diff options
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index e8f6dfba1973..9cc198e81613 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -415,23 +415,33 @@ static void __init sort_ftr_regs(void) /* * Initialise the CPU feature register from Boot CPU values. * Also initiliases the strict_mask for the register. + * Any bits that are not covered by an arm64_ftr_bits entry are considered + * RES0 for the system-wide value, and must strictly match. */ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new) { u64 val = 0; u64 strict_mask = ~0x0ULL; + u64 valid_mask = 0; + const struct arm64_ftr_bits *ftrp; struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg); BUG_ON(!reg); for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) { + u64 ftr_mask = arm64_ftr_mask(ftrp); s64 ftr_new = arm64_ftr_value(ftrp, new); val = arm64_ftr_set_value(ftrp, val, ftr_new); + + valid_mask |= ftr_mask; if (!ftrp->strict) - strict_mask &= ~arm64_ftr_mask(ftrp); + strict_mask &= ~ftr_mask; } + + val &= valid_mask; + reg->sys_val = val; reg->strict_mask = strict_mask; } |