The simulator seems to drop garbage addresses (somewhere in the ROM it
looks like) into this SR at arbitrary times. I don't know if this is
a hardware exception handler that we can't turn off, or a simulator
bug, or what. But our code that assumes it will be cleared to zero or
valid is breaking. Set it every time in every context switch for now
pending someone figuring out what's going wrong.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This commit corrects all `extern K_KERNEL_STACK_ARRAY_DEFINE` macro
usages to use the `K_KERNEL_STACK_ARRAY_DECLARE` macro instead.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
In order to bring consistency in-tree, migrate all arch code to the new
prefix <zephyr/...>. Note that the conversion has been scripted, refer
to zephyrproject-rtos#45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
When building with CONFIG_SCHED_CPU_MASK_PIN_ONLY we can assume that a
thread will always be executed in a same CPU and consequently skip the
cache invalidation.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Making context switch cache-coherent in SMP is hard. The
KERNEL_COHERENCE handling was conservatively invalidating the stack
region of a thread that was being switched in. This was because it
might have (1) run on this CPU in the past, but (2) run most recently
on a different CPU. In that case we might have stale data still in
our local dcache!
But this has performance impact in the (very common!) case of a thread
being switched out briefly and then back in (e.g. k_sleep() for a
small duration). It will come back having lost all of its cached
stack context, and will have to fetch all that information back from
shared SRAM!
Treat this by tracking a "last_cpu" for each thread in the arch part
of the thread struct. If we're coming back to the same CPU we left,
we know we can skip the invalidate.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The kernel coherence cache flush code was using a scratch register to
mark the top of the stack. Likewise a good candidate for ZSR use.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This is trick (mapping RAM twice so you can use alternate Region
Protection Option addresses to control cacheability) is something any
Xtensa hardware designer might productively choose to do. And as it
works really well, we should encourage that by making this a generic
architecture feature for Zephyr.
Now everything works by setting two kconfig values at the soc level
defining the cached and uncached regions. As long as these are
correct, you can then use the new arch_xtensa_un/cached_ptr() APIs to
convert between them and a ARCH_XTENSA_SET_RPO_TLB() macro that
provides much smaller initialization code (in C!) than the HAL
assembly macros. The conversion routines have been generalized to
support conversion between any two regions.
Note that full KERNEL_COHERENCE still requires support from the
platform linker script, that can't be made generic given the way
Zephyr does linkage.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
For some platforms, like NXP's IMX8 or Mediatek's MT8195,
the size of an interrupt vector table entry is 0x1C bytes,
less than usual (0x30 for Intel's platforms).
So, the interrupt handlers don't fit in the vector table
entries.
I've added a small indirection to bypass this size
constraint and moved the default handlers to the end
of vector table, renaming them to
_Level\LVL\()VectorHelper.
For this, I've added a generic configuration -
XTENSA_SMALL_VECTOR_TABLE_ENTRY.
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
On CPU startup, When we reach the cache flush code in arch_switch(),
the outgoing thread is a dummy. The behavior of the existing code was
to leave the existing value in the SR unchanged (probably NULL at
startup). Then the context switch would walk from that address up to
the top of the outgoing stack, flushing everything in between. That's
wrong, because the outgoing stack is a real pointer (generally the
interrupt stack of the current CPU), and we're flushing everything in
memory underneath it.
This also reverts commit 29abc8adc0 ("xtensa: fix booting secondary
cores on the dummy thread"), which appears to have been an early
attempt to address this issue. It worked (modulo all the extra and
potentially incorrect flushing) on cavs v1.5/1.8 because of the way
the entry code worked there. But on 2.5 we now hit the first context
switch in a case where those extra lines are in address space already
marked unwritable by the CPU, so the flush explodes.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
For IMX, for timer interrupt, the interrupt handler
was not the correct one executed and that’s because
the handlers were not at the expected address.
For IMX the size constraint of the interrupt vector
table entry is 0x1C bytes of code, less than usual.
