coresight: Add helper for atomically taking the device

[linux-2.6-microblaze.git] / drivers / hwtracing / coresight / coresight-etm4x-core.c

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 1c64b54..572ac4a 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -840,13 +840,11 @@ static int etm4_enable(struct coresight_device *csdev, struct perf_event *event,
                       enum cs_mode mode)
 {
        int ret;
-       u32 val;
 
-       val = local_cmpxchg(&csdev->mode, CS_MODE_DISABLED, mode);
-
-       /* Someone is already using the tracer */
-       if (val)
+       if (!coresight_take_mode(csdev, mode)) {
+               /* Someone is already using the tracer */
                return -EBUSY;
+       }
 
        switch (mode) {
        case CS_MODE_SYSFS: