1/*
2 * Marvell Wireless LAN device driver: 802.11n Aggregation
3 *
4 * Copyright (C) 2011, Marvell International Ltd.
5 *
6 * This software file (the "File") is distributed by Marvell International
7 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
8 * (the "License").  You may use, redistribute and/or modify this File in
9 * accordance with the terms and conditions of the License, a copy of which
10 * is available by writing to the Free Software Foundation, Inc.,
11 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
12 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
13 *
14 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
16 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
17 * this warranty disclaimer.
18 */
19
20#include "decl.h"
21#include "ioctl.h"
22#include "util.h"
23#include "fw.h"
24#include "main.h"
25#include "wmm.h"
26#include "11n.h"
27#include "11n_aggr.h"
28
29/*
30 * Creates an AMSDU subframe for aggregation into one AMSDU packet.
31 *
32 * The resultant AMSDU subframe format is -
33 *
34 * +---- ~ -----+---- ~ ------+---- ~ -----+----- ~ -----+---- ~ -----+
35 * |     DA     |     SA      |   Length   | SNAP header |   MSDU     |
36 * | data[0..5] | data[6..11] |            |             | data[14..] |
37 * +---- ~ -----+---- ~ ------+---- ~ -----+----- ~ -----+---- ~ -----+
38 * <--6-bytes--> <--6-bytes--> <--2-bytes--><--8-bytes--> <--n-bytes-->
39 *
40 * This function also computes the amount of padding required to make the
41 * buffer length multiple of 4 bytes.
42 *
43 * Data => |DA|SA|SNAP-TYPE|........    .|
44 * MSDU => |DA|SA|Length|SNAP|......   ..|
45 */
46static int
47mwifiex_11n_form_amsdu_pkt(struct sk_buff *skb_aggr,
48			   struct sk_buff *skb_src, int *pad)
49
50{
51	int dt_offset;
52	struct rfc_1042_hdr snap = {
53		0xaa,		/* LLC DSAP */
54		0xaa,		/* LLC SSAP */
55		0x03,		/* LLC CTRL */
56		{0x00, 0x00, 0x00},	/* SNAP OUI */
57		0x0000		/* SNAP type */
58			/*
59			 * This field will be overwritten
60			 * later with ethertype
61			 */
62	};
63	struct tx_packet_hdr *tx_header;
64
65	skb_put(skb_aggr, sizeof(*tx_header));
66
67	tx_header = (struct tx_packet_hdr *) skb_aggr->data;
68
69	/* Copy DA and SA */
70	dt_offset = 2 * ETH_ALEN;
71	memcpy(&tx_header->eth803_hdr, skb_src->data, dt_offset);
72
73	/* Copy SNAP header */
74	snap.snap_type = *(u16 *) ((u8 *)skb_src->data + dt_offset);
75	dt_offset += sizeof(u16);
76
77	memcpy(&tx_header->rfc1042_hdr, &snap, sizeof(struct rfc_1042_hdr));
78
79	skb_pull(skb_src, dt_offset);
80
81	/* Update Length field */
82	tx_header->eth803_hdr.h_proto = htons(skb_src->len + LLC_SNAP_LEN);
83
84	/* Add payload */
85	skb_put(skb_aggr, skb_src->len);
86	memcpy(skb_aggr->data + sizeof(*tx_header), skb_src->data,
87	       skb_src->len);
88	*pad = (((skb_src->len + LLC_SNAP_LEN) & 3)) ? (4 - (((skb_src->len +
89						      LLC_SNAP_LEN)) & 3)) : 0;
90	skb_put(skb_aggr, *pad);
91
92	return skb_aggr->len + *pad;
93}
94
95/*
96 * Adds TxPD to AMSDU header.
97 *
98 * Each AMSDU packet will contain one TxPD at the beginning,
99 * followed by multiple AMSDU subframes.