I've added a small indirection to bypass this size
constraint and moved the default handlers to the end
of vector table, renaming them to
_Level\LVL\()VectorHelper.
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
When secondary cores are booted, they use the dummy thread and
the IRQ stack until they switch over to a real thread. Therefore
dummy threads shouldn't be skipped when cohering outgoing thread
stack, only threads with zero stack size should be skipped.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
When we reach this code in interrupt context, our upper GPRs contain a
cross-stack call that may still include some registers from the
interrupted thread. Those need to go out to memory before we can do
our cache coherence dance here.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Both new thread creation and context switch had the same mistake in
cache management: the bottom of the stack (the "unused" region between
the lower memory bound and the live stack pointer) needs to be
invalidated before we switch, because otherwise any dirty lines we
might have left over can get flushed out on top of the same thread on
another CPU that is putting live data there.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The Xtensa L1 cache layer has straightforward semantics accessible via
single-instructions that operate on cache lines via physical
addresses. These are very amenable to inlining.
Unfortunately the Xtensa HAL layer requires function calls to do this,
leading to significant code waste at the calling site, an extra frame
on the stack and needless runtime instructions for situations where
the call is over a constant region that could elide the loop. This is
made even worse because the HAL library is not built with
-ffunction-sections, so pulling in even one of these tiny cache
functions has the effect of importing a 1500-byte object file into the
link!
Add our own tiny cache layer to include/arch/xtensa/cache.h and use
that instead.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
There was a bunch of dead historical cruft floating around in the
arch/xtensa tree, left over from older code versions. It's time to do
a cleanup pass. This is entirely refactoring and size optimization,
no behavior changes on any in-tree devices should be present.
Among the more notable changes:
+ xtensa_context.h offered an elaborate API to deal with a stack frame
and context layout that we no longer use.
+ xtensa_rtos.h was entirely dead code
+ xtensa_timer.h was a parallel abstraction layer implementing in the
architecture layer what we're already doing in our timer driver.
+ The architecture thread structs (_callee_saved and _thread_arch)
aren't used by current code, and had dead fields that were removed.
Unfortunately for standards compliance and C++ compatibility it's
not possible to leave an empty struct here, so they have a single
byte field.
+ xtensa_api.h was really just some interrupt management inlines used
by irq.h, so fold that code into the outer header.
+ Remove the stale assembly offsets. This architecture doesn't use
that facility.
All told, more than a thousand lines have been removed. Not bad.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
a0 is used as scratch register. Restore value of a0 (return address)
from stack frame before spilling registers on stack
Signed-off-by: Shubham Kulkarni <shubham.kulkarni@espressif.com>
Only the CAVS 1.5 linker script has full support for the coherence
features, don't advertise it on the other SoC's yet.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This change uses stack frame to print backtrace once exception occurs
Printing backtrace helps to identify the cause of exception
Signed-off-by: Shubham Kulkarni <shubham.kulkarni@espressif.com>
Adds the necessary bits to initialize TLS in the stack
area and sets up CPU registers during context switch.
Note that this does not enable TLS for all Xtensa SoC.
This is because Xtensa SoCs are highly configurable
so that each SoC can be considered a whole architecture.
So TLS needs to be enabled on the SoC level, instead of
at the arch level.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Implement the kernel "coherence" API on top of the linker
cached/uncached mapping work.
Add Xtensa handling for the stack coherence API.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This operation is formally defined as rounding down a potential
stack pointer value to meet CPU and ABI requirments.
This was previously defined ad-hoc as STACK_ROUND_DOWN().
A new architecture constant ARCH_STACK_PTR_ALIGN is added.
Z_STACK_PTR_ALIGN() is defined in terms of it. This used to
be inconsistently specified as STACK_ALIGN or STACK_PTR_ALIGN;
in the latter case, STACK_ALIGN meant something else, typically
a required alignment for the base of a stack buffer.
STACK_ROUND_UP() only used in practice by Risc-V, delete
elsewhere.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The set of interrupt stacks is now expressed as an array. We
also define the idle threads and their associated stacks this
way. This allows for iteration in cases where we have multiple
CPUs.
