diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2021-05-20 12:50:31 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-05-26 22:45:46 +0100 |
| commit | 3d8c1a013d78f32ee266097496cbd89b734b5fcb (patch) | |
| tree | 0d3c3057812148a28af6ba503a533e3acc7f9630 /arch/arm64/kernel/smp.c | |
| parent | 8e334d729bc4787f728e9e5abc91649f131124ff (diff) | |
arm64: smp: initialize cpu offset earlier
Now that we have a consistent place to initialize CPU context registers
early in the boot path, let's also initialize the per-cpu offset here.
This makes the primary and secondary boot paths more consistent, and
allows for the use of per-cpu operations earlier, which will be
necessary for instrumentation with KCSAN.
Note that smp_prepare_boot_cpu() still needs to re-initialize CPU0's
offset as immediately prior to this the per-cpu areas may be
reallocated, and hence the boot-time offset may be stale. A comment is
added to make this clear.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210520115031.18509-7-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/smp.c')
| -rw-r--r-- | arch/arm64/kernel/smp.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 73625cc39574..2fe8fab886e2 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -198,10 +198,7 @@ asmlinkage notrace void secondary_start_kernel(void) u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK; struct mm_struct *mm = &init_mm; const struct cpu_operations *ops; - unsigned int cpu; - - cpu = task_cpu(current); - set_my_cpu_offset(per_cpu_offset(cpu)); + unsigned int cpu = smp_processor_id(); /* * All kernel threads share the same mm context; grab a @@ -448,6 +445,11 @@ void __init smp_cpus_done(unsigned int max_cpus) void __init smp_prepare_boot_cpu(void) { + /* + * The runtime per-cpu areas have been allocated by + * setup_per_cpu_areas(), and CPU0's boot time per-cpu area will be + * freed shortly, so we must move over to the runtime per-cpu area. + */ set_my_cpu_offset(per_cpu_offset(smp_processor_id())); cpuinfo_store_boot_cpu(); |