Commit 932bfc5a authored by Thomas Richter's avatar Thomas Richter Committed by Vasily Gorbik
Browse files

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: default avatarThomas Richter <tmricht@linux.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 85134582

arch/s390/include/asm/cpu_mf.h

+4 −1
Original line number Diff line number Diff line
@@ -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			 */

arch/s390/kernel/perf_cpum_sf.c

+6 −0
Original line number Diff line number Diff line
@@ -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;

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