It's now possible to instantiate a thread object, but delay its
execution indefinitely. This was already supported with K_THREAD_DEFINE.
A new API, k_thread_start(), now exists to start threads that are in
this state.
The intended use-case is to initialize a thread with K_USER, then grant
it various access permissions, and only then start it.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
All system calls made from userspace which involve pointers to kernel
objects (including device drivers) will need to have those pointers
validated; userspace should never be able to crash the kernel by passing
it garbage.
The actual validation with _k_object_validate() will be in the system
call receiver code, which doesn't exist yet.
- CONFIG_USERSPACE introduced. We are somewhat far away from having an
end-to-end implementation, but at least need a Kconfig symbol to
guard the incoming code with. Formal documentation doesn't exist yet
either, but will appear later down the road once the implementation is
mostly finalized.
- In the memory region for RAM, the data section has been moved last,
past bss and noinit. This ensures that inserting generated tables
with addresses of kernel objects does not change the addresses of
those objects (which would make the table invalid)
- The DWARF debug information in the generated ELF binary is parsed to
fetch the locations of all kernel objects and pass this to gperf to
create a perfect hash table of their memory addresses.
- The generated gperf code doesn't know that we are exclusively working
with memory addresses and uses memory inefficently. A post-processing
script process_gperf.py adjusts the generated code before it is
compiled to work with pointer values directly and not strings
containing them.
- _k_object_init() calls inserted into the init functions for the set of
kernel object types we are going to support so far
Issue: ZEP-2187
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is necessary in order for k_queue_get to work properly since that
is used with buffer pools which might be used by multiple threads asking
for buffers.
Jira: ZEP-2553
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This has been a limitation caused by k_fifo which could only remove
items from the beggining, but with the change to use k_queue in
k_work_q it is now possible to remove items from any position with
use of k_queue_remove.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This makes use of POLL_EVENT in case k_poll is enabled which is
preferable over wait_q as that allows objects to be removed for the
data_q at any time.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Historically, stacks were just character buffers and could be treated
as such if the user wanted to look inside the stack data, and also
declared as an array of the desired stack size.
This is no longer the case. Certain architectures will create a memory
region much larger to account for MPU/MMU guard pages. Unfortunately,
the kernel interfaces treat both the declared stack, and the valid
stack buffer within it as the same char * data type, even though these
absolutely cannot be used interchangeably.
We introduce an opaque k_thread_stack_t which gets instantiated by
K_THREAD_STACK_DECLARE(), this is no longer treated by the compiler
as a character pointer, even though it really is.
To access the real stack buffer within, the result of
K_THREAD_STACK_BUFFER() can be used, which will return a char * type.
This should catch a bunch of programming mistakes at build time:
- Declaring a character array outside of K_THREAD_STACK_DECLARE() and
passing it to K_THREAD_CREATE
- Directly examining the stack created by K_THREAD_STACK_DECLARE()
which is not actually the memory desired and may trigger a CPU
exception
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Each member of the array may need to have a padding size added
such that the base address of each array element corresponds to
the desired stack alignment.
This would mean that sizeof(some array element) would return
a larger size than what was originally provided.
This won't cause problems at runtime since the space is really
there, but for users who are only enabling this padding for
debug features, they may be surprised when their stacks are
effectively smaller than when this was enabled.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
K_POLL_MODE_INFORM_ONLY was renamed to K_POLL_MODE_NOTIFY_ONLY, but
stale use was in a docstring.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Upcoming memory protection features will be placing some additional
constraints on kernel objects:
- They need to reside in memory owned by the kernel and not the
application
- Certain kernel object validation schemes will require some run-time
initialization of all kernel objects before they can be used.
Per Ben these initializer macros were never intended to be public. It is
not forbidden to use them, but doing so requires care: the memory being
initialized must reside in kernel space, and extra runtime
initialization steps may need to be peformed before they are fully
usable as kernel objects. In particular, kernel subsystems or drivers
whose objects are already in kernel memory may still need to use these
macros if they define kernel objects as members of a larger data
structure.
It is intended that application developers instead use the
K_<object>_DEFINE macros, which will automatically put the object in the
right memory and add them to a section which can be iterated over at
boot to complete initiailization.
There was no K_WORK_DEFINE() macro for creating struct k_work objects,
this is now added.
k_poll_event and k_poll_signal are intended to be instatiated from
application memory and have not been changed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
As explained in the docstrings, a usecase behind these operations is
when other container objects are put in a fifo. The typical
processing iteration make take just some data from a container at
the head of fifo, with the container still being kept at the fifo,
unless it becomes empty, and only then it's removed. Similarly with
adding more data - first step may be to try to add more data to a
container at the tail of fifo, and only if it's full, add another
container to a fifo.
The specific usecase these operations are added for is network
subsystem processing, where net_buf's and net_pkt's are added
to fifo.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
The existing __stack decorator is not flexible enough for upcoming
thread stack memory protection scenarios. Wrap the entire thing in
a declaration macro abstraction instead, which can be implemented
on a per-arch or per-SOC basis.
