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Groups > linux.kernel > #1325828
| From | Mathieu Poirier <mathieu.poirier@linaro.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH V9 14/18] coresight: etb10: moving to local atomic operations |
| Date | 2016-02-03 19:50 +0100 |
| Message-ID | <qYaF4-5Ec-21@gated-at.bofh.it> (permalink) |
| References | <qYavo-5AG-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Moving to use local atomic operations to take advantage of the
lockless implementation, something that will come handy when
the ETB is accessed from the Perf subsystem. Also changing the
name of the variable to something more meaningful.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/hwtracing/coresight/coresight-etb10.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 917562ecf82a..162c9ccc8c33 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -10,6 +10,7 @@
* GNU General Public License for more details.
*/
+#include <asm/local.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
@@ -71,7 +72,7 @@
* @csdev: component vitals needed by the framework.
* @miscdev: specifics to handle "/dev/xyz.etb" entry.
* @spinlock: only one at a time pls.
- * @in_use: synchronise user space access to etb buffer.
+ * @reading: synchronise user space access to etb buffer.
* @buf: area of memory where ETB buffer content gets sent.
* @buffer_depth: size of @buf.
* @enable: this ETB is being used.
@@ -84,7 +85,7 @@ struct etb_drvdata {
struct coresight_device *csdev;
struct miscdevice miscdev;
spinlock_t spinlock;
- atomic_t in_use;
+ local_t reading;
u8 *buf;
u32 buffer_depth;
bool enable;
@@ -277,7 +278,7 @@ static int etb_open(struct inode *inode, struct file *file)
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
- if (atomic_cmpxchg(&drvdata->in_use, 0, 1))
+ if (local_cmpxchg(&drvdata->reading, 0, 1))
return -EBUSY;
dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
@@ -313,7 +314,7 @@ static int etb_release(struct inode *inode, struct file *file)
{
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
- atomic_set(&drvdata->in_use, 0);
+ local_set(&drvdata->reading, 0);
dev_dbg(drvdata->dev, "%s: released\n", __func__);
return 0;
--
2.1.4
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[PATCH V9 00/18] Coresight integration with perf Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:40 +0100 [PATCH V9 11/18] coresight: etm3x: consolidating initial config Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 13/18] coresight: etm3x: implementing perf_enable/disable() API Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 14/18] coresight: etb10: moving to local atomic operations Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 18/18] coresight: introducing a global trace ID function Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 16/18] coresight: etb10: implementing AUX API Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 06/18] coresight: etm3x: unlocking tracers in default arch init Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 10/18] coresight: etm3x: changing default trace configuration Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 17/18] coresight: etm-perf: new PMU driver for ETM tracers Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 08/18] coresight: etm3x: adding operation mode for etm_enable() Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 12/18] coresight: etm3x: implementing user/kernel mode tracing Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 15/18] coresight: etb10: adding operation mode for sink->enable() Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 19:50 +0100 [PATCH V9 09/18] coresight: etm3x: set progbit to stop trace collection Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 20:00 +0100 [PATCH V9 03/18] coresight: moving PM runtime operations to core framework Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 20:00 +0100 [PATCH V9 04/18] coresight: etm3x: moving etm_readl/writel to header file Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 20:00 +0100 [PATCH V9 02/18] coresight: add API to get sink from path Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-03 20:00 +0100
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