/*
   * Marvell Wireless LAN device driver: 802.11n Aggregation
   *
   * Copyright (C) 2011-2014, 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 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;
  
  	tx_header = (void *)skb_put(skb_aggr, sizeof(*tx_header));
  
  	/* 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 = ((struct ethhdr *)skb_src->data)->h_proto;
  
  	dt_offset += sizeof(__be16);
  
  	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 */
  	memcpy(skb_put(skb_aggr, skb_src->len), skb_src->data, skb_src->len);
  
  	/* Add padding for new MSDU to start from 4 byte boundary */
  	*pad = (4 - ((unsigned long)skb_aggr->tail & 0x3)) % 4;
  
  	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;
  	struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
  	unsigned int pad;
  	int headroom = (priv->adapter->iface_type ==
  			MWIFIEX_USB) ? 0 : INTF_HEADER_LEN;
  
  	pad = ((void *)skb->data - sizeof(*local_tx_pd) -
  		headroom - NULL) & (MWIFIEX_DMA_ALIGN_SZ - 1);
  	skb_push(skb, pad);
  
  	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) +
  						 pad);
  	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) -
  						 pad);
  
  	if (tx_info->flags & MWIFIEX_BUF_FLAG_TDLS_PKT)
  		local_tx_pd->flags |= MWIFIEX_TXPD_FLAGS_TDLS_PACKET;
  
  	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;
  		}
  	}
  }
  
  /*
   * 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 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, aggr_num = 0, ret;
  	struct mwifiex_tx_param tx_param;
  	struct txpd *ptx_pd = NULL;
  	int headroom = adapter->iface_type == MWIFIEX_USB ? 0 : INTF_HEADER_LEN;
  
  	skb_src = skb_peek(&pra_list->skb_head);
  	if (!skb_src) {
  		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
  				       ra_list_flags);
  		return 0;
  	}
  
  	tx_info_src = MWIFIEX_SKB_TXCB(skb_src);
  	skb_aggr = mwifiex_alloc_dma_align_buf(adapter->tx_buf_size,
  					       GFP_ATOMIC | GFP_DMA);
  	if (!skb_aggr) {
  		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
  				       ra_list_flags);
  		return -1;
  	}
  	skb_reserve(skb_aggr, MWIFIEX_MIN_DATA_HEADER_LEN);
  	tx_info_aggr =  MWIFIEX_SKB_TXCB(skb_aggr);
  
  	memset(tx_info_aggr, 0, sizeof(*tx_info_aggr));
  	tx_info_aggr->bss_type = tx_info_src->bss_type;
  	tx_info_aggr->bss_num = tx_info_src->bss_num;
  
  	if (tx_info_src->flags & MWIFIEX_BUF_FLAG_TDLS_PKT)
  		tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_TDLS_PKT;
  	tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_AGGR_PKT;
  	skb_aggr->priority = skb_src->priority;
  	skb_aggr->tstamp = skb_src->tstamp;
  
  	skb_aggr->tstamp = ktime_get_real();
  
  	do {
  		/* Check if AMSDU can accommodate this MSDU */
  		if (skb_tailroom(skb_aggr) < (skb_src->len + LLC_SNAP_LEN))
  			break;
  
  		skb_src = skb_dequeue(&pra_list->skb_head);
  		pra_list->total_pkt_count--;
  		atomic_dec(&priv->wmm.tx_pkts_queued);
  		aggr_num++;
  		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
  				       ra_list_flags);
  		mwifiex_11n_form_amsdu_pkt(skb_aggr, skb_src, &pad);
  
  		mwifiex_write_data_complete(adapter, skb_src, 0, 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_tailroom(skb_aggr) < pad) {
  			pad = 0;
  			break;
  		}
  		skb_put(skb_aggr, pad);
  
  		skb_src = skb_peek(&pra_list->skb_head);
  
  	} while (skb_src);
  
  	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_info_aggr->aggr_num = aggr_num * 2;
  	if (adapter->data_sent || adapter->tx_lock_flag) {
  		atomic_add(aggr_num * 2, &adapter->tx_queued);
  		skb_queue_tail(&adapter->tx_data_q, skb_aggr);
  		return 0;
  	}
  
  	if (adapter->iface_type == MWIFIEX_USB) {
  		ret = adapter->if_ops.host_to_card(adapter, priv->usb_port,
  						   skb_aggr, NULL);
  	} else {
  		if (skb_src)
  			tx_param.next_pkt_len =
  					skb_src->len + sizeof(struct txpd);
  		else
  			tx_param.next_pkt_len = 0;
  
  		ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,
  						   skb_aggr, &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, -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;
  				if (ptx_pd)
  					ptx_pd->flags = 0;
  		}
  
  		skb_queue_tail(&pra_list->skb_head, skb_aggr);
  
  		pra_list->total_pkt_count++;
  
  		atomic_inc(&priv->wmm.tx_pkts_queued);
  
  		tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_REQUEUED_PKT;
  		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
  				       ra_list_flags);
  		mwifiex_dbg(adapter, ERROR, "data: -EBUSY is returned
  ");
  		break;
  	case -1:
  		mwifiex_dbg(adapter, ERROR, "%s: host_to_card failed: %#x
  ",
  			    __func__, ret);
  		adapter->dbg.num_tx_host_to_card_failure++;
  		mwifiex_write_data_complete(adapter, skb_aggr, 1, ret);
  		return 0;
  	case -EINPROGRESS:
  		break;
  	case 0:
  		mwifiex_write_data_complete(adapter, skb_aggr, 1, ret);
  		break;
  	default:
  		break;
  	}
  	if (ret != -EBUSY) {
  		mwifiex_rotate_priolists(priv, pra_list, ptrindex);
  	}
  
  	return 0;
  }