brcmfmac: add AMPDU reordering functionality

This feature moves the responsibility of collecting all MPDUs in an
AMPDU session in the correct order from the firmware to the host
driver. This reduces buffer requirement on the firmware side.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 245 insertions, 25 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
index 80099016d21f..9bc2785b4240 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
@@ -38,6 +38,19 @@ MODULE_LICENSE("Dual BSD/GPL");
 
 #define MAX_WAIT_FOR_8021X_TX		50	/* msecs */
 
+/* AMPDU rx reordering definitions */
+#define BRCMF_RXREORDER_FLOWID_OFFSET		0
+#define BRCMF_RXREORDER_MAXIDX_OFFSET		2
+#define BRCMF_RXREORDER_FLAGS_OFFSET		4
+#define BRCMF_RXREORDER_CURIDX_OFFSET		6
+#define BRCMF_RXREORDER_EXPIDX_OFFSET		8
+
+#define BRCMF_RXREORDER_DEL_FLOW		0x01
+#define BRCMF_RXREORDER_FLUSH_ALL		0x02
+#define BRCMF_RXREORDER_CURIDX_VALID		0x04
+#define BRCMF_RXREORDER_EXPIDX_VALID		0x08
+#define BRCMF_RXREORDER_NEW_HOLE		0x10
+
 /* Error bits */
 int brcmf_msg_level;
 module_param_named(debug, brcmf_msg_level, int, S_IRUSR | S_IWUSR);
@@ -279,16 +292,243 @@ void brcmf_txflowblock(struct device *dev, bool state)
 	}
 }
 
