drivers/net/wireless/mwifiex/11n_aggr.c

/*
 * Marvell Wireless LAN device driver: 802.11n Aggregation
 *
 * Copyright (C) 2011, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available by writing to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include "decl.h"
#include "ioctl.h"
#include "util.h"
#include "fw.h"
#include "main.h"
#include "wmm.h"
#include "11n.h"
#include "11n_aggr.h"

/*
 * Creates an AMSDU subframe for aggregation into one AMSDU packet.
 *
 * The resultant AMSDU subframe format is -
 *
 * +---- ~ -----+---- ~ ------+---- ~ -----+----- ~ -----+---- ~ -----+
 * |     DA     |     SA      |   Length   | SNAP header |   MSDU     |
 * | data[0..5] | data[6..11] |            |             | data[14..] |
 * +---- ~ -----+---- ~ ------+---- ~ -----+----- ~ -----+---- ~ -----+
 * <--6-bytes--> <--6-bytes--> <--2-bytes--><--8-bytes--> <--n-bytes-->
 *
 * This function also computes the amount of padding required to make the
 * buffer length multiple of 4 bytes.
 *
 * Data => |DA|SA|SNAP-TYPE|........    .|
 * MSDU => |DA|SA|Length|SNAP|......   ..|
 */
static int
mwifiex_11n_form_amsdu_pkt(struct mwifiex_adapter *adapter,
			   struct sk_buff *skb_aggr,
			   struct sk_buff *skb_src, int *pad)

{
	int dt_offset;
	struct rfc_1042_hdr snap = {
		0xaa,		/* LLC DSAP */
		0xaa,		/* LLC SSAP */
		0x03,		/* LLC CTRL */
		{0x00, 0x00, 0x00},	/* SNAP OUI */
		0x0000		/* SNAP type */
			/*
			 * This field will be overwritten
			 * later with ethertype
			 */
	};
	struct tx_packet_hdr *tx_header = NULL;

	skb_put(skb_aggr, sizeof(*tx_header));

	tx_header = (struct tx_packet_hdr *) skb_aggr->data;

	/* Copy DA and SA */
	dt_offset = 2 * ETH_ALEN;
	memcpy(&tx_header->eth803_hdr, skb_src->data, dt_offset);

	/* Copy SNAP header */
	snap.snap_type = *(u16 *) ((u8 *)skb_src->data + dt_offset);
	dt_offset += sizeof(u16);

	memcpy(&tx_header->rfc1042_hdr, &snap, sizeof(struct rfc_1042_hdr));

	skb_pull(skb_src, dt_offset);

	/* Update Length field */
	tx_header->eth803_hdr.h_proto = htons(skb_src->len + LLC_SNAP_LEN);

	/* Add payload */
	skb_put(skb_aggr, skb_src->len);
	memcpy(skb_aggr->data + sizeof(*tx_header), skb_src->data,
							skb_src->len);
	*pad = (((skb_src->len + LLC_SNAP_LEN) & 3)) ? (4 - (((skb_src->len +
						      LLC_SNAP_LEN)) & 3)) : 0;
	skb_put(skb_aggr, *pad);

	return skb_aggr->len + *pad;
}

/*
 * Adds TxPD to AMSDU header.
 *
 * Each AMSDU packet will contain one TxPD at the beginning,
 * followed by multiple AMSDU subframes.
 */
static void
mwifiex_11n_form_amsdu_txpd(struct mwifiex_private *priv,
			    struct sk_buff *skb)
{
	struct txpd *local_tx_pd;

	skb_push(skb, sizeof(*local_tx_pd));

	local_tx_pd = (struct txpd *) skb->data;
	memset(local_tx_pd, 0, sizeof(struct txpd));

	/* Original priority has been overwritten */
	local_tx_pd->priority = (u8) skb->priority;
	local_tx_pd->pkt_delay_2ms =
		mwifiex_wmm_compute_drv_pkt_delay(priv, skb);
	local_tx_pd->bss_num = priv->bss_num;
	local_tx_pd->bss_type = priv->bss_type;
	/* Always zero as the data is followed by struct txpd */
	local_tx_pd->tx_pkt_offset = cpu_to_le16(sizeof(struct txpd));
	local_tx_pd->tx_pkt_type = cpu_to_le16(PKT_TYPE_AMSDU);
	local_tx_pd->tx_pkt_length = cpu_to_le16(skb->len -
			sizeof(*local_tx_pd));

	if (local_tx_pd->tx_control == 0)
		/* TxCtrl set by user or default */
		local_tx_pd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);

	if ((GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA) &&
		(priv->adapter->pps_uapsd_mode)) {
		if (true == mwifiex_check_last_packet_indication(priv)) {
			priv->adapter->tx_lock_flag = true;
			local_tx_pd->flags =
				MWIFIEX_TxPD_POWER_MGMT_LAST_PACKET;
		}
	}
}

