Index: sys/dev/hwpmc/hwpmc_armv7.c
===================================================================
--- sys/dev/hwpmc/hwpmc_armv7.c
+++ sys/dev/hwpmc/hwpmc_armv7.c
@@ -172,9 +172,10 @@
 	pm  = armv7_pcpu[cpu]->pc_armv7pmcs[ri].phw_pmc;
 
 	if (pm->pm_md.pm_armv7.pm_armv7_evsel == 0xFF)
-		tmp = cp15_pmccntr_get();
+		tmp = (uint32_t)cp15_pmccntr_get();
 	else
 		tmp = armv7_pmcn_read(ri);
+	tmp += 0x100000000llu * pm->pm_overflowcnt;
 
 	PMCDBG2(MDP, REA, 2, "armv7-read id=%d -> %jd", ri, tmp);
 	if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
@@ -244,11 +245,16 @@
 	pm     = phw->phw_pmc;
 	config = pm->pm_md.pm_armv7.pm_armv7_evsel;
 
+	pm->pm_overflowcnt = 0;
+
 	/*
 	 * Configure the event selection.
 	 */
-	cp15_pmselr_set(ri);
-	cp15_pmxevtyper_set(config);
+	if (config != 0xFF) {
+		cp15_pmselr_set(ri);
+		cp15_pmxevtyper_set(config);
+	} else
+		ri = 31;
 
 	/*
 	 * Enable the PMC.
@@ -264,9 +270,13 @@
 {
 	struct pmc_hw *phw;
 	struct pmc *pm;
+	uint32_t config;
 
 	phw    = &armv7_pcpu[cpu]->pc_armv7pmcs[ri];
 	pm     = phw->phw_pmc;
+	config = pm->pm_md.pm_armv7.pm_armv7_evsel;
+	if (config == 0xFF)
+		ri = 31;
 
 	/*
 	 * Disable the PMCs.
@@ -313,8 +323,6 @@
 		pm = armv7_pcpu[cpu]->pc_armv7pmcs[ri].phw_pmc;
 		if (pm == NULL)
 			continue;
-		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
-			continue;
 
 		/* Check if counter has overflowed */
 		if (pm->pm_md.pm_armv7.pm_armv7_evsel == 0xFF)
@@ -330,6 +338,11 @@
 		cp15_pmovsr_set(reg);
 
 		retval = 1; /* Found an interrupting PMC. */
+
+		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
+			pm->pm_overflowcnt += 1;
+			continue;
+		}
 		if (pm->pm_state != PMC_STATE_RUNNING)
 			continue;
 
@@ -430,6 +443,11 @@
 		pc->pc_hwpmcs[i + first_ri] = phw;
 	}
 
+	pmnc = 0xffffffff;
+	cp15_pmcnten_clr(pmnc);
+	cp15_pminten_clr(pmnc);
+	cp15_pmovsr_set(pmnc);
+
 	/* Enable unit */
 	pmnc = cp15_pmcr_get();
 	pmnc |= ARMV7_PMNC_ENABLE;
@@ -447,6 +465,11 @@
 	pmnc &= ~ARMV7_PMNC_ENABLE;
 	cp15_pmcr_set(pmnc);
 
+	pmnc = 0xffffffff;
+	cp15_pmcnten_clr(pmnc);
+	cp15_pminten_clr(pmnc);
+	cp15_pmovsr_set(pmnc);
+
 	return 0;
 }
 
Index: sys/sys/pmc.h
===================================================================
--- sys/sys/pmc.h
+++ sys/sys/pmc.h
@@ -741,6 +741,7 @@
 	struct pmc_owner *pm_owner;	/* owner thread state */
 	int		pm_runcount;	/* #cpus currently on */
 	enum pmc_state	pm_state;	/* current PMC state */
+	uint32_t	pm_overflowcnt;	/* count overflow interrupts */
 
 	/*
 	 * The PMC ID field encodes the row-index for the PMC, its