Commit graph

3183 commits

Author SHA1 Message Date
Anas Nashif
bbbc38ba8f kernel: Make both operands of operators of same essential type category
Add a 'U' suffix to values when computing and comparing against
unsigned variables and other related fixes of the same MISRA rule (10.4)

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-04-01 05:34:17 -04:00
Peter Bigot
fed035231f kernel: work: fix schedule from running work
k_work_schedule() is supposed to be a no-op if the work item is
already scheduled or submitted: the previous schedule is left
unchanged.  The check incorrectly inhibited the schedule operation
when the work item was neither scheduled nor submitted, but was
running.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-29 12:27:36 -04:00
Anas Nashif
d8f698703b kernel: idle/z_sched_prio_cmp: match implementation to prototype
The identifiers used in the declaration and definition of a function
shall be identical [MISRAC2012-RULE_8_3-b]

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-29 07:52:42 -04:00
Katsuhiro Suzuki
19db485737 kernel: arch: use ENOTSUP instead of ENOSYS in k_float_disable()
This patch replaces ENOSYS into ENOTSUP to keep consistency with
the return value specification of k_float_enable().

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
2021-03-25 14:13:23 +01:00
Katsuhiro Suzuki
59903e2934 kernel: arch: introduce k_float_enable()
This patch introduce new API to enable FPU of thread. This is pair of
existed k_float_disable() API. And also add empty arch_float_enable()
into each architectures that have arch_float_disable(). The arc and
riscv already implemented arch_float_enable() so I do not touch
these implementations.

Motivation: Current Zephyr implementation does not allow to use FPU
on main and other system threads like as work queue. Users need to
create an other thread with K_FP_REGS for floating point programs.
Users can use FPU more easily if they can enable FPU on running
threads.

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
2021-03-25 14:13:23 +01:00
Anas Nashif
b503be2d02 kernel: poll: rename reserved 'signal' symbol
This symbol is reserved and usage of reserved symbols violates the
coding guidelines. (MISRA 21.2)

NAME
       signal - ANSI C signal handling

SYNOPSIS
       #include <signal.h>

       sighandler_t signal(int signum, sighandler_t handler);

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-25 07:28:37 -04:00
Anas Nashif
669f7f74b8 kernel: rename reserved symbol 'remove'
This symbol is reserved and usage of reserved symbols violates the
coding guidelines. (MISRA 21.2)

NAME
	remove - remove a file or directory
SYNOPSIS
        #include <stdio.h>
        int remove(const char *pathname);

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-25 07:28:37 -04:00
Anas Nashif
068e0872d7 kernel: remove EXPERIMENTAL from some Kconfigs
both thread monitor and thread names are not EXPERIMENTAL any more. They
have been used across the tree and lots depend on those features
already.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-23 13:01:08 +01:00
Kumar Gala
e3285d5f24 kernel: Remove duplicate include of kswap.h
kswap.h was included twice.  Remove the duplication

Fixes #33524

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2021-03-22 13:04:05 -04:00
Shihao Shen
6525975a0e kernel: pipes: remove simple dead function k_pipe_block_put
Removed k_pipe_block_put and static functions only related to it.
After all the old usage of k_mem_block has been replaced by k_heap,
k_pipe_block_put still taking a deprecated k_mem_block as argument
becomes dead code. All APIs that hook it from kernel.h have been
confirmed to be removed. Since an asynchronous message descriptor
is only allocated in k_pipe_block_put, static functions for pipe_
async are removed as well.

Signed-off-by: Shihao Shen <shihao.shen@intel.com>
2021-03-22 07:20:06 -04:00
Anas Nashif
c076d94eec kernel: remove tickless idle
This feature predated the tickless kernel and has been in legacy mode
for a while. We now have no drivers or systems that do not support
tickless, so remove this option and cleanup the code to only use
tickless.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-19 11:22:17 -04:00
Anas Nashif
a518f48796 clock: renmae z_timeout_end_calc -> sys_clock_timeout_end_calc
Do not use z_ for internal APIs, z_ is for private APIs within one
subsystem only.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-19 11:22:17 -04:00
Anas Nashif
fe0872c0ab clocks: rename z_tick_get -> sys_clock_tick_get
Do not use z_ for internal APIs, z_ is for private APIs within one
subsystem only.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-19 11:22:17 -04:00
Anas Nashif
5c90ceb105 clock: rename z_tick_get_32 -> sys_clock_tick_get_32
Do not use z_ for internal APIs, z_ is for private APIs within one
subsystem only.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-19 11:22:17 -04:00
Anas Nashif
a387221f3c clock: rename z_clock_hw_cycles_per_sec_runtime_get
Do not use z_ for internal APIs, z_ is for private APIs within one
subsystem only.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-03-19 11:22:17 -04:00
Anas Nashif
9c1efe6b4b clock: remove z_ from semi-public APIs
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>
2021-03-19 11:22:17 -04:00
Kumar Gala
7d35a8c93d kernel: remove arch_mem_domain_destroy
The only user of arch_mem_domain_destroy was the deprecated
k_mem_domain_destroy function which has now been removed.  So remove
arch_mem_domain_destroy as well.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2021-03-18 16:30:47 +01:00
Kumar Gala
3a6598054a kernel: remove deprecated mem domain APIs
Remove k_mem_domain_destroy and k_mem_domain_remove_thread as they've
been deprecated for at least 2 releases now.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2021-03-17 13:49:36 -05:00
Andrzej Głąbek
6de16d0013 kernel: Add missing verification for device_usable_check() system call
so that this function and also device_is_ready() can be called from
user mode.

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
2021-03-15 10:45:20 -05:00
Enjia Mai
4aed856d7f kernel: smp: Remove unused internal API z_smp_reacquire_global_lock()
The internal function z_smp_reacquire_global_lock() has not used by
anywhere inside zephyr code, so remove it.

Fixes #33273.

Signed-off-by: Enjia Mai <enjiax.mai@intel.com>
2021-03-14 18:32:26 -04:00
Peter Bigot
b29abe3710 device: add API to visit required devices
The static device dependencies from devicetree are not the only ones
that might be present at runtime.  Add API that allows visiting
required devices without assuming that handles for or pointers to them
can be accessed as a static contiguous sequence.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-11 08:53:18 -05:00
Lauren Murphy
d88ce65463 kernel/sched: only send IPI to abort thread if hardware supports it
Wrap arch_sched_ipi() call in z_thread_abort() with ifdef checking for
hardware support of IPI.

Fixes #32723

Signed-off-by: Lauren Murphy <lauren.murphy@intel.com>
2021-03-10 14:27:33 -05:00
James Harris
33c9be90cc kernel: fix TOCTTOU issue in k_thread_name_set
Previously, a racing write to the provided string could result
in up to CONFIG_THREAD_MAX_NAME_LEN-2 bytes after the end
of user-accessible memory being leaked into the thread name.

For now, make a temporary copy. In an ideal world this could
copy directly from userspace into the thread name, but that
violates the current vrfy / impl split.

Signed-off-by: James Harris <james.harris@intel.com>
2021-03-08 19:27:23 -05:00
Andy Ross
820c94e5dd arch/xtensa: Inline atomics
The xtensa atomics layer was written with hand-coded assembly that had
to be called as functions.  That's needlessly slow, given that the low
level primitives are a two-instruction sequence.  Ideally the compiler
should see this as an inline to permit it to better optimize around
the needed barriers.

There was also a bug with the atomic_cas function, which had a loop
internally instead of returning the old value synchronously on a
failed swap.  That's benign right now because our existing spin lock
does nothing but retry it in a tight loop anyway, but it's incorrect
per spec and would have caused a contention hang with more elaborate
algorithms (for example a spinlock with backoff semantics).

Remove the old implementation and replace with a much smaller inline C
one based on just two assembly primitives.

This patch also contains a little bit of refactoring to address the
scheme has been split out into a separate header for each, and the
ATOMIC_OPERATIONS_CUSTOM kconfig has been renamed to
ATOMIC_OPERATIONS_ARCH to better capture what it means.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-03-08 11:14:27 -05:00
Andy Ross
deca2301f6 kernel/swap: Move arch_cohere_stacks() back under the lock
Commit 6b84ab3830 ("kernel/sched: Adjust locking in z_swap()") moved
the call to arch_cohere_stacks() out of the scheduler lock while doing
some reorgnizing.  On further reflection, this is incorrect.  When
done outside the lock, the two arch_cohere_stacks() calls will race
against each other.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-03-08 11:14:27 -05:00
Eric Johnson
b4aeef4d5b kernel: timer: Fix incorrect behavior for timers with K_FOREVER period
Zephyr docs state that timers will act as one-shot timers when started
with a period of K_NO_WAIT or K_FOREVER. However the code adjusting
period was setting K_FOREVER timeout ticks to 1 which caused the timer
to expire every tick. This adds a check to not adjust K_FOREVER periods

