This change adds `k_cycle_get_64()` on platforms that
support a 64-bit cycle counter.
The interface functions `arch_k_cycle_get_64()` and
`sys_clock_cycle_get_64()` are also introduced.
Fixes#39934
Signed-off-by: Christopher Friedt <chrisfriedt@gmail.com>
If CYC_PER_TICK does not divide the (now - last_count) quantity exactly with integer math, the subsequent multiplication before incrementing last_count causes a drift. This commit eliminates the redundant division-followed-by-multiplication and fixes https://github.com/zephyrproject-rtos/zephyr/issues/37852
Signed-off-by: Berend Ozceri <berend@recogni.com>
This is another API that is being used in all timer drivers and is not
internal to the clock subsystem. Remove the leading z_ and make promote
it to a cross-subsystem API.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The clock/timer APIs are not application facing APIs, however, similar
to arch_ and a few other APIs they are available to implement drivers
and add support for new hardware and are documented and available to be
used outside of the clock/kernel subsystems.
Remove the leading z_ and provide them as clock_* APIs for someone
writing a new timer driver to use.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
If next_timeout() returns INT_MAX and pass it to
z_clock_set_timeout(), and machine goes to freeze or slow down.
Bad scenario as follows:
- If an argument int32_t ticks is set large value 0xffffffff,
ticks = MAX(MIN(ticks - 1, (int32_t)MAX_TICKS), 0);
replaces it into MAX_TICKS.
- uint32_t cyc will be set near by 0xffffffff
(this is 0xfffd7280 in 100 ticks per second).
- Add adjustment to cyc, adjustment max value is MAX_CYC.
(cyc = 0xffff14fd)
- Over 0x80000000 value of uint32_t is considered as negative
value of int32_t.
if ((int32_t)(cyc + last_count - now) < MIN_DELAY)
This condition is always true.
- Because cyc += CYC_PER_TICK will get overflow, driver sets mtimecmp
near value of current mtime.
(cyc = 0x00007fc0)
- Next timer interrupt will happen soon after return from interrupt
handler.
- By repeating these events, machine cannot go to next instruction,
and it's going to freeze or slow down.
Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Replaces all existing variants of value clamping with the MIN and MAX
macros with the CLAMP macro.
Signed-off-by: Trond Einar Snekvik <Trond.Einar.Snekvik@nordicsemi.no>
Now that device_api attribute is unmodified at runtime, as well as all
the other attributes, it is possible to switch all device driver
instance to be constant.
A coccinelle rule is used for this:
@r_const_dev_1
disable optional_qualifier
@
@@
-struct device *
+const struct device *
@r_const_dev_2
disable optional_qualifier
@
@@
-struct device * const
+const struct device *
Fixes#27399
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Marking as unused (ARG_UNUSED) the parameter device in the
initialization function z_clock_driver_init when it is not used.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Add a k_timeout_t type, and use it everywhere that kernel API
functions were accepting a millisecond timeout argument. Instead of
forcing milliseconds everywhere (which are often not integrally
representable as system ticks), do the conversion to ticks at the
point where the timeout is created. This avoids an extra unit
conversion in some application code, and allows us to express the
timeout in units other than milliseconds to achieve greater precision.
The existing K_MSEC() et. al. macros now return initializers for a
k_timeout_t.
The K_NO_WAIT and K_FOREVER constants have now become k_timeout_t
values, which means they cannot be operated on as integers.
Applications which have their own APIs that need to inspect these
vs. user-provided timeouts can now use a K_TIMEOUT_EQ() predicate to
test for equality.
Timer drivers, which receive an integer tick count in ther
z_clock_set_timeout() functions, now use the integer-valued
K_TICKS_FOREVER constant instead of K_FOREVER.
For the initial release, to preserve source compatibility, a
CONFIG_LEGACY_TIMEOUT_API kconfig is provided. When true, the
k_timeout_t will remain a compatible 32 bit value that will work with
any legacy Zephyr application.
Some subsystems present timeout (or timeout-like) values to their own
users as APIs that would re-use the kernel's own constants and
conventions. These will require some minor design work to adapt to
the new scheme (in most cases just using k_timeout_t directly in their
own API), and they have not been changed in this patch, instead
selecting CONFIG_LEGACY_TIMEOUT_API via kconfig. These subsystems
include: CAN Bus, the Microbit display driver, I2S, LoRa modem
drivers, the UART Async API, Video hardware drivers, the console
subsystem, and the network buffer abstraction.
k_sleep() now takes a k_timeout_t argument, with a k_msleep() variant
provided that works identically to the original API.
