The nrf51_timer has a free-running counter which we implement using
the pattern of using two fields (update_counter_ns, counter) to track
the last point at which we calculated the counter value, and the
counter value at that time. Then we can find the current counter
value by converting the difference in wall-clock time between then
and now to a tick count that we need to add to the counter value.
Unfortunately the nrf51_timer's implementation of this has a bug
which means it loses time every time update_counter() is called.
After updating s->counter it always sets s->update_counter_ns to
'now', even though the actual point when s->counter hit the new value
will be some point in the past (half a tick, say). In the worst case
(guest code in a tight loop reading the counter, icount mode) the
counter is continually queried less than a tick after it was last
read, so s->counter never advances but s->update_counter_ns does, and
the guest never makes forward progress.
The fix for this is to only advance update_counter_ns to the
timestamp of the last tick, not all the way to 'now'. (This is the
pattern used in hw/misc/mps2-fpgaio.c's counter.)
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20230606134917.3782215-1-peter.maydell@linaro.org
Add trace event to display timer's counter value updates.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200504072822.18799-5-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The NRF51 series SoC have 3 timer peripherals, each having
4 counters. To help differentiate which peripheral is accessed,
display the timer ID in the trace events.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200504072822.18799-4-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
On the NRF51 series, all peripherals have a fixed I/O size
of 4KiB. Define NRF51_PERIPHERAL_SIZE and use it.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200504072822.18799-2-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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>
In my "build everything" tree, changing hw/irq.h triggers a recompile
of some 5400 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 qemu_irq and.or qemu_irq_handler.
Move the qemu_irq and qemu_irq_handler typedefs from hw/irq.h to
qemu/typedefs.h, and then include hw/irq.h only where it's still
needed. Touching it now recompiles only some 500 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-13-armbru@redhat.com>
This patch adds the model for the nRF51 timer peripheral.
Currently, only the TIMER mode is implemented.
Signed-off-by: Steffen Görtz <contrib@steffen-goertz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190103091119.9367-9-stefanha@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
