[PATCH v2 2/2] reorder: add ability to set min sequence number

[Volodymyr Fialko <vfialko@marvell.com>]

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@marvell.com>
---
 app/test/test_reorder.c   | 69 +++++++++++++++++++++++++++++++++++++++
 lib/reorder/rte_reorder.c | 31 ++++++++++++++++++
 lib/reorder/rte_reorder.h | 18 ++++++++++
 lib/reorder/version.map   |  1 +
 4 files changed, 119 insertions(+)

diff --git a/app/test/test_reorder.c b/app/test/test_reorder.c
index a37dc28f65..f391597a78 100644
--- a/app/test/test_reorder.c
+++ b/app/test/test_reorder.c
@@ -427,6 +427,74 @@ test_reorder_drain_up_to_seqn(void)
 	return ret;
 }
 
+static int
+test_reorder_set_seqn(void)
+{
+	struct rte_mempool *p = test_params->p;
+	struct rte_reorder_buffer *b = NULL;
+	const unsigned int num_bufs = 7;
+	const unsigned int size = 4;
+	unsigned int i;
+	int ret = 0;
+
+	struct rte_mbuf *bufs[num_bufs];
+
+	/* This would create a reorder buffer instance consisting of:
+	 * reorder_seq = 0
+	 * ready_buf: RB[size] = {NULL, NULL, NULL, NULL}
+	 * order_buf: OB[size] = {NULL, NULL, NULL, NULL}
+	 */
+	b = rte_reorder_create("test_min_seqn_set", rte_socket_id(), size);
+	TEST_ASSERT_NOT_NULL(b, "Failed to create reorder buffer");
+
+	for (i = 0; i < num_bufs; i++) {
+		bufs[i] = rte_pktmbuf_alloc(p);
+		if (bufs[i] == NULL) {
+			printf("Packet allocation failed\n");
+			goto exit;
+		}
+		*rte_reorder_seqn(bufs[i]) = i;
+	}
+
+	ret = rte_reorder_min_seqn_set(b, 5);
+	if (ret != 0) {
+		printf("%s:%d: Error in setting min sequence number\n", __func__, __LINE__);
+		ret = -1;
+		goto exit;
+	}
+
+	ret = rte_reorder_insert(b, bufs[0]);
+	if (ret >= 0) {
+		printf("%s:%d: Insertion with value less the min seq number\n", __func__, __LINE__);
+		ret = -1;
+		goto exit;
+	}
+
+	ret = rte_reorder_insert(b, bufs[5]);
+	if (ret != 0) {
+		printf("%s:%d: Error inserting packet with valid seqn\n", __func__, __LINE__);
+		ret = -1;
+		goto exit;
+	}
+	bufs[5] = NULL;
+
+	ret = rte_reorder_min_seqn_set(b, 0);
+	if (ret >= 0) {
+		printf("%s:%d: Error in setting min sequence number with non-empty buffer\n",
+				__func__, __LINE__);
+		ret = -1;
+		goto exit;
+	}
+
+	ret = 0;
+exit:
+	rte_reorder_free(b);
+	for (i = 0; i < num_bufs; i++)
+		rte_pktmbuf_free(bufs[i]);
+
+	return ret;
+}
+
 static int
 test_setup(void)
 {
@@ -478,6 +546,7 @@ static struct unit_test_suite reorder_test_suite  = {
 		TEST_CASE(test_reorder_insert),
 		TEST_CASE(test_reorder_drain),
 		TEST_CASE(test_reorder_drain_up_to_seqn),
+		TEST_CASE(test_reorder_set_seqn),
 		TEST_CASES_END()
 	}
 };
diff --git a/lib/reorder/rte_reorder.c b/lib/reorder/rte_reorder.c
index bd0e1f8793..6e029c9e02 100644
--- a/lib/reorder/rte_reorder.c
+++ b/lib/reorder/rte_reorder.c
@@ -485,3 +485,34 @@ 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, rte_reorder_seqn_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 db740495be..cc95015fa6 100644
--- a/lib/reorder/rte_reorder.h
+++ b/lib/reorder/rte_reorder.h
@@ -193,6 +193,24 @@ 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, rte_reorder_seqn_t min_seqn);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/reorder/version.map b/lib/reorder/version.map
index d322da03bd..e21b91f526 100644
--- a/lib/reorder/version.map
+++ b/lib/reorder/version.map
@@ -18,4 +18,5 @@ EXPERIMENTAL {
 	rte_reorder_seqn_dynfield_offset;
 	# added in 23.03
 	rte_reorder_drain_up_to_seqn;
+	rte_reorder_min_seqn_set;
 };
-- 
2.34.1