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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * NXP Wireless LAN device driver: 802.11n Aggregation
 *
 * Copyright 2011-2020 NXP
 */

#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)

{ … }

/*
 * 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)
{ … }

/*
 * 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)
			  __releases(&priv->wmm.ra_list_spinlock)
{ … }