@@ -105,6 +105,10 @@ struct arm64_cpu_capabilities {
struct { /* To be used for erratum handling only */
u32 midr_model;
u32 midr_range_min, midr_range_max;
+ const struct arm64_midr_revidr {
+ u32 midr_rv; /* revision/variant */
+ u32 revidr_mask;
+ } * const fixed_revs;
};
struct { /* Feature register checking */
@@ -24,10 +24,22 @@
static bool __maybe_unused
is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
{
+ const struct arm64_midr_revidr *fix;
+ u32 midr = read_cpuid_id(), revidr;
+
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
- return MIDR_IS_CPU_MODEL_RANGE(read_cpuid_id(), entry->midr_model,
- entry->midr_range_min,
- entry->midr_range_max);
+ if (!MIDR_IS_CPU_MODEL_RANGE(midr, entry->midr_model,
+ entry->midr_range_min,
+ entry->midr_range_max))
+ return false;
+
+ midr &= MIDR_REVISION_MASK | MIDR_VARIANT_MASK;
+ revidr = read_cpuid(REVIDR_EL1);
+ for (fix = entry->fixed_revs; fix && fix->revidr_mask; fix++)
+ if (midr == fix->midr_rv && (revidr & fix->revidr_mask))
+ return false;
+
+ return true;
}
static bool __maybe_unused
@@ -242,6 +254,9 @@ static int qcom_enable_link_stack_sanitization(void *data)
.midr_range_min = 0, \
.midr_range_max = (MIDR_VARIANT_MASK | MIDR_REVISION_MASK)
+#define MIDR_FIXED(rev, revidr_mask) \
+ .fixed_revs = (struct arm64_midr_revidr[]){{ (rev), (revidr_mask) }, {}}
+
const struct arm64_cpu_capabilities arm64_errata[] = {
#if defined(CONFIG_ARM64_ERRATUM_826319) || \
defined(CONFIG_ARM64_ERRATUM_827319) || \
In some cases, core variants that are affected by a certain erratum also exist in versions that have the erratum fixed, and this fact is recorded in a dedicated bit in system register REVIDR_EL1. Since the architecture does not require that a certain bit retains its meaning across different variants of the same model, each such REVIDR bit is tightly coupled to a certain revision/variant value, and so we need a list of revidr_mask/midr pairs to carry this information. So add the struct member and the associated macros and handling to allow REVIDR fixes to be taken into account. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/include/asm/cpufeature.h | 4 ++++ arch/arm64/kernel/cpu_errata.c | 21 +++++++++++++++++--- 2 files changed, 22 insertions(+), 3 deletions(-)