Adds event based scheduling logic to the kernel. Updates
management of timeouts, timers, idling etc. based on
time tracked at events rather than periodic ticks. Provides
interfaces for timers to announce and get next timer expiry
based on kernel scheduling decisions involving time slicing
of threads, timeouts and idling. Uses wall time units instead
of ticks in all scheduling activities.
The implementation involves changes in the following areas
1. Management of time in wall units like ms/us instead of ticks
The existing implementation already had an option to configure
number of ticks in a second. The new implementation builds on
top of that feature and provides option to set the size of the
scheduling granurality to mili seconds or micro seconds. This
allows most of the current implementation to be reused. Due to
this re-use and co-existence with tick based kernel, the names
of variables may contain the word "tick". However, in the
tickless kernel implementation, it represents the currently
configured time unit, which would be be mili seconds or
micro seconds. The APIs that take time as a parameter are not
impacted and they continue to pass time in mili seconds.
2. Timers would not be programmed in periodic mode
generating ticks. Instead they would be programmed in one
shot mode to generate events at the time the kernel scheduler
needs to gain control for its scheduling activities like
timers, timeouts, time slicing, idling etc.
3. The scheduler provides interfaces that the timer drivers
use to announce elapsed time and get the next time the scheduler
needs a timer event. It is possible that the scheduler may not
need another timer event, in which case the system would wait
for a non-timer event to wake it up if it is idling.
4. New APIs are defined to be implemented by timer drivers. Also
they need to handler timer events differently. These changes
have been done in the HPET timer driver. In future other timers
that support tickles kernel should implement these APIs as well.
These APIs are to re-program the timer, update and announce
elapsed time.
5. Philosopher and timer_api applications have been enabled to
test tickless kernel. Separate configuration files are created
which define the necessary CONFIG flags. Run these apps using
following command
make pristine && make BOARD=qemu_x86 CONF_FILE=prj_tickless.conf qemu
Jira: ZEP-339 ZEP-1946 ZEP-948
Change-Id: I7d950c31bf1ff929a9066fad42c2f0559a2e5983
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
Future tickless kernel patches would be inserting some
code before call to Swap. To enable this it will create
a mcro named as the current _Swap which would call first
the tickless kernel code and then call the real __swap()
Jira: ZEP-339
Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
Unlike assertions, these APIs are active at all times. The kernel will
treat these errors in the same way as fatal CPU exceptions. Ultimately,
the policy of what to do with these errors is implemented in
_SysFatalErrorHandler.
If the archtecture supports it, a real CPU exception can be triggered
which will provide a complete register dump and PC value when the
problem occurs. This will provide more helpful information than a fake
exception stack frame (_default_esf) passed to the arch-specific exception
handling code.
Issue: ZEP-843
Change-Id: I8f136905c05bb84772e1c5ed53b8e920d24eb6fd
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We do the same thing on all arch's right now for thread_monitor_init so
lets put it in a common place. This also should fix an issue on xtensa
when thread monitor can be enabled (reference to _nanokernel.threads).
Change-Id: If2f26c1578aa1f18565a530de4880ae7bd5a0da2
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
We do a bit of the same stuff on all the arch's to setup a new thread.
So lets put that code in a common place so we unify it for everyone and
reduce some duplicated code.
Change-Id: Ic04121bfd6846aece16aa7ffd4382bdcdb6136e3
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
There are a few places that we used an naked unsigned type, lets be
explicit and make it 'unsigned int'.
Change-Id: I33fcbdec4a6a1c0b1a2defb9a5844d282d02d80e
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. 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. There are few places we dont convert over to the new
types because of compatiability with ext/HALs or for ease of transition
at this point. Fixup a few of the PRI formatters so we build with newlib.
Jira: ZEP-2051
Change-Id: I7d2d3697cad04f20aaa8f6e77228f502cd9c8286
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This is a start to move away from the C99 {u}int{8,16,32,64}_t types to
Zephyr defined u{8,16,32,64}_t and s{8,16,32,64}_t. This allows Zephyr
to define the sized types in a consistent manor across all the
architectures we support and not conflict with what various compilers
and libc might do with regards to the C99 types.
We introduce <zephyr/types.h> as part of this and have it include
<stdint.h> for now until we transition all the code away from the C99
types.
We go with u{8,16,32,64}_t and s{8,16,32,64}_t as there are some
existing variables defined u8 & u16 as well as to be consistent with
Zephyr naming conventions.
Jira: ZEP-2051
Change-Id: I451fed0623b029d65866622e478225dfab2c0ca8
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This implementation of _tsc_read returns a 64-bit value that
is derived from the 64-bit tick count multiplied by hwcycles per tick,
and then it adds the current value from the 32-bit timer.
