iwlwifi: code cleanup for connectivity recovery
[safe/jmp/linux-2.6] / drivers / net / wireless / iwlwifi / iwl-rx.c
1 /******************************************************************************
2  *
3  * Copyright(c) 2003 - 2010 Intel Corporation. All rights reserved.
4  *
5  * Portions of this file are derived from the ipw3945 project, as well
6  * as portions of the ieee80211 subsystem header files.
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of version 2 of the GNU General Public License as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along with
18  * this program; if not, write to the Free Software Foundation, Inc.,
19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
20  *
21  * The full GNU General Public License is included in this distribution in the
22  * file called LICENSE.
23  *
24  * Contact Information:
25  *  Intel Linux Wireless <ilw@linux.intel.com>
26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
27  *
28  *****************************************************************************/
29
30 #include <linux/etherdevice.h>
31 #include <net/mac80211.h>
32 #include <asm/unaligned.h>
33 #include "iwl-eeprom.h"
34 #include "iwl-dev.h"
35 #include "iwl-core.h"
36 #include "iwl-sta.h"
37 #include "iwl-io.h"
38 #include "iwl-calib.h"
39 #include "iwl-helpers.h"
40 /************************** RX-FUNCTIONS ****************************/
41 /*
42  * Rx theory of operation
43  *
44  * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
45  * each of which point to Receive Buffers to be filled by the NIC.  These get
46  * used not only for Rx frames, but for any command response or notification
47  * from the NIC.  The driver and NIC manage the Rx buffers by means
48  * of indexes into the circular buffer.
49  *
50  * Rx Queue Indexes
51  * The host/firmware share two index registers for managing the Rx buffers.
52  *
53  * The READ index maps to the first position that the firmware may be writing
54  * to -- the driver can read up to (but not including) this position and get
55  * good data.
56  * The READ index is managed by the firmware once the card is enabled.
57  *
58  * The WRITE index maps to the last position the driver has read from -- the
59  * position preceding WRITE is the last slot the firmware can place a packet.
60  *
61  * The queue is empty (no good data) if WRITE = READ - 1, and is full if
62  * WRITE = READ.
63  *
64  * During initialization, the host sets up the READ queue position to the first
65  * INDEX position, and WRITE to the last (READ - 1 wrapped)
66  *
67  * When the firmware places a packet in a buffer, it will advance the READ index
68  * and fire the RX interrupt.  The driver can then query the READ index and
69  * process as many packets as possible, moving the WRITE index forward as it
70  * resets the Rx queue buffers with new memory.
71  *
72  * The management in the driver is as follows:
73  * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free.  When
74  *   iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
75  *   to replenish the iwl->rxq->rx_free.
76  * + In iwl_rx_replenish (scheduled) if 'processed' != 'read' then the
77  *   iwl->rxq is replenished and the READ INDEX is updated (updating the
78  *   'processed' and 'read' driver indexes as well)
79  * + A received packet is processed and handed to the kernel network stack,
80  *   detached from the iwl->rxq.  The driver 'processed' index is updated.
81  * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free
82  *   list. If there are no allocated buffers in iwl->rxq->rx_free, the READ
83  *   INDEX is not incremented and iwl->status(RX_STALLED) is set.  If there
84  *   were enough free buffers and RX_STALLED is set it is cleared.
85  *
86  *
87  * Driver sequence:
88  *
89  * iwl_rx_queue_alloc()   Allocates rx_free
90  * iwl_rx_replenish()     Replenishes rx_free list from rx_used, and calls
91  *                            iwl_rx_queue_restock
92  * iwl_rx_queue_restock() Moves available buffers from rx_free into Rx
93  *                            queue, updates firmware pointers, and updates
94  *                            the WRITE index.  If insufficient rx_free buffers
95  *                            are available, schedules iwl_rx_replenish
96  *
97  * -- enable interrupts --
98  * ISR - iwl_rx()         Detach iwl_rx_mem_buffers from pool up to the
99  *                            READ INDEX, detaching the SKB from the pool.
100  *                            Moves the packet buffer from queue to rx_used.
101  *                            Calls iwl_rx_queue_restock to refill any empty
102  *                            slots.
103  * ...
104  *
105  */
106
107 /**
108  * iwl_rx_queue_space - Return number of free slots available in queue.
