Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
11n_aggr.c
Go to the documentation of this file.
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  */
46 static int
47 mwifiex_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  tx_header = (void *)skb_put(skb_aggr, sizeof(*tx_header));
66 
67  /* Copy DA and SA */
68  dt_offset = 2 * ETH_ALEN;
69  memcpy(&tx_header->eth803_hdr, skb_src->data, dt_offset);
70 
71  /* Copy SNAP header */
72  snap.snap_type = *(u16 *) ((u8 *)skb_src->data + dt_offset);
73  dt_offset += sizeof(u16);
74 
75  memcpy(&tx_header->rfc1042_hdr, &snap, sizeof(struct rfc_1042_hdr));
76 
77  skb_pull(skb_src, dt_offset);
78 
79  /* Update Length field */
80  tx_header->eth803_hdr.h_proto = htons(skb_src->len + LLC_SNAP_LEN);
81 
82  /* Add payload */
83  memcpy(skb_put(skb_aggr, skb_src->len), skb_src->data, skb_src->len);
84 
85  /* Add padding for new MSDU to start from 4 byte boundary */
86  *pad = (4 - ((unsigned long)skb_aggr->tail & 0x3)) % 4;
87 
88  return skb_aggr->len + *pad;
89 }
90 
91 /*
92  * Adds TxPD to AMSDU header.
93  *
94  * Each AMSDU packet will contain one TxPD at the beginning,
95  * followed by multiple AMSDU subframes.
96  */
97 static void
98 mwifiex_11n_form_amsdu_txpd(struct mwifiex_private *priv,
99  struct sk_buff *skb)
100 {
101  struct txpd *local_tx_pd;
102 
103  skb_push(skb, sizeof(*local_tx_pd));
104 
105  local_tx_pd = (struct txpd *) skb->data;
106  memset(local_tx_pd, 0, sizeof(struct txpd));
107 
108  /* Original priority has been overwritten */
109  local_tx_pd->priority = (u8) skb->priority;
110  local_tx_pd->pkt_delay_2ms =
112  local_tx_pd->bss_num = priv->bss_num;
113  local_tx_pd->bss_type = priv->bss_type;
114  /* Always zero as the data is followed by struct txpd */
115  local_tx_pd->tx_pkt_offset = cpu_to_le16(sizeof(struct txpd));
116  local_tx_pd->tx_pkt_type = cpu_to_le16(PKT_TYPE_AMSDU);
117  local_tx_pd->tx_pkt_length = cpu_to_le16(skb->len -
118  sizeof(*local_tx_pd));
119 
120  if (local_tx_pd->tx_control == 0)
121  /* TxCtrl set by user or default */
122  local_tx_pd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);
123 
124  if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA &&
125  priv->adapter->pps_uapsd_mode) {
126  if (true == mwifiex_check_last_packet_indication(priv)) {
127  priv->adapter->tx_lock_flag = true;
128  local_tx_pd->flags =
130  }
131  }
132 }
133 
134 /*
135  * Create aggregated packet.
136  *
137  * This function creates an aggregated MSDU packet, by combining buffers
138  * from the RA list. Each individual buffer is encapsulated as an AMSDU
139  * subframe and all such subframes are concatenated together to form the
140  * AMSDU packet.
141  *
142  * A TxPD is also added to the front of the resultant AMSDU packets for
143  * transmission. The resultant packets format is -
144  *
145  * +---- ~ ----+------ ~ ------+------ ~ ------+-..-+------ ~ ------+
146  * | TxPD |AMSDU sub-frame|AMSDU sub-frame| .. |AMSDU sub-frame|
147  * | | 1 | 2 | .. | n |
148  * +---- ~ ----+------ ~ ------+------ ~ ------+ .. +------ ~ ------+
149  */
150 int
152  struct mwifiex_ra_list_tbl *pra_list, int headroom,
153  int ptrindex, unsigned long ra_list_flags)
154  __releases(&priv->wmm.ra_list_spinlock)
155 {
156  struct mwifiex_adapter *adapter = priv->adapter;
157  struct sk_buff *skb_aggr, *skb_src;
158  struct mwifiex_txinfo *tx_info_aggr, *tx_info_src;
159  int pad = 0, ret;
160  struct mwifiex_tx_param tx_param;
161  struct txpd *ptx_pd = NULL;
162 
163  skb_src = skb_peek(&pra_list->skb_head);
164  if (!skb_src) {
165  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
166  ra_list_flags);
167  return 0;
168  }
169 
170  tx_info_src = MWIFIEX_SKB_TXCB(skb_src);
171  skb_aggr = dev_alloc_skb(adapter->tx_buf_size);
172  if (!skb_aggr) {
173  dev_err(adapter->dev, "%s: alloc skb_aggr\n", __func__);
174  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
175  ra_list_flags);
176  return -1;
177  }
178  skb_reserve(skb_aggr, headroom + sizeof(struct txpd));
179  tx_info_aggr = MWIFIEX_SKB_TXCB(skb_aggr);
180 
181  tx_info_aggr->bss_type = tx_info_src->bss_type;
