[PATCH v1 1/2] arm64: booting: Document our requirements for fine grained traps with SME
Mark Brown
broonie at kernel.org
Thu Oct 27 14:04:39 PDT 2022
With SME we require that fine grained traps on access to TPIDR2_EL0 and
SMPRI_EL1 are disabled but did not document that fact. Add the relevant
register bits.
Signed-off-by: Mark Brown <broonie at kernel.org>
---
Documentation/arm64/booting.rst | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
index 8aefa1001ae5..8c324ad638de 100644
--- a/Documentation/arm64/booting.rst
+++ b/Documentation/arm64/booting.rst
@@ -340,6 +340,14 @@ Before jumping into the kernel, the following conditions must be met:
- SMCR_EL2.LEN must be initialised to the same value for all CPUs the
kernel will execute on.
+ - HWFGRTR_EL2.nTPIDR2_EL0 (bit 55) must be initialised to 0b01.
+
+ - HWFGWTR_EL2.nTPIDR2_EL0 (bit 55) must be initialised to 0b01.
+
+ - HWFGRTR_EL2.nSMPRI_EL1 (bit 54) must be initialised to 0b01.
+
+ - HWFGWTR_EL2.nSMPRI_EL1 (bit 54) must be initialised to 0b01.
+
For CPUs with the Scalable Matrix Extension FA64 feature (FEAT_SME_FA64)
- If EL3 is present:
--
2.30.2
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