109  */
110 int iwl_rx_queue_space(const struct iwl_rx_queue *q)
111 {
112         int s = q->read - q->write;
113         if (s <= 0)
114                 s += RX_QUEUE_SIZE;
115         /* keep some buffer to not confuse full and empty queue */
116         s -= 2;
117         if (s < 0)
118                 s = 0;
119         return s;
120 }
121 EXPORT_SYMBOL(iwl_rx_queue_space);
122
123 /**
124  * iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue
125  */
126 void iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q)
127 {
128         unsigned long flags;
129         u32 rx_wrt_ptr_reg = priv->hw_params.rx_wrt_ptr_reg;
130         u32 reg;
131
132         spin_lock_irqsave(&q->lock, flags);
133
134         if (q->need_update == 0)
135                 goto exit_unlock;
136
137         /* If power-saving is in use, make sure device is awake */
138         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
139                 reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
140
141                 if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
142                         IWL_DEBUG_INFO(priv, "Rx queue requesting wakeup, GP1 = 0x%x\n",
143                                       reg);
144                         iwl_set_bit(priv, CSR_GP_CNTRL,
145                                     CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
146                         goto exit_unlock;
147                 }
148
149                 q->write_actual = (q->write & ~0x7);
150                 iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
151
152         /* Else device is assumed to be awake */
153         } else {
154                 /* Device expects a multiple of 8 */
155                 q->write_actual = (q->write & ~0x7);
156                 iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
157         }
158
159         q->need_update = 0;
160
161  exit_unlock:
162         spin_unlock_irqrestore(&q->lock, flags);
163 }
164 EXPORT_SYMBOL(iwl_rx_queue_update_write_ptr);
165 /**
166  * iwl_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
167  */
168 static inline __le32 iwl_dma_addr2rbd_ptr(struct iwl_priv *priv,
169                                           dma_addr_t dma_addr)
170 {
171         return cpu_to_le32((u32)(dma_addr >> 8));
172 }
173
174 /**
175  * iwl_rx_queue_restock - refill RX queue from pre-allocated pool
176  *
177  * If there are slots in the RX queue that need to be restocked,
178  * and we have free pre-allocated buffers, fill the ranks as much
179  * as we can, pulling from rx_free.
180  *
181  * This moves the 'write' index forward to catch up with 'processed', and
182  * also updates the memory address in the firmware to reference the new
183  * target buffer.
184  */
185 void iwl_rx_queue_restock(struct iwl_priv *priv)
186 {
187         struct iwl_rx_queue *rxq = &priv->rxq;
188         struct list_head *element;
189         struct iwl_rx_mem_buffer *rxb;
190         unsigned long flags;
191         int write;
192
193         spin_lock_irqsave(&rxq->lock, flags);
194         write = rxq->write & ~0x7;
195         while ((iwl_rx_queue_space(rxq) > 0) && (rxq->free_count)) {
196                 /* Get next free Rx buffer, remove from free list */
197                 element = rxq->rx_free.next;
198                 rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
199                 list_del(element);
200
201                 /* Point to Rx buffer via next RBD in circular buffer */
202                 rxq->bd[rxq->write] = iwl_dma_addr2rbd_ptr(priv, rxb->page_dma);
203                 rxq->queue[rxq->write] = rxb;
204                 rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
205                 rxq->free_count--;
206         }
207         spin_unlock_irqrestore(&rxq->lock, flags);
208         /* If the pre-allocated buffer pool is dropping low, schedule to
209          * refill it */
210         if (rxq->free_count <= RX_LOW_WATERMARK)
211                 queue_work(priv->workqueue, &priv->rx_replenish);
212
213
214         /* If we've added more space for the firmware to place data, tell it.
215          * Increment device's write pointer in multiples of 8. */
216         if (rxq->write_actual != (rxq->write & ~0x7)) {
217                 spin_lock_irqsave(&rxq->lock, flags);
218                 rxq->need_update = 1;
219                 spin_unlock_irqrestore(&rxq->lock, flags);
220                 iwl_rx_queue_update_write_ptr(priv, rxq);
221         }
222 }
223 EXPORT_SYMBOL(iwl_rx_queue_restock);
224
225
226 /**
227  * iwl_rx_replenish - Move all used packet from rx_used to rx_free
228  *
229  * When moving to rx_free an SKB is allocated for the slot.