This produces a 64-bit time. There is a bunch of math here, which
could be avoided if the CPU is built with Real-Time-Clock option.
EM Starter Kit SOCs don't have this. I don't think Arduino 101 does
either.
See ZEP-1559
Change-Id: I9f846d170246556ac40fe2f45809e457c6375d8c
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
This avoids asm files from having to explicitly define the _ASMLANGUAGE
symbol themselves.
Change-Id: I71f5a169f75d7443a58a0365a41c55b20dae3029
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
They are not part of the API, so rename from K_<state> to
_THREAD_<state>.
Change-Id: Iaebb7d3083b80b9769bee5616e0f96ed2abc5c56
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.
Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.
Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file. Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.
Jira: ZEP-1457
Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Force-align all variables defined via asm .word to ensure 4-byte
alignment.
The straddled_tick_on_idle_enter variable was a bool, which resolved in
an one-byte quantity. Changing it to a 32-bit integer. It would have
occupied 4 bytes anyway with alignment.
Fixes ZEP-1549.
Change-Id: If5e0aa1a75dbc73d896b44616f059d221fe191c6
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
I've moved the call for icache_setup from nanoArchInit() to
_PrepC(), because there is a lot of code executed now before
nanoArchInit() is called, and all this time the i-cache would
be off. It should be turned on as early as possible to make
initialization faster.
Change-Id: I76a809d57a1bf9aacf51e7bb9fe8c8425f37aa13
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
These two fields in the thread structure control the preemptibility of a
thread.
sched_locked is decremented when the scheduler gets locked, which means
that the scheduler is locked for values 0xff to 0x01, since it can be
locked recursively. A thread is coop if its priority is negative, thus
if the prio field value is 0x80 to 0xff when looked at as an unsigned
value.
By putting them end-to-end, this means that a thread is non-preemptible
if the bundled value is greater than or equal to 0x0080. This is the
only thing the interrupt exit code has to check to decide to try a
reschedule or not.
Change-Id: I902d36c14859d0d7a951a6aa1bea164613821aca
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Some thread fields were 32-bit wide, when they are not even close to
using that full range of values. They are instead changed to 8-bit fields.
- prio can fit in one byte, limiting the priorities range to -128 to 127
- recursive scheduler locking can be limited to 255; a rollover results
most probably from a logic error
- flags are split into execution flags and thread states; 8 bits is
enough for each of them currently, with at worst two states and four
flags to spare (on x86, on other archs, there are six flags to spare)
Doing this saves 8 bytes per stack. It also sets up an incoming
enhancement when checking if the current thread is preemptible on
interrupt exit.
Change-Id: Ieb5321a5b99f99173b0605dd4a193c3bc7ddabf4
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
This will allow for an enhancement when checking if the thread is
preemptible when exiting an interrupt.
Change-Id: If93ccd1916eacb5e02a4d15b259fb74f9800d6f4
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
replace include <nanokernel.h> with <kernel.h> everywhere and also fix
any remaining mentions of nanokernel.
Keep the legacy samples/tests as is.
Change-Id: Iac48447bd191e83f21a719c69dc26233216d08dc
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Obsolete, replaced by _set_thread_return_value().
Change-Id: I23e9cfc07e43542f0965817edc3552d456fd2ef3
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Also remove mentions of unified kernel in various places in the kernel,
samples and documentation.
Change-Id: Ice43bc73badbe7e14bae40fd6f2a302f6528a77d
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Also remove some old cflags referencing directories that do not exist
anymore.
Also replace references to legacy APIs in doxygen documentation of
various functions.
Change-Id: I8fce3d1fe0f4defc44e6eb0ae09a4863e33a39db
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
- does not pull in printk(), for potential footprint gain
- does not pull in k_thread_abort(), for single-threaded systems
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Change-Id: Ibc6a198b81a6cd73117d1e85aa05b92a4501a34d
Some kernel operations, like scheduler locking can be optmized out,
since coop threads lock the scheduler by their very nature. Also, the
interrupt exit path for all architecture does not have to do any
rescheduling, again by the nature of non-preemptible threads.
Change-Id: I270e926df3ce46e11d77270330f2f4b463971763
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
nano_cpu_idle/nano_cpu_atomic_idle were not ported to the unified
kernel, and only the old APIs were available. There was no real impact
since, in the unified kernel, only the idle thread should really be
doing power management. However, with a single-threaded kernel, these
functions can be useful again.
The kernel internals now make use of these APIs instead of the legacy
ones.
