s390/cpum_sf: Fix cpu hotplug notifier transitions

The cpumf_pmu_notfier() hotplug callback lacks handling of the
CPU_DOWN_FAILED case. That means, if CPU_DOWN_PREPARE failes, the PMC
of the CPU is not setup again. Furthermore the CPU_ONLINE_FROZEN case
will never be processed because of masking the switch expression with
CPU_TASKS_FROZEN.

Add handling for CPU_DOWN_FAILED transition to setup the PMC of the
CPU. Remove CPU_ONLINE_FROZEN case.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Acked-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 1a43474df541a08008d011f0678211ab63eb19fa..eaab9a7cb3be6a43f38dfa10a1a670656ca110dc 100644 (file)
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -1521,7 +1521,7 @@ static int cpumf_pmu_notifier(struct notifier_block *self,
 
        switch (action & ~CPU_TASKS_FROZEN) {
        case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
+       case CPU_DOWN_FAILED:
                flags = PMC_INIT;
                smp_call_function_single(cpu, setup_pmc_cpu, &flags, 1);
                break;