wl1251: add powersave exit logic for transfers
[pandora-kernel.git] / drivers / net / wireless / wl1251 / tx.c
1 /*
2  * This file is part of wl1251
3  *
4  * Copyright (c) 1998-2007 Texas Instruments Incorporated
5  * Copyright (C) 2008 Nokia Corporation
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * version 2 as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19  * 02110-1301 USA
20  *
21  */
22
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25
26 #include "wl1251.h"
27 #include "reg.h"
28 #include "tx.h"
29 #include "ps.h"
30 #include "io.h"
31 #include "event.h"
32
33 static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
34 {
35         int used, data_in_count;
36
37         data_in_count = wl->data_in_count;
38
39         if (data_in_count < data_out_count)
40                 /* data_in_count has wrapped */
41                 data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
42
43         used = data_in_count - data_out_count;
44
45         WARN_ON(used < 0);
46         WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
47
48         if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
49                 return true;
50         else
51                 return false;
52 }
53
54 int wl1251_tx_path_status(struct wl1251 *wl)
55 {
56         u32 status, addr, data_out_count;
57         bool busy;
58
59         addr = wl->data_path->tx_control_addr;
60         status = wl1251_mem_read32(wl, addr);
61         data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
62         busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
63
64         if (busy)
65                 return -EBUSY;
66
67         return 0;
68 }
69
70 static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
71 {
72         int i;
73
74         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
75                 if (wl->tx_frames[i] == NULL) {
76                         wl->tx_frames[i] = skb;
77                         return i;
78                 }
79
80         return -EBUSY;
81 }
82
83 static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
84                               struct ieee80211_tx_info *control, u16 fc)
85 {
86         *(u16 *)&tx_hdr->control = 0;
87
88         tx_hdr->control.rate_policy = 0;
89
90         /* 802.11 packets */
91         tx_hdr->control.packet_type = 0;
92
93         /* Also disable retry and ACK policy for injected packets */
94         if ((control->flags & IEEE80211_TX_CTL_NO_ACK) ||
95             (control->flags & IEEE80211_TX_CTL_INJECTED)) {
96                 tx_hdr->control.rate_policy = 1;
97                 tx_hdr->control.ack_policy = 1;
98         }
99
100         tx_hdr->control.tx_complete = 1;
101
102         if ((fc & IEEE80211_FTYPE_DATA) &&
103             ((fc & IEEE80211_STYPE_QOS_DATA) ||
104              (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
105                 tx_hdr->control.qos = 1;
106 }
107
108 /* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
109 #define MAX_MSDU_SECURITY_LENGTH      16
110 #define MAX_MPDU_SECURITY_LENGTH      16
111 #define WLAN_QOS_HDR_LEN              26
112 #define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
113                                        WLAN_QOS_HDR_LEN)
114 #define HW_BLOCK_SIZE                 252
115 static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
116 {
117         u16 payload_len, frag_threshold, mem_blocks;
118         u16 num_mpdus, mem_blocks_per_frag;
119
120         frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
121         tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
122
123         payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
124
125         if (payload_len > frag_threshold) {
126                 mem_blocks_per_frag =
127                         ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
128                          HW_BLOCK_SIZE) + 1;
129                 num_mpdus = payload_len / frag_threshold;
130                 mem_blocks = num_mpdus * mem_blocks_per_frag;
131                 payload_len -= num_mpdus * frag_threshold;
132                 num_mpdus++;
133
134         } else {
135                 mem_blocks_per_frag = 0;
136                 mem_blocks = 0;
137                 num_mpdus = 1;
138         }
139
140         mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
141
142         if (num_mpdus > 1)
143                 mem_blocks += min(num_mpdus, mem_blocks_per_frag);
144
145         tx_hdr->num_mem_blocks = mem_blocks;
146 }
147
148 static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
149                               struct ieee80211_tx_info *control)
150 {
151         struct tx_double_buffer_desc *tx_hdr;
152         struct ieee80211_rate *rate;
153         int id;
154         u16 fc;
155
156         if (!skb)
157                 return -EINVAL;
158
159         id = wl1251_tx_id(wl, skb);
160         if (id < 0)
161                 return id;
162
163         fc = *(u16 *)skb->data;
164         tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
165                                                            sizeof(*tx_hdr));
166
167         tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
168         rate = ieee80211_get_tx_rate(wl->hw, control);
169         tx_hdr->rate = cpu_to_le16(rate->hw_value);
170         tx_hdr->expiry_time = cpu_to_le32(1 << 16);
171         tx_hdr->id = id;
172
173         tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
174
175         wl1251_tx_control(tx_hdr, control, fc);
176         wl1251_tx_frag_block_num(tx_hdr);
177
178         return 0;
179 }
180
181 /* We copy the packet to the target */
182 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
183                                  struct ieee80211_tx_info *control)
184 {
185         struct tx_double_buffer_desc *tx_hdr;
186         int len;
187         u32 addr;
188
189         if (!skb)
190                 return -EINVAL;
191
192         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
193
194         if (control->control.hw_key &&
195             control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
196                 int hdrlen;
197                 __le16 fc;
198                 u16 length;
199                 u8 *pos;
200
201                 fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
202                 length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
203                 tx_hdr->length = cpu_to_le16(length);
204
205                 hdrlen = ieee80211_hdrlen(fc);
206
207                 pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
208                 memmove(pos, pos + WL1251_TKIP_IV_SPACE,
209                         sizeof(*tx_hdr) + hdrlen);
210         }
211
212         /* Revisit. This is a workaround for getting non-aligned packets.