Change-Id: Ie8a6396ba378d3ddda27b8dd32fa4711bf53eb36
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
The way the ready thread cache was implemented caused it to not always
be "hot", i.e. there could be some misses, which happened when the
cached thread was taken out of the ready queue. When that happened, it
was not replaced immediately, since doing so could mean that the
replacement might not run because the flow could be interrupted and
another thread could take its place. This was the more conservative
approach that insured that moving a thread to the cache would never be
wasted.
However, this caused two problems:
1. The cache could not be refilled until another thread context-switched
in, since there was no thread in the cache to compare priorities
against.
2. Interrupt exit code would always have to call into C to find what
thread to run when the current thread was not coop and did not have the
scheduler locked. Furthermore, it was possible for this code path to
encounter a cold cache and then it had to find out what thread to run
the long way.
To fix this, filling the cache is now more aggressive, i.e. the next
thread to put in the cache is found even in the case the current cached
thread is context-switched out. This ensures the interrupt exit code is
much faster on the slow path. In addition, since finding the next thread
to run is now always "get it from the cache", which is a simple fetch
from memory (_kernel.ready_q.cache), there is no need to call the more
complex C code.
On the ARM FRDM K64F board, this improvement is seen:
Before:
1- Measure time to switch from ISR back to interrupted task
switching time is 215 tcs = 1791 nsec
2- Measure time from ISR to executing a different task (rescheduled)
switch time is 315 tcs = 2625 nsec
After:
1- Measure time to switch from ISR back to interrupted task
switching time is 130 tcs = 1083 nsec
2- Measure time from ISR to executing a different task (rescheduled)
switch time is 225 tcs = 1875 nsec
These are the most dramatic improvements, but most of the numbers
generated by the latency_measure test are improved.
Fixes ZEP-1401.
Change-Id: I2eaac147048b1ec71a93bd0a285e743a39533973
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
When going into DEEP_SLEEP mode, the ARC core now saves
its context. This includes:
- All core registers
- Stack pointer
- Program counter (restored by jumping to the restore code)
The arc reset code now checks if the GPS0 bit 2 is set.
This is similar to the behavior of the x86 core done by
the QMSI bootloader which is setting GPS0 bit 1 in order
to call the restore path instead of cold boot path.
The sample has been adapted in order to support the ARC.
Jira: ZEP-1222
Change-Id: I375f03b16b8a5fd1f07ead55cf7e4947d6290c9f
Signed-off-by: Julien Delayen <julien.delayen@intel.com>
In order to resume the ARC from deep sleep,
the interrupts need to be restored.
The FIRQ stack needs to be saved and restored
when performing sleep operations.
During early initialization, the sp in the 2nd register bank
is made to refer to _firq_stack.
This allows for the FIRQ handler to use its own stack.
Fast Interrupts cannot be used after sleep if this information
is not restored.
This patch adds the suspend and resume functions.
Jira: ZEP-1223
Change-Id: Ic81980f05aee6c1f7b8c46c743f2648c65b29486
Signed-off-by: Julien Delayen <julien.delayen@intel.com>
A build error was resulting if CONFIG_ARC_STACK_CHECKING is enabled.
There is a breq that was too far. Adding conditional code to
re-arrange the branching so that it can be done.
See ZEP-1116.
Change-Id: Idea85817b2e05617bbaa4450437aa74c5737e213
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
Too much code might run with a stale icache, before _PrepC(), so move
the invalidation/disabling code earlier. The asm code does the exact
same thing disable_icache() and invalidate_dcache() were doing.
Change-Id: If52f4e4a1de546fb82873c91ead95614a44b106d
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
There is no FIRQ stack in the system in this case, so do not initialize
it.
Change-Id: I8bc068ce43ac8a39909994d8cc01ba0c6a17f4ae
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Move _thread_base initialization to _init_thread_base(), remove mention
of "nano" in timeouts init and move timeout init to _init_thread_base().
Initialize all base fields via the _init_thread_base in semaphore groups
code.
Change-Id: I05b70b06261f4776bda6d67f358190428d4a954a
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Use the main stack during very early boot so that we can call memset on
the interrupt and FIRQ stacks. Iniitalize the them before one of them is
used for the rest of the pre-kernel initialization.
Change-Id: Ib57856a66273dda9382e08fa91da5a54847b77c2
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Same issue as with ARM. ARC can use _Swap() though, because the call to
it is serial, not generating a low-priority exception and interrupts are
locked until the main() thread is context-switched into and the
interrupt stack is released.
Fixes ZEP-1310.
