[RFC PATCH v3 0/8] arm64: Verify early CPU features

Suzuki K. Poulose
2015-12-09T09:57:45Z

This series adds support for verifying some of the cpufeatures
that are decided early in the boot process based on the boot
CPU and cannot be delayed until all the CPUs are up (e.g, ASIDBits
and may be VHE?). It also adds support for handling the failures
in booting the secondary CPUs which could not be synchronised
with the master CPU, otherwise.

It also adds one of the users of this early hook, check for ASIDBits.
The mm_context id is based on the ASIDBits width supported by the
boot CPU and is used early in the initialisation. So we need to make
sure that all the secondary CPUs supports the width reported by the
booting CPU, failing which we crash the system.

This series has been tested on Juno, Fast model by injecting smaller
ASIDBits and lack of page-size support.

Changes since V2:
- Add support for synchronising the booting status of a secondary
CPU. Added RFC Tag. Patch - 4
- Panic the system with incompatible ASIDBits

Suzuki K. Poulose (8):
arm64: Introduce cpu_die_early
arm64: Move cpu_die_early to smp.c
arm64: head.S : Change register usage
arm64: Handle early CPU boot failures
arm64: Enable CPU capability verification unconditionally
arm64: Add hook for checking early CPU features
arm64: Add helper for extracting ASIDBits
arm64: Ensure the secondary CPUs have safe ASIDBits size

arch/arm64/include/asm/cpufeature.h | 6 ---
arch/arm64/include/asm/mmu_context.h | 2 +
arch/arm64/include/asm/smp.h | 25 +++++++++++-
arch/arm64/kernel/asm-offsets.c | 3 ++
arch/arm64/kernel/cpufeature.c | 48 ++++++++--------------
arch/arm64/kernel/head.S | 22 ++++++++--
arch/arm64/kernel/smp.c | 73 +++++++++++++++++++++++++++++++++-
arch/arm64/mm/context.c | 52 ++++++++++++++++++------
8 files changed, 176 insertions(+), 55 deletions(-)

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1.7.9.5