230  *
231  * Also restock the Rx queue via iwl_rx_queue_restock.
232  * This is called as a scheduled work item (except for during initialization)
233  */
234 void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority)
235 {
236         struct iwl_rx_queue *rxq = &priv->rxq;
237         struct list_head *element;
238         struct iwl_rx_mem_buffer *rxb;
239         struct page *page;
240         unsigned long flags;
241         gfp_t gfp_mask = priority;
242
243         while (1) {
244                 spin_lock_irqsave(&rxq->lock, flags);
245                 if (list_empty(&rxq->rx_used)) {
246                         spin_unlock_irqrestore(&rxq->lock, flags);
247                         return;
248                 }
249                 spin_unlock_irqrestore(&rxq->lock, flags);
250
251                 if (rxq->free_count > RX_LOW_WATERMARK)
252                         gfp_mask |= __GFP_NOWARN;
253
254                 if (priv->hw_params.rx_page_order > 0)
255                         gfp_mask |= __GFP_COMP;
256
257                 /* Alloc a new receive buffer */
258                 page = alloc_pages(gfp_mask, priv->hw_params.rx_page_order);
259                 if (!page) {
260                         if (net_ratelimit())
261                                 IWL_DEBUG_INFO(priv, "alloc_pages failed, "
262                                                "order: %d\n",
263                                                priv->hw_params.rx_page_order);
264
265                         if ((rxq->free_count <= RX_LOW_WATERMARK) &&
266                             net_ratelimit())
267                                 IWL_CRIT(priv, "Failed to alloc_pages with %s. Only %u free buffers remaining.\n",
268                                          priority == GFP_ATOMIC ?  "GFP_ATOMIC" : "GFP_KERNEL",
269                                          rxq->free_count);
270                         /* We don't reschedule replenish work here -- we will
271                          * call the restock method and if it still needs
272                          * more buffers it will schedule replenish */
273                         return;
274                 }
275
276                 spin_lock_irqsave(&rxq->lock, flags);
277
278                 if (list_empty(&rxq->rx_used)) {
279                         spin_unlock_irqrestore(&rxq->lock, flags);
280                         __free_pages(page, priv->hw_params.rx_page_order);
281                         return;
282                 }
283                 element = rxq->rx_used.next;
284                 rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
285                 list_del(element);
286
287                 spin_unlock_irqrestore(&rxq->lock, flags);
288
289                 rxb->page = page;
290                 /* Get physical address of the RB */
291                 rxb->page_dma = pci_map_page(priv->pci_dev, page, 0,
292                                 PAGE_SIZE << priv->hw_params.rx_page_order,
293                                 PCI_DMA_FROMDEVICE);
294                 /* dma address must be no more than 36 bits */
295                 BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
296                 /* and also 256 byte aligned! */
297                 BUG_ON(rxb->page_dma & DMA_BIT_MASK(8));
298
299                 spin_lock_irqsave(&rxq->lock, flags);
300
301                 list_add_tail(&rxb->list, &rxq->rx_free);
302                 rxq->free_count++;
303                 priv->alloc_rxb_page++;
304
305                 spin_unlock_irqrestore(&rxq->lock, flags);
306         }
307 }
308
309 void iwl_rx_replenish(struct iwl_priv *priv)
310 {
311         unsigned long flags;
312
313         iwl_rx_allocate(priv, GFP_KERNEL);
314
315         spin_lock_irqsave(&priv->lock, flags);
316         iwl_rx_queue_restock(priv);
317         spin_unlock_irqrestore(&priv->lock, flags);
318 }
319 EXPORT_SYMBOL(iwl_rx_replenish);
320
321 void iwl_rx_replenish_now(struct iwl_priv *priv)
322 {
323         iwl_rx_allocate(priv, GFP_ATOMIC);
324
325         iwl_rx_queue_restock(priv);
326 }
327 EXPORT_SYMBOL(iwl_rx_replenish_now);
328
329
330 /* Assumes that the skb field of the buffers in 'pool' is kept accurate.
