Like the previous commit to ETR, ETF sinks shouldn't share per-thread events. Fix it by returning -EBUSY if a second per-thread event tries to use the same sink.
Fixes: 880af782c6e8 ("coresight: tmc-etf: Add support for CPU-wide trace scenarios") Signed-off-by: James Clark james.clark@linaro.org --- drivers/hwtracing/coresight/coresight-tmc-core.c | 2 -- drivers/hwtracing/coresight/coresight-tmc-etf.c | 23 +++++++---------------- drivers/hwtracing/coresight/coresight-tmc.h | 4 ---- 3 files changed, 7 insertions(+), 22 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 873868718b14..2c2f2f312e8e 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -800,8 +800,6 @@ static int __tmc_probe(struct device *dev, struct resource *res) devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID); drvdata->config_type = BMVAL(devid, 6, 7); drvdata->memwidth = tmc_get_memwidth(devid); - /* This device is not associated with a session */ - drvdata->pid = -1; drvdata->etr_mode = ETR_MODE_AUTO;
if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) { diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index d90090b846ab..c451f1da3cdd 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -250,11 +250,10 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, struct coresight_path *path) { int ret = 0; - pid_t pid; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); struct perf_output_handle *handle = path->handle; - struct cs_buffers *buf = etm_perf_sink_config(handle); + struct etm_event_data *event_data = perf_get_aux(handle);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); do { @@ -270,10 +269,8 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, break; }
- /* Get a handle on the pid of the process to monitor */ - pid = buf->pid; - - if (drvdata->pid != -1 && drvdata->pid != pid) { + if (!etm_perf_sink_can_share(csdev, &drvdata->perf_session, + handle)) { ret = -EBUSY; break; } @@ -282,19 +279,15 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, if (ret) break;
- /* - * No HW configuration is needed if the sink is already in - * use for this session. - */ - if (drvdata->pid == pid) { + /* No HW configuration is needed if the sink is already in use. */ + if (csdev->refcnt) { csdev->refcnt++; break; }
ret = tmc_etb_enable_hw(drvdata); if (!ret) { - /* Associate with monitored process. */ - drvdata->pid = pid; + drvdata->perf_session = event_data->session_id; coresight_set_mode(csdev, CS_MODE_PERF); csdev->refcnt++; } @@ -351,9 +344,8 @@ static int tmc_disable_etf_sink(struct coresight_device *csdev) /* Complain if we (somehow) got out of sync */ WARN_ON_ONCE(coresight_get_mode(csdev) == CS_MODE_DISABLED); tmc_etb_disable_hw(drvdata); - /* Dissociate from monitored process. */ - drvdata->pid = -1; coresight_set_mode(csdev, CS_MODE_DISABLED); + drvdata->perf_session = (struct etm_session_id) {};
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -433,7 +425,6 @@ static void *tmc_alloc_etf_buffer(struct coresight_device *csdev, if (!buf) return NULL;
- buf->pid = task_pid_nr(event->owner); buf->snapshot = overwrite; buf->nr_pages = nr_pages; buf->data_pages = pages; diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 0125f2ad78ed..99601ac9179d 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -223,9 +223,6 @@ struct tmc_resrv_buf { * @crashdev: specifics to handle "/dev/crash_tmc_xyz" entry for reading * crash tracedata. * @spinlock: only one at a time pls. - * @pid: Process ID of the process that owns the session that is using - * this component. For example this would be the pid of the Perf - * process. * @sysfs_reading: Sysfs mode buffer is being read through "/dev/xyz.tmc" entry. * Note: ETR has a separate software buffer for the two modes so * the device can still be read while in Perf mode if there is a @@ -264,7 +261,6 @@ struct tmc_drvdata { struct miscdevice miscdev; struct miscdevice crashdev; raw_spinlock_t spinlock; - pid_t pid; bool sysfs_reading; bool stop_on_flush; union {