Most of the changes here are just type/configuration management and
documentation, but there are logic changes in mempool, where a loop
that used a timeout numerically has been reworked using a new
z_timeout_end_calc() predicate. Also in queue.c, a (when POLL was
enabled) a similar loop was needlessly used to try to retry the
k_poll() call after a spurious failure. But k_poll() does not fail
spuriously, so the loop was removed.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
When debugging on a long running platform, the MCU may get reset by
the debugger with an ndmreset toggle. Since there is no requirement
that this resets anything in particular on the platform, the CLINT
registers may not get reset. When this occurs with an mtime register
value that is larger than 32 bits the riscv machine timer will
continuously interrupt the system when the mtime register exceeds 32
bits in value. This is because the last_count value is used to update
the mtimecmp register, and its value is initialized to zero. Its
first update is with a 32-bit value, which loses information when the
mtime register exceeds 32 bits.
The proposed solution is to set the last_count value to the current
value in the mtime register when the timer is initialized. Since the
timer is fired at intervals that are less than 32 bits in value, the
next update of last_count will remain valid, and the system will
function as expected.
Signed-off-by: Jaron Kelleher <jkelleher@fb.com>
riscv64 CPUs can access full 64-bit memory-mapped register by a single
instruction, so we can directly access these registers.
Signed-off-by: Jim Shu <cwshu@andestech.com>
Some early tickless drivers had a common pattern where they would
compute a tick maximum for the request (i.e. the maximum the hardware
counter can handle) but apply it only on the input tick value and not
on the adjusted final value, opening up the overflow condition it was
supposed to have prevented.
Fixes#20939 (Strictly it fixes the specific pattern that was
discovered in that bug. It's not impossible that other drivers with
alternative implementations have a similar issue, though they look OK
to me via a quick audit).
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
On some SoCs the frequency of the system clock is obtained at run time
as the exact configuration of the hardware is not known at compile time.
On such platforms using CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC define
directly introduces timing errors.
This commit replaces CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC by the call
to inline function sys_clock_hw_cycles_per_sec() which always returns
correct frequency of the system clock.
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
Move internal and architecture specific headers from include/drivers to
subfolder for timer:
include/drivers/timer
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Update reserved function names starting with one underscore, replacing
them as follows:
'_k_' with 'z_'
'_K_' with 'Z_'
'_handler_' with 'z_handl_'
'_Cstart' with 'z_cstart'
'_Swap' with 'z_swap'
This renaming is done on both global and those static function names
in kernel/include and include/. Other static function names in kernel/
are renamed by removing the leading underscore. Other function names
not starting with any prefix listed above are renamed starting with
a 'z_' or 'Z_' prefix.
Function names starting with two or three leading underscores are not
automatcally renamed since these names will collide with the variants
with two or three leading underscores.
Various generator scripts have also been updated as well as perf,
linker and usb files. These are
drivers/serial/uart_handlers.c
include/linker/kobject-text.ld
kernel/include/syscall_handler.h
scripts/gen_kobject_list.py
scripts/gen_syscall_header.py
Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
The newer series of timer drivers will compare counters vs. the last
tick boundary to compute a number of ticks to announce to the kernel.
In the case of CONFIG_TICKLESS=n, this actually represents a change of
behavior from our old scheme where "ticks" always reflected the number
of interrupts received.
The distinction only matters when an interrupt is delayed more than a
full tick, of course. But that actually makes a difference to some
timekeeping code. Restore the old behavior.
This also has the benefit of further reducing code size when !TICKLESS
and improving performance of the ISR by removing the division
(remember Cortex M0 has no hardware divide!).
Fixes#12409
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
There are issues using lowercase min and max macros when compiling a C++
application with a third-party toolchain such as GNU ARM Embedded when
using some STL headers i.e. <chrono>.
This is because there are actual C++ functions called min and max
defined in some of the STL headers and these macros interfere with them.
By changing the macros to UPPERCASE, which is consistent with almost all
other pre-processor macros this naming conflict is avoided.
All files that use these macros have been updated.
