wireguard-linux/arch/powerpc/kernel/fadump.c, branch jd/unified-crypt-queue

powerpc/kernel: no need to check return value of debugfs_create functions

2020-03-04T11:44:25Z

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200209105901.1620958-1-gregkh@linuxfoundation.org

powerpc/fadump: sysfs for fadump memory reservation

2020-02-19T11:46:07Z

Add a sys interface to allow querying the memory reserved by FADump for saving the crash dump. Also added Documentation/ABI for the new sysfs file. Signed-off-by: Sourabh Jain Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191211160910.21656-7-sourabhjain@linux.ibm.com

powerpc/fadump: Reorganize /sys/kernel/fadump_* sysfs files

2020-02-19T10:07:09Z

As the number of FADump sysfs files increases it is hard to manage all of them inside /sys/kernel directory. It's better to have all the FADump related sysfs files in a dedicated directory /sys/kernel/fadump. But in order to maintain backward compatibility a symlink has been added for every sysfs that has moved to new location. As the FADump sysfs files are now part of a dedicated directory there is no need to prefix their name with fadump_, hence sysfs file names are also updated. For example fadump_enabled sysfs file is now referred as enabled. Also consolidate ABI documentation for all the FADump sysfs files in a single file Documentation/ABI/testing/sysfs-kernel-fadump. Signed-off-by: Sourabh Jain Tested-by: Michal Suchanek Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191211160910.21656-4-sourabhjain@linux.ibm.com

powerpc/fadump: when fadump is supported register the fadump sysfs files.

2019-11-13T05:58:11Z

Currently it is not possible to distinguish the case when fadump is supported by firmware and disabled in kernel and completely unsupported using the kernel sysfs interface. User can investigate the devicetree but it is more reasonable to provide sysfs files in case we get some fadumpv2 in the future. With this patch sysfs files are available whenever fadump is supported by firmware. There is duplicate message about lack of support by firmware in fadump_reserve_mem and setup_fadump. Remove the duplicate message in setup_fadump. Signed-off-by: Michal Suchanek Reviewed-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191107164757.15140-1-msuchanek@suse.de

powerpc/fadump: support holes in kernel boot memory area

2019-09-13T14:04:46Z

With support to copy multiple kernel boot memory regions owing to copy size limitation, also handle holes in the memory area to be preserved. Support as many as 128 kernel boot memory regions. This allows having an adequate FADump capture kernel size for different scenarios. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821385448.5656.6124791213910877759.stgit@hbathini.in.ibm.com

powerpc/fadump: remove RMA_START and RMA_END macros

2019-09-13T14:04:46Z

RMA_START is defined as '0' and there is even a BUILD_BUG_ON() to make sure it is never anything else. Remove this macro and use '0' instead as code change is needed anyway when it has to be something else. Also, remove unused RMA_END macro. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821384096.5656.15026984053970204652.stgit@hbathini.in.ibm.com

powerpc/fadump: consider f/w load area

2019-09-13T14:04:45Z

OPAL loads kernel & initrd at 512MB offset (256MB size), also exported as ibm,opal/dump/fw-load-area. So, if boot memory size of FADump is less than 768MB, kernel memory to be exported as '/proc/vmcore' would be overwritten by f/w while loading kernel & initrd. To avoid such a scenario, enforce a minimum boot memory size of 768MB on OPAL platform and skip using FADump if a newer F/W version loads kernel & initrd above 768MB. Also, irrespective of RMA size, set the minimum boot memory size expected on pseries platform at 320MB. This is to avoid inflating the minimum memory requirements on systems with 512M/1024M RMA size. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821381414.5656.1592867278535469652.stgit@hbathini.in.ibm.com

powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel

2019-09-13T14:04:45Z

Add a new kernel config option, CONFIG_PRESERVE_FA_DUMP that ensures that crash data, from previously crash'ed kernel, is preserved. This helps in cases where FADump is not enabled but the subsequent memory preserving kernel boot is likely to process this crash data. One typical usecase for this config option is petitboot kernel. As OPAL allows registering address with it in the first kernel and retrieving it after MPIPL, use it to store the top of boot memory. A kernel that intends to preserve crash data retrieves it and avoids using memory beyond this address. Move arch_reserved_kernel_pages() function as it is needed for both FA_DUMP and PRESERVE_FA_DUMP configurations. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821375751.5656.11459483669542541602.stgit@hbathini.in.ibm.com

powerpc/fadump: improve how crashed kernel's memory is reserved

2019-09-13T14:04:45Z

The size parameter to fadump_reserve_crash_area() function is not needed as all the memory above boot memory size must be preserved anyway. Update the function by dropping this redundant parameter. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821374440.5656.2945512543806951766.stgit@hbathini.in.ibm.com

powerpc/fadump: consider reserved ranges while releasing memory

2019-09-13T14:04:44Z

Commit 0962e8004e97 ("powerpc/prom: Scan reserved-ranges node for memory reservations") enabled support to parse 'reserved-ranges' DT node to reserve kernel memory falling in these ranges for firmware purposes. Along with the preserved area memory, ensure memory in reserved ranges is not overlapped with memory released by capture kernel aftering saving vmcore. Also, fix the off-by-one error in fadump_release_reserved_area function while releasing memory. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821371358.5656.6061214942558818661.stgit@hbathini.in.ibm.com