summaryrefslogtreecommitdiffstats
path: root/drivers/net/wireless/wl12xx/wl1271_tx.c
blob: a288cc317d7b076d51f63f7f51490c56fd30f5d6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
/*
 * This file is part of wl1271
 *
 * Copyright (C) 2009 Nokia Corporation
 *
 * Contact: Luciano Coelho <luciano.coelho@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "wl1271.h"
#include "wl1271_spi.h"
#include "wl1271_reg.h"
#include "wl1271_ps.h"
#include "wl1271_tx.h"

static int wl1271_tx_id(struct wl1271 *wl, struct sk_buff *skb)
{
	int i;
	for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
		if (wl->tx_frames[i] == NULL) {
			wl->tx_frames[i] = skb;
			return i;
		}

	return -EBUSY;
}

static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
{
	struct wl1271_tx_hw_descr *desc;
	u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
	u32 total_blocks, excluded;
	int id, ret = -EBUSY;

	/* allocate free identifier for the packet */
	id = wl1271_tx_id(wl, skb);
	if (id < 0)
		return id;

	/* approximate the number of blocks required for this packet
	   in the firmware */
	/* FIXME: try to figure out what is done here and make it cleaner */
	total_blocks = (total_len + 20) >> TX_HW_BLOCK_SHIFT_DIV;
	excluded = (total_blocks << 2) + ((total_len + 20) & 0xff) + 34;
	total_blocks += (excluded > 252) ? 2 : 1;
	total_blocks += TX_HW_BLOCK_SPARE;

	if (total_blocks <= wl->tx_blocks_available) {
		desc = (struct wl1271_tx_hw_descr *)skb_push(
			skb, total_len - skb->len);

		desc->extra_mem_blocks = TX_HW_BLOCK_SPARE;
		desc->total_mem_blocks = total_blocks;
		desc->id = id;

		wl->tx_blocks_available -= total_blocks;

		ret = 0;

		wl1271_debug(DEBUG_TX,
			     "tx_allocate: size: %d, blocks: %d, id: %d",
			     total_len, total_blocks, id);
	} else
		wl->tx_frames[id] = NULL;

	return ret;
}

static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
			      u32 extra, struct ieee80211_tx_info *control)
{
	struct wl1271_tx_hw_descr *desc;
	int pad;
	u16 tx_attr;

	desc = (struct wl1271_tx_hw_descr *) skb->data;

	/* relocate space for security header */
	if (extra) {
		void *framestart = skb->data + sizeof(*desc);
		u16 fc = *(u16 *)(framestart + extra);
		int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc));
		memmove(framestart, framestart + extra, hdrlen);
	}

	/* configure packet life time */
	desc->start_time = cpu_to_le32(jiffies_to_usecs(jiffies) -
				       wl->time_offset);
	desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU);

	/* configure the tx attributes */
	tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
	/* FIXME: do we know the packet priority? can we identify mgmt
	   packets, and use max prio for them at least? */
	desc->tid = 0;
	desc->aid = TX_HW_DEFAULT_AID;
	desc->reserved = 0;

	/* align the length (and store in terms of words) */
	pad = WL1271_TX_ALIGN(skb->len);
	desc->length = cpu_to_le16(pad >> 2);

	/* calculate number of padding bytes */
	pad = pad - skb->len;
	tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;

	/* if the packets are destined for AP (have a STA entry) send them
	   with AP rate policies, otherwise use default basic rates */
	if (control->control.sta)
		tx_attr |= ACX_TX_AP_FULL_RATE << TX_HW_ATTR_OFST_RATE_POLICY;

	desc->tx_attr = cpu_to_le16(tx_attr);

	wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
	return 0;
}

static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
				 struct ieee80211_tx_info *control)
{

	struct wl1271_tx_hw_descr *desc;
	int len;

	/* FIXME: This is a workaround for getting non-aligned packets.
	   This happens at least with EAPOL packets from the user space.
	   Our DMA requires packets to be aligned on a 4-byte boundary.
	*/
	if (unlikely((long)skb->data & 0x03)) {
		int offset = (4 - (long)skb->data) & 0x03;
		wl1271_debug(DEBUG_TX, "skb offset %d", offset);

		/* check whether the current skb can be used */
		if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
			unsigned char *src = skb->data;

			/* align the buffer on a 4-byte boundary */
			skb_reserve(skb, offset);
			memmove(skb->data, src, skb->len);
		} else {
			wl1271_info("No handler, fixme!");
			return -EINVAL;
		}
	}

	len = WL1271_TX_ALIGN(skb->len);

	/* perform a fixed address block write with the packet */
	wl1271_spi_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);

	/* write packet new counter into the write access register */
	wl->tx_packets_count++;
	wl1271_spi_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);

	desc = (struct wl1271_tx_hw_descr *) skb->data;
	wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
		     desc->id, skb, len, desc->length);

	return 0;
}

/* caller must hold wl->mutex */
static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
{
	struct ieee80211_tx_info *info;
	u32 extra = 0;
	int ret = 0;
	u8 idx;

	if (!skb)
		return -EINVAL;

	info = IEEE80211_SKB_CB(skb);

	if (info->control.hw_key &&
	    info->control.hw_key->alg == ALG_TKIP)
		extra = WL1271_TKIP_IV_SPACE;

	if (info->control.hw_key) {
		idx = info->control.hw_key->hw_key_idx;

		/* FIXME: do we have to do this if we're not using WEP? */
		if (unlikely(wl->default_key != idx)) {
			ret = wl1271_cmd_set_default_wep_key(wl, idx);
			if (ret < 0)
				return ret;
		}
	}

	ret = wl1271_tx_allocate(wl, skb, extra);
	if (ret < 0)
		return ret;

	ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
	if (ret < 0)
		return ret;

	ret = wl1271_tx_send_packet(wl, skb, info);
	if (ret < 0)
		return ret;

	return ret;
}

static u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
{
	struct ieee80211_supported_band *band;
	u32 enabled_rates = 0;
	int bit;

	band = wl->hw->wiphy->bands[wl->band];
	for (bit = 0; bit < band->n_bitrates; bit++) {
		if (rate_set & 0x1)
			enabled_rates |= band->bitrates[bit].hw_value;
		rate_set >>= 1;
	}

	return enabled_rates;
}

void wl1271_tx_work(struct work_struct *work)
{
	struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
	struct sk_buff *skb;
	bool woken_up = false;
	u32 sta_rates = 0;
	int ret;

	/* check if the rates supported by the AP have changed */
	if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED,
					&wl->flags))) {
		unsigned long flags;
		spin_lock_irqsave(&wl->wl_lock, flags);
		sta_rates = wl->sta_rate_set;
		spin_unlock_irqrestore(&wl->wl_lock, flags);
	}

	mutex_lock(&wl->mutex);

	if (unlikely(wl->state == WL1271_STATE_OFF))
		goto out;

	/* if rates have changed, re-configure the rate policy */
	if (unlikely(sta_rates)) {
		wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates);
		wl1271_acx_rate_policies(wl);
	}

	while ((skb = skb_dequeue(&wl->tx_queue))) {
		if (!woken_up) {
			ret = wl1271_ps_elp_wakeup(wl, false);
			if (ret < 0)
				goto out;
			woken_up = true;
		}

		ret = wl1271_tx_frame(wl, skb);
		if (ret == -EBUSY) {
			/* firmware buffer is full, stop queues */
			wl1271_debug(DEBUG_TX, "tx_work: fw buffer full, "
				     "stop queues");
			ieee80211_stop_queues(wl->hw);
			set_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags);
			skb_queue_head(&wl->tx_queue, skb);
			goto out;
		} else if (ret < 0) {
			dev_kfree_skb(skb);
			goto out;
		} else if (test_and_clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED,
					      &wl->flags)) {
			/* firmware buffer has space, restart queues */
			wl1271_debug(DEBUG_TX,
				     "complete_packet: waking queues");
			ieee80211_wake_queues(wl->hw);
		}
	}

out:
	if (woken_up)
		wl1271_ps_elp_sleep(wl);

	mutex_unlock(&wl->mutex);
}

static void wl1271_tx_complete_packet(struct wl1271 *wl,
				      struct wl1271_tx_hw_res_descr *result)
{
	struct ieee80211_tx_info *info;
	struct sk_buff *skb;
	u16 seq;
	int id = result->id;