Signed-off-by: Eric Johnson <eric@liveathos.com>
2021-03-07 08:00:08 -05:00
Flavio Ceolin
9b246aba78 power: Make pm_system_resume private
This API is not intended to be public and it is called only from the
idle thread.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2021-03-07 07:59:53 -05:00
Flavio Ceolin
2e9b583da9 idle: Remove weak function
pm_system_resume is always implemented when PM is enabled. There is no
need to have this weak function under an ifdef PM.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2021-03-07 07:59:53 -05:00
Flavio Ceolin
6307d19967 power: Remove unused / unimplemented code
pm_system_resume_from_deep_sleep is not implemented or used
anywhere. Just remove it and keep the code base cleaner.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2021-03-07 07:59:53 -05:00
Flavio Ceolin
e2771340af power: Remove unnecessary pm_idle_exit_notification_disable api
This function is useless and the state variable that it was
controlling is also not necessary because the same logic is being
handled by the variable post_ops_done.\

This reasonably simplifies idle thread logic.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2021-03-07 07:59:53 -05:00
Flavio Ceolin
b5e1336e83 power: s/POWER_STATE_ACTIVE/PM_STATE_ACTIVE
Fix some references to old power state names.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2021-03-07 07:59:53 -05:00
Flavio Ceolin
10f29359d7 power: Make pm_system_suspend private
pm_system_suspend is called only from the idle thread and should
not be exported as a public API.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2021-03-07 07:59:53 -05:00
James Harris
53b8179371 kernel: sem: handle resets with outstanding waiting threads
Previously, a k_sem_reset with any outstanding waiting threads would
result in the semaphore in an inconsistent state, with more threads
waiting in the wait_q than the count would indicate.

Explicitly -EAGAIN any waiting threads upon k_sem_reset, to
ensure safety here.

Signed-off-by: James Harris <james.harris@intel.com>
2021-03-06 07:39:43 -05:00
James Harris
b10428163a kernel: sem: add K_SEM_MAX_LIMIT
Currently there is no way to distinguish between a caller
explicitly asking for a semaphore with a limit that
happens to be `UINT_MAX` and a semaphore that just
has a limit "as large as possible".

Add `K_SEM_MAX_LIMIT`, currently defined to `UINT_MAX`, and akin
to `K_FOREVER` versus just passing some very large wait time.

In addition, the `k_sem_*` APIs were type-confused, where
the internal data structure was `uint32_t`, but the APIs took
and returned `unsigned int`. This changes the underlying data
structure to also use `unsigned int`, as changing the APIs
would be a (potentially) breaking change.

These changes are backwards-compatible, but it is strongly suggested
to take a quick scan for `k_sem_init` and `K_SEM_DEFINE` calls with
`UINT_MAX` (or `UINT32_MAX`) and replace them with `K_SEM_MAX_LIMIT`
where appropriate.

Signed-off-by: James Harris <james.harris@intel.com>
2021-03-05 08:13:53 -06:00
Spoorthy Priya Yerabolu
4118ed1d4d kernel: sched: removing dead code
Due to the recent changes to scheduler z_find_first_thread_to_unpend
& z_remove_thread_from_ready_q are not used anymore. So removing the
dead code.

fixes: #32691

Signed-off-by: Spoorthy Priya Yerabolu <spoorthy.priya.yerabolu@intel.com>
2021-03-05 11:05:25 +03:00
Andy Ross
6400bb54d6 kernel/idle: Clean up and refactoring / remove TICKLESS_IDLE_THRESH
While I'm in the idle code, let's clean this loop up.  It was a really
bad #ifdef hell:

* Remove the CONFIG_TICKLESS_IDLE_THRESH logic (and the kconfig),
  which never did anything but needlessly increase latency.

* Move the needed timeout logic from the main loop into
  pm_save_idle(), which eliminates the special case for
  !SYS_CLOCK_EXISTS.

