arm64: Verify CPU errata work arounds on hotplugged CPU

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.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index d39db638774673a2b2efe1bff2365118f0594ea5..224efe730e4614b4ffd6ab105bacf3de6d6890db 100644 (file)
--- 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 2fdecd72ce583ff1efd0b47db13d6ac834649547..d42789499f17eb322a47da83046ca0119e643c75 100644 (file)
--- 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 2b09dc47717895c255d4a6e541254d57cd39f232..811773d1c1d015ca8e47239f5375d3ced3c04b48 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -998,6 +998,7 @@ 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())