From 26b8317f51a20c1e4f61fbd2cc68975faad10b02 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Wed, 8 Aug 2018 10:30:37 +0200 Subject: s390/cpum_cf: introduce kernel_cpumcf_alert() to obtain measurement alerts During a __kernel_cpumcf_begin()/end() session, save measurement alerts for the counter facility in the per-CPU cpu_cf_events variable. Users can obtain and, optionally, clear the alerts by calling kernel_cpumcf_alert() to specifically handle alerts. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/perf_cpum_cf.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'arch/s390/kernel') diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c index 758cbb1b84f5..c05f69142ce4 100644 --- a/arch/s390/kernel/perf_cpum_cf.c +++ b/arch/s390/kernel/perf_cpum_cf.c @@ -27,6 +27,7 @@ DEFINE_PER_CPU(struct cpu_cf_events, cpu_cf_events) = { [CPUMF_CTR_SET_EXT] = ATOMIC_INIT(0), [CPUMF_CTR_SET_MT_DIAG] = ATOMIC_INIT(0), }, + .alert = ATOMIC64_INIT(0), .state = 0, .flags = 0, .txn_flags = 0, @@ -205,6 +206,9 @@ static void cpumf_measurement_alert(struct ext_code ext_code, if (alert & CPU_MF_INT_CF_MTDA) pr_warn("CPU[%i] MT counter data was lost\n", smp_processor_id()); + + /* store alert for special handling by in-kernel users */ + atomic64_or(alert, &cpuhw->alert); } #define PMC_INIT 0 @@ -255,6 +259,20 @@ int __kernel_cpumcf_begin(void) } EXPORT_SYMBOL(__kernel_cpumcf_begin); +/* Obtain the CPU-measurement alerts for the counter facility */ +unsigned long kernel_cpumcf_alert(int clear) +{ + struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events); + unsigned long alert; + + alert = atomic64_read(&cpuhw->alert); + if (clear) + atomic64_set(&cpuhw->alert, 0); + + return alert; +} +EXPORT_SYMBOL(kernel_cpumcf_alert); + /* Release the CPU-measurement counter facility */ void __kernel_cpumcf_end(void) { -- cgit v1.2.3