Add wq drain support. When a wq is being released, it needs to wait for
all in-flight operation to complete. A device control function
idxd_wq_drain() has been added to facilitate this. A wq drain call
is added to the char dev on release to make sure all user operations are
complete. A wq drain is also added before the wq is being disabled.
A drain command can take an unpredictable period of time. Interrupt support
for device commands is added to allow waiting on the command to
finish. If a previous command is in progress, the new submitter can block
until the current command is finished before proceeding. The interrupt
based submission will submit the command and then wait until a command
completion interrupt happens to complete. All commands are moved to the
interrupt based command submission except for the device reset during
probe, which will be polled.
Fixes: 42d279f913 ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/159319502515.69593.13451647706946040301.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Create a char device region that will allow acquisition of user portals in
order to allow applications to submit DMA operations. A char device will be
created per work queue that gets exposed. The workqueue type "user"
is used to mark a work queue for user char device. For example if the
workqueue 0 of DSA device 0 is marked for char device, then a device node
of /dev/dsa/wq0.0 will be created.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965026985.73301.976523230037106742.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add plumbing for dmaengine subsystem connection. The driver register a DMA
device per DSA device. The channels are dynamically registered when a
workqueue is configured to be "kernel:dmanegine" type.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965026376.73301.13867988830650740445.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The device is left unconfigured when the driver is loaded. Various
components are configured via the driver sysfs attributes. Once
configuration is done, the device can be enabled by writing the device name
to the bind attribute of the device driver sysfs. Disabling can be done
similarly. Also the individual work queues can also be enabled and disabled
through the bind/unbind attributes. A constructed hierarchy is created
through the struct device framework in order to provide appropriate
configuration points and device state and status. This hierarchy is
presented off the virtual DSA bus.
i.e. /sys/bus/dsa/...
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965024585.73301.6431413676230150589.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The idxd driver introduces the Intel Data Stream Accelerator [1] that will
be available on future Intel Xeon CPUs. One of the kernel access
point for the driver is through the dmaengine subsystem. It will initially
provide the DMA copy service to the kernel.
Some of the main functionality introduced with this accelerator
are: shared virtual memory (SVM) support, and descriptor submission using
Intel CPU instructions movdir64b and enqcmds. There will be additional
accelerator devices that share the same driver with variations to
capabilities.
This commit introduces the probe and initialization component of the
driver.
[1]: https://software.intel.com/en-us/download/intel-data-streaming-accelerator-preliminary-architecture-specification
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965023991.73301.6186843973135311580.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
