leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

arm64: smp: initialize cpu offset earlier

Browse Source 
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>
This commit is contained in:
Mark Rutland
2021-05-20 12:50:31 +01:00
committed by Will Deacon
parent 8e334d729b
commit 3d8c1a013d
4 changed files with 18 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm64/kernel/setup.c
View File

@@ -87,12 +87,6 @@ void __init smp_setup_processor_id(void)
u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
set_cpu_logical_map(0, mpidr);
/*
* clear __my_cpu_offset on boot CPU to avoid hang caused by
* using percpu variable early, for example, lockdep will
* access percpu variable inside lock_release
*/
set_my_cpu_offset(0);
pr_info("Booting Linux on physical CPU 0x%010lx [0x%08x]\n",
(unsigned long)mpidr, read_cpuid_id());
}