100 */
101static void
102mwifiex_11n_form_amsdu_txpd(struct mwifiex_private *priv,
103			    struct sk_buff *skb)
104{
105	struct txpd *local_tx_pd;
106
107	skb_push(skb, sizeof(*local_tx_pd));
108
109	local_tx_pd = (struct txpd *) skb->data;
110	memset(local_tx_pd, 0, sizeof(struct txpd));
111
112	/* Original priority has been overwritten */
113	local_tx_pd->priority = (u8) skb->priority;
114	local_tx_pd->pkt_delay_2ms =
115		mwifiex_wmm_compute_drv_pkt_delay(priv, skb);
116	local_tx_pd->bss_num = priv->bss_num;
117	local_tx_pd->bss_type = priv->bss_type;
118	/* Always zero as the data is followed by struct txpd */
119	local_tx_pd->tx_pkt_offset = cpu_to_le16(sizeof(struct txpd));
120	local_tx_pd->tx_pkt_type = cpu_to_le16(PKT_TYPE_AMSDU);
121	local_tx_pd->tx_pkt_length = cpu_to_le16(skb->len -
122						 sizeof(*local_tx_pd));
123
124	if (local_tx_pd->tx_control == 0)
125		/* TxCtrl set by user or default */
126		local_tx_pd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);
127
128	if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA &&
129	    priv->adapter->pps_uapsd_mode) {
130		if (true == mwifiex_check_last_packet_indication(priv)) {
131			priv->adapter->tx_lock_flag = true;
132			local_tx_pd->flags =
133				MWIFIEX_TxPD_POWER_MGMT_LAST_PACKET;
134		}
135	}
136}
137
138/*
139 * Create aggregated packet.
140 *
141 * This function creates an aggregated MSDU packet, by combining buffers
142 * from the RA list. Each individual buffer is encapsulated as an AMSDU
143 * subframe and all such subframes are concatenated together to form the
144 * AMSDU packet.
145 *
146 * A TxPD is also added to the front of the resultant AMSDU packets for
147 * transmission. The resultant packets format is -
148 *
149 * +---- ~ ----+------ ~ ------+------ ~ ------+-..-+------ ~ ------+
150 * |    TxPD   |AMSDU sub-frame|AMSDU sub-frame| .. |AMSDU sub-frame|
151 * |           |       1       |       2       | .. |       n       |
152 * +---- ~ ----+------ ~ ------+------ ~ ------+ .. +------ ~ ------+
153 */
154int
155mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
156			  struct mwifiex_ra_list_tbl *pra_list, int headroom,
157			  int ptrindex, unsigned long ra_list_flags)
158			  __releases(&priv->wmm.ra_list_spinlock)
159{
160	struct mwifiex_adapter *adapter = priv->adapter;
161	struct sk_buff *skb_aggr, *skb_src;
162	struct mwifiex_txinfo *tx_info_aggr, *tx_info_src;
163	int pad = 0, ret;
164	struct mwifiex_tx_param tx_param;
165	struct txpd *ptx_pd = NULL;
166
167	skb_src = skb_peek(&pra_list->skb_head);
168	if (!skb_src) {
169		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
170				       ra_list_flags);
171		return 0;
172	}
173
174	tx_info_src = MWIFIEX_SKB_TXCB(skb_src);
175	skb_aggr = dev_alloc_skb(adapter->tx_buf_size);
176	if (!skb_aggr) {
177		dev_err(adapter->dev, "%s: alloc skb_aggr\n", __func__);
178		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
179				       ra_list_flags);
180		return -1;
181	}
182	skb_reserve(skb_aggr, headroom + sizeof(struct txpd));
183	tx_info_aggr =  MWIFIEX_SKB_TXCB(skb_aggr);
184
185	tx_info_aggr->bss_type = tx_info_src->bss_type;
186	tx_info_aggr->bss_num = tx_info_src->bss_num;
187	skb_aggr->priority = skb_src->priority;
188
189	do {
190		/* Check if AMSDU can accommodate this MSDU */
191		if (skb_tailroom(skb_aggr) < (skb_src->len + LLC_SNAP_LEN))
192			break;
193
194		skb_src = skb_dequeue(&pra_list->skb_head);
195
196		pra_list->total_pkts_size -= skb_src->len;
197
198		atomic_dec(&priv->wmm.tx_pkts_queued);
199
200		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
