diff options
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etr.c | 58 | ||||
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc.h | 2 |
2 files changed, 40 insertions, 20 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 11963647e19a..2d6f428176ff 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -895,10 +895,15 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata) tmc_etr_buf_insert_barrier_packet(etr_buf, etr_buf->offset); } -static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata) +static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata, + struct etr_buf *etr_buf) { u32 axictl, sts; - struct etr_buf *etr_buf = drvdata->etr_buf; + + /* Callers should provide an appropriate buffer for use */ + if (WARN_ON(!etr_buf || drvdata->etr_buf)) + return; + drvdata->etr_buf = etr_buf; /* * If this ETR is connected to a CATU, enable it before we turn @@ -960,13 +965,16 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata) * also updating the @bufpp on where to find it. Since the trace data * starts at anywhere in the buffer, depending on the RRP, we adjust the * @len returned to handle buffer wrapping around. + * + * We are protected here by drvdata->reading != 0, which ensures the + * sysfs_buf stays alive. */ ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata, loff_t pos, size_t len, char **bufpp) { s64 offset; ssize_t actual = len; - struct etr_buf *etr_buf = drvdata->etr_buf; + struct etr_buf *etr_buf = drvdata->sysfs_buf; if (pos + actual > etr_buf->len) actual = etr_buf->len - pos; @@ -996,7 +1004,14 @@ tmc_etr_free_sysfs_buf(struct etr_buf *buf) static void tmc_etr_sync_sysfs_buf(struct tmc_drvdata *drvdata) { - tmc_sync_etr_buf(drvdata); + struct etr_buf *etr_buf = drvdata->etr_buf; + + if (WARN_ON(drvdata->sysfs_buf != etr_buf)) { + tmc_etr_free_sysfs_buf(drvdata->sysfs_buf); + drvdata->sysfs_buf = NULL; + } else { + tmc_sync_etr_buf(drvdata); + } } static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) @@ -1017,6 +1032,8 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) /* Disable CATU device if this ETR is connected to one */ tmc_etr_disable_catu(drvdata); + /* Reset the ETR buf used by hardware */ + drvdata->etr_buf = NULL; } static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) @@ -1024,7 +1041,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) int ret = 0; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - struct etr_buf *new_buf = NULL, *free_buf = NULL; + struct etr_buf *sysfs_buf = NULL, *new_buf = NULL, *free_buf = NULL; /* * If we are enabling the ETR from disabled state, we need to make @@ -1035,7 +1052,8 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) * with the lock released. */ spin_lock_irqsave(&drvdata->spinlock, flags); - if (!drvdata->etr_buf || (drvdata->etr_buf->size != drvdata->size)) { + sysfs_buf = READ_ONCE(drvdata->sysfs_buf); + if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) { spin_unlock_irqrestore(&drvdata->spinlock, flags); /* Allocate memory with the locks released */ @@ -1064,14 +1082,14 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) * If we don't have a buffer or it doesn't match the requested size, * use the buffer allocated above. Otherwise reuse the existing buffer. */ - if (!drvdata->etr_buf || - (new_buf && drvdata->etr_buf->size != new_buf->size)) { - free_buf = drvdata->etr_buf; - drvdata->etr_buf = new_buf; + sysfs_buf = READ_ONCE(drvdata->sysfs_buf); + if (!sysfs_buf || (new_buf && sysfs_buf->size != new_buf->size)) { + free_buf = sysfs_buf; + drvdata->sysfs_buf = new_buf; } drvdata->mode = CS_MODE_SYSFS; - tmc_etr_enable_hw(drvdata); + tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -1156,13 +1174,13 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) goto out; } - /* If drvdata::etr_buf is NULL the trace data has been read already */ - if (drvdata->etr_buf == NULL) { + /* If sysfs_buf is NULL the trace data has been read already */ + if (!drvdata->sysfs_buf) { ret = -EINVAL; goto out; } - /* Disable the TMC if need be */ + /* Disable the TMC if we are trying to read from a running session */ if (drvdata->mode == CS_MODE_SYSFS) tmc_etr_disable_hw(drvdata); @@ -1176,7 +1194,7 @@ out: int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) { unsigned long flags; - struct etr_buf *etr_buf = NULL; + struct etr_buf *sysfs_buf = NULL; /* config types are set a boot time and never change */ if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR)) @@ -1191,22 +1209,22 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) * buffer. Since the tracer is still enabled drvdata::buf can't * be NULL. */ - tmc_etr_enable_hw(drvdata); + tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf); } else { /* * The ETR is not tracing and the buffer was just read. * As such prepare to free the trace buffer. */ - etr_buf = drvdata->etr_buf; - drvdata->etr_buf = NULL; + sysfs_buf = drvdata->sysfs_buf; + drvdata->sysfs_buf = NULL; } drvdata->reading = false; spin_unlock_irqrestore(&drvdata->spinlock, flags); /* Free allocated memory out side of the spinlock */ - if (etr_buf) - tmc_free_etr_buf(etr_buf); + if (sysfs_buf) + tmc_etr_free_sysfs_buf(sysfs_buf); return 0; } diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 7027bd60c4cc..872f63e3651b 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -170,6 +170,7 @@ struct etr_buf { * @trigger_cntr: amount of words to store after a trigger. * @etr_caps: Bitmask of capabilities of the TMC ETR, inferred from the * device configuration register (DEVID) + * @sysfs_data: SYSFS buffer for ETR. */ struct tmc_drvdata { void __iomem *base; @@ -189,6 +190,7 @@ struct tmc_drvdata { enum tmc_mem_intf_width memwidth; u32 trigger_cntr; u32 etr_caps; + struct etr_buf *sysfs_buf; }; struct etr_buf_operations { |