powerpc/perf: Add new power PMU flag "PPMU_P10_DD1" for power10 DD1

Add a new power PMU flag "PPMU_P10_DD1" which can be used to
conditionally add any code path for power10 DD1 processor version.
Also modify power10 PMU driver code to set this flag only for DD1,
based on the Processor Version Register (PVR) value.
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021085329.384535-1-maddy@linux.ibm.com

arch/powerpc/include/asm/perf_event_server.h

@@ -82,6 +82,7 @@ struct power_pmu {
 #define PPMU_ARCH_207S		0x00000080 /* PMC is architecture v2.07S */
 #define PPMU_NO_SIAR		0x00000100 /* Do not use SIAR */
 #define PPMU_ARCH_31		0x00000200 /* Has MMCR3, SIER2 and SIER3 */
+#define PPMU_P10_DD1		0x00000400 /* Is power10 DD1 processor version */
 
 /*
  * Values for flags to get_alternatives()

arch/powerpc/perf/power10-pmu.c

@@ -403,6 +403,7 @@ static struct power_pmu power10_pmu = {
 
 int init_power10_pmu(void)
 {
+	unsigned int pvr;
 	int rc;
 
 	/* Comes from cpu_specs[] */
@@ -410,6 +411,11 @@ int init_power10_pmu(void)
 	    strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power10"))
 		return -ENODEV;
 
+	pvr = mfspr(SPRN_PVR);
+	/* Add the ppmu flag for power10 DD1 */
+	if ((PVR_CFG(pvr) == 1))
+		power10_pmu.flags |= PPMU_P10_DD1;
+
 	/* Set the PERF_REG_EXTENDED_MASK here */
 	PERF_REG_EXTENDED_MASK = PERF_REG_PMU_MASK_31;