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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-09-28 21:17:05 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-10-21 01:02:27 +0300 |
| commit | 6cc9203b8e325d0ef21a7dc345d04fdb50b52a8a (patch) | |
| tree | d3c4afea980996fd6fe3f96549e3fea2070ba843 /arch/arm64/Kconfig | |
| parent | 49f88c70edccf4c967697597e0b99072dc4007c2 (diff) | |
| download | linux-6cc9203b8e325d0ef21a7dc345d04fdb50b52a8a.tar.xz | |
arch/arm64: Add ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option
The arm64 architecture uses either an LL/SC loop (old systems) or an LSE
stadd instruction (new systems) to implement this_cpu_add(), both of which
are NMI safe. This means that the old and more-efficient srcu_read_lock()
may be used in NMI context, without the need for srcu_read_lock_nmisafe().
Therefore, add the new Kconfig option ARCH_HAS_NMI_SAFE_THIS_CPU_OPS to
arch/arm64/Kconfig, which will cause NEED_SRCU_NMI_SAFE to be deselected,
thus preserving the current srcu_read_lock() behavior.
Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/
Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Suggested-by: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Diffstat (limited to 'arch/arm64/Kconfig')
| -rw-r--r-- | arch/arm64/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 505c8a1ccbe0..099ee812f3f1 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -31,6 +31,7 @@ config ARM64 select ARCH_HAS_KCOV select ARCH_HAS_KEEPINITRD select ARCH_HAS_MEMBARRIER_SYNC_CORE + select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PTE_DEVMAP select ARCH_HAS_PTE_SPECIAL |