Signed-off-by: Carlos Stuart <carlosstuart1970@gmail.com>
Rewritten driver along the lines of all the other new drivers,
implementing the new timer API. Structurally, the machine timer is an
up-counter with comparator, so it works broadly the same way HPET and
NRF do. The quirk here is that it's a 64 bit counter, which needs a
little more care.
Unlike the other timer reworks, this driver has grown by a few lines
as it used to be very simple. But in exchange, we get full tickless
support on the platform.
Fixes#10609 in the process (the 64 bit timer registers are unlatched
for sub-word transfers, so you have to use careful ordering).
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Rename timer driver API functions to be consistent. ADD DOCS TO THE
HEADER so implementations understand what the requirements are.
Remove some unused functions that don't need declarations here.
Also removes the per-platform #if's around the power control callback
in favor of a weak-linked noop function in the driver initialization
(adds a few bytes of code to default platforms -- we'll live, I
think).
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The existing API had two almost identical functions: _set_time() and
_timer_idle_enter(). Both simply instruct the timer driver to set the
next timer interrupt expiration appropriately so that the call to
z_clock_announce() will be made at the requested number of ticks. On
most/all hardware, these should be implementable identically.
Unfortunately because they are specified differently, existing drivers
have implemented them in parallel.
Specify a new, unified, z_clock_set_timeout(). Document it clearly
for implementors. And provide a shim layer for legacy drivers that
will continue to use the old functions.
Note that this patch fixes an existing bug found by inspection: the
old call to _set_time() out of z_clock_announce() failed to test for
the "wait forever" case in the situation where clock_always_on is
true, meaning that a system that reached this point and then never set
another timeout would freeze its uptime clock incorrectly.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
There were three separate "announce ticks" entry points exposed for
use by drivers. Unify them to just a single z_clock_announce()
function, making the "final" tick announcement the business of the
driver only, not the kernel.
Note the oddness with "_sys_idle_elapsed_ticks": this was a global
variable exposed by the kernel. But it was never actually used by the
kernel. It was updated and inspected only within the timer drivers,
and only so that it could be passed back to the kernel as the default
(actually hidden) argument to the announce function. Break this false
dependency by putting this variable into each timer driver
individually.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This was another "global variable" API. Give it function syntax too.
Also add a warning, because on nRF devices (at least) the cycle clock
runs in kHz and is too slow to give a precise answer here.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This patch provides support needed to get timing related
information from riscv32 based SOC.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types. This handles the remaining includes and kernel, plus
touching up various points that we skipped because of include
dependancies. We also convert the PRI printf formatters in the arch
code over to normal formatters.
Jira: ZEP-2051
Change-Id: Iecbb12601a3ee4ea936fd7ddea37788a645b08b0
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types.
Jira: ZEP-2051
Change-Id: I08f51e2bfd475f6245771c1bd2df7ffc744c48c4
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Rearming the riscv machine timer is done by first updating the
mtimecmp low value register. If the low value is updated with a
relatively small value, a timer interrupt can be generated while
updating the mtimecmp high value.
To avoid such a spurious interrupt to occur, disable the timer
interrupt while rearming the timer.
Change-Id: I50ab3f19554a9a8dfe70943b6da0d20be3de88dc
Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
Some arches may want to define this as an inline function, or
define in core arch code instead of timer driver code.
Unfortunately, this means we need to remove from the footprint
tests, but this is not typically a large function.
Issue: ZEP-1546
Change-Id: Ic0d7a33507da855995838f4703d872cd613a2ca2
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
There are race conditions trying to coordinate the value between
the accumulated_cycle_count (updated at interrupt time) and
trying to compute the delta from the last interrupt using the
mtime registers. An unlucky call could result in the timestamp
appearing to move backwards in time.
the 'mtime' register isn't reset at every interrupt. Since we just
want a cycle counter, report its raw value.
Issue: ZEP-1546
Change-Id: I9f404b33214d6502fea47374fcf0ecbf84ef8136
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
riscv defines the machine-mode timer registers that are implemented
by the all riscv SOCs that follow the riscv privileged architecture
specification.
The timer registers implemented in riscv-qemu follow this specification.
To account for future riscv SOCs, reimplement the riscv_qemu_driver by
the riscv_machine_driver.
Change-Id: I645b03c91b4e07d0f2609908decc27ba9b8240d4
Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
