- Add a new API `rtio_sqe_cancel` to attempt canceling a queued SQE
- Add a new syscall `rtio_sqe_copy_in_get_handles` which allows getting
back the SQE handles generated by the copy_in operation so that they
can be canceled.
Signed-off-by: Yuval Peress <peress@google.com>
Reworks the zephyr macros and pools to be objects in their own right. Each
pool can be statically defined with a Z_ private macro. The objects can
then be initialized with an rtio instance statically.
This cleans up a lot of code that was otherwise doing little bits of
management around allocation/freeing and reduces the scope those functions
has to the data it needs.
This should enable sharing the pools of sqe, cqe, and mem blocks among rtio
instances in a future improvement easily.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
Rather than the rings, which weren't shared between userspace and kernel
space in Zephyr like they are in Linux with io_uring, use atomic mpsc
queues for submission and completion queues.
Most importantly this removes a potential head of line blocker in the
submission queue as the sqe would be held until a task is completed.
As additional bonuses this avoids some additional locks and restrictions
about what can be submitted and where. It also removes the need for
two executors as all chains/transactions are done concurrently.
Lastly this opens up the possibility for a common pool of sqe's to
allocate from potentially saving lots of memory.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
It was previously assumed that the 'sys_mem_blocks' struct would maintain
information about contiguous blocks allocated so the release API only
took the starting address. This led to an issue where allocating 2+
blocks would end up with a memory leak because any block not being the
first would never be released.
Add the buffer length as an argument so the correct number of blocks can
be released. Also, ammend the tests to match and verify.
Signed-off-by: Yuval Peress <peress@google.com>
- 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>
Adds the transceive op which is needed for full SPI support. Notably
in RTIO transceive is expected to be a balanced buffer pair of the same
length and have non-null tx/rx bufs.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
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>
When sending small buffers out it makes sense to copy rather than
reference to avoid having to keep the small buffer around for the
lifetime of the write request.
Adjusts the op numbers to always be +1 from the previously defined op
id making it easier to re-arrange if needed in the future.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
Add support for userspace with RTIO by making rtio and rtio_iodev
k_objects. As well as adding three syscalls for copying in submissions,
copying out completions, and starting tasks with submit.
For the small devices Zephyr typically runs on one of the most important
attributes tends to be low memory usage. To maintain the low footprint of
RTIO and its current executor implementations the rings are not shared with
userspace. Sharing the rings it turns out would require copying submissions
before working with them to avoid TOCTOU issues.
The API could still support shared rings in the future so that a
kernel thread could directly poll, copy, verify, and start the submitted
work. This would require a third executor implementation that maintains its
own copy of submissions similiar to how io_uring in Linux works.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
Yuval Peress