331  * If an SKB has been detached, the POOL needs to have its SKB set to NULL
332  * This free routine walks the list of POOL entries and if SKB is set to
333  * non NULL it is unmapped and freed
334  */
335 void iwl_rx_queue_free(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
336 {
337         int i;
338         for (i = 0; i < RX_QUEUE_SIZE + RX_FREE_BUFFERS; i++) {
339                 if (rxq->pool[i].page != NULL) {
340                         pci_unmap_page(priv->pci_dev, rxq->pool[i].page_dma,
341                                 PAGE_SIZE << priv->hw_params.rx_page_order,
342                                 PCI_DMA_FROMDEVICE);
343                         __iwl_free_pages(priv, rxq->pool[i].page);
344                         rxq->pool[i].page = NULL;
345                 }
346         }
347
348         dma_free_coherent(&priv->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
349                           rxq->dma_addr);
350         dma_free_coherent(&priv->pci_dev->dev, sizeof(struct iwl_rb_status),
351                           rxq->rb_stts, rxq->rb_stts_dma);
352         rxq->bd = NULL;
353         rxq->rb_stts  = NULL;
354 }
355 EXPORT_SYMBOL(iwl_rx_queue_free);
356
357 int iwl_rx_queue_alloc(struct iwl_priv *priv)
358 {
359         struct iwl_rx_queue *rxq = &priv->rxq;
360         struct device *dev = &priv->pci_dev->dev;
361         int i;
362
363         spin_lock_init(&rxq->lock);
364         INIT_LIST_HEAD(&rxq->rx_free);
365         INIT_LIST_HEAD(&rxq->rx_used);
366
367         /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
368         rxq->bd = dma_alloc_coherent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr,
369                                      GFP_KERNEL);
370         if (!rxq->bd)
371                 goto err_bd;
372
373         rxq->rb_stts = dma_alloc_coherent(dev, sizeof(struct iwl_rb_status),
374                                           &rxq->rb_stts_dma, GFP_KERNEL);
375         if (!rxq->rb_stts)
376                 goto err_rb;
377
378         /* Fill the rx_used queue with _all_ of the Rx buffers */
379         for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
380                 list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
381
382         /* Set us so that we have processed and used all buffers, but have
383          * not restocked the Rx queue with fresh buffers */
384         rxq->read = rxq->write = 0;
385         rxq->write_actual = 0;
386         rxq->free_count = 0;
387         rxq->need_update = 0;
388         return 0;
389
390 err_rb:
391         dma_free_coherent(&priv->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
392                           rxq->dma_addr);
393 err_bd:
394         return -ENOMEM;
395 }
396 EXPORT_SYMBOL(iwl_rx_queue_alloc);
397
398 void iwl_rx_queue_reset(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
399 {
400         unsigned long flags;
401         int i;
402         spin_lock_irqsave(&rxq->lock, flags);
403         INIT_LIST_HEAD(&rxq->rx_free);
404         INIT_LIST_HEAD(&rxq->rx_used);
405         /* Fill the rx_used queue with _all_ of the Rx buffers */
406         for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) {
407                 /* In the reset function, these buffers may have been allocated
408                  * to an SKB, so we need to unmap and free potential storage */
409                 if (rxq->pool[i].page != NULL) {
410                         pci_unmap_page(priv->pci_dev, rxq->pool[i].page_dma,
411                                 PAGE_SIZE << priv->hw_params.rx_page_order,
412                                 PCI_DMA_FROMDEVICE);
413                         __iwl_free_pages(priv, rxq->pool[i].page);
414                         rxq->pool[i].page = NULL;
415                 }
416                 list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
417         }
418
419         /* Set us so that we have processed and used all buffers, but have
420          * not restocked the Rx queue with fresh buffers */
421         rxq->read = rxq->write = 0;
422         rxq->write_actual = 0;
423         rxq->free_count = 0;
424         spin_unlock_irqrestore(&rxq->lock, flags);
425 }
426
427 int iwl_rx_init(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
428 {
429         u32 rb_size;
430         const u32 rfdnlog = RX_QUEUE_SIZE_LOG; /* 256 RBDs */
431         u32 rb_timeout = 0; /* FIXME: RX_RB_TIMEOUT for all devices? */
432
433         if (!priv->cfg->use_isr_legacy)
434                 rb_timeout = RX_RB_TIMEOUT;
435
436         if (priv->cfg->mod_params->amsdu_size_8K)
437                 rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_8K;
