[PATCH v2 0/2] efi: arm64: Introduce /proc/efi/memreserve to tell the persistent pages

From: Masayoshi Mizuma
Date: Tue Dec 03 2019 - 15:14:51 EST


From: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>

kexec reboot sometime fails in early boot sequence on aarch64 machine.
That is because kexec overwrites the LPI property tables and pending
tables with the initrd.

To avoid the overwrite, introduce /proc/efi/memreserve to tell the
tables region to kexec so that kexec can avoid the memory region to
locate initrd.

kexec also needs a patch to handle /proc/efi/memreserve. I'm preparing
the patch for kexec.

Changelog
v2: - Change memreserve file location from sysfs to procfs.
memreserve may exceed the PAGE_SIZE in case efi_memreserve_root
has a lot of entries. So we cannot use sysfs_kf_seq_show().
Use seq_printf() in procfs instead.

Masayoshi Mizuma (2):
efi: add /proc/efi directory
efi: arm64: Introduce /proc/efi/memreserve to tell the persistent
pages

drivers/firmware/efi/efi.c | 93 +++++++++++++++++++++++++++++++++++++-
1 file changed, 92 insertions(+), 1 deletion(-)

--
2.18.1