From: Mathieu Poirier Date: Thu, 18 Feb 2016 00:51:59 +0000 (-0700) Subject: coresight: etb10: adding operation mode for sink->enable() X-Git-Tag: firefly_0821_release~176^2~4^2~44^2~59 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=5e1df2fa7a6dd8452f56e17c0db9b1214fd8590f;p=firefly-linux-kernel-4.4.55.git coresight: etb10: adding operation mode for sink->enable() Adding an operation mode to the sink->enable() API in order to prevent simultaneous access from different callers. TPIU and TMC won't be supplemented with the AUX area API immediately and as such ignore the new mode. Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman (cherry picked from commit e827d4550aa3225b8965ce4c266208cfe0297509) --- diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index 162c9ccc8c33..79099f95ba3f 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -73,9 +73,9 @@ * @miscdev: specifics to handle "/dev/xyz.etb" entry. * @spinlock: only one at a time pls. * @reading: synchronise user space access to etb buffer. + * @mode: this ETB is being used. * @buf: area of memory where ETB buffer content gets sent. * @buffer_depth: size of @buf. - * @enable: this ETB is being used. * @trigger_cntr: amount of words to store after a trigger. */ struct etb_drvdata { @@ -86,9 +86,9 @@ struct etb_drvdata { struct miscdevice miscdev; spinlock_t spinlock; local_t reading; + local_t mode; u8 *buf; u32 buffer_depth; - bool enable; u32 trigger_cntr; }; @@ -133,16 +133,31 @@ static void etb_enable_hw(struct etb_drvdata *drvdata) CS_LOCK(drvdata->base); } -static int etb_enable(struct coresight_device *csdev) +static int etb_enable(struct coresight_device *csdev, u32 mode) { - struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + u32 val; unsigned long flags; + struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + val = local_cmpxchg(&drvdata->mode, + CS_MODE_DISABLED, mode); + /* + * When accessing from Perf, a HW buffer can be handled + * by a single trace entity. In sysFS mode many tracers + * can be logging to the same HW buffer. + */ + if (val == CS_MODE_PERF) + return -EBUSY; + + /* Nothing to do, the tracer is already enabled. */ + if (val == CS_MODE_SYSFS) + goto out; spin_lock_irqsave(&drvdata->spinlock, flags); etb_enable_hw(drvdata); - drvdata->enable = true; spin_unlock_irqrestore(&drvdata->spinlock, flags); +out: dev_info(drvdata->dev, "ETB enabled\n"); return 0; } @@ -243,9 +258,10 @@ static void etb_disable(struct coresight_device *csdev) spin_lock_irqsave(&drvdata->spinlock, flags); etb_disable_hw(drvdata); etb_dump_hw(drvdata); - drvdata->enable = false; spin_unlock_irqrestore(&drvdata->spinlock, flags); + local_set(&drvdata->mode, CS_MODE_DISABLED); + dev_info(drvdata->dev, "ETB disabled\n"); } @@ -263,7 +279,7 @@ static void etb_dump(struct etb_drvdata *drvdata) unsigned long flags; spin_lock_irqsave(&drvdata->spinlock, flags); - if (drvdata->enable) { + if (local_read(&drvdata->mode) == CS_MODE_SYSFS) { etb_disable_hw(drvdata); etb_dump_hw(drvdata); etb_enable_hw(drvdata); diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 932f34a84d96..333eddaed339 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -62,7 +62,7 @@ static inline void CS_UNLOCK(void __iomem *addr) } void coresight_disable_path(struct list_head *path); -int coresight_enable_path(struct list_head *path); +int coresight_enable_path(struct list_head *path, u32 mode); struct coresight_device *coresight_get_sink(struct list_head *path); struct list_head *coresight_build_path(struct coresight_device *csdev); void coresight_release_path(struct list_head *path); diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c index b526396d80b6..ac91b0b40ec2 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.c +++ b/drivers/hwtracing/coresight/coresight-tmc.c @@ -265,7 +265,7 @@ static int tmc_enable(struct tmc_drvdata *drvdata, enum tmc_mode mode) return 0; } -static int tmc_enable_sink(struct coresight_device *csdev) +static int tmc_enable_sink(struct coresight_device *csdev, u32 mode) { struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c index 0d8fce651ff7..71582f6dfd4c 100644 --- a/drivers/hwtracing/coresight/coresight-tpiu.c +++ b/drivers/hwtracing/coresight/coresight-tpiu.c @@ -70,7 +70,7 @@ static void tpiu_enable_hw(struct tpiu_drvdata *drvdata) CS_LOCK(drvdata->base); } -static int tpiu_enable(struct coresight_device *csdev) +static int tpiu_enable(struct coresight_device *csdev, u32 mode) { struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 95cccb179763..6ec2b66af9ee 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -121,13 +121,13 @@ static int coresight_find_link_outport(struct coresight_device *csdev, return 0; } -static int coresight_enable_sink(struct coresight_device *csdev) +static int coresight_enable_sink(struct coresight_device *csdev, u32 mode) { int ret; if (!csdev->enable) { if (sink_ops(csdev)->enable) { - ret = sink_ops(csdev)->enable(csdev); + ret = sink_ops(csdev)->enable(csdev, mode); if (ret) return ret; } @@ -283,7 +283,7 @@ void coresight_disable_path(struct list_head *path) } } -int coresight_enable_path(struct list_head *path) +int coresight_enable_path(struct list_head *path, u32 mode) { int ret = 0; @@ -296,7 +296,7 @@ int coresight_enable_path(struct list_head *path) switch (csdev->type) { case CORESIGHT_DEV_TYPE_SINK: case CORESIGHT_DEV_TYPE_LINKSINK: - ret = coresight_enable_sink(csdev); + ret = coresight_enable_sink(csdev, mode); if (ret) goto err; break; @@ -454,7 +454,7 @@ int coresight_enable(struct coresight_device *csdev) goto out; } - ret = coresight_enable_path(path); + ret = coresight_enable_path(path, CS_MODE_SYSFS); if (ret) goto err_path; diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 6801dd64ee5d..9fa92dcdd2ea 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -186,7 +186,7 @@ struct coresight_device { * @disable: disables the sink. */ struct coresight_ops_sink { - int (*enable)(struct coresight_device *csdev); + int (*enable)(struct coresight_device *csdev, u32 mode); void (*disable)(struct coresight_device *csdev); };