From: Mark Brown <broonie@kernel.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>,
will@kernel.org, catalin.marinas@arm.com
Cc: Mark Brown <broonie@kernel.org>, linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] arm64: Clarify when cpu_enable() is called
Date: Thu, 8 Aug 2019 14:53:28 +0100 [thread overview]
Message-ID: <20190808135328.12655-1-broonie@kernel.org> (raw)
Strengthen the wording in the documentation for cpu_enable() to make it
more obvious to readers not already familiar with the code when the core
will call this callback and that this is intentional.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
v2: Much more verbose wording from Suzuki.
arch/arm64/include/asm/cpufeature.h | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index cf65a47ee6b4..2447d4afbf54 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -289,9 +289,17 @@ struct arm64_cpu_capabilities {
u16 type;
bool (*matches)(const struct arm64_cpu_capabilities *caps, int scope);
/*
- * Take the appropriate actions to enable this capability for this CPU.
- * For each successfully booted CPU, this method is called for each
- * globally detected capability.
+ * Take the appropriate actions to configure this capability
+ * for this CPU. If the capability is detected by the kernel
+ * this will be called on all the CPUs in the system,
+ * including the hotplugged CPUs, regardless of if the
+ * capability was *available* on that specific CPU. This is
+ * useful for some capabilities (e.g, working around CPU
+ * errata), where all the CPUs must take some action (e.g,
+ * changing system control/configuration). Thus, if an action
+ * is required only if the CPU has the capability then the
+ * routine must check it before taking any action.
+
*/
void (*cpu_enable)(const struct arm64_cpu_capabilities *cap);
union {
--
2.20.1
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next reply other threads:[~2019-08-08 13:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-08 13:53 Mark Brown [this message]
2019-08-08 13:57 ` [PATCH v2] arm64: Clarify when cpu_enable() is called Suzuki K Poulose
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