aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/wireless/iwlwifi/iwl-rx.c
blob: 0a5d7cf25196031d635c55f8d5ab23a8ca16e0cf (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
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
/******************************************************************************
 *
 * Copyright(c) 2003 - 2010 Intel Corporation. All rights reserved.
 *
 * Portions of this file are derived from the ipw3945 project, as well
 * as portions of the ieee80211 subsystem header files.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License 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 Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <linux/etherdevice.h>
#include <linux/slab.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>
#include "iwl-eeprom.h"
#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"
#include "iwl-io.h"
#include "iwl-calib.h"
#include "iwl-helpers.h"
/************************** RX-FUNCTIONS ****************************/
/*
 * Rx theory of operation
 *
 * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
 * each of which point to Receive Buffers to be filled by the NIC.  These get
 * used not only for Rx frames, but for any command response or notification
 * from the NIC.  The driver and NIC manage the Rx buffers by means
 * of indexes into the circular buffer.
 *
 * Rx Queue Indexes
 * The host/firmware share two index registers for managing the Rx buffers.
 *
 * The READ index maps to the first position that the firmware may be writing
 * to -- the driver can read up to (but not including) this position and get
 * good data.
 * The READ index is managed by the firmware once the card is enabled.
 *
 * The WRITE index maps to the last position the driver has read from -- the
 * position preceding WRITE is the last slot the firmware can place a packet.
 *
 * The queue is empty (no good data) if WRITE = READ - 1, and is full if
 * WRITE = READ.
 *
 * During initialization, the host sets up the READ queue position to the first
 * INDEX position, and WRITE to the last (READ - 1 wrapped)
 *
 * When the firmware places a packet in a buffer, it will advance the READ index
 * and fire the RX interrupt.  The driver can then query the READ index and
 * process as many packets as possible, moving the WRITE index forward as it
 * resets the Rx queue buffers with new memory.
 *
 * The management in the driver is as follows:
 * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free.  When
 *   iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
 *   to replenish the iwl->rxq->rx_free.
 * + In iwl_rx_replenish (scheduled) if 'processed' != 'read' then the
 *   iwl->rxq is replenished and the READ INDEX is updated (updating the
 *   'processed' and 'read' driver indexes as well)
 * + A received packet is processed and handed to the kernel network stack,
 *   detached from the iwl->rxq.  The driver 'processed' index is updated.
 * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free
 *   list. If there are no allocated buffers in iwl->rxq->rx_free, the READ
 *   INDEX is not incremented and iwl->status(RX_STALLED) is set.  If there
 *   were enough free buffers and RX_STALLED is set it is cleared.
 *
 *
 * Driver sequence:
 *
 * iwl_rx_queue_alloc()   Allocates rx_free
 * iwl_rx_replenish()     Replenishes rx_free list from rx_used, and calls
 *                            iwl_rx_queue_restock
 * iwl_rx_queue_restock() Moves available buffers from rx_free into Rx
 *                            queue, updates firmware pointers, and updates
 *                            the WRITE index.  If insufficient rx_free buffers
 *                            are available, schedules iwl_rx_replenish
 *
 * -- enable interrupts --
 * ISR - iwl_rx()         Detach iwl_rx_mem_buffers from pool up to the
 *                            READ INDEX, detaching the SKB from the pool.
 *                            Moves the packet buffer from queue to rx_used.
 *                            Calls iwl_rx_queue_restock to refill any empty
 *                            slots.
 * ...
 *
 */

/**
 * iwl_rx_queue_space - Return number of free slots available in queue.
 */
int iwl_rx_queue_space(const struct iwl_rx_queue *q)
{
	int s = q->read - q->write;
	if (s <= 0)
		s += RX_QUEUE_SIZE;
	/* keep some buffer to not confuse full and empty queue */
	s -= 2;
	if (s < 0)
		s = 0;
	return s;
}
EXPORT_SYMBOL(iwl_rx_queue_space);

/**
 * iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue
 */
void iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q)
{
	unsigned long flags;
	u32 rx_wrt_ptr_reg = priv->hw_params.rx_wrt_ptr_reg;
	u32 reg;

	spin_lock_irqsave(&q->lock, flags);

	if (q->need_update == 0)
		goto exit_unlock;

	/* If power-saving is in use, make sure device is awake */
	if (test_bit(STATUS_POWER_PMI, &priv->status)) {
		reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);

		if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
			IWL_DEBUG_INFO(priv, "Rx queue requesting wakeup, GP1 = 0x%x\n",
				      reg);
			iwl_set_bit(priv, CSR_GP_CNTRL,
				    CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
			goto exit_unlock;
		}

		q->write_actual = (q->write & ~0x7);
		iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);

