From 6a6efbb45b7d95c84840010095367eb06a64f342 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Fri, 22 Apr 2016 12:25:34 +0100 Subject: [PATCH] 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 Cc: Mark Rutland Cc: Andre Przywara Reviewed-by: Catalin Marinas Signed-off-by: Suzuki K Poulose Signed-off-by: Will Deacon --- 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 d39db6387746..224efe730e46 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 2fdecd72ce58..d42789499f17 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 2b09dc477178..811773d1c1d0 100644 --- 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()) -- 2.39.5