Merge branch 'timers-for-linus-migration' of git://git.kernel.org/pub/scm/linux/kerne...
[linux-2.6] / drivers / net / wireless / libertas / rx.c
1 /**
2   * This file contains the handling of RX in wlan driver.
3   */
4 #include <linux/etherdevice.h>
5 #include <linux/types.h>
6
7 #include "hostcmd.h"
8 #include "radiotap.h"
9 #include "decl.h"
10 #include "dev.h"
11 #include "wext.h"
12
13 struct eth803hdr {
14         u8 dest_addr[6];
15         u8 src_addr[6];
16         u16 h803_len;
17 } __attribute__ ((packed));
18
19 struct rfc1042hdr {
20         u8 llc_dsap;
21         u8 llc_ssap;
22         u8 llc_ctrl;
23         u8 snap_oui[3];
24         u16 snap_type;
25 } __attribute__ ((packed));
26
27 struct rxpackethdr {
28         struct eth803hdr eth803_hdr;
29         struct rfc1042hdr rfc1042_hdr;
30 } __attribute__ ((packed));
31
32 struct rx80211packethdr {
33         struct rxpd rx_pd;
34         void *eth80211_hdr;
35 } __attribute__ ((packed));
36
37 static int process_rxed_802_11_packet(struct lbs_private *priv,
38         struct sk_buff *skb);
39
40 /**
41  *  @brief This function computes the avgSNR .
42  *
43  *  @param priv    A pointer to struct lbs_private structure
44  *  @return        avgSNR
45  */
46 static u8 lbs_getavgsnr(struct lbs_private *priv)
47 {
48         u8 i;
49         u16 temp = 0;
50         if (priv->numSNRNF == 0)
51                 return 0;
52         for (i = 0; i < priv->numSNRNF; i++)
53                 temp += priv->rawSNR[i];
54         return (u8) (temp / priv->numSNRNF);
55
56 }
57
58 /**
59  *  @brief This function computes the AvgNF
60  *
61  *  @param priv    A pointer to struct lbs_private structure
62  *  @return        AvgNF
63  */
64 static u8 lbs_getavgnf(struct lbs_private *priv)
65 {
66         u8 i;
67         u16 temp = 0;
68         if (priv->numSNRNF == 0)
69                 return 0;
70         for (i = 0; i < priv->numSNRNF; i++)
71                 temp += priv->rawNF[i];
72         return (u8) (temp / priv->numSNRNF);
73
74 }
75
76 /**
77  *  @brief This function save the raw SNR/NF to our internel buffer
78  *
79  *  @param priv    A pointer to struct lbs_private structure
80  *  @param prxpd   A pointer to rxpd structure of received packet
81  *  @return        n/a
82  */
83 static void lbs_save_rawSNRNF(struct lbs_private *priv, struct rxpd *p_rx_pd)
84 {
85         if (priv->numSNRNF < DEFAULT_DATA_AVG_FACTOR)
86                 priv->numSNRNF++;
87         priv->rawSNR[priv->nextSNRNF] = p_rx_pd->snr;
88         priv->rawNF[priv->nextSNRNF] = p_rx_pd->nf;
89         priv->nextSNRNF++;
90         if (priv->nextSNRNF >= DEFAULT_DATA_AVG_FACTOR)
91                 priv->nextSNRNF = 0;
92         return;
93 }
94
95 /**
96  *  @brief This function computes the RSSI in received packet.