There is now a centralized declaration in kernel_internal.h.
On uniprocessor systems, z_interrupt_stacks has one element
and can be used in the same way as _interrupt_stack.
The IRQ stack for CPU 0 is now set in init.c instead of in
arch code.
The extern definition of the main thread stack is now removed,
this doesn't need to be in a header.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Xtensa uses two instructions to perform atomic compare-and-set
instruction: first the comparison register, then the actual
instruction to do compare-and-set. There is a potential that
context switching is performed before these two instructions.
A restored context may have the wrong value in the comparison
register. So we need to save and restore the comparison
register during context switching.
Fixes#21800
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Promote the private z_arch_* namespace, which specifies
the interface between the core kernel and the
architecture code, to a new top-level namespace named
arch_*.
This allows our documentation generation to create
online documentation for this set of interfaces,
and this set of interfaces is worth treating in a
more formal way anyway.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit refactors kernel and arch headers to establish a boundary
between private and public interface headers.
The refactoring strategy used in this commit is detailed in the issue
This commit introduces the following major changes:
1. Establish a clear boundary between private and public headers by
removing "kernel/include" and "arch/*/include" from the global
include paths. Ideally, only kernel/ and arch/*/ source files should
reference the headers in these directories. If these headers must be
used by a component, these include paths shall be manually added to
the CMakeLists.txt file of the component. This is intended to
discourage applications from including private kernel and arch
headers either knowingly and unknowingly.
- kernel/include/ (PRIVATE)
This directory contains the private headers that provide private
kernel definitions which should not be visible outside the kernel
and arch source code. All public kernel definitions must be added
to an appropriate header located under include/.
- arch/*/include/ (PRIVATE)
This directory contains the private headers that provide private
architecture-specific definitions which should not be visible
outside the arch and kernel source code. All public architecture-
specific definitions must be added to an appropriate header located
under include/arch/*/.
- include/ AND include/sys/ (PUBLIC)
This directory contains the public headers that provide public
kernel definitions which can be referenced by both kernel and
application code.
- include/arch/*/ (PUBLIC)
This directory contains the public headers that provide public
architecture-specific definitions which can be referenced by both
kernel and application code.
2. Split arch_interface.h into "kernel-to-arch interface" and "public
arch interface" divisions.
- kernel/include/kernel_arch_interface.h
* provides private "kernel-to-arch interface" definition.
* includes arch/*/include/kernel_arch_func.h to ensure that the
interface function implementations are always available.
* includes sys/arch_interface.h so that public arch interface
definitions are automatically included when including this file.
- arch/*/include/kernel_arch_func.h
* provides architecture-specific "kernel-to-arch interface"
implementation.
* only the functions that will be used in kernel and arch source
files are defined here.
- include/sys/arch_interface.h
* provides "public arch interface" definition.
* includes include/arch/arch_inlines.h to ensure that the
architecture-specific public inline interface function
implementations are always available.
- include/arch/arch_inlines.h
* includes architecture-specific arch_inlines.h in
include/arch/*/arch_inline.h.
- include/arch/*/arch_inline.h
* provides architecture-specific "public arch interface" inline
function implementation.
* supersedes include/sys/arch_inline.h.
3. Refactor kernel and the existing architecture implementations.
- Remove circular dependency of kernel and arch headers. The
following general rules should be observed:
* Never include any private headers from public headers
* Never include kernel_internal.h in kernel_arch_data.h
* Always include kernel_arch_data.h from kernel_arch_func.h
* Never include kernel.h from kernel_struct.h either directly or
indirectly. Only add the kernel structures that must be referenced
from public arch headers in this file.
- Relocate syscall_handler.h to include/ so it can be used in the
public code. This is necessary because many user-mode public codes
reference the functions defined in this header.
- Relocate kernel_arch_thread.h to include/arch/*/thread.h. This is
necessary to provide architecture-specific thread definition for
'struct k_thread' in kernel.h.
