@@ -289,9 +289,16 @@ 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 {
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> --- v3: Whitespace v2: Much more verbose wording from Suzuki. arch/arm64/include/asm/cpufeature.h | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)