213            This happens at least with EAPOL packets from the user space.
214            Our DMA requires packets to be aligned on a 4-byte boundary.
215         */
216         if (unlikely((long)skb->data & 0x03)) {
217                 int offset = (4 - (long)skb->data) & 0x03;
218                 wl1251_debug(DEBUG_TX, "skb offset %d", offset);
219
220                 /* check whether the current skb can be used */
221                 if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
222                         struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
223                                                                  GFP_KERNEL);
224
225                         if (unlikely(newskb == NULL)) {
226                                 wl1251_error("Can't allocate skb!");
227                                 return -EINVAL;
228                         }
229
230                         tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
231
232                         dev_kfree_skb_any(skb);
233                         wl->tx_frames[tx_hdr->id] = skb = newskb;
234
235                         offset = (4 - (long)skb->data) & 0x03;
236                         wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
237                 }
238
239                 /* align the buffer on a 4-byte boundary */
240                 if (offset) {
241                         unsigned char *src = skb->data;
242                         skb_reserve(skb, offset);
243                         memmove(skb->data, src, skb->len);
244                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
245                 }
246         }
247
248         /* Our skb->data at this point includes the HW header */
249         len = WL1251_TX_ALIGN(skb->len);
250
251         if (wl->data_in_count & 0x1)
252                 addr = wl->data_path->tx_packet_ring_addr +
253                         wl->data_path->tx_packet_ring_chunk_size;
254         else
255                 addr = wl->data_path->tx_packet_ring_addr;
256
257         wl1251_mem_write(wl, addr, skb->data, len);
258
259         wl1251_update_rate(wl, len);
260         wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
261                      "queue %d", tx_hdr->id, skb, tx_hdr->length,
262                      tx_hdr->rate, tx_hdr->xmit_queue);
263
264         return 0;
265 }
266
267 static void wl1251_tx_trigger(struct wl1251 *wl)
268 {
269         u32 data, addr;
270
271         if (wl->data_in_count & 0x1) {
272                 addr = ACX_REG_INTERRUPT_TRIG_H;
273                 data = INTR_TRIG_TX_PROC1;
274         } else {
275                 addr = ACX_REG_INTERRUPT_TRIG;
276                 data = INTR_TRIG_TX_PROC0;
277         }
278
279         wl1251_reg_write32(wl, addr, data);
280
281         /* Bumping data in */
282         wl->data_in_count = (wl->data_in_count + 1) &
283                 TX_STATUS_DATA_OUT_COUNT_MASK;
284 }
285
286 static void enable_tx_for_packet_injection(struct wl1251 *wl)
287 {
288         int ret;
289
290         ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
291                               wl->beacon_int, wl->dtim_period);
292         if (ret < 0) {
293                 wl1251_warning("join failed");
294                 return;
295         }
296
297         ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
298         if (ret < 0) {
299                 wl1251_warning("join timeout");
300                 return;
301         }
302
303         wl->joined = true;
304 }
305
306 /* caller must hold wl->mutex */
307 int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
308 {
309         struct ieee80211_tx_info *info;
310         int ret = 0;
311         u8 idx;
312
313         info = IEEE80211_SKB_CB(skb);
314
315         if (info->control.hw_key) {
316                 if (unlikely(wl->monitor_present))
317                         return -EINVAL;
318
319                 idx = info->control.hw_key->hw_key_idx;
320                 if (unlikely(wl->default_key != idx)) {
321                         ret = wl1251_acx_default_key(wl, idx);
322                         if (ret < 0)
323                                 return ret;
324                 }
325         }
326
327         /* Enable tx path in monitor mode for packet injection */
328         if ((wl->vif == NULL) && !wl->joined)
329                 enable_tx_for_packet_injection(wl);
330
331         ret = wl1251_tx_path_status(wl);
332         if (ret < 0)
333                 return ret;
334
335         ret = wl1251_tx_fill_hdr(wl, skb, info);
336         if (ret < 0)
337                 return ret;
338
339         ret = wl1251_tx_send_packet(wl, skb, info);
340         if (ret < 0)
341                 return ret;
342
343         wl1251_tx_trigger(wl);
344
345         return ret;
346 }
347
348 void wl1251_tx_work(struct work_struct *work)
349 {
350         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
351         struct sk_buff *skb;
352         bool woken_up = false;
353         int ret;
354
355         mutex_lock(&wl->mutex);
356
357         if (unlikely(wl->state == WL1251_STATE_OFF))
358                 goto out;
359
360         while ((skb = skb_dequeue(&wl->tx_queue))) {
361                 if (!woken_up) {
362                         ret = wl1251_ps_elp_wakeup(wl);
363                         if (ret < 0)
364                                 goto out;
365                         woken_up = true;
366                 }
367
368                 ret = wl1251_tx_frame(wl, skb);
369                 if (ret == -EBUSY) {
370                         skb_queue_head(&wl->tx_queue, skb);
371                         goto out;
372                 } else if (ret < 0) {
373                         dev_kfree_skb(skb);
374                         goto out;
375                 }
376         }
377
378 out:
379         if (woken_up)
380                 wl1251_ps_elp_sleep(wl);
381
382         mutex_unlock(&wl->mutex);
383 }
384
385 static const char *wl1251_tx_parse_status(u8 status)
386 {
387         /* 8 bit status field, one character per bit plus null */
388         static char buf[9];
389         int i = 0;
390
391         memset(buf, 0, sizeof(buf));
392
393         if (status & TX_DMA_ERROR)
394                 buf[i++] = 'm';
395         if (status & TX_DISABLED)
396                 buf[i++] = 'd';
397         if (status & TX_RETRY_EXCEEDED)
398                 buf[i++] = 'r';
399         if (status & TX_TIMEOUT)
400                 buf[i++] = 't';
401         if (status & TX_KEY_NOT_FOUND)
402                 buf[i++] = 'k';
403         if (status & TX_ENCRYPT_FAIL)
404                 buf[i++] = 'e';
405         if (status & TX_UNAVAILABLE_PRIORITY)
406                 buf[i++] = 'p';
407
408         /* bit 0 is unused apparently */
409
410         return buf;
411 }
412
413 static void wl1251_tx_packet_cb(struct wl1251 *wl,
414                                 struct tx_result *result)
415 {
416         struct ieee80211_tx_info *info;
417         struct sk_buff *skb;
418         int hdrlen;
419         u8 *frame;
420
421         skb = wl->tx_frames[result->id];
422         if (skb == NULL) {
423                 wl1251_error("SKB for packet %d is NULL", result->id);
424                 return;
425         }
426
427         info = IEEE80211_SKB_CB(skb);
428
429         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
430             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
431             (result->status == TX_SUCCESS))
432                 info->flags |= IEEE80211_TX_STAT_ACK;
433
434         info->status.rates[0].count = result->ack_failures + 1;
435         wl->stats.retry_count += result->ack_failures;
436
437         /*
438          * We have to remove our private TX header before pushing
439          * the skb back to mac80211.
