diff options
Diffstat (limited to 'arch/x86/kernel/cpu/cpuid-deps.c')
| -rw-r--r-- | arch/x86/kernel/cpu/cpuid-deps.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index df838e3bdbe0..a2fbea0be535 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -147,3 +147,38 @@ void setup_clear_cpu_cap(unsigned int feature) { do_clear_cpu_cap(NULL, feature); } + +/* + * Return the feature "name" if available, otherwise return + * the X86_FEATURE_* numerals to make it easier to identify + * the feature. + */ +static const char *x86_feature_name(unsigned int feature, char *buf) +{ + if (x86_cap_flags[feature]) + return x86_cap_flags[feature]; + + snprintf(buf, 16, "%d*32+%2d", feature / 32, feature % 32); + + return buf; +} + +void check_cpufeature_deps(struct cpuinfo_x86 *c) +{ + char feature_buf[16], depends_buf[16]; + const struct cpuid_dep *d; + + for (d = cpuid_deps; d->feature; d++) { + if (cpu_has(c, d->feature) && !cpu_has(c, d->depends)) { + /* + * Only warn about the first unmet dependency on the + * first CPU where it is encountered to avoid spamming + * the kernel log. + */ + pr_warn_once("x86 CPU feature dependency check failure: CPU%d has '%s' enabled but '%s' disabled. Kernel might be fine, but no guarantees.\n", + smp_processor_id(), + x86_feature_name(d->feature, feature_buf), + x86_feature_name(d->depends, depends_buf)); + } + } +} |