- Remove any private header dependencies from public headers using
the following methods:
* If dependency is not required, simply omit
* If dependency is required,
- Relocate a portion of the required dependencies from the
private header to an appropriate public header OR
- Relocate the required private header to make it public.
This commit supersedes #20047, addresses #19666, and fixes#3056.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
include/sys/arch_inlines.h will contain all architecture APIs
that are used by public inline functions and macros,
with implementations deriving from include/arch/cpu.h.
kernel/include/arch_interface.h will contain everything
else, with implementations deriving from
arch/*/include/kernel_arch_func.h.
Instances of duplicate documentation for these APIs have been
removed; implementation details have been left in place.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is part of the core kernel -> architecture interface and
has been renamed z_arch_kernel_init().
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
k_cpu_idle() and k_cpu_atomic_idle() were being directly
implemented by arch code.
Rename these implementations to z_arch_cpu_idle() and
z_arch_cpu_atomic_idle(), and call them from new inline
function definitions in kernel.h.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is part of the core kernel -> architecture interface
and is appropriately renamed z_arch_is_in_isr().
References from test cases changed to k_is_in_isr().
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We re-wrote the xtensa arch code, but never got around
to purging the old implementation.
Removed those boards which hadn't been moved to the new
arch code. These were all xt-sim simulator targets and not
real hardware.
Fixes: #18138
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Consistently place C++ use of extern "C" after all include directives,
within the negative branch of _ASMLANGUAGE if used.
Background from issue #17997:
Declarations that use C linkage should be placed within extern "C"
so the language linkage is correct when the header is included by
a C++ compiler.
Similarly #include directives should be outside the extern "C" to
ensure the language-specific default linkage is applied to any
declarations provided by the included header.
See: https://en.cppreference.com/w/cpp/language/language_linkage
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
When coming out of an exception, we need to mask interrupts
to avoid races when decrementing the nested count. Move
the instruction that does this earlier.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is now called z_arch_esf_t, conforming to our naming
convention.
This needs to remain a typedef due to how our offset generation
header mechanism works.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
* z_NanoFatalErrorHandler() is now moved to common kernel code
and renamed z_fatal_error(). Arches dump arch-specific info
before calling.
* z_SysFatalErrorHandler() is now moved to common kernel code
and renamed k_sys_fatal_error_handler(). It is now much simpler;
the default policy is simply to lock interrupts and halt the system.
If an implementation of this function returns, then the currently
running thread is aborted.
* New arch-specific APIs introduced:
- z_arch_system_halt() simply powers off or halts the system.
* We now have a standard set of fatal exception reason codes,
namespaced under K_ERR_*
* CONFIG_SIMPLE_FATAL_ERROR_HANDLER deleted
* LOG_PANIC() calls moved to k_sys_fatal_error_handler()
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The SoC initialization code used system clock frequency
as a CPU clock frequency. This commit corrects that by
obtaining the needed value from DTS.
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
move misc/util.h to sys/util.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
move misc/dlist.h to sys/dlist.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Found a few annoying typos and figured I better run script and
fix anything it can find, here are the results...
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The struct _caller_saved is not used. Most architectures put
automatically the registers onto stack, in others architectures the
exception code does it.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
The struct _kernel_ach exists only because ARC' s port needed it, in
all other ports this was defined as an empty struct. Turns out that
this struct is not required even for ARC anymore, this is a legacy
code from nanokernel time.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
This macro is slated for complete removal, as it's not possible
on arches with an MPU stack guard to know the true buffer bounds
without also knowing the runtime state of its associated thread.
As removing this completely would be invasive to where we are
in the 1.14 release, demote to a private kernel Z_ API instead.
The current way that the macro is being used internally will
not cause any undue harm, we just don't want any external code
depending on it.
The final work to remove this (and overhaul stack specification in
general) will take place in 1.15 in the context of #14269Fixes: #14766
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Rename reserved function names in arch/ subdirectory. The Python
script gen_priv_stacks.py was updated to follow the 'z_' prefix
naming.
Signed-off-by: Patrik Flykt <patrik.flykt@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>
