| Message ID | 20221019225846.2501109-7-paulmck@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | a517e11556ac874eab897475a0e033bb70d30fe9 |
| Headers | show |
| Series | NMI-safe SRCU readers for v6.2 | expand |
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 903096bd87f88..386adde2feffb 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -10,6 +10,7 @@ config LOONGARCH select ARCH_ENABLE_MEMORY_HOTPLUG select ARCH_ENABLE_MEMORY_HOTREMOVE select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI + select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_INLINE_READ_LOCK if !PREEMPTION
The loongarch architecture uses the atomic read-modify-write amadd instruction to implement this_cpu_add(), which is 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/x86/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: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Ogness <john.ogness@linutronix.de> Cc: Petr Mladek <pmladek@suse.com> Cc: <loongarch@lists.linux.dev> --- arch/loongarch/Kconfig | 1 + 1 file changed, 1 insertion(+)