perfcounters/powerpc: add support for POWER4 processors

Impact: more hardware support

This adds the back-end for the PMU on the POWER4 and POWER4+ processors
(GP and GQ).  This is quite similar to the PPC970, with 8 PMCs, but has
fewer events than the PPC970.

Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/Makefile

@@ -94,7 +94,7 @@ obj-$(CONFIG_AUDIT)		+= audit.o
 obj64-$(CONFIG_AUDIT)		+= compat_audit.o
 
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o
-obj-$(CONFIG_PERF_COUNTERS)	+= perf_counter.o ppc970-pmu.o \
+obj-$(CONFIG_PERF_COUNTERS)	+= perf_counter.o power4-pmu.o ppc970-pmu.o \
 				   power5-pmu.o power5+-pmu.o power6-pmu.o
 
 obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o

arch/powerpc/kernel/perf_counter.c

@@ -824,6 +824,7 @@ void hw_perf_counter_setup(int cpu)
 	cpuhw->mmcr[0] = MMCR0_FC;
 }
 
+extern struct power_pmu power4_pmu;
 extern struct power_pmu ppc970_pmu;
 extern struct power_pmu power5_pmu;
 extern struct power_pmu power5p_pmu;
@@ -841,6 +842,10 @@ static int init_perf_counters(void)
 	/* XXX should get this from cputable */
 	pvr = mfspr(SPRN_PVR);
 	switch (PVR_VER(pvr)) {
+	case PV_POWER4:
+	case PV_POWER4p:
+		ppmu = &power4_pmu;
+		break;
 	case PV_970:
 	case PV_970FX:
 	case PV_970MP: