CPU Errata work arounds are detected and applied to the
kernel code at boot time and the data is then freed up.
If a new hotplugged CPU requires a work around which
was not applied at boot time, there is nothing we can
do but simply fail the booting.
Cc: Will Deacon <will.dea...@arm.com>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Andre Przywara <andre.przyw...@arm.com>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
arch/arm64/include/asm/cpufeature.h | 1 +
arch/arm64/kernel/cpu_errata.c | 20 ++++++++++++++++++++
arch/arm64/kernel/cpufeature.c | 1 +
3 files changed, 22 insertions(+)
diff --git a/arch/arm64/include/asm/cpufeature.h
b/arch/arm64/include/asm/cpufeature.h
index d39db63..224efe7 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -193,6 +193,7 @@ void update_cpu_capabilities(const struct
arm64_cpu_capabilities *caps,
const char *info);
void check_local_cpu_errata(void);
+void verify_local_cpu_errata(void);
void verify_local_cpu_capabilities(void);
u64 read_system_reg(u32 id);
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 2fdecd7..d427894 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -103,6 +103,26 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
}
};
+/*
+ * The CPU Errata work arounds are detected and applied at boot time
+ * and the related information is freed soon after. If the new CPU requires
+ * an errata not detected at boot, fail this CPU.
+ */
+void verify_local_cpu_errata(void)
+{
+ const struct arm64_cpu_capabilities *caps = arm64_errata;
+
+ for (; caps->matches; caps++)
+ if (!cpus_have_cap(caps->capability) &&
+ caps->matches(caps, SCOPE_LOCAL_CPU)) {
+ pr_crit("CPU%d: Requires work around for %s, not
detected"
+ " at boot time\n",
+ smp_processor_id(),
+ caps->desc ? : "an erratum");
+ cpu_die_early();
+ }
+}
+
void check_local_cpu_errata(void)
{
update_cpu_capabilities(arm64_errata, "enabling workaround for");
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 79ec6c6..1cc3446 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -993,6 +993,7 @@ void verify_local_cpu_capabilities(void)
if (!sys_caps_initialised)
return;
+ verify_local_cpu_errata();
verify_local_cpu_features(arm64_features);
verify_local_elf_hwcaps(arm64_elf_hwcaps);
if (system_supports_32bit_el0())
--
1.7.9.5
