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>
Clarify that while any number of kernel objects can be created, there is
a limit which is set by the available RAM.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Following the change to use the C domain for parsing, update all
existing :cpp:func: references to :c:func:. Remove the parentheses as
well, if used, because they are not needed, this is already known to be
a function, and how it is displayed in the documentation later is a
semantic decision done by the output builder.
Signed-off-by: Fabio Utzig <fabio.utzig@nordicsemi.no>
Remove leading/trailing blank lines in .c, .h, .py, .rst, .yml, and
.yaml files.
Will avoid failures with the new CI test in
https://github.com/zephyrproject-rtos/ci-tools/pull/112, though it only
checks changed files.
Move the 'target-notes' target in boards/xtensa/odroid_go/doc/index.rst
to get rid of the trailing blank line there. It was probably misplaced.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Move guides and APIs into separate directories and cleanup naming
introducing index files rather than named section files.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
