coresight: etm4x: Handle accesses to TRCSTALLCTLR

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@arm.com
Cc: stable@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-32-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 8b6666e..74d3e2f 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -131,7 +131,8 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
        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);
@@ -1187,7 +1188,8 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
        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);
@@ -1297,7 +1299,8 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
        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);

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index 989ce7b..4682f26 100644 (file)
--- 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 *dev,
                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);