Adds a callback op to RTIO enabling C logic to be interspersed with
I/O operations. This is not safe from userspace but allowable in kernel
space.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
The pending_sqe logic to track where in the ring queue the concurrent
executor had left off was slightly flawed. It didn't account for starting
all sqes in the queue and ending back up at the beginning.
Instead track the last SQE in the queue, from which the next one in the
queue will the one to start next.
If we happen to sweep the last known SQE in the queue, reset it to NULL
so the next time prepare is called we start at the beginning of the queue
again.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
Transactional submissions treat a sequence of sqes as a single atomic
submission given to a single iodev and expect as a reply a single
completion.
This is useful for scatter gather like APIs that exist in Zephyr already
for I2C and SPI.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
By using an mpsc queue for each iodev, the iodev itself is shareable across
contexts. Since its lock free, submits may occur even from an ISR context.
Rather than a fixed size queue, and with it the possibility of running
out of pre-allocated spots, each iodev now holds a wait-free mpsc
queue head.
This changes the parameter of iodev submit to be a struct containing 4
pointers for the rtio context, the submission queue entry, and the mpsc
node for the iodevs submission queue.
This solves the problem involving busy iodevs working with real
devices. For example a busy SPI bus driver could enqueue, without locking,
a request to start once the current request is done.
The queue entries are expected to be owned and allocated by the
executor rather than the iodev. This helps simplify potential
tuning knobs to one place, the RTIO context and its executor an
application directly uses.
As the test case shows iodevs can operate effectively lock free
with the mpsc queue and a single atomic denoting the current task.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
Add the "zephyr/" prefix to various #include statements that are
preventing the CI form running with LEGACY_INCLUDE_PATH=n.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Any project with Kconfig option CONFIG_LEGACY_INCLUDE_PATH set to n
couldn't be built because some files were missing zephyr/ prefix in
includes
Re-run the migrate_includes.py script to fix all legacy include paths
Signed-off-by: Tomislav Milkovic <milkovic@byte-lab.com>
Schedules I/O chains in the same order as they arrive providing a fixed
amount of concurrency. The low memory cost comes at the cost of some
computational cost that is likely to be acceptable with small amounts
of concurrency.
The code cost is about 4x higher than the simple linear executor
which isn't entirely unexpected as the logic requirements are quite a bit
more than doing the next thing in the queue.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