	/* Else device is assumed to be awake */
	} else {
		/* Device expects a multiple of 8 */
		q->write_actual = (q->write & ~0x7);
		iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
	}

	q->need_update = 0;

 exit_unlock:
	spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(iwl_rx_queue_update_write_ptr);

int iwl_rx_queue_alloc(struct iwl_priv *priv)
{
	struct iwl_rx_queue *rxq = &priv->rxq;
	struct device *dev = &priv->pci_dev->dev;
	int i;

	spin_lock_init(&rxq->lock);
	INIT_LIST_HEAD(&rxq->rx_free);
	INIT_LIST_HEAD(&rxq->rx_used);

	/* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
	rxq->bd = dma_alloc_coherent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr,
				     GFP_KERNEL);
	if (!rxq->bd)
		goto err_bd;

	rxq->rb_stts = dma_alloc_coherent(dev, sizeof(struct iwl_rb_status),
					  &rxq->rb_stts_dma, GFP_KERNEL);
	if (!rxq->rb_stts)
		goto err_rb;

	/* Fill the rx_used queue with _all_ of the Rx buffers */
	for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
		list_add_tail(&rxq->pool[i].list, &rxq->rx_used);

	/* Set us so that we have processed and used all buffers, but have
	 * not restocked the Rx queue with fresh buffers */
	rxq->read = rxq->write = 0;
	rxq->write_actual = 0;
	rxq->free_count = 0;
	rxq->need_update = 0;
	return 0;

err_rb:
	dma_free_coherent(&priv->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
			  rxq->dma_addr);
err_bd:
	return -ENOMEM;
}
EXPORT_SYMBOL(iwl_rx_queue_alloc);

void iwl_rx_missed_beacon_notif(struct iwl_priv *priv,
				struct iwl_rx_mem_buffer *rxb)

{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_missed_beacon_notif *missed_beacon;

	missed_beacon = &pkt->u.missed_beacon;
	if (le32_to_cpu(missed_beacon->consecutive_missed_beacons) >
	    priv->missed_beacon_threshold) {
		IWL_DEBUG_CALIB(priv, "missed bcn cnsq %d totl %d rcd %d expctd %d\n",
		    le32_to_cpu(missed_beacon->consecutive_missed_beacons),
		    le32_to_cpu(missed_beacon->total_missed_becons),
		    le32_to_cpu(missed_beacon->num_recvd_beacons),
		    le32_to_cpu(missed_beacon->num_expected_beacons));
		if (!test_bit(STATUS_SCANNING, &priv->status))
			iwl_init_sensitivity(priv);
	}
}
EXPORT_SYMBOL(iwl_rx_missed_beacon_notif);

void iwl_rx_spectrum_measure_notif(struct iwl_priv *priv,
					  struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_spectrum_notification *report = &(pkt->u.spectrum_notif);

	if (!report->state) {
		IWL_DEBUG_11H(priv,
			"Spectrum Measure Notification: Start\n");
		return;
	}

	memcpy(&priv->measure_report, report, sizeof(*report));
	priv->measurement_status |= MEASUREMENT_READY;
}
EXPORT_SYMBOL(iwl_rx_spectrum_measure_notif);



/* Calculate noise level, based on measurements during network silence just
 *   before arriving beacon.  This measurement can be done only if we know
 *   exactly when to expect beacons, therefore only when we're associated. */
static void iwl_rx_calc_noise(struct iwl_priv *priv)
{
	struct statistics_rx_non_phy *rx_info
				= &(priv->statistics.rx.general);
	int num_active_rx = 0;
	int total_silence = 0;
	int bcn_silence_a =
		le32_to_cpu(rx_info->beacon_silence_rssi_a) & IN_BAND_FILTER;
	int bcn_silence_b =
		le32_to_cpu(rx_info->beacon_silence_rssi_b) & IN_BAND_FILTER;
	int bcn_silence_c =
		le32_to_cpu(rx_info->beacon_silence_rssi_c) & IN_BAND_FILTER;
	int last_rx_noise;

	if (bcn_silence_a) {
		total_silence += bcn_silence_a;
		num_active_rx++;
	}
	if (bcn_silence_b) {
		total_silence += bcn_silence_b;
		num_active_rx++;
	}
	if (bcn_silence_c) {
		total_silence += bcn_silence_c;
		num_active_rx++;
	}

	/* Average among active antennas */
	if (num_active_rx)
		last_rx_noise = (total_silence / num_active_rx) - 107;
	else
		last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;

	IWL_DEBUG_CALIB(priv, "inband silence a %u, b %u, c %u, dBm %d\n",
			bcn_silence_a, bcn_silence_b, bcn_silence_c,
			last_rx_noise);
}