Issue: ZEP-2185
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This patch amounts to a mostly complete rewrite of the k_mem_pool
allocator, which had been the source of historical complaints vs. the
one easily available in newlib. The basic design of the allocator is
unchanged (it's still a 4-way buddy allocator), but the implementation
has made different choices throughout. Major changes:
Space efficiency: The old implementation required ~2.66 bytes per
"smallest block" in overhead, plus 16 bytes per log4 "level" of the
allocation tree, plus a global tracking struct of 32 bytes and a very
surprising 12 byte overhead (in struct k_mem_block) per active
allocation on top of the returned data pointer. This new allocator
uses a simple bit array as the only per-block storage and places the
free list into the freed blocks themselves, requiring only ~1.33 bits
per smallest block, 12 bytes per level, 32 byte globally and only 4
bytes of per-allocation bookeeping. And it puts more of the generated
tree into BSS, slightly reducing binary sizes for non-trivial pool
sizes (even as the code size itself has increased a tiny bit).
IRQ safe: atomic operations on the store have been cut down to be at
most "4 bit sets and dlist operations" (i.e. a few dozen
instructions), reducing latency significantly and allowing us to lock
against interrupts cleanly from all APIs. Allocations and frees can
be done from ISRs now without limitation (well, obviously you can't
sleep, so "timeout" must be K_NO_WAIT).
Deterministic performance: there is no more "defragmentation" step
that must be manually managed. Block coalescing is done synchronously
at free time and takes constant time (strictly log4(num_levels)), as
the detection of four free "partner bits" is just a simple shift and
mask operation.
Cleaner behavior with odd sizes. The old code assumed that the
specified maximum size would be a power of four multiple of the
minimum size, making use of non-standard buffer sizes problematic.
This implementation re-aligns the sub-blocks at each level and can
handle situations wehre alignment restrictions mean fewer than 4x will
be available. If you want precise layout control, you can still
specify the sizes rigorously. It just doesn't break if you don't.
More portable: the original implementation made use of GNU assembler
macros embedded inline within C __asm__ statements. Not all
toolchains are actually backed by a GNU assembler even when the
support the GNU assembly syntax. This is pure C, albeit with some
hairy macros to expand the compile-time-computed values.
Related changes that had to be rolled into this patch for bisectability:
* The new allocator has a firm minimum block size of 8 bytes (to store
the dlist_node_t). It will "work" with smaller requested min_size
values, but obviously makes no firm promises about layout or how
many will be available. Unfortunately many of the tests were
written with very small 4-byte minimum sizes and to assume exactly
how many they could allocate. Bump the sizes to match the allocator
minimum.
* The mbox and pipes API made use of the internals of k_mem_block and
had to be ported to the new scheme. Blocks no longer store a
backpointer to the pool that allocated them (it's an integer ID in a
bitfield) , so if you want to "nullify" them you have to use the
data pointer.
* test_mbox_api had a bug were it was prematurely freeing k_mem_blocks
that it sent through the mailbox. This worked in the old allocator
because the memory wouldn't be touched when freed, but now we stuff
list pointers in there and the bug was exposed.
* Remove test_mpool_options: the options (related to defragmentation
behavior) tested no longer exist.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Unline k_thread_spawn(), the struct k_thread can live anywhere and not
in the thread's stack region. This will be useful for memory protection
scenarios where private kernel structures for a thread are not
accessible by that thread, or we want to allow the thread to use all the
stack space we gave it.
This requires a change to the internal _new_thread() API as we need to
provide a separate pointer for the k_thread.
By default, we still create internal threads with the k_thread in stack
memory. Forthcoming patches will change this, but we first need to make
it easier to define k_thread memory of variable size depending on
whether we need to store coprocessor state or not.
Change-Id: I533bbcf317833ba67a771b356b6bbc6596bf60f5
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Currently, a queue/fifo getter chooses how long to wait for an
element. But there are scenarios when putter would know better,
there should be a way to expire getter's timeout to make it run
again. k_queue_cancel_wait() and k_fifo_cancel_wait() functions
do just that. They cause corresponding *_get() functions to return
with NULL value, as if timeout expired on getter's side (even
K_FOREVER).
This can be used to signal out of band conditions from putter to
getter, e.g. end of processing, error, configuration change, etc.
A specific event would be communicated to getter by other means
(e.g. using existing shared context structures).
Without this call, achieving the same effect would require e.g.
calling k_fifo_put() with a pointer to a special sentinal memory
structure - such structure would need to be allocated somewhere
and somehow, and getter would need to recognize it from a normal
data item. Having cancel_wait() functions offers an elegant
alternative. From this perspective, these calls can be seen as
an equivalent to e.g. k_fifo_put(fifo, NULL), except that such
call won't work in practice.
