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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-09-28 21:11:18 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-10-21 01:02:27 +0300 |
| commit | 49f88c70edccf4c967697597e0b99072dc4007c2 (patch) | |
| tree | 44cec73cf352f8bd086272f080a19507db4249d2 /arch/x86/Kconfig | |
| parent | 36f65f1d1553e35cd9e6b281271f40d639a128c3 (diff) | |
| download | linux-49f88c70edccf4c967697597e0b99072dc4007c2.tar.xz | |
arch/x86: Add ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option
The x86 architecture uses an add-to-memory 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/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>
Cc: <x86@kernel.org>
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 6d1879ef933a..bcb3190eaa26 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -81,6 +81,7 @@ config X86 select ARCH_HAS_KCOV if X86_64 select ARCH_HAS_MEM_ENCRYPT select ARCH_HAS_MEMBARRIER_SYNC_CORE + select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PMEM_API if X86_64 select ARCH_HAS_PTE_DEVMAP if X86_64 |