diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h index 371fb7d2e829..5b29d5540fe5 100644 --- a/drivers/hwtracing/coresight/coresight-etm.h +++ b/drivers/hwtracing/coresight/coresight-etm.h @@ -13,6 +13,7 @@ #ifndef _CORESIGHT_CORESIGHT_ETM_H #define _CORESIGHT_CORESIGHT_ETM_H +#include #include #include "coresight-priv.h" @@ -214,7 +215,7 @@ struct etm_config { * @port_size: port size as reported by ETMCR bit 4-6 and 21. * @arch: ETM/PTM version number. * @use_cpu14: true if management registers need to be accessed via CP14. - * @enable: is this ETM/PTM currently tracing. + * @mode: this tracer's mode, i.e sysFS, Perf or disabled. * @sticky_enable: true if ETM base configuration has been done. * @boot_enable:true if we should start tracing at boot time. * @os_unlock: true if access to management registers is allowed. @@ -238,7 +239,7 @@ struct etm_drvdata { int port_size; u8 arch; bool use_cp14; - bool enable; + local_t mode; bool sticky_enable; bool boot_enable; bool os_unlock; diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c index 456df2378a6f..387c79fd9d5e 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c @@ -716,7 +716,7 @@ static ssize_t cntr_val_show(struct device *dev, struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etm_config *config = &drvdata->config; - if (!drvdata->enable) { + if (!local_read(&drvdata->mode)) { spin_lock(&drvdata->spinlock); for (i = 0; i < drvdata->nr_cntr; i++) ret += sprintf(buf, "counter %d: %x\n", @@ -935,7 +935,7 @@ static ssize_t seq_curr_state_show(struct device *dev, struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etm_config *config = &drvdata->config; - if (!drvdata->enable) { + if (!local_read(&drvdata->mode)) { val = config->seq_curr_state; goto out; } diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c index 1952dc31fee4..e16501b41ed8 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x.c @@ -306,7 +306,7 @@ int etm_get_trace_id(struct etm_drvdata *drvdata) if (!drvdata) goto out; - if (!drvdata->enable) + if (!local_read(&drvdata->mode)) return drvdata->traceid; pm_runtime_get_sync(drvdata->dev); @@ -332,7 +332,7 @@ static int etm_trace_id(struct coresight_device *csdev) return etm_get_trace_id(drvdata); } -static int etm_enable(struct coresight_device *csdev) +static int etm_enable_sysfs(struct coresight_device *csdev) { struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); int ret; @@ -351,18 +351,44 @@ static int etm_enable(struct coresight_device *csdev) goto err; } - drvdata->enable = true; drvdata->sticky_enable = true; - spin_unlock(&drvdata->spinlock); dev_info(drvdata->dev, "ETM tracing enabled\n"); return 0; + err: spin_unlock(&drvdata->spinlock); return ret; } +static int etm_enable(struct coresight_device *csdev, u32 mode) +{ + int ret; + u32 val; + struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode); + + /* Someone is already using the tracer */ + if (val) + return -EBUSY; + + switch (mode) { + case CS_MODE_SYSFS: + ret = etm_enable_sysfs(csdev); + break; + default: + ret = -EINVAL; + } + + /* The tracer didn't start */ + if (ret) + local_set(&drvdata->mode, CS_MODE_DISABLED); + + return ret; +} + static void etm_disable_hw(void *info) { int i; @@ -387,7 +413,7 @@ static void etm_disable_hw(void *info) dev_dbg(drvdata->dev, "cpu: %d disable smp call done\n", drvdata->cpu); } -static void etm_disable(struct coresight_device *csdev) +static void etm_disable_sysfs(struct coresight_device *csdev) { struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -405,7 +431,6 @@ static void etm_disable(struct coresight_device *csdev) * ensures that register writes occur when cpu is powered. */ smp_call_function_single(drvdata->cpu, etm_disable_hw, drvdata, 1); - drvdata->enable = false; spin_unlock(&drvdata->spinlock); put_online_cpus(); @@ -413,6 +438,33 @@ static void etm_disable(struct coresight_device *csdev) dev_info(drvdata->dev, "ETM tracing disabled\n"); } +static void etm_disable(struct coresight_device *csdev) +{ + u32 mode; + struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + /* + * For as long as the tracer isn't disabled another entity can't + * change its status. As such we can read the status here without + * fearing it will change under us. + */ + mode = local_read(&drvdata->mode); + + switch (mode) { + case CS_MODE_DISABLED: + break; + case CS_MODE_SYSFS: + etm_disable_sysfs(csdev); + break; + default: + WARN_ON_ONCE(mode); + return; + } + + if (mode) + local_set(&drvdata->mode, CS_MODE_DISABLED); +} + static const struct coresight_ops_source etm_source_ops = { .cpu_id = etm_cpu_id, .trace_id = etm_trace_id, @@ -440,7 +492,7 @@ static int etm_cpu_callback(struct notifier_block *nfb, unsigned long action, etmdrvdata[cpu]->os_unlock = true; } - if (etmdrvdata[cpu]->enable) + if (local_read(&etmdrvdata[cpu]->mode)) etm_enable_hw(etmdrvdata[cpu]); spin_unlock(&etmdrvdata[cpu]->spinlock); break; @@ -453,7 +505,7 @@ static int etm_cpu_callback(struct notifier_block *nfb, unsigned long action, case CPU_DYING: spin_lock(&etmdrvdata[cpu]->spinlock); - if (etmdrvdata[cpu]->enable) + if (local_read(&etmdrvdata[cpu]->mode)) etm_disable_hw(etmdrvdata[cpu]); spin_unlock(&etmdrvdata[cpu]->spinlock); break; diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index c2f518fbc9a8..0026092fec7f 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -187,7 +187,7 @@ static void etm4_enable_hw(void *info) dev_dbg(drvdata->dev, "cpu: %d enable smp call done\n", drvdata->cpu); } -static int etm4_enable(struct coresight_device *csdev) +static int etm4_enable(struct coresight_device *csdev, u32 mode) { struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); int ret; diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 14f245a2018d..ed116b303e87 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -34,6 +34,12 @@ #define TIMEOUT_US 100 #define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb) +enum cs_mode { + CS_MODE_DISABLED, + CS_MODE_SYSFS, + CS_MODE_PERF, +}; + static inline void CS_LOCK(void __iomem *addr) { do { diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 6b44928c1076..b20afb709141 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -222,7 +222,7 @@ static void coresight_disable_link(struct coresight_device *csdev, csdev->enable = false; } -static int coresight_enable_source(struct coresight_device *csdev) +static int coresight_enable_source(struct coresight_device *csdev, u32 mode) { int ret; @@ -234,7 +234,7 @@ static int coresight_enable_source(struct coresight_device *csdev) if (!csdev->enable) { if (source_ops(csdev)->enable) { - ret = source_ops(csdev)->enable(csdev); + ret = source_ops(csdev)->enable(csdev, mode); if (ret) return ret; } @@ -458,7 +458,7 @@ int coresight_enable(struct coresight_device *csdev) if (ret) goto err_path; - ret = coresight_enable_source(csdev); + ret = coresight_enable_source(csdev, CS_MODE_SYSFS); if (ret) goto err_source; diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 851ecb22397e..61dfb8d511ea 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -213,7 +213,7 @@ struct coresight_ops_link { struct coresight_ops_source { int (*cpu_id)(struct coresight_device *csdev); int (*trace_id)(struct coresight_device *csdev); - int (*enable)(struct coresight_device *csdev); + int (*enable)(struct coresight_device *csdev, u32 mode); void (*disable)(struct coresight_device *csdev); };