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

Mike Leach
2019-10-15T21:22:58Z

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.poirier@linaro.org>
Signed-off-by: Mike Leach <mike.leach@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);