arm64: booting: Document our requirements for fine grained traps with SME

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@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221101112716.52035-2-broonie@kernel.org
This commit is contained in:
Mark Brown 2022-11-01 11:27:14 +00:00 committed by Marc Zyngier
parent 4151bb636a
commit be0ddf5293

View File

@ -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: