[PATCH RFC net-next v4 09/14] xsk: extend xskq_cons_read_desc_batch to count nb_pkts

[Jason Xing <kerneljasonxing@gmail.com>]

From: Jason Xing <kernelxing@tencent.com>

Add a new parameter nb_pkts to count how many packets are needed
practically by copy mode with the help of XDP_PKT_CONTD option.

Add descs to provide a way to pass xs->desc_cache to store the
descriptors for copy mode.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
---
 net/xdp/xsk_queue.h | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index ec08d9c102b1..354f6fe86893 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -263,12 +263,12 @@ static inline void parse_desc(struct xsk_queue *q, struct xsk_buff_pool *pool,
 	parsed->mb = xp_mb_desc(desc);
 }
 
-static inline
-u32 xskq_cons_read_desc_batch(struct xsk_queue *q, struct xsk_buff_pool *pool,
-			      u32 max)
+static inline u32
+__xskq_cons_read_desc_batch(struct xsk_queue *q, struct xsk_buff_pool *pool,
+			    struct xdp_desc *descs, u32 max, u32 *nb_pkts,
+			    u32 max_segs)
 {
 	u32 cached_cons = q->cached_cons, nb_entries = 0;
-	struct xdp_desc *descs = pool->tx_descs;
 	u32 total_descs = 0, nr_frags = 0;
 
 	/* track first entry, if stumble upon *any* invalid descriptor, rewind
@@ -288,9 +288,11 @@ u32 xskq_cons_read_desc_batch(struct xsk_queue *q, struct xsk_buff_pool *pool,
 		if (likely(!parsed.mb)) {
 			total_descs += (nr_frags + 1);
 			nr_frags = 0;
+			if (nb_pkts)
+				(*nb_pkts)++;
 		} else {
 			nr_frags++;
-			if (nr_frags == pool->xdp_zc_max_segs) {
+			if (nr_frags == max_segs) {
 				nr_frags = 0;
 				break;
 			}
@@ -304,6 +306,14 @@ u32 xskq_cons_read_desc_batch(struct xsk_queue *q, struct xsk_buff_pool *pool,
 	return total_descs;
 }
 
+static inline u32
+xskq_cons_read_desc_batch(struct xsk_queue *q, struct xsk_buff_pool *pool,
+			  u32 max)
+{
+	return __xskq_cons_read_desc_batch(q, pool, pool->tx_descs, max,
+					   NULL, pool->xdp_zc_max_segs);
+}
+
 /* Functions for consumers */
 
 static inline void __xskq_cons_release(struct xsk_queue *q)
-- 
2.41.3