	/* check for id legality */
	if (id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL) {
		wl1271_warning("TX result illegal id: %d", id);
		return;
	}

	skb = wl->tx_frames[id];
	info = IEEE80211_SKB_CB(skb);

	/* update packet status */
	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
		if (result->status == TX_SUCCESS)
			info->flags |= IEEE80211_TX_STAT_ACK;
		if (result->status & TX_RETRY_EXCEEDED) {
			/* FIXME */
			/* info->status.excessive_retries = 1; */
			wl->stats.excessive_retries++;
		}
	}

	/* FIXME */
	/* info->status.retry_count = result->ack_failures; */
	wl->stats.retry_count += result->ack_failures;

	/* update security sequence number */
	seq = wl->tx_security_seq_16 +
		(result->lsb_security_sequence_number -
		 wl->tx_security_last_seq);
	wl->tx_security_last_seq = result->lsb_security_sequence_number;

	if (seq < wl->tx_security_seq_16)
		wl->tx_security_seq_32++;
	wl->tx_security_seq_16 = seq;

	/* remove private header from packet */
	skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));

	/* remove TKIP header space if present */
	if (info->control.hw_key &&
	    info->control.hw_key->alg == ALG_TKIP) {
		int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
		memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
		skb_pull(skb, WL1271_TKIP_IV_SPACE);
	}

	wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
		     " status 0x%x",
		     result->id, skb, result->ack_failures,
		     result->rate_class_index, result->status);

	/* return the packet to the stack */
	ieee80211_tx_status(wl->hw, skb);
	wl->tx_frames[result->id] = NULL;
}

/* Called upon reception of a TX complete interrupt */
void wl1271_tx_complete(struct wl1271 *wl, u32 count)
{
	struct wl1271_acx_mem_map *memmap =
		(struct wl1271_acx_mem_map *)wl->target_mem_map;
	u32 i;

	wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);

	/* read the tx results from the chipset */
	wl1271_spi_read(wl, le32_to_cpu(memmap->tx_result),
			wl->tx_res_if, sizeof(*wl->tx_res_if), false);

	/* verify that the result buffer is not getting overrun */
	if (count > TX_HW_RESULT_QUEUE_LEN) {
		wl1271_warning("TX result overflow from chipset: %d", count);
		count = TX_HW_RESULT_QUEUE_LEN;
	}

	/* process the results */
	for (i = 0; i < count; i++) {
		struct wl1271_tx_hw_res_descr *result;
		u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;

		/* process the packet */
		result =  &(wl->tx_res_if->tx_results_queue[offset]);
		wl1271_tx_complete_packet(wl, result);

		wl->tx_results_count++;
	}

	/* write host counter to chipset (to ack) */
	wl1271_spi_write32(wl, le32_to_cpu(memmap->tx_result) +
			   offsetof(struct wl1271_tx_hw_res_if,
				    tx_result_host_counter),
			   le32_to_cpu(wl->tx_res_if->tx_result_fw_counter));
}

/* caller must hold wl->mutex */
void wl1271_tx_flush(struct wl1271 *wl)
{
	int i;
	struct sk_buff *skb;
	struct ieee80211_tx_info *info;

	/* TX failure */
/* 	control->flags = 0; FIXME */

	while ((skb = skb_dequeue(&wl->tx_queue))) {
		info = IEEE80211_SKB_CB(skb);

		wl1271_debug(DEBUG_TX, "flushing skb 0x%p", skb);

		if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
				continue;

		ieee80211_tx_status(wl->hw, skb);
	}

	for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
		if (wl->tx_frames[i] != NULL) {
			skb = wl->tx_frames[i];
			info = IEEE80211_SKB_CB(skb);

			if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
				continue;

			ieee80211_tx_status(wl->hw, skb);
			wl->tx_frames[i] = NULL;
		}
}
OpenPOWER on IntegriCloud