[0/2] arm64: E0PD support

Message

Mark Brown Aug. 12, 2019, 12:57 p.m. UTC

This series adds support for E0PD. We enable E0PD unconditionally where
present and on systems where all the CPUs in the system support E0PD we
will not automatically enable KPTI for KASLR. The integration with KPTI
is safe but not optimal for big.LITTLE systems where only some CPUs
support E0PD since for them it will still use KPTI even on the CPUs that
have E0PD, I've not yet come up with something I like for integrating
support for them with the command line overrides.

	arm64: Add initial support for E0PD
	arm64: Don't use KPTI where we have E0PD

 arch/arm64/Kconfig                     | 14 ++++++++++++++
 arch/arm64/include/asm/cpucaps.h       |  3 ++-
 arch/arm64/include/asm/pgtable-hwdef.h |  2 ++
 arch/arm64/include/asm/sysreg.h        |  1 +
 arch/arm64/kernel/cpufeature.c         | 29 ++++++++++++++++++++++++++++-
 5 files changed, 47 insertions(+), 2 deletions(-)