+static void brcmf_netif_rx(struct brcmf_if *ifp, struct sk_buff *skb)
+{
+	skb->dev = ifp->ndev;
+	skb->protocol = eth_type_trans(skb, skb->dev);
+
+	if (skb->pkt_type == PACKET_MULTICAST)
+		ifp->stats.multicast++;
+
+	/* Process special event packets */
+	brcmf_fweh_process_skb(ifp->drvr, skb);
+
+	if (!(ifp->ndev->flags & IFF_UP)) {
+		brcmu_pkt_buf_free_skb(skb);
+		return;
+	}
+
+	ifp->stats.rx_bytes += skb->len;
+	ifp->stats.rx_packets++;
+
+	brcmf_dbg(DATA, "rx proto=0x%X\n", ntohs(skb->protocol));
+	if (in_interrupt())
+		netif_rx(skb);
+	else
+		/* If the receive is not processed inside an ISR,
+		 * the softirqd must be woken explicitly to service
+		 * the NET_RX_SOFTIRQ.  This is handled by netif_rx_ni().
+		 */
+		netif_rx_ni(skb);
+}
+
+static void brcmf_rxreorder_get_skb_list(struct brcmf_ampdu_rx_reorder *rfi,
+					 u8 start, u8 end,
+					 struct sk_buff_head *skb_list)
+{
+	/* initialize return list */
+	__skb_queue_head_init(skb_list);
+
+	if (rfi->pend_pkts == 0) {
+		brcmf_dbg(INFO, "no packets in reorder queue\n");
+		return;
+	}
+
+	do {
+		if (rfi->pktslots[start]) {
+			__skb_queue_tail(skb_list, rfi->pktslots[start]);
+			rfi->pktslots[start] = NULL;
+		}
+		start++;
+		if (start > rfi->max_idx)
+			start = 0;
+	} while (start != end);
+	rfi->pend_pkts -= skb_queue_len(skb_list);
+}
+
+static void brcmf_rxreorder_process_info(struct brcmf_if *ifp, u8 *reorder_data,
+					 struct sk_buff *pkt)
+{
+	u8 flow_id, max_idx, cur_idx, exp_idx, end_idx;
+	struct brcmf_ampdu_rx_reorder *rfi;
+	struct sk_buff_head reorder_list;
+	struct sk_buff *pnext;
+	u8 flags;
+	u32 buf_size;
+
+	flow_id = reorder_data[BRCMF_RXREORDER_FLOWID_OFFSET];
+	flags = reorder_data[BRCMF_RXREORDER_FLAGS_OFFSET];
+
+	/* validate flags and flow id */
+	if (flags == 0xFF) {
+		brcmf_err("invalid flags...so ignore this packet\n");
+		brcmf_netif_rx(ifp, pkt);
+		return;
+	}
+
+	rfi = ifp->drvr->reorder_flows[flow_id];
+	if (flags & BRCMF_RXREORDER_DEL_FLOW) {
+		brcmf_dbg(INFO, "flow-%d: delete\n",
+			  flow_id);
+
+		if (rfi == NULL) {
+			brcmf_dbg(INFO, "received flags to cleanup, but no flow (%d) yet\n",
+				  flow_id);
+			brcmf_netif_rx(ifp, pkt);
+			return;
+		}
+
+		brcmf_rxreorder_get_skb_list(rfi, rfi->exp_idx, rfi->exp_idx,
+					     &reorder_list);
+		/* add the last packet */
+		__skb_queue_tail(&reorder_list, pkt);
+		kfree(rfi);
+		ifp->drvr->reorder_flows[flow_id] = NULL;
+		goto netif_rx;
+	}
+	/* from here on we need a flow reorder instance */
+	if (rfi == NULL) {
+		buf_size = sizeof(*rfi);
+		max_idx = reorder_data[BRCMF_RXREORDER_MAXIDX_OFFSET];
+
+		buf_size += (max_idx + 1) * sizeof(pkt);
+
+		/* allocate space for flow reorder info */
+		brcmf_dbg(INFO, "flow-%d: start, maxidx %d\n",
+			  flow_id, max_idx);
+		rfi = kzalloc(buf_size, GFP_ATOMIC);
+		if (rfi == NULL) {
+			brcmf_err("failed to alloc buffer\n");
+			brcmf_netif_rx(ifp, pkt);
+			return;
+		}
+
+		ifp->drvr->reorder_flows[flow_id] = rfi;
+		rfi->pktslots = (struct sk_buff **)(rfi+1);
+		rfi->max_idx = max_idx;
+	}
+	if (flags & BRCMF_RXREORDER_NEW_HOLE)  {
+		if (rfi->pend_pkts) {
+			brcmf_rxreorder_get_skb_list(rfi, rfi->exp_idx,
+						     rfi->exp_idx,
+						     &reorder_list);
+			WARN_ON(rfi->pend_pkts);
+		} else {
+			__skb_queue_head_init(&reorder_list);
+		}
+		rfi->cur_idx = reorder_data[BRCMF_RXREORDER_CURIDX_OFFSET];
+		rfi->exp_idx = reorder_data[BRCMF_RXREORDER_EXPIDX_OFFSET];
+		rfi->max_idx = reorder_data[BRCMF_RXREORDER_MAXIDX_OFFSET];
+		rfi->pktslots[rfi->cur_idx] = pkt;
+		rfi->pend_pkts++;
+		brcmf_dbg(DATA, "flow-%d: new hole %d (%d), pending %d\n",
+			  flow_id, rfi->cur_idx, rfi->exp_idx, rfi->pend_pkts);
+	} else if (flags & BRCMF_RXREORDER_CURIDX_VALID) {
+		cur_idx = reorder_data[BRCMF_RXREORDER_CURIDX_OFFSET];
+		exp_idx = reorder_data[BRCMF_RXREORDER_EXPIDX_OFFSET];
+
+		if ((exp_idx == rfi->exp_idx) && (cur_idx != rfi->exp_idx)) {
+			/* still in the current hole */
+			/* enqueue the current on the buffer chain */
+			if (rfi->pktslots[cur_idx] != NULL) {
+				brcmf_dbg(INFO, "HOLE: ERROR buffer pending..free it\n");
+				brcmu_pkt_buf_free_skb(rfi->pktslots[cur_idx]);
+				rfi->pktslots[cur_idx] = NULL;
+			}
+			rfi->pktslots[cur_idx] = pkt;
+			rfi->pend_pkts++;
+			rfi->cur_idx = cur_idx;
+			brcmf_dbg(DATA, "flow-%d: store pkt %d (%d), pending %d\n",
+				  flow_id, cur_idx, exp_idx, rfi->pend_pkts);
+
+			/* can return now as there is no reorder
+			 * list to process.
+			 */
+			return;
+		}
+		if (rfi->exp_idx == cur_idx) {
+			if (rfi->pktslots[cur_idx] != NULL) {
+				brcmf_dbg(INFO, "error buffer pending..free it\n");
+				brcmu_pkt_buf_free_skb(rfi->pktslots[cur_idx]);
+				rfi->pktslots[cur_idx] = NULL;
+			}
+			rfi->pktslots[cur_idx] = pkt;
+			rfi->pend_pkts++;
+
+			/* got the expected one. flush from current to expected
+			 * and update expected
+			 */
+			brcmf_dbg(DATA, "flow-%d: expected %d (%d), pending %d\n",
+				  flow_id, cur_idx, exp_idx, rfi->pend_pkts);
+
+			rfi->cur_idx = cur_idx;
+			rfi->exp_idx = exp_idx;
+
+			brcmf_rxreorder_get_skb_list(rfi, cur_idx, exp_idx,
+						     &reorder_list);
+			brcmf_dbg(DATA, "flow-%d: freeing buffers %d, pending %d\n",
+				  flow_id, skb_queue_len(&reorder_list),
+				  rfi->pend_pkts);
+		} else {
+			u8 end_idx;
+
+			brcmf_dbg(DATA, "flow-%d (0x%x): both moved, old %d/%d, new %d/%d\n",
+				  flow_id, flags, rfi->cur_idx, rfi->exp_idx,
+				  cur_idx, exp_idx);
+			if (flags & BRCMF_RXREORDER_FLUSH_ALL)
+				end_idx = rfi->exp_idx;
+			else
+				end_idx = exp_idx;
+
+			/* flush pkts first */
+			brcmf_rxreorder_get_skb_list(rfi, rfi->exp_idx, end_idx,
+						     &reorder_list);
+
+			if (exp_idx == ((cur_idx + 1) % (rfi->max_idx + 1))) {
+				__skb_queue_tail(&reorder_list, pkt);
+			} else {
+				rfi->pktslots[cur_idx] = pkt;
+				rfi->pend_pkts++;
+			}
+			rfi->exp_idx = exp_idx;
+			rfi->cur_idx = cur_idx;
+		}
+	} else {
+		/* explicity window move updating the expected index */
+		exp_idx = reorder_data[BRCMF_RXREORDER_EXPIDX_OFFSET];
+
+		brcmf_dbg(DATA, "flow-%d (0x%x): change expected: %d -> %d\n",
+			  flow_id, flags, rfi->exp_idx, exp_idx);
+		if (flags & BRCMF_RXREORDER_FLUSH_ALL)
+			end_idx =  rfi->exp_idx;
+		else
+			end_idx =  exp_idx;
+
+		brcmf_rxreorder_get_skb_list(rfi, rfi->exp_idx, end_idx,
+					     &reorder_list);
+		__skb_queue_tail(&reorder_list, pkt);
+		/* set the new expected idx */
+		rfi->exp_idx = exp_idx;
+	}
+netif_rx:
+	skb_queue_walk_safe(&reorder_list, pkt, pnext) {
+		__skb_unlink(pkt, &reorder_list);
+		brcmf_netif_rx(ifp, pkt);
+	}
+}
+
 void brcmf_rx_frames(struct device *dev, struct sk_buff_head *skb_list)
 {
 	struct sk_buff *skb, *pnext;
 	struct brcmf_if *ifp;
 	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
 	struct brcmf_pub *drvr = bus_if->drvr;
+	struct brcmf_skb_reorder_data *rd;
 	u8 ifidx;
 	int ret;
 
