perf/marvell_cn10k: Fix TAD PMU register offset

The existing offset of TAD_PRF and TAD_PFC registers are incorrect.
Hence, fix with the right register offsets.

Also, drop read of TAD_PRF register in tad_pmu_event_counter_start()
since we don't have to preserve any bit fields and always write
an updated value.
Signed-off-by: Tanmay Jagdale <tanmay@marvell.com>
Link: https://lore.kernel.org/r/20220614171356.773967-1-tanmay@marvell.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/marvell_cn10k_tad_pmu.c

@@ -14,9 +14,9 @@
 #include <linux/perf_event.h>
 #include <linux/platform_device.h>
 
-#define TAD_PFC_OFFSET		0x0
+#define TAD_PFC_OFFSET		0x800
 #define TAD_PFC(counter)	(TAD_PFC_OFFSET | (counter << 3))
-#define TAD_PRF_OFFSET		0x100
+#define TAD_PRF_OFFSET		0x900
 #define TAD_PRF(counter)	(TAD_PRF_OFFSET | (counter << 3))
 #define TAD_PRF_CNTSEL_MASK	0xFF
 #define TAD_MAX_COUNTERS	8
@@ -96,9 +96,7 @@ static void tad_pmu_event_counter_start(struct perf_event *event, int flags)
 	 * which sets TAD()_PRF()[CNTSEL] != 0
 	 */
 	for (i = 0; i < tad_pmu->region_cnt; i++) {
-		reg_val = readq_relaxed(tad_pmu->regions[i].base +
-					TAD_PRF(counter_idx));
-		reg_val |= (event_idx & 0xFF);
+		reg_val = event_idx & 0xFF;
 		writeq_relaxed(reg_val,	tad_pmu->regions[i].base +
 			       TAD_PRF(counter_idx));
 	}