[RESEND] [PATCH 0/8] arm64: Work around for mismatched cache line size

From: Suzuki K Poulose
Date: Thu Aug 18 2016 - 09:11:04 EST


This series adds a work around for systems with mismatched {I,D}-cache
line sizes. When a thread of execution gets migrated to a different CPU,
the cache line size it had cached could be larger than that of the new
CPU. This could cause data corruption issues. We work around this by

- Dynamically patching the kernel to use the smallest line size on the
system (from the CPU feature infrastructure)
- Trapping the userspace access to CTR_EL0 (by clearing SCTLR_EL1.UCT) and
emulating it with the system wide safe value of CTR.

The series also adds support for alternative code patching of adrp
instructions by adjusting the PC-relative address offset to reflect
the new PC.

The series has been tested on Juno with a hack to forced enabling
of the capability.

Applies on aarch64: for-next/core. The tree is avaiable at :

git://linux-arm.org/linux-skp.git ctr-emulation

Suzuki K Poulose (8):
arm64: Set the safe value for L1 icache policy
arm64: Use consistent naming for errata handling
arm64: Rearrange CPU errata workaround checks
arm64: insn: Add helpers for adrp offsets
arm64: alternative: Add support for patching adrp instructions
arm64: Introduce raw_{d,i}cache_line_size
arm64: Refactor sysinstr exception handling
arm64: Work around systems with mismatched cache line sizes

arch/arm64/include/asm/assembler.h | 45 +++++++++++++++++--
arch/arm64/include/asm/cpufeature.h | 14 +++---
arch/arm64/include/asm/esr.h | 56 ++++++++++++++++++++++++
arch/arm64/include/asm/insn.h | 4 ++
arch/arm64/include/asm/sysreg.h | 1 +
arch/arm64/kernel/alternative.c | 13 ++++++
arch/arm64/kernel/asm-offsets.c | 2 +
arch/arm64/kernel/cpu_errata.c | 26 ++++++++++-
arch/arm64/kernel/cpufeature.c | 44 ++++++++++++++-----
arch/arm64/kernel/cpuinfo.c | 2 -
arch/arm64/kernel/hibernate-asm.S | 2 +-
arch/arm64/kernel/insn.c | 13 ++++++
arch/arm64/kernel/relocate_kernel.S | 2 +-
arch/arm64/kernel/smp.c | 8 +++-
arch/arm64/kernel/traps.c | 87 ++++++++++++++++++++++++++-----------
15 files changed, 264 insertions(+), 55 deletions(-)

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2.7.4