182  tx_info_aggr->bss_num = tx_info_src->bss_num;
183  skb_aggr->priority = skb_src->priority;
184 
185  do {
186  /* Check if AMSDU can accommodate this MSDU */
187  if (skb_tailroom(skb_aggr) < (skb_src->len + LLC_SNAP_LEN))
188  break;
189 
190  skb_src = skb_dequeue(&pra_list->skb_head);
191 
192  pra_list->total_pkts_size -= skb_src->len;
193 
194  atomic_dec(&priv->wmm.tx_pkts_queued);
195 
196  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
197  ra_list_flags);
198  mwifiex_11n_form_amsdu_pkt(skb_aggr, skb_src, &pad);
199 
200  mwifiex_write_data_complete(adapter, skb_src, 0);
201 
202  spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
203 
204  if (!mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
205  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
206  ra_list_flags);
207  return -1;
208  }
209 
210  if (skb_tailroom(skb_aggr) < pad) {
211  pad = 0;
212  break;
213  }
214  skb_put(skb_aggr, pad);
215 
216  skb_src = skb_peek(&pra_list->skb_head);
217 
218  } while (skb_src);
219 
220  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, ra_list_flags);
221 
222  /* Last AMSDU packet does not need padding */
223  skb_trim(skb_aggr, skb_aggr->len - pad);
224 
225  /* Form AMSDU */
226  mwifiex_11n_form_amsdu_txpd(priv, skb_aggr);
227  if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA)
228  ptx_pd = (struct txpd *)skb_aggr->data;
229 
230  skb_push(skb_aggr, headroom);
231 
232  if (adapter->iface_type == MWIFIEX_USB) {
233  adapter->data_sent = true;
234  ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_USB_EP_DATA,
235  skb_aggr, NULL);
236  } else {
237  /*
238  * Padding per MSDU will affect the length of next
239  * packet and hence the exact length of next packet
240  * is uncertain here.
241  *
242  * Also, aggregation of transmission buffer, while
243  * downloading the data to the card, wont gain much
244  * on the AMSDU packets as the AMSDU packets utilizes
245  * the transmission buffer space to the maximum
246  * (adapter->tx_buf_size).
247  */
248  tx_param.next_pkt_len = 0;
249 
250  ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,
251  skb_aggr, &tx_param);
252  }
253  switch (ret) {
254  case -EBUSY:
255  spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
256  if (!mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
257  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
258  ra_list_flags);
259  mwifiex_write_data_complete(adapter, skb_aggr, -1);
260  return -1;
261  }
262  if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA &&
263  adapter->pps_uapsd_mode && adapter->tx_lock_flag) {
264  priv->adapter->tx_lock_flag = false;
265  if (ptx_pd)
266  ptx_pd->flags = 0;
267  }
268 
269  skb_queue_tail(&pra_list->skb_head, skb_aggr);
270 
271  pra_list->total_pkts_size += skb_aggr->len;
272 
273  atomic_inc(&priv->wmm.tx_pkts_queued);
274 
275  tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_REQUEUED_PKT;
276  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
277  ra_list_flags);
278  dev_dbg(adapter->dev, "data: -EBUSY is returned\n");
279  break;
280  case -1:
281  adapter->data_sent = false;
282  dev_err(adapter->dev, "%s: host_to_card failed: %#x\n",
283  __func__, ret);
284  adapter->dbg.num_tx_host_to_card_failure++;
285  mwifiex_write_data_complete(adapter, skb_aggr, ret);
286  return 0;
287  case -EINPROGRESS:
288  adapter->data_sent = false;
289  break;
290  case 0:
291  mwifiex_write_data_complete(adapter, skb_aggr, ret);
292  break;
293  default:
294  break;
295  }
296  if (ret != -EBUSY) {
297  spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);
298  if (mwifiex_is_ralist_valid(priv, pra_list, ptrindex)) {
299  priv->wmm.packets_out[ptrindex]++;
300  priv->wmm.tid_tbl_ptr[ptrindex].ra_list_curr = pra_list;
301  }
302  /* Now bss_prio_cur pointer points to next node */
303  adapter->bss_prio_tbl[priv->bss_priority].bss_prio_cur =
305  &adapter->bss_prio_tbl[priv->bss_priority]
306  .bss_prio_cur->list,
307  struct mwifiex_bss_prio_node, list);
308  spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
309  ra_list_flags);
310  }
311 
312  return 0;
313 }