@@ -4144,6 +4144,14 @@
 			Override pmtimer IOPort with a hex value.
 			e.g. pmtmr=0x508
 
+	pmu_override=	[PPC] Override the PMU.
+			This option takes over the PMU facility, so it is no
+			longer usable by perf. Setting this option starts the
+			PMU counters by setting MMCR0 to 0 (the FC bit is
+			cleared). If a number is given, then MMCR1 is set to
+			that number, otherwise (e.g., 'pmu_override=on'), MMCR1
+			remains 0.
+
 	pm_debug_messages	[SUSPEND,KNL]
 			Enable suspend/resume debug messages during boot up.
 

@@ -2419,8 +2419,24 @@ int register_power_pmu(struct power_pmu *pmu)
 }
 
 #ifdef CONFIG_PPC64
+static bool pmu_override = false;
+static unsigned long pmu_override_val;
+static void do_pmu_override(void *data)
+{
+	ppc_set_pmu_inuse(1);
+	if (pmu_override_val)
+		mtspr(SPRN_MMCR1, pmu_override_val);
+	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC);
+}
+
 static int __init init_ppc64_pmu(void)
 {
+	if (cpu_has_feature(CPU_FTR_HVMODE) && pmu_override) {
+		pr_warn("disabling perf due to pmu_override= command line option.\n");
+		on_each_cpu(do_pmu_override, NULL, 1);
+		return 0;
+	}
+
 	/* run through all the pmu drivers one at a time */
 	if (!init_power5_pmu())
 		return 0;

@@ -2442,4 +2458,23 @@ static int __init init_ppc64_pmu(void)
 		return init_generic_compat_pmu();
 }
 early_initcall(init_ppc64_pmu);
+
+static int __init pmu_setup(char *str)
+{
+	unsigned long val;
+
+	if (!early_cpu_has_feature(CPU_FTR_HVMODE))
+		return 0;
+
+	pmu_override = true;
+
+	if (kstrtoul(str, 0, &val))
+		val = 0;
+
+	pmu_override_val = val;
+
+	return 1;
+}
+__setup("pmu_override=", pmu_setup);
+
 #endif