97  *
98  *  @param priv    A pointer to struct lbs_private structure
99  *  @param prxpd   A pointer to rxpd structure of received packet
100  *  @return        n/a
101  */
102 static void lbs_compute_rssi(struct lbs_private *priv, struct rxpd *p_rx_pd)
103 {
104
105         lbs_deb_enter(LBS_DEB_RX);
106
107         lbs_deb_rx("rxpd: SNR %d, NF %d\n", p_rx_pd->snr, p_rx_pd->nf);
108         lbs_deb_rx("before computing SNR: SNR-avg = %d, NF-avg = %d\n",
109                priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
110                priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
111
112         priv->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr;
113         priv->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf;
114         lbs_save_rawSNRNF(priv, p_rx_pd);
115
116         priv->SNR[TYPE_RXPD][TYPE_AVG] = lbs_getavgsnr(priv) * AVG_SCALE;
117         priv->NF[TYPE_RXPD][TYPE_AVG] = lbs_getavgnf(priv) * AVG_SCALE;
118         lbs_deb_rx("after computing SNR: SNR-avg = %d, NF-avg = %d\n",
119                priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
120                priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
121
122         priv->RSSI[TYPE_RXPD][TYPE_NOAVG] =
123             CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_NOAVG],
124                      priv->NF[TYPE_RXPD][TYPE_NOAVG]);
125
126         priv->RSSI[TYPE_RXPD][TYPE_AVG] =
127             CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
128                      priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
129
130         lbs_deb_leave(LBS_DEB_RX);
131 }
132
133 /**
134  *  @brief This function processes received packet and forwards it
135  *  to kernel/upper layer
136  *
137  *  @param priv    A pointer to struct lbs_private
138  *  @param skb     A pointer to skb which includes the received packet
139  *  @return        0 or -1
140  */
141 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
142 {
143         int ret = 0;
144         struct net_device *dev = priv->dev;
145         struct rxpackethdr *p_rx_pkt;
146         struct rxpd *p_rx_pd;
147         int hdrchop;
148         struct ethhdr *p_ethhdr;
149         const u8 rfc1042_eth_hdr[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
150
151         lbs_deb_enter(LBS_DEB_RX);
152
153         BUG_ON(!skb);
154
155         skb->ip_summed = CHECKSUM_NONE;
156
157         if (priv->monitormode)
158                 return process_rxed_802_11_packet(priv, skb);
159
160         p_rx_pd = (struct rxpd *) skb->data;
161         p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
162                 le32_to_cpu(p_rx_pd->pkt_ptr));
163         if (priv->mesh_dev) {
164                 if (priv->mesh_fw_ver == MESH_FW_OLD) {
165                         if (p_rx_pd->rx_control & RxPD_MESH_FRAME)
166                                 dev = priv->mesh_dev;
167                 } else if (priv->mesh_fw_ver == MESH_FW_NEW) {
168                         if (p_rx_pd->u.bss.bss_num == MESH_IFACE_ID)
169                                 dev = priv->mesh_dev;
170                 }
171         }
172
173         lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
174                  min_t(unsigned int, skb->len, 100));
175
176         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
177                 lbs_deb_rx("rx err: frame received with bad length\n");
178                 dev->stats.rx_length_errors++;
179                 ret = 0;
180                 dev_kfree_skb(skb);
181                 goto done;
182         }
183
184         lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
185                 skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
186                 skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
187
188         lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
189                 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
190         lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
191                 sizeof(p_rx_pkt->eth803_hdr.src_addr));
192
193         if (memcmp(&p_rx_pkt->rfc1042_hdr,
194                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
195                 /*
196                  *  Replace the 803 header and rfc1042 header (llc/snap) with an
197                  *    EthernetII header, keep the src/dst and snap_type (ethertype)
198                  *
199                  *  The firmware only passes up SNAP frames converting
200                  *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
201                  *
202                  *  To create the Ethernet II, just move the src, dst address right
203                  *    before the snap_type.
