[PATCH V6 03/26] coresight: etm3x: unlocking tracers in default arch init

Mathieu Poirier
2015-12-03T21:14:23Z

Calling function 'smp_call_function_single()' to unlock a
tracer and calling it again right after to perform the
default initialisation doesn't make sense.

Moving 'etm_os_unlock()' just before making the default
initialisation results in the same outcome while saving
one call to 'smp_call_function_single()'.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/hwtracing/coresight/coresight-etm3x.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index 2a1950d0753d..737b6164f4a5 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -47,11 +47,11 @@ static struct etm_drvdata *etmdrvdata[NR_CPUS];
* and OS lock must be unlocked before any memory mapped access on such
* processors, otherwise memory mapped reads/writes will be invalid.
*/
-static void etm_os_unlock(void *info)
+static void etm_os_unlock(struct etm_drvdata *drvdata)
{
- struct etm_drvdata *drvdata = (struct etm_drvdata *)info;
/* Writing any value to ETMOSLAR unlocks the trace registers */
etm_writel(drvdata, 0x0, ETMOSLAR);
+ drvdata->os_unlock = true;
isb();
}

@@ -478,6 +478,9 @@ static void etm_init_arch_data(void *info)
u32 etmccr;
struct etm_drvdata *drvdata = info;

+ /* Make sure all registers are accessible */
+ etm_os_unlock(drvdata);
+
CS_UNLOCK(drvdata->base);

/* First dummy read */
@@ -602,9 +605,6 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
get_online_cpus();
etmdrvdata[drvdata->cpu] = drvdata;

- if (!smp_call_function_single(drvdata->cpu, etm_os_unlock, drvdata, 1))
- drvdata->os_unlock = true;
-
if (smp_call_function_single(drvdata->cpu,
etm_init_arch_data, drvdata, 1))
dev_err(dev, "ETM arch init failed\n");
--
2.1.4