/*
 * Counts the number of subframes in an aggregate packet.
 *
 * This function parses an aggregate packet buffer, looking for
 * subframes and counting the number of such subframe found. The
 * function automatically skips the DA/SA fields at the beginning
 * of each subframe and padding at the end.
 */
static int
mwifiex_11n_get_num_aggr_pkts(u8 *data, int total_pkt_len)
{
	int pkt_count = 0, pkt_len, pad;

	while (total_pkt_len > 0) {
		/* Length will be in network format, change it to host */
		pkt_len = ntohs((*(__be16 *)(data + 2 * ETH_ALEN)));
		pad = (((pkt_len + sizeof(struct ethhdr)) & 3)) ?
			(4 - ((pkt_len + sizeof(struct ethhdr)) & 3)) : 0;
		data += pkt_len + pad + sizeof(struct ethhdr);
		total_pkt_len -= pkt_len + pad + sizeof(struct ethhdr);
		++pkt_count;
	}

	return pkt_count;
}

/*
 * De-aggregate received packets.
 *
 * This function parses the received aggregate buffer, extracts each subframe,
 * strips off the SNAP header from them and sends the data portion for further
 * processing.
 *
 * Each subframe body is copied onto a separate buffer, which are freed by
 * upper layer after processing. The function also performs sanity tests on
 * the received buffer.
 */
int mwifiex_11n_deaggregate_pkt(struct mwifiex_private *priv,
				struct sk_buff *skb)
{
	u16 pkt_len;
	int total_pkt_len;
	u8 *data;
	int pad;
	struct mwifiex_rxinfo *rx_info = MWIFIEX_SKB_RXCB(skb);
	struct rxpd *local_rx_pd = (struct rxpd *) skb->data;
	struct sk_buff *skb_daggr;
	struct mwifiex_rxinfo *rx_info_daggr = NULL;
	int ret = -1;
	struct rx_packet_hdr *rx_pkt_hdr;
	struct mwifiex_adapter *adapter = priv->adapter;
	u8 rfc1042_eth_hdr[ETH_ALEN] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00};

	data = (u8 *) (local_rx_pd + local_rx_pd->rx_pkt_offset);
	total_pkt_len = local_rx_pd->rx_pkt_length;

	/* Sanity test */
	if (total_pkt_len > MWIFIEX_RX_DATA_BUF_SIZE) {
		dev_err(adapter->dev, "total pkt len greater than buffer"
		       " size %d\n", total_pkt_len);
		return -1;
	}

	rx_info->use_count = mwifiex_11n_get_num_aggr_pkts(data, total_pkt_len);

	while (total_pkt_len > 0) {
		rx_pkt_hdr = (struct rx_packet_hdr *) data;
		/* Length will be in network format, change it to host */
		pkt_len = ntohs((*(__be16 *) (data + 2 * ETH_ALEN)));
		if (pkt_len > total_pkt_len) {
			dev_err(adapter->dev, "pkt_len %d > total_pkt_len %d\n",
			       total_pkt_len, pkt_len);
			break;
		}

		pad = (((pkt_len + sizeof(struct ethhdr)) & 3)) ?
			(4 - ((pkt_len + sizeof(struct ethhdr)) & 3)) : 0;

		total_pkt_len -= pkt_len + pad + sizeof(struct ethhdr);

		if (memcmp(&rx_pkt_hdr->rfc1042_hdr,
			   rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
			memmove(data + LLC_SNAP_LEN, data, 2 * ETH_ALEN);
			data += LLC_SNAP_LEN;
			pkt_len += sizeof(struct ethhdr) - LLC_SNAP_LEN;
		} else {
			*(u16 *) (data + 2 * ETH_ALEN) = (u16) 0;
			pkt_len += sizeof(struct ethhdr);
		}

		skb_daggr = dev_alloc_skb(pkt_len);
		if (!skb_daggr) {
			dev_err(adapter->dev, "%s: failed to alloc skb_daggr\n",
			       __func__);
			return -1;
		}
		rx_info_daggr = MWIFIEX_SKB_RXCB(skb_daggr);

		rx_info_daggr->bss_index = rx_info->bss_index;
		skb_daggr->tstamp = skb->tstamp;
		rx_info_daggr->parent = skb;
		skb_daggr->priority = skb->priority;
		skb_put(skb_daggr, pkt_len);
		memcpy(skb_daggr->data, data, pkt_len);

		ret = mwifiex_recv_packet(adapter, skb_daggr);

		switch (ret) {
		case -EINPROGRESS:
			break;
		case -1:
			dev_err(adapter->dev, "deaggr: host_to_card failed\n");
		case 0:
			mwifiex_recv_packet_complete(adapter, skb_daggr, ret);
			break;
		default:
			break;
		}

