en Copyright 2015 Java http://172.16.0.5:8080/history/linux-6.15/Documentation/ABI/testing/sysfs-class-stm_source#7bd1d409 stm class: Introduce an abstraction for System Trace Module devicesA System Trace Module (STM) is a device exporting data in System TraceProtocol (STP) format as defined by MIPI STP standards. Examples of suchdevices are Intel(R) Trace Hub and Coresight STM.This abstraction provides a unified interface for software trace sourcesto send their data over an STM device to a debug host. In order to dothat, such a trace source needs to be assigned a pair of master/channelidentifiers that all the data from this source will be tagged with. TheSTP decoder on the debug host side will use these master/channel tags todistinguish different trace streams from one another inside one STPstream.This abstraction provides a configfs-based policy management mechanismfor dynamic allocation of these master/channel pairs based on tracesource-supplied string identifier. It has the flexibility of beingdefined at runtime and at the same time (provided that the policydefinition is aligned with the decoding end) consistency.For userspace trace sources, this abstraction provides write()-based andmmap()-based (if the underlying stm device allows this) output mechanism.For kernel-side trace sources, we provide "stm_source" device class thatcan be connected to an stm device at run time.Cc: linux-api@vger.kernel.orgReviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> List of files: /linux-6.15/Documentation/ABI/testing/sysfs-class-stm_source Tue, 22 Sep 2015 12:47:10 +0000 Alexander Shishkin <alexander.shishkin@linux.intel.com>