Commit Graph

9 Commits

Author SHA1 Message Date
Yuval Peress
dbb470ea7a rtio: Add a managed memory pool for reads
- Introduce a new Kconfig to enable mempool in RTIO
- Introduce a new RTIO_DEFINE_WITH_MEMPOOL to allocate an RTIO context
  with an associated memory pool.
- Add a new sqe read function rtio_sqe_read_with_pool() for memory pool
  enabled RTIO contexts
- Allow IODevs to allocate only the memory they need via rtio_sqe_rx_buf()
- Allow the consumer to get the allocated buffer via
  rtio_cqe_get_mempool_buffer()
- Consumers need to release the buffer via rtio_release_buffer() when
  processing is complete.

Signed-off-by: Yuval Peress <peress@google.com>
2023-04-10 18:34:43 -04:00
Yuval Peress
80d70b4e96 rtio: Add cqe per each sqe in transaction
Update the policy such that every completed sqe has a parallel cqe.
This has the primary purpose of making any reads in the sqe visible
to the consumer (since they might have different buffers).

Signed-off-by: Yuval Peress <peress@google.com>
2023-04-10 18:34:43 -04:00
Tom Burdick
912e7ff863 rtio: Add callback op
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>
2023-04-03 09:51:02 +02:00
Tom Burdick
610d307fa0 rtio: Properly track last sqe in the queue
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>
2023-03-17 12:49:57 -05:00
Tom Burdick
3353342e5f rtio: Add transactional submissions
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>
2023-03-17 12:49:57 -05:00
Tom Burdick
3998f9f898 rtio: Shareable lock-free iodevs
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>
2023-03-03 09:18:09 +01:00
Fabio Baltieri
24d09d363c include: fix the remaining legacy #include paths
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>
2022-08-02 16:41:41 +01:00
Tomislav Milkovic
0fe2c1fe90 everywhere: Fix legacy include paths
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>
2022-07-18 16:16:47 +00:00
Tom Burdick
121462b129 rtio: Low (Memory) Cost Concurrent scheduler
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>
2022-06-28 13:53:13 -04:00