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authorKristina Martsenko <[email protected]>2023-05-09 15:22:28 +0100
committerCatalin Marinas <[email protected]>2023-06-05 17:05:31 +0100
commitf32c053b9806e42209d40e9ce7ed6f7f8be3be3b (patch)
tree60c8af8e37a4e91287a3b7207fec31235b9fff07
parent306b4c9f7120c485607cbbfa1ac3ecec005d8231 (diff)
arm64: mops: document boot requirements for MOPS
FEAT_MOPS introduces new instructions, we require that these instructions not execute as UNDEFINED when we identify that the feature is supported. Signed-off-by: Kristina Martsenko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>
-rw-r--r--Documentation/arm64/booting.rst6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
index ffeccdd6bdac..b3bbf330ed0a 100644
--- a/Documentation/arm64/booting.rst
+++ b/Documentation/arm64/booting.rst
@@ -379,6 +379,12 @@ Before jumping into the kernel, the following conditions must be met:
- SMCR_EL2.EZT0 (bit 30) must be initialised to 0b1.
+ For CPUs with Memory Copy and Memory Set instructions (FEAT_MOPS):
+
+ - If the kernel is entered at EL1 and EL2 is present:
+
+ - HCRX_EL2.MSCEn (bit 11) must be initialised to 0b1.
+
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