201				       ra_list_flags);
202		mwifiex_11n_form_amsdu_pkt(skb_aggr, skb_src, &pad);
203
204		mwifiex_write_data_complete(adapter, skb_src, 0);
205
206		spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
207
208		if (!mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
209			spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
210					       ra_list_flags);
211			return -1;
212		}
213
214		if (skb_tailroom(skb_aggr) < pad) {
215			pad = 0;
216			break;
217		}
218		skb_put(skb_aggr, pad);
219
220		skb_src = skb_peek(&pra_list->skb_head);
221
222	} while (skb_src);
223
224	spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, ra_list_flags);
225
226	/* Last AMSDU packet does not need padding */
227	skb_trim(skb_aggr, skb_aggr->len - pad);
228
229	/* Form AMSDU */
230	mwifiex_11n_form_amsdu_txpd(priv, skb_aggr);
231	if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA)
232		ptx_pd = (struct txpd *)skb_aggr->data;
233
234	skb_push(skb_aggr, headroom);
235
236	/*
237	 * Padding per MSDU will affect the length of next
238	 * packet and hence the exact length of next packet
239	 * is uncertain here.
240	 *
241	 * Also, aggregation of transmission buffer, while
242	 * downloading the data to the card, wont gain much
243	 * on the AMSDU packets as the AMSDU packets utilizes
244	 * the transmission buffer space to the maximum
245	 * (adapter->tx_buf_size).
246	 */
247	tx_param.next_pkt_len = 0;
248
249	ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,
250					   skb_aggr, &tx_param);
251	switch (ret) {
252	case -EBUSY:
253		spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
254		if (!mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
255			spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
256					       ra_list_flags);
257			mwifiex_write_data_complete(adapter, skb_aggr, -1);
258			return -1;
259		}
260		if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA &&
261		    adapter->pps_uapsd_mode && adapter->tx_lock_flag) {
262				priv->adapter->tx_lock_flag = false;
263				if (ptx_pd)
264					ptx_pd->flags = 0;
265		}
266
267		skb_queue_tail(&pra_list->skb_head, skb_aggr);
268
269		pra_list->total_pkts_size += skb_aggr->len;
270
271		atomic_inc(&priv->wmm.tx_pkts_queued);
272
273		tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_REQUEUED_PKT;
274		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
275				       ra_list_flags);
276		dev_dbg(adapter->dev, "data: -EBUSY is returned\n");
277		break;
278	case -1:
279		adapter->data_sent = false;
280		dev_err(adapter->dev, "%s: host_to_card failed: %#x\n",
281			__func__, ret);
282		adapter->dbg.num_tx_host_to_card_failure++;
283		mwifiex_write_data_complete(adapter, skb_aggr, ret);
284		return 0;
285	case -EINPROGRESS:
286		adapter->data_sent = false;
287		break;
288	case 0:
289		mwifiex_write_data_complete(adapter, skb_aggr, ret);
290		break;
291	default:
292		break;
293	}
294	if (ret != -EBUSY) {
295		spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
296		if (mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
297			priv->wmm.packets_out[ptrindex]++;
298			priv->wmm.tid_tbl_ptr[ptrindex].ra_list_curr = pra_list;
299		}
300		/* Now bss_prio_cur pointer points to next node */
301		adapter->bss_prio_tbl[priv->bss_priority].bss_prio_cur =
302			list_first_entry(
303				&adapter->bss_prio_tbl[priv->bss_priority]
304				.bss_prio_cur->list,
305				struct mwifiex_bss_prio_node, list);
306		spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
307				       ra_list_flags);
308	}
309
310	return 0;
311}
312