stm class: Add source type

Currently kernel HW tracing infrastrtucture and specifically its SyS-T
part treats all source data in the same way. Treating and encoding
different trace data sources diff

stm class: Add source type

Currently kernel HW tracing infrastrtucture and specifically its SyS-T
part treats all source data in the same way. Treating and encoding
different trace data sources differently might allow decoding software
to make use of e.g. ftrace event ids by converting them to a SyS-T
message catalog.

The solution is to keep source type stored within stm_source_data
structure to allow different handling by stm output/protocol.
Currently we only differentiate between STM_USER and STM_FTRACE sources.

Signed-off-by: Mikhail Lappo <[email protected]>
Signed-off-by: Alexander Shishkin <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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stm class: Spelling fix

Drop the repeated word "the" in a comment.

Cc: Alexander Shishkin <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Greg Kroah-Hartman <

stm class: Spelling fix

Drop the repeated word "the" in a comment.

Cc: Alexander Shishkin <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
[alexander.shishkin: fixed the commit message]
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Alexander Shishkin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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stm class: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate

This adds SPDX GPL-2.0 header to to stm core files and removes the
GPLv2 boilerplate text.

Signed-off-by: Alexander Shishkin <alexand

stm class: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate

This adds SPDX GPL-2.0 header to to stm core files and removes the
GPLv2 boilerplate text.

Signed-off-by: Alexander Shishkin <[email protected]>

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stm: Mark the functions of writing STM with notrace

If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be
writen to sink via STM, all functions that related to writing data
packets to

stm: Mark the functions of writing STM with notrace

If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be
writen to sink via STM, all functions that related to writing data
packets to STM should be marked 'notrace' to avoid being traced by
Ftrace, otherwise the program would stall into an endless loop.

Link: http://lkml.kernel.org/r/[email protected]

Signed-off-by: Chunyan Zhang <[email protected]>
Acked-by: Alexander Shishkin <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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stm class: Support devices that override software assigned masters

Some STM devices adjust software assigned master numbers depending on
the trace source and its runtime state and whatnot. This patc

stm class: Support devices that override software assigned masters

Some STM devices adjust software assigned master numbers depending on
the trace source and its runtime state and whatnot. This patch adds
a sysfs attribute to inform the trace-side software that master numbers
assigned to software sources will not match those in the STP stream,
so that, for example, master/channel allocation policy can be adjusted
accordingly.

Signed-off-by: Alexander Shishkin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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stm class: Plug stm device's unlink callback

STM device's unlink callback is never actually called from anywhere in
the stm class code.

This patch adds calls to stm driver's unlink method after the

stm class: Plug stm device's unlink callback

STM device's unlink callback is never actually called from anywhere in
the stm class code.

This patch adds calls to stm driver's unlink method after the unlinking
has succeeded.

Signed-off-by: Alexander Shishkin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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stm class: Use driver's packet callback return value

STM drivers provide a callback to generate/send individual STP packets;
it also tells the stm core how many bytes of payload it has consumed.
How

stm class: Use driver's packet callback return value

STM drivers provide a callback to generate/send individual STP packets;
it also tells the stm core how many bytes of payload it has consumed.
However, we would also need to use the negative space of this return
value to communicate errors that occur during the packet generation,
in which case the stm core will have to take appropriate action.

For now, we need to account for the possibility that the stm driver may
not support certain combinations of packet type/flags, in which case
it is expected to signal an error.

Signed-off-by: Alexander Shishkin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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stm class: Introduce an abstraction for System Trace Module devices

A System Trace Module (STM) is a device exporting data in System Trace
Protocol (STP) format as defined by MIPI STP standards. Exa

stm class: Introduce an abstraction for System Trace Module devices

A System Trace Module (STM) is a device exporting data in System Trace
Protocol (STP) format as defined by MIPI STP standards. Examples of such
devices are Intel(R) Trace Hub and Coresight STM.

This abstraction provides a unified interface for software trace sources
to send their data over an STM device to a debug host. In order to do
that, such a trace source needs to be assigned a pair of master/channel
identifiers that all the data from this source will be tagged with. The
STP decoder on the debug host side will use these master/channel tags to
distinguish different trace streams from one another inside one STP
stream.

This abstraction provides a configfs-based policy management mechanism
for dynamic allocation of these master/channel pairs based on trace
source-supplied string identifier. It has the flexibility of being
defined at runtime and at the same time (provided that the policy
definition is aligned with the decoding end) consistency.

For userspace trace sources, this abstraction provides write()-based and
mmap()-based (if the underlying stm device allows this) output mechanism.

For kernel-side trace sources, we provide "stm_source" device class that
can be connected to an stm device at run time.

Cc: [email protected]
Reviewed-by: Mathieu Poirier <[email protected]>
Signed-off-by: Alexander Shishkin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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