1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/wil6210/rx_reorder.c b/drivers/net/wireless/ath/wil6210/rx_reorder.c
new file mode 100644
index 00000000000..747ae127587
--- /dev/null
+++ b/drivers/net/wireless/ath/wil6210/rx_reorder.c
@@ -0,0 +1,201 @@
+#include "wil6210.h"
+#include "txrx.h"
+
+#define SEQ_MODULO 0x1000
+#define SEQ_MASK   0xfff
+
+static inline int seq_less(u16 sq1, u16 sq2)
+{
+	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
+}
+
+static inline u16 seq_inc(u16 sq)
+{
+	return (sq + 1) & SEQ_MASK;
+}
+
+static inline u16 seq_sub(u16 sq1, u16 sq2)
+{
+	return (sq1 - sq2) & SEQ_MASK;
+}
+
+static inline int reorder_index(struct wil_tid_ampdu_rx *r, u16 seq)
+{
+	return seq_sub(seq, r->ssn) % r->buf_size;
+}
+
+static void wil_release_reorder_frame(struct wil6210_priv *wil,
+				      struct wil_tid_ampdu_rx *r,
+				      int index)
+{
+	struct net_device *ndev = wil_to_ndev(wil);
+	struct sk_buff *skb = r->reorder_buf[index];
+
+	if (!skb)
+		goto no_frame;
+
+	/* release the frame from the reorder ring buffer */
+	r->stored_mpdu_num--;
+	r->reorder_buf[index] = NULL;
+	wil_netif_rx_any(skb, ndev);
+
+no_frame:
+	r->head_seq_num = seq_inc(r->head_seq_num);
+}
+
+static void wil_release_reorder_frames(struct wil6210_priv *wil,
+				       struct wil_tid_ampdu_rx *r,
+				       u16 hseq)
+{
+	int index;
+
+	/* note: this function is never called with
+	 * hseq preceding r->head_seq_num, i.e it is always true
+	 * !seq_less(hseq, r->head_seq_num)
+	 * and thus on loop exit it should be
+	 * r->head_seq_num == hseq
+	 */
+	while (seq_less(r->head_seq_num, hseq) && r->stored_mpdu_num) {
+		index = reorder_index(r, r->head_seq_num);
+		wil_release_reorder_frame(wil, r, index);
+	}
+	r->head_seq_num = hseq;
+}
+
+static void wil_reorder_release(struct wil6210_priv *wil,
+				struct wil_tid_ampdu_rx *r)
+{
+	int index = reorder_index(r, r->head_seq_num);
+
+	while (r->reorder_buf[index]) {
+		wil_release_reorder_frame(wil, r, index);
+		index = reorder_index(r, r->head_seq_num);
+	}
+}
+
+void wil_rx_reorder(struct wil6210_priv *wil, struct sk_buff *skb)
+{
+	struct net_device *ndev = wil_to_ndev(wil);
+	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
+	int tid = wil_rxdesc_tid(d);
+	int cid = wil_rxdesc_cid(d);
+	int mid = wil_rxdesc_mid(d);
+	u16 seq = wil_rxdesc_seq(d);
+	struct wil_sta_info *sta = &wil->sta[cid];
+	struct wil_tid_ampdu_rx *r = sta->tid_rx[tid];
+	u16 hseq;
+	int index;
+
+	wil_dbg_txrx(wil, "MID %d CID %d TID %d Seq 0x%03x\n",
+		     mid, cid, tid, seq);
+
+	if (!r) {
+		wil_netif_rx_any(skb, ndev);
+		return;
+	}
+
+	hseq = r->head_seq_num;
+
+	spin_lock(&r->reorder_lock);
+
+	/** Due to the race between WMI events, where BACK establishment
+	 * reported, and data Rx, few packets may be pass up before reorder
+	 * buffer get allocated. Catch up by pretending SSN is what we
+	 * see in the 1-st Rx packet
+	 */
+	if (r->first_time) {
+		r->first_time = false;
+		if (seq != r->head_seq_num) {
+			wil_err(wil, "Error: 1-st frame with wrong sequence"
+				" %d, should be %d. Fixing...\n", seq,
+				r->head_seq_num);
+			r->head_seq_num = seq;
+			r->ssn = seq;
+		}
+	}
+
+	/* frame with out of date sequence number */
+	if (seq_less(seq, r->head_seq_num)) {
+		dev_kfree_skb(skb);
+		goto out;
+	}
+
+	/*
+	 * If frame the sequence number exceeds our buffering window
+	 * size release some previous frames to make room for this one.
+	 */
+	if (!seq_less(seq, r->head_seq_num + r->buf_size)) {
+		hseq = seq_inc(seq_sub(seq, r->buf_size));
+		/* release stored frames up to new head to stack */
+		wil_release_reorder_frames(wil, r, hseq);
+	}
+
+	/* Now the new frame is always in the range of the reordering buffer */
+
+	index = reorder_index(r, seq);
+
+	/* check if we already stored this frame */
+	if (r->reorder_buf[index]) {
+		dev_kfree_skb(skb);
+		goto out;
+	}
+
+	/*
+	 * If the current MPDU is in the right order and nothing else
+	 * is stored we can process it directly, no need to buffer it.
+	 * If it is first but there's something stored, we may be able
+	 * to release frames after this one.
+	 */
+	if (seq == r->head_seq_num && r->stored_mpdu_num == 0) {
+		r->head_seq_num = seq_inc(r->head_seq_num);
+		wil_netif_rx_any(skb, ndev);
+		goto out;
+	}
+
+	/* put the frame in the reordering buffer */
+	r->reorder_buf[index] = skb;
+	r->reorder_time[index] = jiffies;
+	r->stored_mpdu_num++;
+	wil_reorder_release(wil, r);
+
+out:
+	spin_unlock(&r->reorder_lock);
+}
+
+struct wil_tid_ampdu_rx *wil_tid_ampdu_rx_alloc(struct wil6210_priv *wil,
+						int size, u16 ssn)
+{
+	struct wil_tid_ampdu_rx *r = kzalloc(sizeof(*r), GFP_KERNEL);
+	if (!r)
+		return NULL;
+
+	r->reorder_buf =
+		kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
+	r->reorder_time =
+		kcalloc(size, sizeof(unsigned long), GFP_KERNEL);
+	if (!r->reorder_buf || !r->reorder_time) {
+		kfree(r->reorder_buf);
+		kfree(r->reorder_time);
+		kfree(r);
+		return NULL;
+	}
+
+	spin_lock_init(&r->reorder_lock);
+	r->ssn = ssn;
+	r->head_seq_num = ssn;
+	r->buf_size = size;
+	r->stored_mpdu_num = 0;
+	r->first_time = true;
+	return r;
+}
+
+void wil_tid_ampdu_rx_free(struct wil6210_priv *wil,
+			   struct wil_tid_ampdu_rx *r)
+{
+	if (!r)
+		return;
+	wil_release_reorder_frames(wil, r, r->head_seq_num + r->buf_size);
+	kfree(r->reorder_buf);
+	kfree(r->reorder_time);
+	kfree(r);
+}