diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2020-10-05 17:43:03 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-10-05 18:54:49 +0100 |
| commit | 353e228eb355be5a65a3c0996c774a0f46737fda (patch) | |
| tree | 1bd5619d6b4765e8dd452f4144e20e0bfe04dc94 /arch/arm64/include | |
| parent | 4dafc08d0ba4768e8540f49ab40c3ea26e40d554 (diff) | |
arm64: initialize per-cpu offsets earlier
The current initialization of the per-cpu offset register is difficult
to follow and this initialization is not always early enough for
upcoming instrumentation with KCSAN, where the instrumentation callbacks
use the per-cpu offset.
To make it possible to support KCSAN, and to simplify reasoning about
early bringup code, let's initialize the per-cpu offset earlier, before
we run any C code that may consume it. To do so, this patch adds a new
init_this_cpu_offset() helper that's called before the usual
primary/secondary start functions. For consistency, this is also used to
re-initialize the per-cpu offset after the runtime per-cpu areas have
been allocated (which can change CPU0's offset).
So that init_this_cpu_offset() isn't subject to any instrumentation that
might consume the per-cpu offset, it is marked with noinstr, preventing
instrumentation.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201005164303.21389-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/cpu.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h index 7faae6ff3ab4..d9d60b18e811 100644 --- a/arch/arm64/include/asm/cpu.h +++ b/arch/arm64/include/asm/cpu.h @@ -68,4 +68,6 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info); void update_cpu_features(int cpu, struct cpuinfo_arm64 *info, struct cpuinfo_arm64 *boot); +void init_this_cpu_offset(void); + #endif /* __ASM_CPU_H */ |