ARM: 7358/1: perf: add PMU hotplug notifier

When a CPU is taken out of reset, either cold booted or hotplugged in,
some of its PMU registers can contain UNKNOWN values.

This patch adds a hotplug notifier to ARM core perf code so that upon
CPU restart the PMU unit is reset and becomes ready to use again.

Signed-off-by: Lorenzo Pieralisi <>
Signed-off-by: Will Deacon <>
Signed-off-by: Russell King <>
1 file changed