vhost: rework mergeable Rx

Extract codes into a function:
update_secure_len which is used to accumulate the buffer len in the
vring descriptors and to fill struct buf_vec.

Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
Acked-by: Huawei Xie <huawei.xie@intel.com>

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index c547096..37609e0 100644 (file)
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -436,6 +436,34 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint16_t res_base_idx,
        return entry_success;
 }
 
+static inline void __attribute__((always_inline))
+update_secure_len(struct vhost_virtqueue *vq, uint32_t id,
+       uint32_t *secure_len, uint32_t *vec_idx)
+{
+       uint16_t wrapped_idx = id & (vq->size - 1);
+       uint32_t idx = vq->avail->ring[wrapped_idx];
+       uint8_t next_desc;
+       uint32_t len = *secure_len;
+       uint32_t vec_id = *vec_idx;
+
+       do {
+               next_desc = 0;
+               len += vq->desc[idx].len;
+               vq->buf_vec[vec_id].buf_addr = vq->desc[idx].addr;
+               vq->buf_vec[vec_id].buf_len = vq->desc[idx].len;
+               vq->buf_vec[vec_id].desc_idx = idx;
+               vec_id++;
+
+               if (vq->desc[idx].flags & VRING_DESC_F_NEXT) {
+                       idx = vq->desc[idx].next;
+                       next_desc = 1;
+               }
+       } while (next_desc);
+
+       *secure_len = len;
+       *vec_idx = vec_id;
+}
+
 /*
  * This function works for mergeable RX.
  */
@@ -445,8 +473,8 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 {
        struct vhost_virtqueue *vq;
        uint32_t pkt_idx = 0, entry_success = 0;
-       uint16_t avail_idx, res_cur_idx;
-       uint16_t res_base_idx, res_end_idx;
+       uint16_t avail_idx;
+       uint16_t res_base_idx, res_cur_idx;
        uint8_t success = 0;
 
        LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_merge_rx()\n",
@@ -462,17 +490,16 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
                return 0;
 
        for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
-               uint32_t secure_len = 0;
-               uint16_t need_cnt;
-               uint32_t vec_idx = 0;
                uint32_t pkt_len = pkts[pkt_idx]->pkt_len + vq->vhost_hlen;
-               uint16_t i, id;
 
                do {
                        /*
                         * As many data cores may want access to available
                         * buffers, they need to be reserved.
                         */
+                       uint32_t secure_len = 0;
+                       uint32_t vec_idx = 0;
+
                        res_base_idx = vq->last_used_idx_res;
                        res_cur_idx = res_base_idx;
 
@@ -486,22 +513,7 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
                                                dev->device_fh);
                                        return pkt_idx;
                                } else {
-                                       uint16_t wrapped_idx =
-                                               (res_cur_idx) & (vq->size - 1);
-                                       uint32_t idx =
-                                               vq->avail->ring[wrapped_idx];
-                                       uint8_t next_desc;
-
-                                       do {
-                                               next_desc = 0;
-                                               secure_len += vq->desc[idx].len;
-                                               if (vq->desc[idx].flags &
-                                                       VRING_DESC_F_NEXT) {
-                                                       idx = vq->desc[idx].next;
-                                                       next_desc = 1;
-                                               }
-                                       } while (next_desc);
-
+                                       update_secure_len(vq, res_cur_idx, &secure_len, &vec_idx);
                                        res_cur_idx++;
                                }
                        } while (pkt_len > secure_len);
@@ -512,33 +524,8 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
                                                        res_cur_idx);
                } while (success == 0);
 
-               id = res_base_idx;
-               need_cnt = res_cur_idx - res_base_idx;
-
-               for (i = 0; i < need_cnt; i++, id++) {
-                       uint16_t wrapped_idx = id & (vq->size - 1);
-                       uint32_t idx = vq->avail->ring[wrapped_idx];
-                       uint8_t next_desc;
-                       do {
-                               next_desc = 0;
-                               vq->buf_vec[vec_idx].buf_addr =
-                                       vq->desc[idx].addr;
-                               vq->buf_vec[vec_idx].buf_len =
-                                       vq->desc[idx].len;
-                               vq->buf_vec[vec_idx].desc_idx = idx;
-                               vec_idx++;
-
-                               if (vq->desc[idx].flags & VRING_DESC_F_NEXT) {
-                                       idx = vq->desc[idx].next;
-                                       next_desc = 1;
-                               }
-                       } while (next_desc);
-               }
-
-               res_end_idx = res_cur_idx;
-
                entry_success = copy_from_mbuf_to_vring(dev, res_base_idx,
-                       res_end_idx, pkts[pkt_idx]);
+                       res_cur_idx, pkts[pkt_idx]);
 
                rte_compiler_barrier();
 
@@ -550,7 +537,7 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
                        rte_pause();
 
                *(volatile uint16_t *)&vq->used->idx += entry_success;
-               vq->last_used_idx = res_end_idx;
+               vq->last_used_idx = res_cur_idx;
 
                /* flush used->idx update before we read avail->flags. */
                rte_mb();