		data += pkt_len + pad;
	}

	return ret;
}

/*
 * Create aggregated packet.
 *
 * This function creates an aggregated MSDU packet, by combining buffers
 * from the RA list. Each individual buffer is encapsulated as an AMSDU
 * subframe and all such subframes are concatenated together to form the
 * AMSDU packet.
 *
 * A TxPD is also added to the front of the resultant AMSDU packets for
 * transmission. The resultant packets format is -
 *
 * +---- ~ ----+------ ~ ------+------ ~ ------+-..-+------ ~ ------+
 * |    TxPD   |AMSDU sub-frame|AMSDU sub-frame| .. |AMSDU sub-frame|
 * |           |       1       |       2       | .. |       n       |
 * +---- ~ ----+------ ~ ------+------ ~ ------+ .. +------ ~ ------+
 */
int
mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
			  struct mwifiex_ra_list_tbl *pra_list, int headroom,
			  int ptrindex, unsigned long ra_list_flags)
			  __releases(&priv->wmm.ra_list_spinlock)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	struct sk_buff *skb_aggr, *skb_src;
	struct mwifiex_txinfo *tx_info_aggr, *tx_info_src;
	int pad = 0;
	int ret = 0;
	struct mwifiex_tx_param tx_param;
	struct txpd *ptx_pd = NULL;

	if (skb_queue_empty(&pra_list->skb_head)) {
		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
				       ra_list_flags);
		return 0;
	}
	skb_src = skb_peek(&pra_list->skb_head);
	tx_info_src = MWIFIEX_SKB_TXCB(skb_src);
	skb_aggr = dev_alloc_skb(adapter->tx_buf_size);
	if (!skb_aggr) {
		dev_err(adapter->dev, "%s: alloc skb_aggr\n", __func__);
		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
				       ra_list_flags);
		return -1;
	}
	skb_reserve(skb_aggr, headroom + sizeof(struct txpd));
	tx_info_aggr =  MWIFIEX_SKB_TXCB(skb_aggr);

	tx_info_aggr->bss_index = tx_info_src->bss_index;
	skb_aggr->priority = skb_src->priority;

	while (skb_src && ((skb_headroom(skb_aggr) + skb_src->len
					+ LLC_SNAP_LEN)
				<= adapter->tx_buf_size)) {

		if (!skb_queue_empty(&pra_list->skb_head))
			skb_src = skb_dequeue(&pra_list->skb_head);
		else
			skb_src = NULL;

		pra_list->total_pkts_size -= skb_src->len;

		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
				       ra_list_flags);
		mwifiex_11n_form_amsdu_pkt(adapter, skb_aggr, skb_src, &pad);

		mwifiex_write_data_complete(adapter, skb_src, 0);

		spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);

		if (!mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
			spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
					       ra_list_flags);
			return -1;
		}

		if (!skb_queue_empty(&pra_list->skb_head))
			skb_src = skb_peek(&pra_list->skb_head);
		else
			skb_src = NULL;
	}

	spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, ra_list_flags);

	/* Last AMSDU packet does not need padding */
	skb_trim(skb_aggr, skb_aggr->len - pad);

	/* Form AMSDU */
	mwifiex_11n_form_amsdu_txpd(priv, skb_aggr);
	if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA)
		ptx_pd = (struct txpd *)skb_aggr->data;

	skb_push(skb_aggr, headroom);

	tx_param.next_pkt_len = ((pra_list->total_pkts_size) ?
				 (((pra_list->total_pkts_size) >
				   adapter->tx_buf_size) ? adapter->
				  tx_buf_size : pra_list->total_pkts_size +
				  LLC_SNAP_LEN + sizeof(struct txpd)) : 0);
	ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,
					     skb_aggr->data,
					     skb_aggr->len, &tx_param);
	switch (ret) {
	case -EBUSY:
		spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
		if (!mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
			spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
					       ra_list_flags);
			mwifiex_write_data_complete(adapter, skb_aggr, -1);
			return -1;
		}
		if ((GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA) &&
			(adapter->pps_uapsd_mode) &&
			(adapter->tx_lock_flag)) {
				priv->adapter->tx_lock_flag = false;
				ptx_pd->flags = 0;
		}

		skb_queue_tail(&pra_list->skb_head, skb_aggr);

		pra_list->total_pkts_size += skb_aggr->len;

		tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_REQUEUED_PKT;
		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
				       ra_list_flags);
		dev_dbg(adapter->dev, "data: -EBUSY is returned\n");
		break;
	case -1:
		adapter->data_sent = false;
		dev_err(adapter->dev, "%s: host_to_card failed: %#x\n",
						__func__, ret);
		adapter->dbg.num_tx_host_to_card_failure++;
		mwifiex_write_data_complete(adapter, skb_aggr, ret);
		return 0;
	case -EINPROGRESS:
		adapter->data_sent = false;
		break;
	case 0:
		mwifiex_write_data_complete(adapter, skb_aggr, ret);
		break;
	default:
		break;
	}
	if (ret != -EBUSY) {
		spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
		if (mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
			priv->wmm.packets_out[ptrindex]++;
			priv->wmm.tid_tbl_ptr[ptrindex].ra_list_curr = pra_list;
		}
		/* Now bss_prio_cur pointer points to next node */
		adapter->bss_prio_tbl[priv->bss_priority].bss_prio_cur =
			list_first_entry(
				&adapter->bss_prio_tbl[priv->bss_priority]
				.bss_prio_cur->list,
				struct mwifiex_bss_prio_node, list);
		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
				       ra_list_flags);
	}

	return 0;
}