This patch adds a helper to insert barrier packets for a given
size (aligned to packet size) at given offset in an etr_buf. This
will be used later for perf mode when we try to start in the
middle of an SG buffer.
Cc: Mathieu Poirier <mathieu.poir...@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 53 ++++++++++++++++++++++---
1 file changed, 47 insertions(+), 6 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c
b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 7551272..8159e84 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1083,18 +1083,59 @@ static ssize_t tmc_etr_buf_get_data(struct etr_buf
*etr_buf,
return etr_buf->ops->get_data(etr_buf, (u64)offset, len, bufpp);
}
+/*
+ * tmc_etr_buf_insert_barrier_packets : Insert barrier packets at @offset upto
+ * @size of bytes in the given buffer. @size should be aligned to the barrier
+ * packet size.
+ *
+ * Returns the new @offset after filling the barriers on success. Otherwise
+ * returns error.
+ */
static inline s64
-tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
+tmc_etr_buf_insert_barrier_packets(struct etr_buf *etr_buf,
+ u64 offset, u64 size)
{
ssize_t len;
char *bufp;
- len = tmc_etr_buf_get_data(etr_buf, offset,
- CORESIGHT_BARRIER_PKT_SIZE, &bufp);
- if (WARN_ON(len <= CORESIGHT_BARRIER_PKT_SIZE))
+ if (size < CORESIGHT_BARRIER_PKT_SIZE)
return -EINVAL;
- coresight_insert_barrier_packet(bufp);
- return offset + CORESIGHT_BARRIER_PKT_SIZE;
+ /*
+ * Normally the size should be aligned to the frame size
+ * of the ETR. Even if it isn't, the decoder looks for a
+ * barrier packet at a frame size aligned offset. So align
+ * the buffer to frame size first and then fill barrier
+ * packets.
+ */
+ do {
+ len = tmc_etr_buf_get_data(etr_buf, offset, size, &bufp);
+ if (WARN_ON(len <= 0))
+ return -EINVAL;
+ /*
+ * We are guaranteed that @bufp will point to a linear range
+ * of @len bytes, where @len <= @size.
+ */
+ size -= len;
+ offset += len;
+ while (len >= CORESIGHT_BARRIER_PKT_SIZE) {
+ coresight_insert_barrier_packet(bufp);
+ bufp += CORESIGHT_BARRIER_PKT_SIZE;
+ len -= CORESIGHT_BARRIER_PKT_SIZE;
+ }
+
+ /* If we reached the end of the buffer, wrap around */
+ if (offset == etr_buf->size)
+ offset -= etr_buf->size;
+ } while (size);
+
+ return offset;
+}
+
+static inline s64
+tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
+{
+ return tmc_etr_buf_insert_barrier_packets(etr_buf, offset,
+ CORESIGHT_BARRIER_PKT_SIZE);
}
/*
--
2.7.4
