[PATCH v2 6/7] platform/x86/intel/ifs: Update IFS doc
From: Jithu Joseph
Date: Tue Feb 14 2023 - 18:46:17 EST
Array BIST is the second test supported by IFS. Modify IFS doc
entry to be more general.
Signed-off-by: Jithu Joseph <jithu.joseph@xxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
drivers/platform/x86/intel/ifs/ifs.h | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
index e5375191b56d..00bc86db1193 100644
--- a/drivers/platform/x86/intel/ifs/ifs.h
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -17,7 +17,7 @@
* In Field Scan (IFS) is a hardware feature to run circuit level tests on
* a CPU core to detect problems that are not caught by parity or ECC checks.
* Future CPUs will support more than one type of test which will show up
- * with a new platform-device instance-id, for now only .0 is exposed.
+ * with a new platform-device instance-id.
*
*
* IFS Image
@@ -25,7 +25,10 @@
*
* Intel provides a firmware file containing the scan tests via
* github [#f1]_. Similar to microcode there is a separate file for each
- * family-model-stepping.
+ * family-model-stepping. IFS Images are not applicable for some test types.
+ * Wherever applicable the sysfs directory would provide a "current_batch" file
+ * (see below) for loading the image.
+ *
*
* IFS Image Loading
* -----------------
@@ -35,7 +38,7 @@
* SHA hashes for the test. Then the tests themselves. Status MSRs provide
* feedback on the success/failure of these steps.
*
- * The test files are kept in a fixed location: /lib/firmware/intel/ifs_0/
+ * The test files are kept in a fixed location: /lib/firmware/intel/ifs_<n>/
* For e.g if there are 3 test files, they would be named in the following
* fashion:
* ff-mm-ss-01.scan
@@ -47,7 +50,7 @@
* (e.g 1, 2 or 3 in the above scenario) into the curent_batch file.
* To load ff-mm-ss-02.scan, the following command can be used::
*
- * # echo 2 > /sys/devices/virtual/misc/intel_ifs_0/current_batch
+ * # echo 2 > /sys/devices/virtual/misc/intel_ifs_<n>/current_batch
*
* The above file can also be read to know the currently loaded image.
*
@@ -69,16 +72,16 @@
* to migrate those applications to other cores before running a core test.
* It may also be necessary to redirect interrupts to other CPUs.
*
- * In all cases reading the SCAN_STATUS MSR provides details on what
+ * In all cases reading the corresponding test's STATUS MSR provides details on what
* happened. The driver makes the value of this MSR visible to applications
* via the "details" file (see below). Interrupted tests may be restarted.
*
- * The IFS driver provides sysfs interfaces via /sys/devices/virtual/misc/intel_ifs_0/
+ * The IFS driver provides sysfs interfaces via /sys/devices/virtual/misc/intel_ifs_<n>/
* to control execution:
*
* Test a specific core::
*
- * # echo <cpu#> > /sys/devices/virtual/misc/intel_ifs_0/run_test
+ * # echo <cpu#> > /sys/devices/virtual/misc/intel_ifs_<n>/run_test
*
* when HT is enabled any of the sibling cpu# can be specified to test
* its corresponding physical core. Since the tests are per physical core,
@@ -87,18 +90,18 @@
*
* For e.g. to test core corresponding to cpu5
*
- * # echo 5 > /sys/devices/virtual/misc/intel_ifs_0/run_test
+ * # echo 5 > /sys/devices/virtual/misc/intel_ifs_<n>/run_test
*
* Results of the last test is provided in /sys::
*
- * $ cat /sys/devices/virtual/misc/intel_ifs_0/status
+ * $ cat /sys/devices/virtual/misc/intel_ifs_<n>/status
* pass
*
* Status can be one of pass, fail, untested
*
* Additional details of the last test is provided by the details file::
*
- * $ cat /sys/devices/virtual/misc/intel_ifs_0/details
+ * $ cat /sys/devices/virtual/misc/intel_ifs_<n>/details
* 0x8081
*
* The details file reports the hex value of the SCAN_STATUS MSR.
--
2.25.1