Change DEFINE_SEMAPHORE() to take a number argument

Fundamentally semaphores are a counted primitive, but
DEFINE_SEMAPHORE() does not expose this and explicitly creates a
binary semaphore.

Change DEFINE_SEMAPHORE() to take a number argument and use that in the
few places that open-coded it using __SEMAPHORE_INITIALIZER().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[mcgrof: add some tribal knowledge about why some folks prefer
binary sempahores over mutexes]
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

platform/x86/intel/ifs: Sysfs interface for Array BIST

The interface to trigger Array BIST test and obtain its result
is similar to the existing scan test. The only notable
difference is that, Array BIST doesn't require any test content
to be loaded. So binary load related options are not needed for
this test.

Add sysfs interface for array BIST test, the testing support will
be added by subsequent patch.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20230322003359.213046-7-jithu.joseph@intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86/intel/ifs: IFS cleanup

Cleanup incorporating misc review comments

- Remove the subdirectory intel_ifs/0 for devicenode [1]
- Make plat_ifs_groups non static and use it directly without using a
function [2]

Link: https://lore.kernel.org/lkml/Y+4kQOtrHt5pdsSO@kroah.com/ [1]
Link: https://lore.kernel.org/lkml/Y9nyxNesVHCUXAcH@kroah.com/ [2]

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230322003359.213046-4-jithu.joseph@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86/intel/ifs: Add current_batch sysfs entry

Initial implementation assumed a single IFS test image file with a
fixed name ff-mm-ss.scan. (where ff, mm, ss refers to family, model and
stepping of the core).

Subsequently, it became evident that supporting more than one test
image file is needed to provide more comprehensive test coverage. (Test
coverage in this scenario refers to testing more transistors in the core
to identify faults).

The other alternative of increasing the size of a single scan test image
file would not work as the upper bound is limited by the size of memory
area reserved by BIOS for loading IFS test image.

Introduce "current_batch" file which accepts a number. Writing a
number to the current_batch file would load the test image file by
name ff-mm-ss-<xy>.scan, where <xy> is the number written to the
"current_batch" file in hex. Range check of the input is done to verify
it not greater than 0xff.

For e.g if the scan test image comprises of 6 files, they would be named:

06-8f-06-01.scan
06-8f-06-02.scan
06-8f-06-03.scan
06-8f-06-04.scan
06-8f-06-05.scan
06-8f-06-06.scan

And writing 3 to current_batch would result in loading 06-8f-06-03.scan
above. The file can also be read to know the currently loaded file.

And testing a system looks like:

for each scan file
do
load the IFS test image file (write to the batch file)
for each core
do
test the core with this set of tests
done
done

Qualify few error messages with the test image file suffix to provide
better context.

[ bp: Massage commit message. Add link to the discussion. ]

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221107225323.2733518-13-jithu.joseph@intel.com

platform/x86/intel/ifs: Remove reload sysfs entry

Reload sysfs entry will be replaced by current_batch, drop it.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-14-jithu.joseph@intel.com

platform/x86/intel/ifs: Remove image loading during init

IFS test image is unnecessarily loaded during driver initialization.
Drop image loading during ifs_init() and improve module load time. With
this change, user has to load one when starting the tests.

As a consequence, make ifs_sem static as it is only used within sysfs.c

Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-4-jithu.joseph@intel.com

platform/x86/intel/ifs: Add IFS sysfs interface

Implement sysfs interface to trigger ifs test for a specific cpu.
Additional interfaces related to checking the status of the
scan test and seeing the version of the loaded IFS binary
are also added.

The basic usage is as below.
- To start test, for example on cpu5:
echo 5 > /sys/devices/platform/intel_ifs/run_test
- To see the status of the last test
cat /sys/devices/platform/intel_ifs/status
- To see the version of the loaded scan binary
cat /sys/devices/platform/intel_ifs/image_version

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-10-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>