coresight: etm4x: Fix issues on trcseqevr access

[ Upstream commit 4cd8303 ]

The TRCSEQEVR(3) is reserved, using '@nrseqstate - 1' instead to avoid
accessing the reserved register.

Fixes: f188b5e ("coresight: etm4x: Save/restore state across CPU low power states")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
[Fixed capital letter in title]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200916191737.4001561-12-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/hwtracing/coresight/coresight-etm4x.c

@@ -1193,7 +1193,7 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	state->trcvdsacctlr = readl(drvdata->base + TRCVDSACCTLR);
 	state->trcvdarcctlr = readl(drvdata->base + TRCVDARCCTLR);
 
-	for (i = 0; i < drvdata->nrseqstate; i++)
+	for (i = 0; i < drvdata->nrseqstate - 1; i++)
 		state->trcseqevr[i] = readl(drvdata->base + TRCSEQEVRn(i));
 
 	state->trcseqrstevr = readl(drvdata->base + TRCSEQRSTEVR);
@@ -1298,7 +1298,7 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 	writel_relaxed(state->trcvdsacctlr, drvdata->base + TRCVDSACCTLR);
 	writel_relaxed(state->trcvdarcctlr, drvdata->base + TRCVDARCCTLR);
 
-	for (i = 0; i < drvdata->nrseqstate; i++)
+	for (i = 0; i < drvdata->nrseqstate - 1; i++)
 		writel_relaxed(state->trcseqevr[i],
 			       drvdata->base + TRCSEQEVRn(i));