The ARM code base provides for three mutually exclusive ARM
architecture related conditional compilation choices. M0_M0PLUS,
M3_M4 and M7. Throughout the code base we have conditional
compilation gated around these three choices. Adjust the form of this
conditional compilation to adopt a uniform structure. The uniform
structure always selects code based on the definition of an
appropriate config option rather the the absence of a definition.
Removing the extensive use of #else ensures that when support for
other ARM architecture versions is added we get hard compilation
failures rather than attempting to compile inappropriate code for the
added architecture with unexpected runtime consequences.
Adopting this uniform structure makes it straight forward to replace
the adhoc CPU_CORTEX_M3_M4 and CPU_CORTEX_M0_M0PLUS configuration
variables with ones that directly represent the actual underlying ARM
architectures we provide support for. This change also paves the way
for folding adhoc conditional compilation related to CPU_CORTEX_M7
directly in support for ARMv7-M.
This change is mechanical in nature involving two transforms:
1)
#if !defined(CONFIG_CPU_CORTEX_M0_M0PLUS)
...
is transformed to:
#if defined(CONFIG_CPU_CORTEX_M0_M0PLUS)
#elif defined(CONFIG_CPU_CORTEX_M3_M4) || defined(CONFIG_CPU_CORTEX_M7)
...
2)
#if defined(CONFIG_CPU_CORTEX_M0_M0PLUS)
...
#else
...
#endif
is transformed to:
#if defined(CONFIG_CPU_CORTEX_M0_M0PLUS)
...
#elif defined(CONFIG_CPU_CORTEX_M3_M4) || defined(CONFIG_CPU_CORTEX_M7)
...
#else
#error Unknown ARM architecture
#endif
Change-Id: I7229029b174da3a8b3c6fb2eec63d776f1d11e24
Signed-off-by: Marcus Shawcroft <marcus.shawcroft@arm.com>
Adjust the layout of various ARM assember files to conform to the norm
used in the majority of files.
Change-Id: Ia5007628be5ad36ef587946861c6ea90a8062585
Signed-off-by: Marcus Shawcroft <marcus.shawcroft@arm.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>
The Cortex-M0(+) and in general processors that support only the ARMv6-M
instruction set have a reduced set of registers and fields compared to
the ARMv7-M compliant processors.
This change goes through all core registers and disables or removes
everything that is not part of the ARMv6-M architecture when compiling
for Cortex-M0.
Jira: ZEP-1497
Change-id: I13e2637bb730e69d02f2a5ee687038dc69ad28a8
Signed-off-by: Vinayak Chettimada <vinayak.kariappa.chettimada@nordicsemi.no>
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
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>
That module is not used anymore: it was introduced pre-Zephyr to add
some kind of awareness when debugging ARM Cortex-M3 code with GDB but
was never really used by anyone. It has bitrotted, and with the recent
move of the tTCS and tNANO data structures to common _kernel and
k_thread, it does not even compile anymore.
Jira: ZEP-1284, ZEP-951
Change-Id: Ic9afed00f4229324fe5d2aa97dc6f1c935953244
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
And also remove now obsolete ARCH_HAS_TASK_ABORT.
ARC does not need the options either.
Change-Id: Ie52d63178a367ce12b911dacfe2d389f4f75ed2d
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.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>
Cortex-M0/M0+ do not have other faults than the hard fault at priority
-1, so they do not need to reserve a priority to allow exceptions to
trigger during handling of ISRs.
Change-Id: I479e439f7bcac70b4b2b787bcd744a4c65437e80
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
This allows using it in _EXC_PRIO() instead of hardcoding 2 and 3.
Change-Id: I3549be54602643e06823ba63beb6a6992f39f776
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Use it to flag which CPUs can do zero latency interrupts, which depend
on being able to lock up to a specific interrupt priority.
Change-Id: I09f71366ea1d05486e38c513a09abc270884879f
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Add a "memory" clobber to inline asm SVC call to ensure the compiler
does not reorder the instruction relative to other memory accesses.