Change-Id: Ie1f27f7ad0502191ca2867b5400d6e0bfb7f0fc6
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Artifact from microkernel, for handling multiple pending tasks on
nanokernel objects.
Change-Id: I3c2959ea2b87f568736384e6534ce8e275f1098f
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Prio should be an int, since values are small integers, not a fixed-size
int32_t. It aligns with the prio parameters of the other APIs.
Stack size should be size_t.
Change-Id: Id29751b86c4ad7a7c2a7ffe446c2a96ae83c77bf
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
When a thread dies, at least print the pointer to it, so we can debug
better.
Change-Id: Ief6bbc0c221e2d5271c240a4b73df16413aa5e22
Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
There was a lot of duplication between architectures for the definition
of threads and the "nanokernel" guts. These have been consolidated.
Now, a common file kernel/unified/include/kernel_structs.h holds the
common definitions. Architectures provide two files to complement it:
kernel_arch_data.h and kernel_arch_func.h. The first one contains at
least the struct _thread_arch and struct _kernel_arch data structures,
as well as the struct _callee_saved and struct _caller_saved register
layouts. The second file contains anything that needs what is provided
by the common stuff in kernel_structs.h. Those two files are only meant
to be included in kernel_structs.h in very specific locations.
The thread data structure has been separated into three major parts:
common struct _thread_base and struct k_thread, and arch-specific struct
_thread_arch. The first and third ones are included in the second.
The struct s_NANO data structure has been split into two: common struct
_kernel and arch-specific struct _kernel_arch. The latter is included in
the former.
Offsets files have also changed: nano_offsets.h has been renamed
kernel_offsets.h and is still included by the arch-specific offsets.c.
Also, since the thread and kernel data structures are now made of
sub-structures, offsets have to be added to make up the full offset.
Some of these additions have been consolidated in shorter symbols,
available from kernel/unified/include/offsets_short.h, which includes an
arch-specific offsets_arch_short.h. Most of the code include
offsets_short.h now instead of offsets.h.
Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Regardless of the number of interrupt priorities
supported, the exit of the trap handler can check
AUX_IRQ_ACT to see if it interrupted a FIRQ or IRQ.
Change-Id: I0b84d8298d3e6e437c934c01db4535fa8fe29458
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
PRIMARY, SECONDARY, NANOKERNEL, MICROKERNEL init levels are now
deprecated.
New init levels introduced: PRE_KERNEL_1, PRE_KERNEL_2, POST_KERNEL
to replace them.
Most existing code has instances of PRIMARY replaced with PRE_KERNEL_1,
SECONDARY with POST_KERNEL as SECONDARY has had a longstanding bug
where the documentation specified SECONDARY ran before the kernel started
up, but actually ran afterwards.
Change-Id: I771bc634e9caf7f17dbf214a270bc9967eed7d32
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Verify the thread priorities are within the bounds when starting a new
thread and when changing the priority of a thread.
Change-Id: I007b3b249e4b80235b6439cbee44cad2f31973bb
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
A race condition would happend if a FIRQ interrupted a
return-from-interrupt from a RIRQ at the wrong moment: if a decision was
already taken which thread to context switch in and the FIRQ woke up
another thread of higher priority, the ready queue would be corrupted.
The solution is to lock interrupts at the moment the interrupt return
code starts looking at the kernel queues. Interrupts do not need to be
unlocked before exiting: the return-from-interrupt (rtie) instruction
will restore the correct interrupt locking state for the thread being
context switched in.
Change-Id: I777665c2faeca7b1f2a77ddd9ee2a520080bae88
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
An implementation to flush multiple d-cache lines has been added
per the top-level cache.h API. ZEP-1153 was opened to express
the need for MORE i-cache and d-cache APIs. For example, the current
cache.h API doesn't provide a means to invalidate d-cache lines
and has nothing for i-cache.
I've also modified some of the i-cache related aux registers to have
better names so that they won't be confused with d-cache.
These changes are for
ZEP-1176.
Change-Id: If4c5410451cc40dcd5618fc871093c8febf7e061
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
Adds standard prefix to symbolic option that flags a thread
as essential to system operation.
Change-Id: Ia904a81ce343fdd1cd44caaaeae641d822777f9b
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
We can derive NUM_REGULAR_IRQ_PRIO_LEVELS by subtracting 1
from CONFIG_IRQ_PRIO_LEVELS if FIRQ is present (which is currently
always the case). If FIRQ is not present, the value will be equal
to CONFIG_IRQ_PRIO_LEVELS since all interrupts will be regular.
Change-Id: Ibefc939e3771bf0adf712127db0d36cb49bf732b
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
Ramesh Thomas