Change-Id: I47b7f690dc325a80943082bcf5345c41649e7024
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
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>
Historically, space for struct k_thread was always carved out of the
thread's stack region. However, we want more control on where this data
will reside; in memory protection scenarios the stack may only be used
for actual stack data and nothing else.
On some platforms (particularly ARM), including kernel_arch_data.h from
the toplevel kernel.h exposes intractable circular dependency issues.
We create a new per-arch header "kernel_arch_thread.h" with very limited
scope; it only defines the three data structures necessary to instantiate
the arch-specific bits of a struct k_thread.
Change-Id: I3a55b4ed4270512e58cf671f327bb033ad7f4a4f
Signed-off-by: Andrew Boie <andrew.p.boie@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>
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>
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>
We need to move using the PRI* defines to use newlib as the default libc
as different arch's define various base types like {u}int32_t
differently. To deal with that in a consistent manor we need access to
the defines in most spots for print{f,k} or logging functions.
Change-Id: Ic1fbef75cbaee211803d9aaf506056e5e31e73f3
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This code is non-functional and is a left over from an old version of
the kernel that does not work and is covered through other new features
in the kernel, for example object tracing.
Jira: ZEP-2013
Change-Id: Id12ad09e2d06186b53cd2f0dd030ac6d37d1229f
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
_THREAD_TIMEOUT_INIT() has been replaced by _nano_timeout_thread_init(),
so it can be removed.
_THREAD_ERRNO_INIT() is defined, but never used. Ben suspects that this
is a bug, and that there should be some code that calls it.
Jira: ZEP-1326
Change-Id: I476c316b80e9f34d1ed61971229ed9afafc80d8a
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Once all users of k_lifo migrate to k_queue this should no longer be
needed.
Change-Id: Ib8af40c57bf8feba7b06d6d891cfa57b44faad42
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This makes k_fifo functions rely on k_queue and port k_poll to use
k_queue directly.
Once all users of k_fifo migrate to k_queue this should no longer be
needed.
Change-Id: Icf16d580f88d11b2cb89e1abd23ae314f43dbd20
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This unifies k_fifo and k_lifo APIs thus making it more flexible regarding
where the data elements are inserted.
Change-Id: Icd6e2f62fc8b374c8273bb763409e9e22c40f9f8
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.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>
The old syntax is not accepted by some compilers including XCC.
Change-Id: Id90849a2159652ec225dd2c50d2dc2ddc22a3e08
Signed-off-by: Mazen NEIFER <mazen@nestwave.com>
It was in the static initializers, but was missing from the object
runtime init functions.
Change-Id: I10d519760eabdbe640a19cc5cfa9241c1356b070
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
This will allow users to install a way of finding out what the event and
the objects are used for without looking at the object itself, or to
tag a bunch of objects that belong together.
The runtime init function _does not_ take a tag so that there is no
runtime hit if not needed. The static initializer macro _does_ take the
tag, so that it does not have to be initialized at runtime if needed,
and thus avoids a runtime hit.
Change-Id: I89a36c6f969ff952f9d1673b1bb5136e407535c6
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
k_poll() is similar to the POSIX poll() API in spirit in that it allows
a single thread to monitor multiple events without actively polling
them, but rather pending for one or more to become ready. Such events
can be a direct event, or kernel objects (currently only semaphores and
fifos).
When a kernel object being polled on is ready, it is not "given" to the
poller: the poller must then acquire it via the regular API for the
object (e.g. k_sem_take()). Only one thread can poll on a particular
object at one time. These restrictions mean that k_poll() is most
effective when a single thread monitors multiple events that are not
subject for contention. For example, being the sole reader on multiple
fifos, or the only thread being signalled by multiple semaphores, or a
combination of both.
Change-Id: I7035a9baf4aa016fb87afc5f5c0f5f8cb216480f
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
Allow peeking at the fifo to see if there is an element without
dequeuing it.
Change-Id: I99cbe4495c81f1d7b77ad6a37cef4ec8c24d48eb
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
The K_<thread option> flags/options avaialble to users were hidden in
the kernel private header files: move them to include/kernel.h to
publicize them.
Also, to avoid any future confusion, rename the k_thread.execution_flags
field to user_options.
Change-Id: I65a6fd5e9e78d4ccf783f3304b607a1e6956aeac
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
This will be needed for some thread user options that will move to
kernel.h since they are part of the user API.
Change-Id: I46e302b6cafcdddbad3458134b98feb5b8d45d9b
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
Had only been called from ASM domain, but upcoming interrupt changes
invoke it from core arch C code as well.
Change-Id: Ifd831826068e130e2936cfa4da6c082c3433a5ae
Signed-off-by: Andrew Boie <andrew.p.boie@intel.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>
The idle priority was not accounted for.
With this change, the philosophers demo runs in coop-only mode.
Change-Id: I23db33687bcf3b2107d5fc07977143730f62e476
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
In such a case, the system must take the idle coop priority into
account.
Change-Id: Ica5a4a7a659cb165073e9b8042a77ed23a6a662a
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