440          */
441         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
442         if (info->control.hw_key &&
443             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
444                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
445                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
446                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
447         }
448
449         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
450                      " status 0x%x (%s)",
451                      result->id, skb, result->ack_failures, result->rate,
452                      result->status, wl1251_tx_parse_status(result->status));
453
454
455         ieee80211_tx_status(wl->hw, skb);
456
457         wl->tx_frames[result->id] = NULL;
458 }
459
460 /* Called upon reception of a TX complete interrupt */
461 void wl1251_tx_complete(struct wl1251 *wl)
462 {
463         int i, result_index, num_complete = 0, queue_len;
464         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
465         unsigned long flags;
466
467         if (unlikely(wl->state != WL1251_STATE_ON))
468                 return;
469
470         /* First we read the result */
471         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
472                             result, sizeof(result));
473
474         result_index = wl->next_tx_complete;
475
476         for (i = 0; i < ARRAY_SIZE(result); i++) {
477                 result_ptr = &result[result_index];
478
479                 if (result_ptr->done_1 == 1 &&
480                     result_ptr->done_2 == 1) {
481                         wl1251_tx_packet_cb(wl, result_ptr);
482
483                         result_ptr->done_1 = 0;
484                         result_ptr->done_2 = 0;
485
486                         result_index = (result_index + 1) &
487                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
488                         num_complete++;
489                 } else {
490                         break;
491                 }
492         }
493
494         queue_len = skb_queue_len(&wl->tx_queue);
495
496         if ((num_complete > 0) && (queue_len > 0)) {
497                 /* firmware buffer has space, reschedule tx_work */
498                 wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
499                 ieee80211_queue_work(wl->hw, &wl->tx_work);
500         }
501
502         if (wl->tx_queue_stopped &&
503             queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
504                 /* tx_queue has space, restart queues */
505                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
506                 spin_lock_irqsave(&wl->wl_lock, flags);
507                 ieee80211_wake_queues(wl->hw);
508                 wl->tx_queue_stopped = false;
509                 spin_unlock_irqrestore(&wl->wl_lock, flags);
510         }
511
512         /* Every completed frame needs to be acknowledged */
513         if (num_complete) {
514                 /*
515                  * If we've wrapped, we have to clear
516                  * the results in 2 steps.
517                  */
518                 if (result_index > wl->next_tx_complete) {
519                         /* Only 1 write is needed */
520                         wl1251_mem_write(wl,
521                                          wl->data_path->tx_complete_addr +
522                                          (wl->next_tx_complete *
523                                           sizeof(struct tx_result)),
524                                          &result[wl->next_tx_complete],
525                                          num_complete *
526                                          sizeof(struct tx_result));
527
528
529                 } else if (result_index < wl->next_tx_complete) {
530                         /* 2 writes are needed */
531                         wl1251_mem_write(wl,
532                                          wl->data_path->tx_complete_addr +
533                                          (wl->next_tx_complete *
534                                           sizeof(struct tx_result)),
535                                          &result[wl->next_tx_complete],
536                                          (FW_TX_CMPLT_BLOCK_SIZE -
537                                           wl->next_tx_complete) *
538                                          sizeof(struct tx_result));
539
540                         wl1251_mem_write(wl,
541                                          wl->data_path->tx_complete_addr,
542                                          result,
543                                          (num_complete -
544                                           FW_TX_CMPLT_BLOCK_SIZE +
545                                           wl->next_tx_complete) *
546                                          sizeof(struct tx_result));
547
548                 } else {
549                         /* We have to write the whole array */
550                         wl1251_mem_write(wl,
551                                          wl->data_path->tx_complete_addr,
552                                          result,
553                                          FW_TX_CMPLT_BLOCK_SIZE *
554                                          sizeof(struct tx_result));
555                 }
556
557         }
558
559         wl->next_tx_complete = result_index;
560 }
561
562 /* caller must hold wl->mutex */
563 void wl1251_tx_flush(struct wl1251 *wl)
564 {
565         int i;
566         struct sk_buff *skb;
567         struct ieee80211_tx_info *info;
568
569         /* TX failure */
570 /*      control->flags = 0; FIXME */
571
572         while ((skb = skb_dequeue(&wl->tx_queue))) {
573                 info = IEEE80211_SKB_CB(skb);
574
575                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
576
577                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
578                                 continue;
579
580                 ieee80211_tx_status(wl->hw, skb);
581         }
582
583         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
584                 if (wl->tx_frames[i] != NULL) {
585                         skb = wl->tx_frames[i];
586                         info = IEEE80211_SKB_CB(skb);
587
588                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
589                                 continue;
590
591                         ieee80211_tx_status(wl->hw, skb);
592                         wl->tx_frames[i] = NULL;
593                 }
594 }