| Message ID | 20240213-arm64-fp-init-vec-cr-v1-2-7e7c2d584f26@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64/fp: Initialise all bits in vector control registers to known values | expand |
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index cc3c9ad877a8..f96907b813fa 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1247,6 +1247,9 @@ void cpu_enable_sme(const struct arm64_cpu_capabilities *__always_unused p) write_sysreg(read_sysreg(CPACR_EL1) | CPACR_EL1_SMEN_EL1EN, CPACR_EL1); isb(); + /* Ensure all bits in SMCR are set to known values */ + write_sysreg_s(0, SYS_SMCR_EL1); + /* Allow EL0 to access TPIDR2 */ write_sysreg(read_sysreg(SCTLR_EL1) | SCTLR_ELx_ENTP2, SCTLR_EL1); isb();
At present nothing in our CPU initialisation code ever sets unknown fields in SMCR_EL1 to known values, all updates to SMCR_EL1 are read/modify/write sequences. All the unknown fields are RES0, explicitly initialise them as such to avoid future surprises. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/kernel/fpsimd.c | 3 +++ 1 file changed, 3 insertions(+)