Issue found by inspect the source code. There is no evidence to
suggest that this bug will manifest for any current ARM target using a
current compiler.
Change-Id: I32b1e5ede02a6dbea02bb8f98729fff1cca1ef2a
Signed-off-by: Marcus Shawcroft <marcus.shawcroft@arm.com>
This patch fixes the unused parameter warning found at the
arch/arm/core/fault.c and arch/arm/soc/st_stm32/stm32f1/soc_gpio.c
files.
Change-Id: I5b3013c1514cff30f4e98feb31169fb28546c534
Signed-off-by: Flavio Santes <flavio.santes@intel.com>
Initializing the interrupt stack before initializing (turning off) the
watchdog on the FRDM board pushed the initialization of the watchdog too
late, causing it to fire and reset the board. The board would be kept in
a reboot loop.
Move the initialization of the watchdog earlier: this runs on the main
stack now, instead of the interrupt stack, the same stack the interrupt
stack initalization code runs on.
Change-Id: Ic0006f4f4f4090393571d8355a80dc9390c9fbc6
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Make the systick feature optional that can be selected by the SoC.
Change-Id: I4a405640b84daecc17fc1882743d3cafb78ff861
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
An IRQ would always register as a ZIL interrupt.
Change-Id: If82a85f472a60512745652aacc7e8b7dfacaa268
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
The assembler was passed immediate values that are too large for the
limited Cortex-M0 thumb assembly. Load values in registers instead of
using immediate values.
Change-Id: Ib5541c92dea03e0efb1b88ab91eeb408d151a71b
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
This patch enables REBOOT when RUNTIME_NMI is selected via defconfig
file. This action is required to prevent compilation errors.
Change-Id: I67c18b2860ac34ba8f96e780737b4857a6063ece
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@linaro.org>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
If CORTEX_M_SYSTICK is not selected, do not reference
_timer_int_handler. SoC will need to define a custom system
clock implementation.
Change-Id: I655f3abf66953e434fef69ed16db2d9c2dcc486e
Signed-off-by: Vinayak Chettimada <vinayak.kariappa.chettimada@nordicsemi.no>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Zephyr kernel is unable to compile when CONFIG_RUNTIME_NMI is enabled in
defconfig on ARM's architectures.
This patch addresses the following issues:
* In nmi.c _DefaultHandler() is referencing a function
(_ScbSystemReset()) not defined in Zephyr. This has now been replaced
with sys_arch_reboot.
* nmi.h is included in ASM files and due to the usage of "extern" the
compilation ends with an error. Added the directive _ASMLANGUAGE to
prevent the problem.
Jira: ZEP-1319
Change-Id: I7623ca97523cde04e4c6db40dc332d93ca801928
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@linaro.org>
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 stack. Initialize the interrupt stack before it is used
for the rest of the pre-kernel initialization.
Change-Id: I6fcc9a08678afdb82e83465cda1c7a2a8c849c9b
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
The ARM Cortex-M early boot was using a custom stack at the end of the
SRAM instead of the interrupt stack. This works as long as no static
data that needs a known initial value occupies that stack space. This
has probably not been an issue because the .noinit section is at the
very end of the image, but it was still wrong to use that region of
memory for that initial stack.
To be able to use the interrupt stack during early boot, the stack has
to be released before an interrupt can happen. Since ARM Cortex-M uses
PendSV as a very low priority exception for context switching, if a
device driver installs and enables an interrupt during the PRE_KERNEL
initialization points, an interrupt could take precedence over PendSV
while the initial dummy thread has not yet been context switched of and
thus released the interrupt stack. To address this, rather than using
_Swap() and thus triggering PendSV, the initialization logic switches to
the main stack and branches to _main() directly instead.
Fixes ZEP-1309
Change-Id: If0b62cc66470b45b601e63826b5b3306e6a25ae9
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>
There was a possible race condition when setting the return value of a
thread that is pending, from an ISR.
A kernel function causes a thread to pend, with the following series of
steps:
- disable interrupts
- move current thread to wait_q
- call _Swap
Depending if running on M3/4 or M0+, _Swap will either issue a svc #0,
or pend PendSV directly. The same problem exists in both cases.
M3/4:
__svc will:
- enable interrupts
- trigger __pendsv
M0+:
_Swap() will enable interrupts.
__pendsv will:
- save register context including PSP into the thread struct
If an interrupt occurs between interrupts being enabled them and
__pendsv saving PSP, and the ISR sets the pending thread's return value,
this will happen:
- sees the thread in a wait_q
- removes it
- makes it ready
- calls _set_thread_return_value
- _set_thread_return_value looks at the thread's saved PSP to poke
the value
In this scenario, PSP hasn't yet been updated by __pendsv so it's a
stale value from the previous context switch, resulting in unpredictable
word on the stack getting set to the return value.
There is no way to fix this issue and still have the return value being
delivered directly in the pending thread's exception stack frame, in the
M0+ case. There will always be a window between the unlocking of
interrupts and PendSV being handled. On M3/4, it could be possible with
the mix of SVC and PendSV, since the exception stack frame is created in
the __svc handler. However, because we want to keep the two
implementations as close as possible, and there were talks of moving
M3/4 to using PendSV only, to save an exception, the approach taken
solves both cases.
The approach taken is similar to the ARC and Nios2 ports, where
there is a field in the thread structure that holds the return value.
_Swap() then loads r0/a1 with that value just before returning.
Fixes ZEP-1289.
Change-Id: Iee7e06fe3f8ded84aff918fd43408c7f589344d9
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>
This reverts commit
"kernel/arm: add comment about _is_next_thread_current"
and fixes the interrupt locking issue.
The comment would have been right if only reads were done the ready
queue, but that is not the case. It turns out that the comment was written
ignoring the fact that _is_next_thread_current() updates the next thread
cache when fetching the next thread.
Change-Id: I21c9230f85f4f87a6bbf14fd4a9eb7e19b59f8c5
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Normally, _is_next_thread_current() must be called with interrupts
locked, but the ARM interrupt exit code does not have to do that. Add
explanation why.
Change-Id: Id383b47a055fdd6fbd5afffa52772e92febde98f
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.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>
The unified kernel is now the only supported kernel, so this
option is unnessary. Eliminating this option also enables
the removal of some legacy code that is no longer required.
Change-Id: Ibfc339d643c8de16a2ed2009c9b468848b8b4972
Signed-off-by: Allan Stephens <allan.stephens@windriver.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>
Symbols now use the K_ prefix which is now standard for the
unified kernel. Legacy support for these symbols is retained
to allow existing applications to build successfully.
Change-Id: I3ff12c96f729b535eecc940502892cbaa52526b6
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
This change is required to support unified kernel.
Change-Id: I47bd644239eb3e624c7a5cb456eedad5aca79e8e
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>
The unified kernel expect the default return value from a _Swap() call
to be set to -EAGAIN by the architecture code. Cortex-M3/M4 does this in
the SVC call handler, and it was missing from the Cortex-M0/M0+ before
pending PendSV.
Change-Id: I3316901186ab409f49043eb4f1972c4b0dd9a4a2
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.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>
All M7 features common to M3/M4 are working. New features like Tightly
Coupled Memory (TCM) are not yet supported.
Change-Id: I5f7b292e70843aec415728f24c973bb003014f4b
Jira: ZEP-977
Signed-off-by: Piotr Mienkowski <Piotr.Mienkowski@schmid-telecom.ch>
Existing code wasn't removing a thread from the kernel's list
of active threads if the thread terminated or aborted. (It did
remove it if the delayed starting of a thread was cancelled.)
Change-Id: Icc97917e33765696480d0e9bf31e882ef555d095
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
