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authorDave Jiang <dave.jiang@intel.com>2022-09-17 09:12:21 -0700
committerVinod Koul <vkoul@kernel.org>2022-09-29 22:46:08 +0530
commit1f2737521af2b7d018971f1d873856fff02d2b33 (patch)
treeb8f7273557384110095409f7d271f0eb6b12826f /Documentation/ABI
parentb0325aefd398d8b536ba46ee2e5d24252c1b2258 (diff)
downloadlinux-1f2737521af2b7d018971f1d873856fff02d2b33.tar.gz
dmaengine: idxd: add configuration for concurrent work descriptor processing
Add sysfs knob to allow control of the number of work descriptors that can
be concurrently processed by an engine in the group as a fraction of the
Maximum Work Descriptors in Progress value specified in ENGCAP register.
This control knob is part of toggle for QoS control.

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/20220917161222.2835172-5-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/stable/sysfs-driver-dma-idxd12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index 3f9f93b5e48c..02a721a8ea68 100644
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -266,3 +266,15 @@ Contact:	dmaengine@vger.kernel.org
 Description:	Indicates the number of Read Buffers reserved for the use of
 		engines in the group. See DSA spec v1.2 9.2.18 GRPCFG Read Buffers
 		Reserved.
+
+What:		/sys/bus/dsa/devices/group<m>.<n>/desc_progress_limit
+Date:		Sept 14, 2022
+KernelVersion:	6.0.0
+Contact:	dmaengine@vger.kernel.org
+Description:	Allows control of the number of work descriptors that can be
+		concurrently processed by an engine in the group as a fraction
+		of the Maximum Work Descriptors in Progress value specified in
+		the ENGCAP register. The acceptable values are 0 (default),
+		1 (1/2 of max value), 2 (1/4 of the max value), and 3 (1/8 of
+		the max value). It's visible only on platforms that support
+		the capability.