[PATCH ARM64 v4.4 V3 17/44] arm64: Verify CPU errata work arounds on hotplugged CPU
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: 2019-08-29 11:35:39
Also in:
stable
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
From: Suzuki K Poulose <suzuki.poulose@arm.com> commit 6a6efbb45b7d95c84840010095367eb06a64f342 upstream. 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 <redacted> 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 <redacted> [ Viresh: Resolved rebase conflict ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- arch/arm64/include/asm/cpufeature.h | 2 ++ arch/arm64/kernel/cpu_errata.c | 20 ++++++++++++++++++++ arch/arm64/kernel/cpufeature.c | 2 ++ 3 files changed, 24 insertions(+)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 4c31e14c0f0e..dd1aab8e52aa 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h@@ -173,6 +173,8 @@ 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); + #ifdef CONFIG_HOTPLUG_CPU void verify_local_cpu_capabilities(void); #else
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 0971d80d3623..a3567881c01b 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c@@ -116,6 +116,26 @@ 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 a0273cd8be51..9a4b638b1c18 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -872,6 +872,8 @@ void verify_local_cpu_capabilities(void) if (!sys_caps_initialised) return; + verify_local_cpu_errata(); + caps = arm64_features; for (i = 0; caps[i].matches; i++) { if (!cpus_have_cap(caps[i].capability) || !caps[i].sys_reg)
--
2.21.0.rc0.269.g1a574e7a288b
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