204                  */
205                 p_ethhdr = (struct ethhdr *)
206                     ((u8 *) & p_rx_pkt->eth803_hdr
207                      + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
208                      - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
209                      - sizeof(p_rx_pkt->eth803_hdr.src_addr)
210                      - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
211
212                 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
213                        sizeof(p_ethhdr->h_source));
214                 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
215                        sizeof(p_ethhdr->h_dest));
216
217                 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
218                  *   that was removed
219                  */
220                 hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
221         } else {
222                 lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
223                         (u8 *) & p_rx_pkt->rfc1042_hdr,
224                         sizeof(p_rx_pkt->rfc1042_hdr));
225
226                 /* Chop off the rxpd */
227                 hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
228         }
229
230         /* Chop off the leading header bytes so the skb points to the start of
231          *   either the reconstructed EthII frame or the 802.2/llc/snap frame
232          */
233         skb_pull(skb, hdrchop);
234
235         /* Take the data rate from the rxpd structure
236          * only if the rate is auto
237          */
238         if (priv->enablehwauto)
239                 priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
240
241         lbs_compute_rssi(priv, p_rx_pd);
242
243         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
244         dev->stats.rx_bytes += skb->len;
245         dev->stats.rx_packets++;
246
247         skb->protocol = eth_type_trans(skb, dev);
248         if (in_interrupt())
249                 netif_rx(skb);
250         else
251                 netif_rx_ni(skb);
252
253         ret = 0;
254 done:
255         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
256         return ret;
257 }
258 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
259
260 /**
261  *  @brief This function converts Tx/Rx rates from the Marvell WLAN format
262  *  (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
263  *
264  *  @param rate    Input rate
265  *  @return        Output Rate (0 if invalid)
266  */
267 static u8 convert_mv_rate_to_radiotap(u8 rate)
268 {
269         switch (rate) {
270         case 0:         /*   1 Mbps */
271                 return 2;
272         case 1:         /*   2 Mbps */
273                 return 4;
274         case 2:         /* 5.5 Mbps */
275                 return 11;
276         case 3:         /*  11 Mbps */
277                 return 22;
278         /* case 4: reserved */
279         case 5:         /*   6 Mbps */
280                 return 12;
281         case 6:         /*   9 Mbps */
282                 return 18;
283         case 7:         /*  12 Mbps */
284                 return 24;
285         case 8:         /*  18 Mbps */
286                 return 36;
287         case 9:         /*  24 Mbps */
288                 return 48;
289         case 10:                /*  36 Mbps */
290                 return 72;
291         case 11:                /*  48 Mbps */
292                 return 96;
293         case 12:                /*  54 Mbps */
294                 return 108;
295         }
296         lbs_pr_alert("Invalid Marvell WLAN rate %i\n", rate);
297         return 0;
298 }
299
300 /**
301  *  @brief This function processes a received 802.11 packet and forwards it
302  *  to kernel/upper layer
303  *
304  *  @param priv    A pointer to struct lbs_private
305  *  @param skb     A pointer to skb which includes the received packet
306  *  @return        0 or -1
307  */
308 static int process_rxed_802_11_packet(struct lbs_private *priv,
309         struct sk_buff *skb)
310 {
311         int ret = 0;
312         struct net_device *dev = priv->dev;
313         struct rx80211packethdr *p_rx_pkt;
314         struct rxpd *prxpd;
315         struct rx_radiotap_hdr radiotap_hdr;
316         struct rx_radiotap_hdr *pradiotap_hdr;
317
318         lbs_deb_enter(LBS_DEB_RX);
319
320         p_rx_pkt = (struct rx80211packethdr *) skb->data;
321         prxpd = &p_rx_pkt->rx_pd;
322
323         // lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100));
324
325         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
326                 lbs_deb_rx("rx err: frame received with bad length\n");
327                 dev->stats.rx_length_errors++;
328                 ret = -EINVAL;
329                 kfree_skb(skb);
330                 goto done;
331         }
332
333         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
334                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
335
336         /* create the exported radio header */
337
338         /* radiotap header */
339         radiotap_hdr.hdr.it_version = 0;
340         /* XXX must check this value for pad */
341         radiotap_hdr.hdr.it_pad = 0;
342         radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
343         radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
344         radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
345         /* XXX must check no carryout */
346         radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
347
348         /* chop the rxpd */
349         skb_pull(skb, sizeof(struct rxpd));
350
351         /* add space for the new radio header */
352         if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
353             pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
354                 lbs_pr_alert("%s: couldn't pskb_expand_head\n", __func__);
355                 ret = -ENOMEM;
356                 kfree_skb(skb);
357                 goto done;
358         }
359
360         pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
361         memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
362
363         /* Take the data rate from the rxpd structure
364          * only if the rate is auto
365          */
366         if (priv->enablehwauto)
367                 priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
368
369         lbs_compute_rssi(priv, prxpd);
370
371         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
372         dev->stats.rx_bytes += skb->len;
373         dev->stats.rx_packets++;
374
375         skb->protocol = eth_type_trans(skb, priv->rtap_net_dev);
376         netif_rx(skb);
377
378         ret = 0;
379
380 done:
381         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
382         return ret;
383 }