Commit 39533e12 authored Jul 16, 2020 by Marc Zyngier Committed by Will Deacon Sep 29, 2020

arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUs



Commit 606f8e7b ("arm64: capabilities: Use linear array for
detection and verification") changed the way we deal with per-CPU errata
by only calling the .matches() callback until one CPU is found to be
affected. At this point, .matches() stop being called, and .cpu_enable()
will be called on all CPUs.

This breaks the ARCH_WORKAROUND_2 handling, as only a single CPU will be
mitigated.

In order to address this, forcefully call the .matches() callback from a
.cpu_enable() callback, which brings us back to the original behaviour.

Fixes: 606f8e7b ("arm64: capabilities: Use linear array for detection and verification")
Cc: <stable@vger.kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

parent 18fce561

arch/arm64/kernel/cpu_errata.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -457,6 +457,12 @@ out_printmsg:
		return required;
		}

		static void cpu_enable_ssbd_mitigation(const struct arm64_cpu_capabilities *cap)
		{
		if (ssbd_state != ARM64_SSBD_FORCE_DISABLE)
		cap->matches(cap, SCOPE_LOCAL_CPU);
		}

		/* known invulnerable cores */
		static const struct midr_range arm64_ssb_cpus[] = {
		MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
		@@ -914,6 +920,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
		.capability = ARM64_SSBD,
		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
		.matches = has_ssbd_mitigation,
		.cpu_enable = cpu_enable_ssbd_mitigation,
		.midr_range_list = arm64_ssb_cpus,
		},
		#ifdef CONFIG_ARM64_ERRATUM_1418040

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