From: Hendrik Brueckner <brueckner@linux.ibm.com>
Date: Thu, 25 Oct 2018 16:58:15 +0200
Subject: s390/cpum_cf: introduce kernel_cpumcf_avail() function
Git-commit: 869f4f98fafadddb3a871b9513f24a44479d8296
Patch-mainline: v5.1-rc1
References: jsc#SLE-6904 FATE#327581
A preparation to move out common CPU-MF counter facility support
functions, first introduce a function that indicates whether the
support is ready to use.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
arch/s390/include/asm/cpu_mcf.h | 1 +
arch/s390/kernel/perf_cpum_cf.c | 20 +++++++++++++++++---
2 files changed, 18 insertions(+), 3 deletions(-)
--- a/arch/s390/include/asm/cpu_mcf.h
+++ b/arch/s390/include/asm/cpu_mcf.h
@@ -59,6 +59,7 @@ struct cpu_cf_events {
};
DECLARE_PER_CPU(struct cpu_cf_events, cpu_cf_events);
+bool kernel_cpumcf_avail(void);
int __kernel_cpumcf_begin(void);
unsigned long kernel_cpumcf_alert(int clear);
void __kernel_cpumcf_end(void);
--- a/arch/s390/kernel/perf_cpum_cf.c
+++ b/arch/s390/kernel/perf_cpum_cf.c
@@ -36,6 +36,9 @@ DEFINE_PER_CPU(struct cpu_cf_events, cpu
.txn_flags = 0,
};
+/* Indicator whether the CPU-Measurement Counter Facility Support is ready */
+static bool cpum_cf_initalized;
+
static enum cpumf_ctr_set get_counter_set(u64 event)
{
int set = CPUMF_CTR_SET_MAX;
@@ -236,6 +239,12 @@ static void setup_pmc_cpu(void *flags)
lcctl(0);
}
+bool kernel_cpumcf_avail(void)
+{
+ return cpum_cf_initalized;
+}
+EXPORT_SYMBOL(kernel_cpumcf_avail);
+
/* Reserve/release functions for sharing perf hardware */
static DEFINE_SPINLOCK(cpumcf_owner_lock);
static void *cpumcf_owner;
@@ -712,8 +721,13 @@ static int __init cpumf_pmu_init(void)
cpumf_measurement_alert);
return rc;
}
- return cpuhp_setup_state(CPUHP_AP_PERF_S390_CF_ONLINE,
- "perf/s390/cf:online",
- s390_pmu_online_cpu, s390_pmu_offline_cpu);
+
+ rc = cpuhp_setup_state(CPUHP_AP_PERF_S390_CF_ONLINE,
+ "perf/s390/cf:online",
+ s390_pmu_online_cpu, s390_pmu_offline_cpu);
+ if (!rc)
+ cpum_cf_initalized = true;
+
+ return rc;
}
early_initcall(cpumf_pmu_init);