[PATCH v4.4 V2 19/43] arm64: Run enable method for errata work arounds on late CPUs

From: Viresh Kumar <viresh.kumar@linaro.org>
To: stable@vger.kernel.org, Julien Thierry <Julien.Thierry@arm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Russell King <rmk+kernel@arm.linux.org.uk>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	mark.brown@arm.com
Subject: [PATCH v4.4 V2 19/43] arm64: Run enable method for errata work arounds on late CPUs
Date: Fri, 12 Jul 2019 10:58:07 +0530	[thread overview]
Message-ID: <3da005579bba7e4b225408b18c6aff7400933bd5.1562908075.git.viresh.kumar@linaro.org> (raw)
In-Reply-To: <cover.1562908074.git.viresh.kumar@linaro.org>

From: Suzuki K Poulose <suzuki.poulose@arm.com>

commit 55b35d070c2534dfb714b883f3c3ae05d02032da upstream.

When a CPU is brought up after we have finalised the system
wide capabilities (i.e, features and errata), we make sure the
new CPU doesn't need a new errata work around which has not been
detected already. However we don't run enable() method on the new
CPU for the errata work arounds already detected. This could
cause the new CPU running without potential work arounds.
It is upto the "enable()" method to decide if this CPU should
do something about the errata.

Fixes: commit 6a6efbb45b7d95c84 ("arm64: Verify CPU errata work arounds on hotplugged CPU")
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 arch/arm64/kernel/cpu_errata.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index d9f095439011..047f1da59cb1 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -125,15 +125,18 @@ 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)) {
+	for (; caps->matches; caps++) {
+		if (cpus_have_cap(caps->capability)) {
+			if (caps->enable)
+				caps->enable((void *)caps);
+		} else if (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)
-- 
2.21.0.rc0.269.g1a574e7a288b

