[PATCH 2/3] reorder: add ability to set min sequence number

[Volodymyr Fialko]

Add API `rte_reorder_min_seqn_set` to allow user to specify minimum
sequence number.
Currently sequence number of first inserted packet is used as minimum
sequence number. But for case when we want to wait for packets before
the received one this will not work.

Signed-off-by: Volodymyr Fialko <vfialko at marvell.com>
---
 lib/reorder/rte_reorder.c | 31 +++++++++++++++++++++++++++++++
 lib/reorder/rte_reorder.h | 18 ++++++++++++++++++
 lib/reorder/version.map   |  1 +
 3 files changed, 50 insertions(+)

diff --git a/lib/reorder/rte_reorder.c b/lib/reorder/rte_reorder.c
index 57cc1b286b..0d4c7209f9 100644
--- a/lib/reorder/rte_reorder.c
+++ b/lib/reorder/rte_reorder.c
@@ -483,3 +483,34 @@ rte_reorder_drain_up_to_seqn(struct rte_reorder_buffer *b, struct rte_mbuf **mbu
 
 	return drain_cnt;
 }
+
+static bool
+rte_reorder_is_empty(const struct rte_reorder_buffer *b)
+{
+	const struct cir_buffer *order_buf = &b->order_buf, *ready_buf = &b->ready_buf;
+	unsigned int i;
+
+	/* Ready buffer does not have gaps */
+	if (ready_buf->tail != ready_buf->head)
+		return false;
+
+	/* Order buffer could have gaps, iterate */
+	for (i = 0; i < order_buf->size; i++) {
+		if (order_buf->entries[i] != NULL)
+			return false;
+	}
+
+	return true;
+}
+
+unsigned int
+rte_reorder_min_seqn_set(struct rte_reorder_buffer *b, uint32_t min_seqn)
+{
+	if (!rte_reorder_is_empty(b))
+		return -ENOTEMPTY;
+
+	b->min_seqn = min_seqn;
+	b->is_initialized = true;
+
+	return 0;
+}
diff --git a/lib/reorder/rte_reorder.h b/lib/reorder/rte_reorder.h
index c5b354b53d..9f6710bad2 100644
--- a/lib/reorder/rte_reorder.h
+++ b/lib/reorder/rte_reorder.h
@@ -192,6 +192,24 @@ __rte_experimental
 unsigned int
 rte_reorder_drain_up_to_seqn(struct rte_reorder_buffer *b, struct rte_mbuf **mbufs,
 		unsigned int max_mbufs, rte_reorder_seqn_t seqn);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Set minimum sequence number of packet allowed to be buffered.
+ * To successfully set new value reorder buffer has to be empty(after create, reset or drain_all).
+ *
+ * @param b
+ *   Empty reorder buffer instance to modify.
+ * @param min_seqn
+ *   New sequence number to set.
+ * @return
+ *   0 on success, a negative value otherwise.
+ */
+__rte_experimental
+unsigned int
+rte_reorder_min_seqn_set(struct rte_reorder_buffer *b, uint32_t min_seqn);
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/reorder/version.map b/lib/reorder/version.map
index e3f41ea7ef..aafdf0b5ae 100644
--- a/lib/reorder/version.map
+++ b/lib/reorder/version.map
@@ -17,4 +17,5 @@ EXPERIMENTAL {
 
 	rte_reorder_seqn_dynfield_offset;
 	rte_reorder_drain_up_to_seqn;
+	rte_reorder_min_seqn_set;
 };
-- 
2.34.1