linux.git/include/linux/coresight.h, branch v5.7-rc2

coresight: cti: Enable CTI associated with devices

2020-03-21T10:32:20+00:00

The CoreSight subsystem enables a path of devices from source to sink.
Any CTI devices associated with the path devices must be enabled at the
same time.

This patch adds an associated coresight_device element to the main
coresight device structure, and uses this to create associations between
the CTI and other devices based on the device tree data. The associated
device element is used to enable CTI in conjunction with the path elements.

CTI devices are reference counted so where a single CTI is associated with
multiple elements on the path, it will be enabled on the first associated
device enable, and disabled with the last associated device disable.

Signed-off-by: Mike Leach 
Reviewed-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Link: https://lore.kernel.org/r/20200320165303.13681-9-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman

coresight: cti: Initial CoreSight CTI Driver

2020-03-21T10:32:18+00:00

This introduces a baseline CTI driver and associated configuration files.

Uses the platform agnostic naming standard for CoreSight devices, along
with a generic platform probing method that currently supports device
tree descriptions, but allows for the ACPI bindings to be added once these
have been defined for the CTI devices.

Driver will probe for the device on the AMBA bus, and load the CTI driver
on CoreSight ID match to CTI IDs in tables.

Initial sysfs support for enable / disable provided.

Default CTI interconnection data is generated based on hardware
register signal counts, with no additional connection information.

Signed-off-by: Mike Leach 
Reviewed-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Link: https://lore.kernel.org/r/20200320165303.13681-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman

coresight: etm4x: Save/restore state across CPU low power states

2019-11-04T20:57:51+00:00

Some hardware will ignore bit TRCPDCR.PU which is used to signal
to hardware that power should not be removed from the trace unit.
Let's mitigate against this by conditionally saving and restoring
the trace unit state when the CPU enters low power states.

This patchset introduces a firmware property named
'arm,coresight-loses-context-with-cpu' - when this is present the
hardware state will be conditionally saved and restored.

A module parameter 'pm_save_enable' is also introduced which can
be configured to override the firmware property. This can be set
to never allow save/restore or to conditionally allow it (only for
self-hosted). The default value is determined by firmware.

We avoid saving the hardware state when self-hosted coresight isn't
in use to reduce PM latency - we can't determine this by reading the
claim tags (TRCCLAIMCLR) as these are 'trace' registers which need
power and clocking, something we can't easily provide in the PM
context. Therefore we rely on the existing drvdata->mode internal
state that is set when self-hosted coresight is used (and powered).

Signed-off-by: Andrew Murray 
Reviewed-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Link: https://lore.kernel.org/r/20191104181251.26732-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman

coresight: Use platform agnostic names

2019-06-20T05:56:13+00:00

So far we have reused the name of the "platform" device for
the CoreSight device. But this is not very intuitive when
we move to ACPI. Also, the ACPI device names have ":" in them
(e.g, ARMHC97C:01), which the perf tool doesn't like very much.
This patch introduces a generic naming scheme, givin more intuitive
names for the devices that appear on the CoreSight bus.
The names follow the pattern "prefix" followed by "index" (e.g, etm5).
We maintain a list of allocated devices per "prefix" to make sure
we don't allocate a new name when it is reprobed (e.g, due to
unsatisifed device dependencies). So, we maintain the list
of "fwnodes" of the parent devices to allocate a consistent name.
All devices except the ETMs get an index allocated in the order
of probing. ETMs get an index based on the CPU they are attached to.

TMC devices are named using "tmc_etf", "tmc_etb", and "tmc_etr"
prefixes depending on the configuration of the device.

The replicators and funnels are not classified as dynamic/static
anymore. One could easily figure that out by checking the presence
of "mgmt" registers under sysfs.

Signed-off-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman

coresight: Use fwnode handle instead of device names

2019-06-20T05:56:13+00:00

We rely on the device names to find a CoreSight device on the
coresight bus. The device name however is obtained from the platform,
which is bound to the real platform/amba device. As we are about
to use different naming scheme for the coresight devices, we can't
rely on the platform device name to find the corresponding
coresight device. Instead we use the platform agnostic
"fwnode handle" of the parent device to find the devices.
We also reuse the same fwnode as the parent for the Coresight
device we create.

Signed-off-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman

coresight: Reuse platform data structure for connection tracking

2019-06-20T05:56:12+00:00

The platform specific information describes the connections and
the ports of a given coresigh device. This information is also
recorded in the coresight device as separate fields. Let us reuse
the original platform description to streamline the handling
of the data.

Signed-off-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman

coresight: Remove name from platform description

2019-06-20T05:56:12+00:00

We are about to use a name independent of the parent AMBA device
name. As such, there is no need to have it in the platform description.
Let us move this to coresight description instead.

Signed-off-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman

coresight: Remove cpu field from platform data

2019-06-20T05:56:12+00:00

CPU field is only used by ETMs and there is a separate API
for fetching the same. So, let us use that instead of using
the common platform probing helper. Also, remove it from the
platform_data.

Signed-off-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman

coresight: Make device to CPU mapping generic

2019-06-20T05:56:11+00:00

The CoreSight components ETM and CPU-Debug are always associated
with CPUs. Replace the of_coresight_get_cpu() with a platform
agnostic helper, in preparation to add ACPI support.

Signed-off-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman

coresight: Introduce generic platform data helper

2019-06-20T05:56:11+00:00

So far we have hard coded the DT platform parsing code in
every driver. Introduce generic helper to parse the information
provided by the firmware in a platform agnostic manner, in preparation
for the ACPI support.

Signed-off-by: Suzuki K Poulose 
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman