diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 61d849b11c268cf44b27e34be16bd895f43ecd04..73160cd0e0d16d9e81885f46548d4dd45c1d8dc5 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -109,6 +109,24 @@ static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata) CS_LOCK(drvdata->base); } +/* + * Return the available trace data in the buffer from @pos, with + * a maximum limit of @len, updating the @bufpp on where to + * find it. + */ +ssize_t tmc_etb_get_sysfs_trace(struct tmc_drvdata *drvdata, + loff_t pos, size_t len, char **bufpp) +{ + ssize_t actual = len; + + /* Adjust the len to available size @pos */ + if (pos + actual > drvdata->len) + actual = drvdata->len - pos; + if (actual > 0) + *bufpp = drvdata->buf + pos; + return actual; +} + static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev) { int ret = 0; diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 02f747afa2bacf80c6669df6147a7690b63c579f..f88342d400ef3e8f83f5537e9bd523de093278ea 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -58,6 +58,40 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata) CS_LOCK(drvdata->base); } +/* + * Return the available trace data in the buffer @pos, with a maximum + * limit of @len, also updating the @bufpp on where to find it. + */ +ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata, + loff_t pos, size_t len, char **bufpp) +{ + ssize_t actual = len; + char *bufp = drvdata->buf + pos; + char *bufend = (char *)(drvdata->vaddr + drvdata->size); + + /* Adjust the len to available size @pos */ + if (pos + actual > drvdata->len) + actual = drvdata->len - pos; + + if (actual <= 0) + return actual; + + /* + * Since we use a circular buffer, with trace data starting + * @drvdata->buf, possibly anywhere in the buffer @drvdata->vaddr, + * wrap the current @pos to within the buffer. + */ + if (bufp >= bufend) + bufp -= drvdata->size; + /* + * For simplicity, avoid copying over a wrapped around buffer. + */ + if ((bufp + actual) > bufend) + actual = bufend - bufp; + *bufpp = bufp; + return actual; +} + static void tmc_etr_dump_hw(struct tmc_drvdata *drvdata) { const u32 *barrier; diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c index 456f122df74f4a2256e53caac36e5c4d8141f5a3..bb57e7f57eb5d8aa99703b222ffa72a99a285fc3 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.c +++ b/drivers/hwtracing/coresight/coresight-tmc.c @@ -123,35 +123,40 @@ static int tmc_open(struct inode *inode, struct file *file) return 0; } +static inline ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata, + loff_t pos, size_t len, char **bufpp) +{ + switch (drvdata->config_type) { + case TMC_CONFIG_TYPE_ETB: + case TMC_CONFIG_TYPE_ETF: + return tmc_etb_get_sysfs_trace(drvdata, pos, len, bufpp); + case TMC_CONFIG_TYPE_ETR: + return tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp); + } + + return -EINVAL; +} + static ssize_t tmc_read(struct file *file, char __user *data, size_t len, loff_t *ppos) { + char *bufp; + ssize_t actual; struct tmc_drvdata *drvdata = container_of(file->private_data, struct tmc_drvdata, miscdev); - char *bufp = drvdata->buf + *ppos; - - if (*ppos + len > drvdata->len) - len = drvdata->len - *ppos; - - if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) { - if (bufp == (char *)(drvdata->vaddr + drvdata->size)) - bufp = drvdata->vaddr; - else if (bufp > (char *)(drvdata->vaddr + drvdata->size)) - bufp -= drvdata->size; - if ((bufp + len) > (char *)(drvdata->vaddr + drvdata->size)) - len = (char *)(drvdata->vaddr + drvdata->size) - bufp; - } + actual = tmc_get_sysfs_trace(drvdata, *ppos, len, &bufp); + if (actual <= 0) + return 0; - if (copy_to_user(data, bufp, len)) { + if (copy_to_user(data, bufp, actual)) { dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__); return -EFAULT; } - *ppos += len; + *ppos += actual; + dev_dbg(drvdata->dev, "%zu bytes copied\n", actual); - dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n", - __func__, len, (int)(drvdata->len - *ppos)); - return len; + return actual; } static int tmc_release(struct inode *inode, struct file *file) diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index dfaff077a7fc7f149a708dd418c190d6e2072db1..1d7cd582919bbab660360df44e8b2c5b66a28e95 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -172,10 +172,14 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata); extern const struct coresight_ops tmc_etb_cs_ops; extern const struct coresight_ops tmc_etf_cs_ops; +ssize_t tmc_etb_get_sysfs_trace(struct tmc_drvdata *drvdata, + loff_t pos, size_t len, char **bufpp); /* ETR functions */ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata); int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata); extern const struct coresight_ops tmc_etr_cs_ops; +ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata, + loff_t pos, size_t len, char **bufpp); #define TMC_REG_PAIR(name, lo_off, hi_off) \