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| author | Dave Jiang <dave.jiang@intel.com> | 2022-09-17 09:12:20 -0700 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2022-09-29 22:46:08 +0530 |
| commit | b0325aefd398d8b536ba46ee2e5d24252c1b2258 (patch) | |
| tree | c161c2f74c0c3988d775c05dfa9e7c453ddb7432 /Documentation/ABI/stable | |
| parent | a8563a33a5e26064061f2fb34215c97f0e2995f4 (diff) | |
| download | linux-b0325aefd398d8b536ba46ee2e5d24252c1b2258.tar.gz linux-b0325aefd398d8b536ba46ee2e5d24252c1b2258.tar.bz2 linux-b0325aefd398d8b536ba46ee2e5d24252c1b2258.zip | |
dmaengine: idxd: add WQ operation cap restriction support
DSA 2.0 add the capability of configuring DMA ops on a per workqueue basis.
This means that certain ops can be disabled by the system administrator for
certain wq. By default, all ops are available. A bitmap is used to store
the ops due to total op size of 256 bits and it is more convenient to use a
range list to specify which bits are enabled.
One of the usage to support this is for VM migration between different
iteration of devices. The newer ops are disabled in order to allow guest to
migrate to a host that only support older ops. Another usage is to
restrict the WQ to certain operations for QoS of performance.
A sysfs of ops_config attribute is added per wq. It is only usable when the
ops_config bit is set under WQ_CAP register. This means that this attribute
will return -EOPNOTSUPP on DSA 1.x devices. The expected input is a range
list for the bits per operation the WQ supports.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220917161222.2835172-4-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'Documentation/ABI/stable')
| -rw-r--r-- | Documentation/ABI/stable/sysfs-driver-dma-idxd | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd index 0c2b613f2373..3f9f93b5e48c 100644 --- a/Documentation/ABI/stable/sysfs-driver-dma-idxd +++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd @@ -227,6 +227,17 @@ Contact: dmaengine@vger.kernel.org Description: Indicate the number of retires for an enqcmds submission on a sharedwq. A max value to set attribute is capped at 64. +What: /sys/bus/dsa/devices/wq<m>.<n>/op_config +Date: Sept 14, 2022 +KernelVersion: 6.0.0 +Contact: dmaengine@vger.kernel.org +Description: Shows the operation capability bits displayed in bitmap format + presented by %*pb printk() output format specifier. + The attribute can be configured when the WQ is disabled in + order to configure the WQ to accept specific bits that + correlates to the operations allowed. It's visible only + on platforms that support the capability. + What: /sys/bus/dsa/devices/engine<m>.<n>/group_id Date: Oct 25, 2019 KernelVersion: 5.6.0 |