#ifdef CONFIG_IWLWIFI_DEBUG
/*
 *  based on the assumption of all statistics counter are in DWORD
 *  FIXME: This function is for debugging, do not deal with
 *  the case of counters roll-over.
 */
static void iwl_accumulative_statistics(struct iwl_priv *priv,
					__le32 *stats)
{
	int i;
	__le32 *prev_stats;
	u32 *accum_stats;
	u32 *delta, *max_delta;

	prev_stats = (__le32 *)&priv->statistics;
	accum_stats = (u32 *)&priv->accum_statistics;
	delta = (u32 *)&priv->delta_statistics;
	max_delta = (u32 *)&priv->max_delta;

	for (i = sizeof(__le32); i < sizeof(struct iwl_notif_statistics);
	     i += sizeof(__le32), stats++, prev_stats++, delta++,
	     max_delta++, accum_stats++) {
		if (le32_to_cpu(*stats) > le32_to_cpu(*prev_stats)) {
			*delta = (le32_to_cpu(*stats) -
				le32_to_cpu(*prev_stats));
			*accum_stats += *delta;
			if (*delta > *max_delta)
				*max_delta = *delta;
		}
	}

	/* reset accumulative statistics for "no-counter" type statistics */
	priv->accum_statistics.general.temperature =
		priv->statistics.general.temperature;
	priv->accum_statistics.general.temperature_m =
		priv->statistics.general.temperature_m;
	priv->accum_statistics.general.ttl_timestamp =
		priv->statistics.general.ttl_timestamp;
	priv->accum_statistics.tx.tx_power.ant_a =
		priv->statistics.tx.tx_power.ant_a;
	priv->accum_statistics.tx.tx_power.ant_b =
		priv->statistics.tx.tx_power.ant_b;
	priv->accum_statistics.tx.tx_power.ant_c =
		priv->statistics.tx.tx_power.ant_c;
}
#endif

#define REG_RECALIB_PERIOD (60)

/**
 * iwl_good_plcp_health - checks for plcp error.
 *
 * When the plcp error is exceeding the thresholds, reset the radio
 * to improve the throughput.
 */
bool iwl_good_plcp_health(struct iwl_priv *priv,
				struct iwl_rx_packet *pkt)
{
	bool rc = true;
	int combined_plcp_delta;
	unsigned int plcp_msec;
	unsigned long plcp_received_jiffies;

	/*
	 * check for plcp_err and trigger radio reset if it exceeds
	 * the plcp error threshold plcp_delta.
	 */
	plcp_received_jiffies = jiffies;
	plcp_msec = jiffies_to_msecs((long) plcp_received_jiffies -
					(long) priv->plcp_jiffies);
	priv->plcp_jiffies = plcp_received_jiffies;
	/*
	 * check to make sure plcp_msec is not 0 to prevent division
	 * by zero.
	 */
	if (plcp_msec) {
		combined_plcp_delta =
			(le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err) -
			le32_to_cpu(priv->statistics.rx.ofdm.plcp_err)) +
			(le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err) -
			le32_to_cpu(priv->statistics.rx.ofdm_ht.plcp_err));

		if ((combined_plcp_delta > 0) &&
		    ((combined_plcp_delta * 100) / plcp_msec) >
			priv->cfg->plcp_delta_threshold) {
			/*
			 * if plcp_err exceed the threshold,
			 * the following data is printed in csv format:
			 *    Text: plcp_err exceeded %d,
			 *    Received ofdm.plcp_err,
			 *    Current ofdm.plcp_err,
			 *    Received ofdm_ht.plcp_err,
			 *    Current ofdm_ht.plcp_err,
			 *    combined_plcp_delta,
			 *    plcp_msec
			 */
			IWL_DEBUG_RADIO(priv, "plcp_err exceeded %u, "
				"%u, %u, %u, %u, %d, %u mSecs\n",
				priv->cfg->plcp_delta_threshold,
				le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err),
				le32_to_cpu(priv->statistics.rx.ofdm.plcp_err),
				le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err),
				le32_to_cpu(
				  priv->statistics.rx.ofdm_ht.plcp_err),
				combined_plcp_delta, plcp_msec);
			rc = false;
		}
	}
	return rc;
}
EXPORT_SYMBOL(iwl_good_plcp_health);

void iwl_recover_from_statistics(struct iwl_priv *priv,
				struct iwl_rx_packet *pkt)
{
	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
		return;
	if (iwl_is_associated(priv)) {
		if (priv->cfg->ops->lib->check_ack_health) {
			if (!priv->cfg->ops->lib->check_ack_health(
			    priv, pkt)) {
				/*
				 * low ack count detected
				 * restart Firmware
				 */
				IWL_ERR(priv, "low ack count detected, "
					"restart firmware\n");
				if (!iwl_force_reset(priv, IWL_FW_RESET))
					return;
			}
		}
		if (priv->cfg->ops->lib->check_plcp_health) {
			if (!priv->cfg->ops->lib->check_plcp_health(
			    priv, pkt)) {
				/*
				 * high plcp error detected
				 * reset Radio
				 */
				iwl_force_reset(priv, IWL_RF_RESET);
			}
		}
	}
}
EXPORT_SYMBOL(iwl_recover_from_statistics);

void iwl_rx_statistics(struct iwl_priv *priv,
			      struct iwl_rx_mem_buffer *rxb)
{
	int change;
	struct iwl_rx_packet *pkt = rxb_addr(rxb);


