.
Switch the entire code base to using the new timer API.
Note this patch may introduce some line length issues.
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
