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-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etf.c18
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etr.c34
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc.c41
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc.h4
4 files changed, 79 insertions, 18 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 61d849b11c26..73160cd0e0d1 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 02f747afa2ba..f88342d400ef 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 456f122df74f..bb57e7f57eb5 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 dfaff077a7fc..1d7cd582919b 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) \