-	brcmf_dbg(DATA, "Enter\n");
+	brcmf_dbg(DATA, "Enter: %s: count=%u\n", dev_name(dev),
+		  skb_queue_len(skb_list));
 
 	skb_queue_walk_safe(skb_list, skb, pnext) {
 		skb_unlink(skb, skb_list);
@@ -304,31 +544,11 @@ void brcmf_rx_frames(struct device *dev, struct sk_buff_head *skb_list)
 			continue;
 		}
 
-		skb->dev = ifp->ndev;
-		skb->protocol = eth_type_trans(skb, skb->dev);
-
-		if (skb->pkt_type == PACKET_MULTICAST)
-			ifp->stats.multicast++;
-
-		/* Process special event packets */
-		brcmf_fweh_process_skb(drvr, skb);
-
-		if (!(ifp->ndev->flags & IFF_UP)) {
-			brcmu_pkt_buf_free_skb(skb);
-			continue;
-		}
-
-		ifp->stats.rx_bytes += skb->len;
-		ifp->stats.rx_packets++;
-
-		if (in_interrupt())
-			netif_rx(skb);
+		rd = (struct brcmf_skb_reorder_data *)skb->cb;
+		if (rd->reorder)
+			brcmf_rxreorder_process_info(ifp, rd->reorder, skb);
 		else
-			/* If the receive is not processed inside an ISR,
-			 * the softirqd must be woken explicitly to service the
-			 * NET_RX_SOFTIRQ. This is handled by netif_rx_ni().
-			 */
-			netif_rx_ni(skb);
+			brcmf_netif_rx(ifp, skb);
 	}
 }