Behavior (modulo that one kconfig) should be completely unchanged, and
now the inner part of the idle loop looks like:

    while (true) {
        (void) arch_irq_lock();

        if (IS_ENABLED(CONFIG_PM)) {
            pm_save_idle();
        } else {
            k_cpu_idle();
        }
    }

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-03-04 14:31:12 -05:00
Andy Ross
39a8f3b4f9 kernel/idle: Replace stolen IRQ lock
The removal of the abort handling also absconded with an IRQ lock that
is required for reliable operation in the idle loop.  Put it back.

Once the idle loop has made a decision to enter idle, any interrupt
that arrives needs to be masked and delivered AFTER the system enters
idle.  Otherwise we run the risk of races where the system accepts and
processes an interrupt that should have prevented idle, but then goes
to sleep anyway having already made the decision.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-03-04 14:31:12 -05:00
Peter Bigot
b706a5e999 kernel: remove old work queue implementation
Now that the old API has been reimplemented with the new API remove
the old implementation and its tests.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-03 20:06:00 -05:00
Peter Bigot
d1affd9118 kernel: default to new work API implementation
Switch the default and clean up some test workarounds.  This will enable
final conversions necessary to transition to the new API.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-03 20:06:00 -05:00
Peter Bigot
dc34e7c6f6 kernel: add new work queue implementation
This commit provides a complete reimplementation of the work queue
infrastructure intended to eliminate the race conditions and feature
gaps in the existing implementation.

Both bare and delayable work structures are supported.  Items can be
submitted; delayable items can be scheduled for submission at a future
time.  Items can be delayed, queued, and running all at the same time.
A running item can also be canceling.

The new implementation:
* replaces "pending" with "busy" which identifies the active states;
* supports canceling delayed and submitted items;
* prevents resubmission of a item being canceled until cancellation
  completes;
* supports waiting for cancellation to complete;
* supports flushing a work item (waiting for the last submission to
  complete without preventing resubmission);
* supports waiting for a queue to drain (only allows resubmission from
  the work thread);
* supports stopping a work queue in conjunction with draining it;
* prevents handler-reentrancy during resubmission.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-03 20:06:00 -05:00
Peter Bigot
44539ed645 kernel: select work queue implementation
Attempts to reimplement the existing work API using a new work
implementation failed, primarily due to heavy use of whitebox testing
in validating the original API.  Add a temporary Kconfig that will
select between the two implementations so we can use the same
identifiers but select which implementation they reference.

This commit just adds the selection infrastructure and uses it to
conditionalize the existing implementation in anticipation of the new
one in the next commit.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-03 20:06:00 -05:00
Peter Bigot
0259c864df kernel: add private scheduler APIs
These functions are a subset of proposed public APIs to clean up
several issues related to safely handling waking of threads.  They
have been made private as they interface may change, but their use
will simplify the reimplementation of the k_work functionality.

See: https://github.com/zephyrproject-rtos/zephyr/pull/29668

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-03 20:06:00 -05:00
James Harris
c7bb423f3e kernel: fix race conditions with z_ready_thread
Several internal APIs wrote thread attributes (return value, mainly)
_after_ calling `z_ready_thread`. This is unsafe, at least in SMP,
because another core could have already picked up and run the thread.

Fixes #32800.

Signed-off-by: James Harris <james.harris@intel.com>
2021-03-03 13:54:47 -05:00
James Harris
6543e06914 kernel: sched: avoid unnecessary lock in z_impl_k_yield
`z_impl_k_yield` unlocked sched_spinlock, only to lock it again
immediately, do a little bit more work, then unlock it again.
This causes performance issues on SMP, where `sched_spinlock`
is often fairly highly contended and cores often end up spinning
for quite a while waiting to retake the lock in `z_swap_unlocked`.

Instead directly pass the spinlock key to `z_swap` and avoid the
extra lock+unlock.

Signed-off-by: James Harris <james.harris@intel.com>
2021-03-02 14:35:21 -05:00
James Harris
2cd0f66515 kernel: sched: change to 3-way thread priority comparison
`z_is_t1_higher_prio_than_t2` was being called twice in both the
context-switch fastpath and in `z_priq_rb_lessthan`, just to
dealing with priority ties. In addition, the API was error-prone
(and too much in the fastpath to be able to assert its invarients)
- see also #32710 for a previous example of this API breaking
and returning a>b but also b>a.

