[PATCH v2 1/2] arm64: booting: Document our requirements for fine grained traps with SME

[Mark Brown]

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>
Reviewed-by: Oliver Upton <oliver.upton at linux.dev>
Acked-by: Catalin Marinas <catalin.marinas at arm.com>
---
 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