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authorThomas Richter <tmricht@linux.ibm.com>2019-09-20 11:57:43 +0200
committerVasily Gorbik <gor@linux.ibm.com>2019-10-01 09:41:36 +0200
commit932bfc5aae08f3cb20c1c9f051542f5933710151 (patch)
tree185eaf035fa7cc887d86004541b55a2a569e657d /arch
parent851345828095f1e40d383ec1a1e91767a2051976 (diff)
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 <tmricht@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/cpu_mf.h5
-rw-r--r--arch/s390/kernel/perf_cpum_sf.c6
2 files changed, 10 insertions, 1 deletions
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;