powerpc/perf: Add kconfig option for hypervisor provided counters

The commit adds a Kconfig option which allows the hv_gpci and hv_24x7
PMUs, added in the preceeding commits, to be built.
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/perf/Makefile

@@ -11,5 +11,7 @@ obj32-$(CONFIG_PPC_PERF_CTRS)	+= mpc7450-pmu.o
 obj-$(CONFIG_FSL_EMB_PERF_EVENT) += core-fsl-emb.o
 obj-$(CONFIG_FSL_EMB_PERF_EVENT_E500) += e500-pmu.o e6500-pmu.o
 
+obj-$(CONFIG_HV_PERF_CTRS) += hv-24x7.o hv-gpci.o hv-common.o
+
 obj-$(CONFIG_PPC64)		+= $(obj64-y)
 obj-$(CONFIG_PPC32)		+= $(obj32-y)

arch/powerpc/platforms/pseries/Kconfig

@@ -111,6 +111,18 @@ config CMM
 	  will be reused for other LPARs. The interface allows firmware to
 	  balance memory across many LPARs.
 
+config HV_PERF_CTRS
+       bool "Hypervisor supplied PMU events (24x7 & GPCI)"
+       default y
+       depends on PERF_EVENTS && PPC_PSERIES
+       help
+	  Enable access to hypervisor supplied counters in perf. Currently,
+	  this enables code that uses the hcall GetPerfCounterInfo and 24x7
+	  interfaces to retrieve counters. GPCI exists on Power 6 and later
+	  systems. 24x7 is available on Power 8 systems.
+
+          If unsure, select Y.
+
 config DTL
 	bool "Dispatch Trace Log"
 	depends on PPC_SPLPAR && DEBUG_FS