Commit Graph

14 Commits

Author SHA1 Message Date
Dave Jiang
dd41a0e515 dmaengine: idxd: fix cdev setup and free device lifetime issues
[ Upstream commit 04922b7445a1950b86f130a1fe8c52cc27b3e30b ]

The char device setup and cleanup has device lifetime issues regarding when
parts are initialized and cleaned up. The initialization of struct device is
done incorrectly. device_initialize() needs to be called on the 'struct
device' and then additional changes can be added. The ->release() function
needs to be setup via device_type before dev_set_name() to allow proper
cleanup. The change re-parents the cdev under the wq->conf_dev to get
natural reference inheritance. No known dependency on the old device path exists.

Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Fixes: 42d279f913 ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/161852987721.2203940.1478218825576630810.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:13:04 +02:00
Dave Jiang
a5ad12d5d6 dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback
[ Upstream commit ea941ac294d75d0ace50797aebf0056f6f8f7a7f ]

Current code blindly writes over the SWERR and the OVERFLOW bits. Write
back the bits actually read instead so the driver avoids clobbering the
OVERFLOW bit that comes after the register is read.

Fixes: bfe1d56091 ("dmaengine: idxd: Init and probe for Intel data accelerators")
Reported-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161352082229.3511254.1002151220537623503.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-21 13:00:50 +02:00
Dave Jiang
c39cdf559d dmaengine: idxd: fix misc interrupt completion
[ Upstream commit f5cc9ace24fbdf41b4814effbb2f9bad7046e988 ]

Nikhil reported the misc interrupt handler can sometimes miss handling
the command interrupt when an error interrupt happens near the same time.
Have the irq handling thread continue to process the misc interrupts until
all interrupts are processed. This is a low usage interrupt and is not
expected to handle high volume traffic. Therefore there is no concern of
this thread running for a long time.

Fixes: 0d5c10b4c8 ("dmaengine: idxd: add work queue drain support")
Reported-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161074755329.2183844.13295528344116907983.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-17 11:02:25 +01:00
Vinod Koul
4c80e93239 Merge tag 'v5.9-rc4' into next
Linux 5.9-rc4
2020-09-11 17:45:36 +05:30
Dave Jiang
0ec083e50c dmaengine: idxd: clear misc interrupt cause after read
Move the clearing of misc interrupt cause to immediately after reading the
register in order to allow the next interrupt to be asserted.

Suggested-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159603824665.28647.5344356370364397996.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-08-17 10:49:11 +05:30
Dave Jiang
df841b17e8 dmaengine: idxd: reset states after device disable or reset
The state for WQs should be reset to disabled when a device is reset or
disabled.

Fixes: da32b28c95 ("dmaengine: idxd: cleanup workqueue config after disabling")
Reported-by: Mona Hossain <mona.hossain@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159586777684.27150.17589406415773568534.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-08-17 10:25:04 +05:30
Vinod Koul
0b5ad7b952 Merge branch 'for-linus' into fixes
Signed-off-by: Vinod Koul <vkoul@kernel.org>

 Conflicts:
	drivers/dma/idxd/sysfs.c
2020-08-05 19:02:07 +05:30
Dave Jiang
4548a6ad3d dmaengine: idxd: move idxd interrupt handling to mask instead of ignore
Switch driver to use MSIX mask and unmask instead of the ignore bit.
When ignore bit is cleared, we must issue an MMIO read to ensure writes
have all arrived and check and process any additional completions. The
ignore bit does not queue up any pending MSIX interrupts. The mask bit
however does. Use API call from interrupt subsystem to mask MSIX
interrupt since the hardware does not have convenient mask bit register.

Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159319517621.70410.11816465052708900506.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-07-13 14:48:02 +05:30
Dave Jiang
0d5c10b4c8 dmaengine: idxd: add work queue drain support
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>
2020-07-13 14:48:02 +05:30
Dave Jiang
e3122822a7 dmaengine: idxd: fix misc interrupt handler thread unmasking
Fix unmasking of misc interrupt handler when completing normal. It exits
early and skips the unmasking with the current implementation. Fix to
unmask interrupt when exiting normally.

Fixes: bfe1d56091 ("dmaengine: idxd: Init and probe for Intel data accelerators")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159311256528.855.11527922406329728512.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-07-02 19:02:20 +05:30
Dave Jiang
4f302642b7 dmaengine: idxd: fix interrupt completion after unmasking
The current implementation may miss completions after we unmask the
interrupt. In order to make sure we process all competions, we need to:
1. Do an MMIO read from the device as a barrier to ensure that all PCI
   writes for completions have arrived.
2. Check for any additional completions that we missed.

Fixes: 8f47d1a5e5 ("dmaengine: idxd: connect idxd to dmaengine subsystem")

Reported-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/158834641769.35613.1341160109892008587.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-05-04 14:25:37 +05:30
Dave Jiang
42d279f913 dmaengine: idxd: add char driver to expose submission portal to userland
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>
2020-01-24 11:18:45 +05:30
Dave Jiang
8f47d1a5e5 dmaengine: idxd: connect idxd to dmaengine subsystem
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>
2020-01-24 11:18:45 +05:30
Dave Jiang
bfe1d56091 dmaengine: idxd: Init and probe for Intel data accelerators
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>
2020-01-24 11:18:45 +05:30