[PATCH v4 25/25] powernv/fadump: update documentation about option to release opalcore
From: Hari Bathini <hbathini@linux.ibm.com>
Date: 2019-07-16 12:31:31
Subsystem:
documentation, the rest · Maintainers:
Jonathan Corbet, Linus Torvalds
With /sys/firmware/opal/core support available on OPAL based machines and an option to the release memory used by kernel in exporting this core file, update FADump documentation with these details. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> --- Documentation/powerpc/firmware-assisted-dump.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt
index 373a9fb..9933fa6 100644
--- a/Documentation/powerpc/firmware-assisted-dump.txt
+++ b/Documentation/powerpc/firmware-assisted-dump.txt@@ -107,6 +107,16 @@ capture kernel boot to process this crash data. Kernel config option CONFIG_PRESERVE_FA_DUMP has to be enabled on such kernel to ensure that crash data is preserved to process later. +-- On OPAL based machines (PowerNV), if the kernel is build with + CONFIG_OPAL_CORE=y, OPAL memory at the time of crash is also + exported as /sys/firmware/opal/core file. This procfs file is + helpful in debugging OPAL crashes with GDB. The kernel memory + used for exporting this procfs file can be released by echo'ing + '1' to /sys/kernel/fadump_release_opalcore node. + + e.g. + # echo 1 > /sys/kernel/fadump_release_opalcore + Implementation details: ----------------------
@@ -270,6 +280,15 @@ Here is the list of files under kernel sysfs: enhanced to use this interface to release the memory reserved for dump and continue without 2nd reboot. + /sys/kernel/fadump_release_opalcore + + This file is available only on OPAL based machines when FADump is + active during capture kernel. This is used to release the memory + used by the kernel to export /sys/firmware/opal/core file. To + release this memory, echo '1' to it: + + echo 1 > /sys/kernel/fadump_release_opalcore + Here is the list of files under powerpc debugfs: (Assuming debugfs is mounted on /sys/kernel/debug directory.)