[PATCH 5.11 692/775] coresight: etm4x: Handle accesses to TRCSTALLCTLR

[Greg Kroah-Hartman]

From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>

commit f72896063396b0cb205cbf0fd76ec6ab3ca11c8a upstream.

TRCSTALLCTLR register is only implemented if

   TRCIDR3.STALLCTL == 0b1

Make sure the driver touches the register only it is implemented.

Link: https://lore.kernel.org/r/20210127184617.3684379-1-suzuki.poulose@xxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Mike Leach <mike.leach@xxxxxxxxxx>
Cc: Leo Yan <leo.yan@xxxxxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210201181351.1475223-32-mathieu.poirier@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/hwtracing/coresight/coresight-etm4x-core.c  |    9 ++++++---
 drivers/hwtracing/coresight/coresight-etm4x-sysfs.c |    2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -226,7 +226,8 @@ static int etm4_enable_hw(struct etmv4_d
 	writel_relaxed(0x0, drvdata->base + TRCAUXCTLR);
 	writel_relaxed(config->eventctrl0, drvdata->base + TRCEVENTCTL0R);
 	writel_relaxed(config->eventctrl1, drvdata->base + TRCEVENTCTL1R);
-	writel_relaxed(config->stall_ctrl, drvdata->base + TRCSTALLCTLR);
+	if (drvdata->stallctl)
+		writel_relaxed(config->stall_ctrl, drvdata->base + TRCSTALLCTLR);
 	writel_relaxed(config->ts_ctrl, drvdata->base + TRCTSCTLR);
 	writel_relaxed(config->syncfreq, drvdata->base + TRCSYNCPR);
 	writel_relaxed(config->ccctlr, drvdata->base + TRCCCCTLR);
@@ -1288,7 +1289,8 @@ static int etm4_cpu_save(struct etmv4_dr
 	state->trcauxctlr = readl(drvdata->base + TRCAUXCTLR);
 	state->trceventctl0r = readl(drvdata->base + TRCEVENTCTL0R);
 	state->trceventctl1r = readl(drvdata->base + TRCEVENTCTL1R);
-	state->trcstallctlr = readl(drvdata->base + TRCSTALLCTLR);
+	if (drvdata->stallctl)
+		state->trcstallctlr = readl(drvdata->base + TRCSTALLCTLR);
 	state->trctsctlr = readl(drvdata->base + TRCTSCTLR);
 	state->trcsyncpr = readl(drvdata->base + TRCSYNCPR);
 	state->trcccctlr = readl(drvdata->base + TRCCCCTLR);
@@ -1398,7 +1400,8 @@ static void etm4_cpu_restore(struct etmv
 	writel_relaxed(state->trcauxctlr, drvdata->base + TRCAUXCTLR);
 	writel_relaxed(state->trceventctl0r, drvdata->base + TRCEVENTCTL0R);
 	writel_relaxed(state->trceventctl1r, drvdata->base + TRCEVENTCTL1R);
-	writel_relaxed(state->trcstallctlr, drvdata->base + TRCSTALLCTLR);
+	if (drvdata->stallctl)
+		writel_relaxed(state->trcstallctlr, drvdata->base + TRCSTALLCTLR);
 	writel_relaxed(state->trctsctlr, drvdata->base + TRCTSCTLR);
 	writel_relaxed(state->trcsyncpr, drvdata->base + TRCSYNCPR);
 	writel_relaxed(state->trcccctlr, drvdata->base + TRCCCCTLR);
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -389,7 +389,7 @@ static ssize_t mode_store(struct device
 		config->eventctrl1 &= ~BIT(12);
 
 	/* bit[8], Instruction stall bit */
-	if (config->mode & ETM_MODE_ISTALL_EN)
+	if ((config->mode & ETM_MODE_ISTALL_EN) && (drvdata->stallctl == true))
 		config->stall_ctrl |= BIT(8);
 	else
 		config->stall_ctrl &= ~BIT(8);