	IWL_DEBUG_RX(priv, "Statistics notification received (%d vs %d).\n",
		     (int)sizeof(priv->statistics),
		     le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK);

	change = ((priv->statistics.general.temperature !=
		   pkt->u.stats.general.temperature) ||
		  ((priv->statistics.flag &
		    STATISTICS_REPLY_FLG_HT40_MODE_MSK) !=
		   (pkt->u.stats.flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK)));

#ifdef CONFIG_IWLWIFI_DEBUG
	iwl_accumulative_statistics(priv, (__le32 *)&pkt->u.stats);
#endif
	iwl_recover_from_statistics(priv, pkt);

	memcpy(&priv->statistics, &pkt->u.stats, sizeof(priv->statistics));

	set_bit(STATUS_STATISTICS, &priv->status);

	/* Reschedule the statistics timer to occur in
	 * REG_RECALIB_PERIOD seconds to ensure we get a
	 * thermal update even if the uCode doesn't give
	 * us one */
	mod_timer(&priv->statistics_periodic, jiffies +
		  msecs_to_jiffies(REG_RECALIB_PERIOD * 1000));

	if (unlikely(!test_bit(STATUS_SCANNING, &priv->status)) &&
	    (pkt->hdr.cmd == STATISTICS_NOTIFICATION)) {
		iwl_rx_calc_noise(priv);
		queue_work(priv->workqueue, &priv->run_time_calib_work);
	}
	if (priv->cfg->ops->lib->temp_ops.temperature && change)
		priv->cfg->ops->lib->temp_ops.temperature(priv);
}
EXPORT_SYMBOL(iwl_rx_statistics);

void iwl_reply_statistics(struct iwl_priv *priv,
			      struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);

	if (le32_to_cpu(pkt->u.stats.flag) & UCODE_STATISTICS_CLEAR_MSK) {
#ifdef CONFIG_IWLWIFI_DEBUG
		memset(&priv->accum_statistics, 0,
			sizeof(struct iwl_notif_statistics));
		memset(&priv->delta_statistics, 0,
			sizeof(struct iwl_notif_statistics));
		memset(&priv->max_delta, 0,
			sizeof(struct iwl_notif_statistics));
#endif
		IWL_DEBUG_RX(priv, "Statistics have been cleared\n");
	}
	iwl_rx_statistics(priv, rxb);
}
EXPORT_SYMBOL(iwl_reply_statistics);

/*
 * returns non-zero if packet should be dropped
 */
int iwl_set_decrypted_flag(struct iwl_priv *priv,
			   struct ieee80211_hdr *hdr,
			   u32 decrypt_res,
			   struct ieee80211_rx_status *stats)
{
	u16 fc = le16_to_cpu(hdr->frame_control);

	if (priv->active_rxon.filter_flags & RXON_FILTER_DIS_DECRYPT_MSK)
		return 0;

	if (!(fc & IEEE80211_FCTL_PROTECTED))
		return 0;

	IWL_DEBUG_RX(priv, "decrypt_res:0x%x\n", decrypt_res);
	switch (decrypt_res & RX_RES_STATUS_SEC_TYPE_MSK) {
	case RX_RES_STATUS_SEC_TYPE_TKIP:
		/* The uCode has got a bad phase 1 Key, pushes the packet.
		 * Decryption will be done in SW. */
		if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
		    RX_RES_STATUS_BAD_KEY_TTAK)
			break;

	case RX_RES_STATUS_SEC_TYPE_WEP:
		if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
		    RX_RES_STATUS_BAD_ICV_MIC) {
			/* bad ICV, the packet is destroyed since the
			 * decryption is inplace, drop it */
			IWL_DEBUG_RX(priv, "Packet destroyed\n");
			return -1;
		}
	case RX_RES_STATUS_SEC_TYPE_CCMP:
		if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
		    RX_RES_STATUS_DECRYPT_OK) {
			IWL_DEBUG_RX(priv, "hw decrypt successfully!!!\n");
			stats->flag |= RX_FLAG_DECRYPTED;
		}
		break;

	default:
		break;
	}
	return 0;
}
EXPORT_SYMBOL(iwl_set_decrypted_flag);