Commit 26b8317f authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by Martin Schwidefsky
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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: default avatarHendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent f944bcdf

arch/s390/include/asm/cpu_mcf.h

+2 −0
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ static inline void ctr_set_stop(u64 *state, int ctr_set) 
struct cpu_cf_events {

	struct cpumf_ctr_info	info;

	atomic_t		ctr_set[CPUMF_CTR_SET_MAX];

	atomic64_t		alert;

	u64			state, tx_state;

	unsigned int		flags;

	unsigned int		txn_flags;
@@ -59,6 +60,7 @@ struct cpu_cf_events { 
DECLARE_PER_CPU(struct cpu_cf_events, cpu_cf_events);



int __kernel_cpumcf_begin(void);

unsigned long kernel_cpumcf_alert(int clear);

void __kernel_cpumcf_end(void);



#endif /* _ASM_S390_CPU_MCF_H */

arch/s390/kernel/perf_cpum_cf.c

+18 −0
Original line number Diff line number Diff line
@@ -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)

{