write_bm_pid_to_resctrl() uses resctrl_val to check test name which is
not a good interface generic resctrl FS functions should provide.

Tests define mongrp when needed. Remove the test name check in
write_bm_pid_to_resctrl() to only rely on the mongrp parameter being
non-NULL.

Remove write_bm_pid_to_resctrl() resctrl_val parameter and resctrl_val
member from the struct resctrl_val_param that are not used anymore.
Similarly, remove the test name constants that are no longer used.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The struct resctrl_val_param has control and monitor groups as char
arrays but they are not supposed to be mutated within resctrl_val().

Convert the ctrlgrp and mongrp char array within resctrl_val_param to
plain const char pointers and adjust the strlen() based checks to
check NULL instead.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Control group, monitor group and resctrl_val are not mutated and
should not be mutated within resctrlfs.c functions.

Mark this by using const char * for the arguments.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

bw_report is only needed for selecting the correct value from the
values IMC measured. It is a member in the resctrl_val_param struct and
is always set to "reads". The value is then checked in resctrl_val()
using validate_bw_report_request() that besides validating the input,
assumes it can mutate the string which is questionable programming
practice.

Simplify handling bw_report:

- Convert validate_bw_report_request() into get_bw_report_type() that
  inputs and returns const char *. Use NULL to indicate error.

- Validate the report types inside measure_mem_bw(), not in
  resctrl_val().

- Pass bw_report to measure_mem_bw() from ->measure() hook because
  resctrl_val() no longer needs bw_report for anything.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

A few functions receive PIDs through int arguments. PIDs variables
should be of type pid_t, not int.

Convert pid arguments from int to pid_t.

Before printing PID, match the type to %d by casting to int which is
enough for Linux (standard would allow using a longer integer type but
generalizing for that would complicate the code unnecessarily, the
selftest code does not need to be portable).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Resctrl selftests refer to "bandwidth" currently in two other forms in
the code ("B/W" and "band width").

Use "bandwidth" consistently everywhere. While at it, fix also one
"over flow" -> "overflow" on a line that is touched by the change.

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Feature checking done by resctrl_mon_feature_exists() covers features
represented by the feature name presence inside the 'mon_features' file
in /sys/fs/resctrl/info/L3_MON directory. There exists a different way
to represent feature support and that is by the presence of 0 or 1 in a
single file in the info/resource directory. In this case the filename
represents what feature support is being indicated.

Add a generic function to check file presence in the
/sys/fs/resctrl/info/<RESOURCE> directory.

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

validate_resctrl_feature_request() is used to test both if a resource is
present in the info directory, and if a passed monitoring feature is
present in the mon_features file.

Refactor validate_resctrl_feature_request() into two smaller functions
that each accomplish one check to give feature checking more
granularity:
- Resource directory presence in the /sys/fs/resctrl/info directory.
- Feature name presence in the /sys/fs/resctrl/info/<RESOURCE>/mon_features
  file.

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The CAT non-contiguous selftests have to read the file responsible for
reporting support of non-contiguous CBMs in kernel (resctrl). Then the
test compares if that information matches what is reported by CPUID
output.

Add a generic helper function to read an unsigned number from
/sys/fs/resctrl/info/<RESOURCE>/<FILE>.

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Domain id is acquired differently depending on CPU. AMD tests use id
from L3 cache, whereas CPUs from other vendors base the id on topology
package id. In order to support L2 CAT test, this has to be
generalized.

The driver side code seems to get the domain ids from cache ids so the
approach used by the AMD branch seems to match the kernel-side code. It
will also work with L2 domain IDs as long as the cache level is
generalized.

Using the topology id was always fragile due to mismatch with the
kernel-side way to acquire the domain id. It got incorrect domain id,
e.g., when Cluster-on-Die (CoD) is enabled for CPU (but CoD is not well
suited for resctrl in the first place so it has not been a big issue if
tests don't work correctly with it).

Taking all the above into account, generalize acquiring the domain id
by taking it from the cache id and do not hard-code the cache level.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>