From 932bfc5aae08f3cb20c1c9f051542f5933710151 Mon Sep 17 00:00:00 2001 From: Thomas Richter Date: Fri, 20 Sep 2019 11:57:43 +0200 Subject: [PATCH] s390/cpumsf: Check for CPU Measurement sampling s390 IBM z15 introduces a check if the CPU Mesurement Facility sampling is temporarily unavailable. If this is the case return -EBUSY and abort the setup of CPU Measuement facility sampling. Signed-off-by: Thomas Richter Reviewed-by: Christian Borntraeger Signed-off-by: Vasily Gorbik --- arch/s390/include/asm/cpu_mf.h | 5 ++++- arch/s390/kernel/perf_cpum_sf.c | 6 ++++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/s390/include/asm/cpu_mf.h b/arch/s390/include/asm/cpu_mf.h index ceeb552d3472..753669bfbe99 100644 --- a/arch/s390/include/asm/cpu_mf.h +++ b/arch/s390/include/asm/cpu_mf.h @@ -28,6 +28,8 @@ asm(".include \"asm/cpu_mf-insn.h\"\n"); CPU_MF_INT_SF_PRA|CPU_MF_INT_SF_SACA| \ CPU_MF_INT_SF_LSDA) +#define CPU_MF_SF_RIBM_NOTAV 0x1 /* Sampling unavailable */ + /* CPU measurement facility support */ static inline int cpum_cf_avail(void) { @@ -69,7 +71,8 @@ struct hws_qsi_info_block { /* Bit(s) */ unsigned long max_sampl_rate; /* 16-23: maximum sampling interval*/ unsigned long tear; /* 24-31: TEAR contents */ unsigned long dear; /* 32-39: DEAR contents */ - unsigned int rsvrd0; /* 40-43: reserved */ + unsigned int rsvrd0:24; /* 40-42: reserved */ + unsigned int ribm:8; /* 43: Reserved by IBM */ unsigned int cpu_speed; /* 44-47: CPU speed */ unsigned long long rsvrd1; /* 48-55: reserved */ unsigned long long rsvrd2; /* 56-63: reserved */ diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index 544a02e944c6..2421f0b62630 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -803,6 +803,12 @@ static int __hw_perf_event_init(struct perf_event *event) goto out; } + if (si.ribm & CPU_MF_SF_RIBM_NOTAV) { + pr_warn("CPU Measurement Facility sampling is temporarily not available\n"); + err = -EBUSY; + goto out; + } + /* Always enable basic sampling */ SAMPL_FLAGS(hwc) = PERF_CPUM_SF_BASIC_MODE;