diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S index 2038f31..a0babb0 100644 --- a/lib/cpus/aarch64/neoverse_n1.S +++ b/lib/cpus/aarch64/neoverse_n1.S @@ -49,11 +49,31 @@ b cpu_rev_var_ls endfunc check_errata_1043202 +/* -------------------------------------------------- + * Disable speculative loads if Neoverse N1 supports + * SSBS. + * + * Shall clobber: x0. + * -------------------------------------------------- + */ +func neoverse_n1_disable_speculative_loads + /* Check if the PE implements SSBS */ + mrs x0, id_aa64pfr1_el1 + tst x0, #(ID_AA64PFR1_EL1_SSBS_MASK << ID_AA64PFR1_EL1_SSBS_SHIFT) + b.eq 1f + + /* Disable speculative loads */ + msr SSBS, xzr + isb + +1: + ret +endfunc neoverse_n1_disable_speculative_loads + func neoverse_n1_reset_func mov x19, x30 - /* Disables speculative loads */ - msr SSBS, xzr + bl neoverse_n1_disable_speculative_loads /* Forces all cacheable atomic instructions to be near */ mrs x0, NEOVERSE_N1_CPUACTLR2_EL1