Replacing this with a direct 3-way comparison `z_cmp_t1_prio_with_t2`
sidesteps most of these issues. There is still a concern that
`sgn(z_cmp_t1_prio_with_t2(a,b)) != -sgn(z_cmp_t1_prio_with_t2(b,a))`
but I don't see any way to alleviate this aside from adding an
assert to the fastpath.

Signed-off-by: James Harris <james.harris@intel.com>
2021-03-02 14:27:14 -05:00
James Harris
3330ab12d8 kernel: fix yielding between tasks with same deadline
Previously two tasks with the same deadline and priority would
always have `z_is_t1_higher_prio_than_t2` `true` in both directions.

This is logically inconsistent, and results in `k_yield` not actually
yielding between identical threads.

Signed-off-by: James Harris <james.harris@intel.com>
2021-02-27 10:25:47 +01:00
Andy Ross
6fb6d3cfbe kernel: Add new k_thread_abort()/k_thread_join()
Add a newer, much smaller and simpler implementation of abort and
join.  No need to involve the idle thread.  No need for a special code
path for self-abort.  Joining a thread and waiting for an aborting one
to terminate elsewhere share an implementation.  All work in both
calls happens under a single locked path with no unexpected
synchronization points.

This fixes a bug with the current implementation where the action of
z_sched_single_abort() was nonatomic, releasing the lock internally at
a point where the thread to be aborted could self-abort and confuse
the state such that it failed to abort at all.

Note that the arm32 and native_posix architectures, which have their
own thread abort implementations, now see a much simplified
"z_thread_abort()" internal API.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-02-24 16:39:15 -05:00
Andy Ross
c0c8cb0e97 kernel: Remove abort and join implementation (UNBISECTABLE)
THIS COMMIT DELIBERATELY BREAKS BISECTABILITY FOR EASE OF REVIEW.
SKIP IF YOU LAND HERE.

Remove the existing implementatoin of k_thread_abort(),
k_thread_join(), and the attendant facilities in the thread subsystem
and idle thread that support them.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-02-24 16:39:15 -05:00
Andy Ross
bf99f3105f kernel/timeout: Correctly clamp z_clock_set_timeout() argument
This function would correctly suppress attempts to set timeouts that
were too soon for the driver or farther out than what was already set,
but when it actually set the timeout it would use the requested value
and not clamp it to the minimum of it and the current timeout
expiration, leading to "too-long" timeouts being set at the driver.

In uniprocessor configurations, that turns out to have been benign
because something else would always come back along when timeout state
changed and fix the broken value before the expiration.

But in SMP, this opens up races.  For example, the idle thread on one
CPU can see that there are no active threads and schedule a maximum
value timeout at the same time as the other thread adds a new timeout
that expects a near-term expiration.  The broken code here would see
that the new timeout exists, decide that yes it needs to override, but
then set the K_TICKS_FOREVER value it got from the idle thread!

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-02-24 16:39:15 -05:00
Andy Ross
419f37043b kernel/sched: Clamp minimum timeslice when TICKLESS
When the kernel is TICKLESS, timeouts are set as needed, and drivers
all have some minimum amount of time before which they can reliably
schedule an interrupt.  When this happens, drivers will kick the
requested interrupt out by one tick.  This means that it's not
reliably possible to get a timeout set for "one tick in the
future"[1].

And attempting to do that is dangerous anyway.  If the driver will
delay a one-tick interrupt, then code that repeatedly tries to
schedule an imminent interrupt may end up in a state where it is
constantly pushing the interrupt out into the future, and timer
interrupts stop arriving!  The timeout layer actually has protection
against this case.

Finally getting to the point: in recent changes, the timeslice layer
lost its integration with the "imminent" test in the timeout code, so
it's now able to run into this situation: very rapidly context
switching code (or rapidly arriving interrupts) will have the effect
of infinitely[2] delaying timeouts and stalling the whole timeout
subsystem.

Don't try to be fancy.  Just clamp timeslice duration such that a
slice is 2 ticks at minimum and we'll never hit the problem.  Adjust
the two tests that were explicitly requesting very short slice rates.

[1] Of course, the tradeoff is that the tick rate can be 100x higher
or more, so on balance tickless is a huge win.

[2] Actually it only lasts until a 31 bit signed rollover in the HPET
cycle count in practice.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2021-02-24 16:39:15 -05:00