[PATCH v3 06/11] coresight: etm4x: Improve usability of sysfs - CID and VMID masks.

[Mike Leach]

Context ID and VM ID masks required 2 value inputs, even when the
second value is ignored as insufficient CID / VMID comparators are
implemented.

Permit a single value to be used if that is sufficient to cover all
implemented comparators.

Reviewed-by: Mathieu Poirier <mathieu.poir...@linaro.org>
Signed-off-by: Mike Leach <mike.le...@linaro.org>
---
 drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c 
b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index d772765dcd29..d6fcb9fee97a 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -1794,6 +1794,7 @@ static ssize_t ctxid_masks_store(struct device *dev,
        unsigned long val1, val2, mask;
        struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
        struct etmv4_config *config = &drvdata->config;
+       int nr_inputs;
 
        /*
         * Don't use contextID tracing if coming from a PID namespace.  See
@@ -1809,7 +1810,9 @@ static ssize_t ctxid_masks_store(struct device *dev,
         */
        if (!drvdata->ctxid_size || !drvdata->numcidc)
                return -EINVAL;
-       if (sscanf(buf, "%lx %lx", &val1, &val2) != 2)
+       /* one mask if <= 4 comparators, two for up to 8 */
+       nr_inputs = sscanf(buf, "%lx %lx", &val1, &val2);
+       if ((drvdata->numcidc > 4) && (nr_inputs != 2))
                return -EINVAL;
 
        spin_lock(&drvdata->spinlock);
@@ -1983,6 +1986,7 @@ static ssize_t vmid_masks_store(struct device *dev,
        unsigned long val1, val2, mask;
        struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
        struct etmv4_config *config = &drvdata->config;
+       int nr_inputs;
 
        /*
         * only implemented when vmid tracing is enabled, i.e. at least one
@@ -1990,7 +1994,9 @@ static ssize_t vmid_masks_store(struct device *dev,
         */
        if (!drvdata->vmid_size || !drvdata->numvmidc)
                return -EINVAL;
-       if (sscanf(buf, "%lx %lx", &val1, &val2) != 2)
+       /* one mask if <= 4 comparators, two for up to 8 */
+       nr_inputs = sscanf(buf, "%lx %lx", &val1, &val2);
+       if ((drvdata->numvmidc > 4) && (nr_inputs != 2))
                return -EINVAL;
 
        spin_lock(&drvdata->spinlock);
-- 
2.17.1