s390/perf: remove perf_release/reserver_sampling functions

Now that the oprofile sampling code is gone there is only one user of
the sampling facility left. Therefore the reserve and release
functions can be removed.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/perf_event.h

@@ -86,16 +86,4 @@ struct sf_raw_sample {
 	u8		    padding[];	  /* Padding to next multiple of 8 */
 } __packed;
 
-/* Perf hardware reserve and release functions */
-#ifdef CONFIG_PERF_EVENTS
-int perf_reserve_sampling(void);
-void perf_release_sampling(void);
-#else /* CONFIG_PERF_EVENTS */
-static inline int perf_reserve_sampling(void)
-{
-	return 0;
-}
-static inline void perf_release_sampling(void) {}
-#endif /* CONFIG_PERF_EVENTS */
-
 #endif /* _ASM_S390_PERF_EVENT_H */

arch/s390/kernel/perf_cpum_sf.c

@@ -601,17 +601,12 @@ static void release_pmc_hardware(void)
 
 	irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
 	on_each_cpu(setup_pmc_cpu, &flags, 1);
-	perf_release_sampling();
 }
 
 static int reserve_pmc_hardware(void)
 {
 	int flags = PMC_INIT;
-	int err;
 
-	err = perf_reserve_sampling();
-	if (err)
-		return err;
 	on_each_cpu(setup_pmc_cpu, &flags, 1);
 	if (flags & PMC_FAILURE) {
 		release_pmc_hardware();

arch/s390/kernel/perf_event.c

@@ -248,33 +248,3 @@ ssize_t cpumf_events_sysfs_show(struct device *dev,
 	return sprintf(page, "event=0x%04llx,name=%s\n",
 		       pmu_attr->id, attr->attr.name);
 }
-
-/* Reserve/release functions for sharing perf hardware */
-static DEFINE_SPINLOCK(perf_hw_owner_lock);
-static void *perf_sampling_owner;
-
-int perf_reserve_sampling(void)
-{
-	int err;
-
-	err = 0;
-	spin_lock(&perf_hw_owner_lock);
-	if (perf_sampling_owner) {
-		pr_warn("The sampling facility is already reserved by %p\n",
-			perf_sampling_owner);
-		err = -EBUSY;
-	} else
-		perf_sampling_owner = __builtin_return_address(0);
-	spin_unlock(&perf_hw_owner_lock);
-	return err;
-}
-EXPORT_SYMBOL(perf_reserve_sampling);
-
-void perf_release_sampling(void)
-{
-	spin_lock(&perf_hw_owner_lock);
-	WARN_ON(!perf_sampling_owner);
-	perf_sampling_owner = NULL;
-	spin_unlock(&perf_hw_owner_lock);
-}
-EXPORT_SYMBOL(perf_release_sampling);