diff options
Diffstat (limited to 'Documentation/powerpc/firmware-assisted-dump.rst')
| -rw-r--r-- | Documentation/powerpc/firmware-assisted-dump.rst | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/Documentation/powerpc/firmware-assisted-dump.rst b/Documentation/powerpc/firmware-assisted-dump.rst index 0455a78486d5..e363fc48529a 100644 --- a/Documentation/powerpc/firmware-assisted-dump.rst +++ b/Documentation/powerpc/firmware-assisted-dump.rst @@ -112,13 +112,13 @@ 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 + exported as /sys/firmware/opal/mpipl/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. + '1' to /sys/firmware/opal/mpipl/release_core node. e.g. - # echo 1 > /sys/kernel/fadump_release_opalcore + # echo 1 > /sys/firmware/opal/mpipl/release_core Implementation details: ----------------------- @@ -171,7 +171,7 @@ that were present in CMA region:: (meta area) | | | - Metadata: This area holds a metadata struture whose + Metadata: This area holds a metadata structure whose address is registered with f/w and retrieved in the second kernel after crash, on platforms that support tags (OPAL). Having such structure with info needed @@ -207,7 +207,7 @@ Currently the dump will be copied from /proc/vmcore to a new file upon user intervention. The dump data available through /proc/vmcore will be in ELF format. Hence the existing kdump infrastructure (kdump scripts) to save the dump works fine with minor modifications. KDump scripts on -major Distro releases have already been modified to work seemlessly (no +major Distro releases have already been modified to work seamlessly (no user intervention in saving the dump) when FADump is used, instead of KDump, as dump mechanism. @@ -268,6 +268,11 @@ Here is the list of files under kernel sysfs: be handled and vmcore will not be captured. This interface can be easily integrated with kdump service start/stop. + /sys/kernel/fadump/mem_reserved + + This is used to display the memory reserved by FADump for saving the + crash dump. + /sys/kernel/fadump_release_mem This file is available only when FADump is active during second kernel. This is used to release the reserved memory @@ -283,14 +288,29 @@ 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 +Note: /sys/kernel/fadump_release_opalcore sysfs has moved to + /sys/firmware/opal/mpipl/release_core + + /sys/firmware/opal/mpipl/release_core 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 + used by the kernel to export /sys/firmware/opal/mpipl/core file. To release this memory, echo '1' to it: - echo 1 > /sys/kernel/fadump_release_opalcore + echo 1 > /sys/firmware/opal/mpipl/release_core + +Note: The following FADump sysfs files are deprecated. + ++----------------------------------+--------------------------------+ +| Deprecated | Alternative | ++----------------------------------+--------------------------------+ +| /sys/kernel/fadump_enabled | /sys/kernel/fadump/enabled | ++----------------------------------+--------------------------------+ +| /sys/kernel/fadump_registered | /sys/kernel/fadump/registered | ++----------------------------------+--------------------------------+ +| /sys/kernel/fadump_release_mem | /sys/kernel/fadump/release_mem | ++----------------------------------+--------------------------------+ Here is the list of files under powerpc debugfs: (Assuming debugfs is mounted on /sys/kernel/debug directory.) @@ -324,7 +344,7 @@ Here is the list of files under powerpc debugfs: NOTE: - Please refer to Documentation/filesystems/debugfs.txt on + Please refer to Documentation/filesystems/debugfs.rst on how to mount the debugfs filesystem. |