[PATCH 06/17] arm64/booting: Document boot requirements for FEAT_NMI

[Jinjie Ruan]

From: Mark Brown <broonie@xxxxxxxxxx>

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: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221112151708.175147-2-broonie@xxxxxxxxxx
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
 Documentation/arch/arm64/booting.rst | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst
index 13ef311dace8..aaabe8fa4cdd 100644
--- a/Documentation/arch/arm64/booting.rst
+++ b/Documentation/arch/arm64/booting.rst
@@ -419,6 +419,12 @@ Before jumping into the kernel, the following conditions must be met:
 
     - HCR_EL2.ATA (bit 56) 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.
+
   For CPUs with the Scalable Matrix Extension version 2 (FEAT_SME2):
 
   - If EL3 is present:
-- 
2.34.1