Commit c8b89f40 authored by Mark Brown's avatar Mark Brown Committed by Jie Liu
Browse files

arm64/booting: Document boot requirements for FEAT_NMI 

kunpeng inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I90N2C
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc.git/commit/?h=arm64-nmi&id=1ae51a93c0f3b34c9cb85aa29d4113bab5c5c440



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In order to use FEAT_NMI we must be able to use ALLINT, require that it
behave as though not trapped when it is present.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarJie Liu <liujie375@h-partners.com>
parent d4a92cc8

Documentation/arch/arm64/booting.rst

+6 −0
Original line number Diff line number Diff line
@@ -411,6 +411,12 @@ Before jumping into the kernel, the following conditions must be met: 


    - HFGRWR_EL2.nPIRE0_EL1 (bit 57) must be initialised to 0b1.



 For CPUs with Non-maskable Interrupts (FEAT_NMI):



 - If the kernel is entered at EL1 and EL2 is present:



   - HCRX_EL2.TALLINT must be initialised to 0b0.



The requirements described above for CPU mode, caches, MMUs, architected

timers, coherency and system registers apply to all CPUs.  All CPUs must

enter the kernel in the same exception level.  Where the values documented