438         else
439                 rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K;
440
441         /* Stop Rx DMA */
442         iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
443
444         /* Reset driver's Rx queue write index */
445         iwl_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_WPTR_REG, 0);
446
447         /* Tell device where to find RBD circular buffer in DRAM */
448         iwl_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_BASE_REG,
449                            (u32)(rxq->dma_addr >> 8));
450
451         /* Tell device where in DRAM to update its Rx status */
452         iwl_write_direct32(priv, FH_RSCSR_CHNL0_STTS_WPTR_REG,
453                            rxq->rb_stts_dma >> 4);
454
455         /* Enable Rx DMA
456          * FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY is set because of HW bug in
457          *      the credit mechanism in 5000 HW RX FIFO
458          * Direct rx interrupts to hosts
459          * Rx buffer size 4 or 8k
460          * RB timeout 0x10
461          * 256 RBDs
462          */
463         iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG,
464                            FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL |
465                            FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY |
466                            FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL |
467                            FH_RCSR_CHNL0_RX_CONFIG_SINGLE_FRAME_MSK |
468                            rb_size|
469                            (rb_timeout << FH_RCSR_RX_CONFIG_REG_IRQ_RBTH_POS)|
470                            (rfdnlog << FH_RCSR_RX_CONFIG_RBDCB_SIZE_POS));
471
472         /* Set interrupt coalescing timer to default (2048 usecs) */
473         iwl_write8(priv, CSR_INT_COALESCING, IWL_HOST_INT_TIMEOUT_DEF);
474
475         return 0;
476 }
477
478 int iwl_rxq_stop(struct iwl_priv *priv)
479 {
480
481         /* stop Rx DMA */
482         iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
483         iwl_poll_direct_bit(priv, FH_MEM_RSSR_RX_STATUS_REG,
484                             FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE, 1000);
485
486         return 0;
487 }
488 EXPORT_SYMBOL(iwl_rxq_stop);
489
490 void iwl_rx_missed_beacon_notif(struct iwl_priv *priv,
491                                 struct iwl_rx_mem_buffer *rxb)
492
493 {
494         struct iwl_rx_packet *pkt = rxb_addr(rxb);
495         struct iwl_missed_beacon_notif *missed_beacon;
496
497         missed_beacon = &pkt->u.missed_beacon;
498         if (le32_to_cpu(missed_beacon->consecutive_missed_beacons) >
499             priv->missed_beacon_threshold) {
500                 IWL_DEBUG_CALIB(priv, "missed bcn cnsq %d totl %d rcd %d expctd %d\n",
501                     le32_to_cpu(missed_beacon->consecutive_missed_beacons),
502                     le32_to_cpu(missed_beacon->total_missed_becons),
503                     le32_to_cpu(missed_beacon->num_recvd_beacons),
504                     le32_to_cpu(missed_beacon->num_expected_beacons));
505                 if (!test_bit(STATUS_SCANNING, &priv->status))
506                         iwl_init_sensitivity(priv);
507         }
508 }
509 EXPORT_SYMBOL(iwl_rx_missed_beacon_notif);
510
511 void iwl_rx_spectrum_measure_notif(struct iwl_priv *priv,
512                                           struct iwl_rx_mem_buffer *rxb)
513 {
514         struct iwl_rx_packet *pkt = rxb_addr(rxb);
515         struct iwl_spectrum_notification *report = &(pkt->u.spectrum_notif);
516
517         if (!report->state) {
518                 IWL_DEBUG_11H(priv,
519                         "Spectrum Measure Notification: Start\n");
520                 return;
521         }
522
523         memcpy(&priv->measure_report, report, sizeof(*report));
524         priv->measurement_status |= MEASUREMENT_READY;
525 }
526 EXPORT_SYMBOL(iwl_rx_spectrum_measure_notif);
527
528
529
530 /* Calculate noise level, based on measurements during network silence just
531  *   before arriving beacon.  This measurement can be done only if we know
532  *   exactly when to expect beacons, therefore only when we're associated. */
533 static void iwl_rx_calc_noise(struct iwl_priv *priv)
534 {
535         struct statistics_rx_non_phy *rx_info
536                                 = &(priv->statistics.rx.general);
537         int num_active_rx = 0;
538         int total_silence = 0;
539         int bcn_silence_a =
540                 le32_to_cpu(rx_info->beacon_silence_rssi_a) & IN_BAND_FILTER;
541         int bcn_silence_b =
542                 le32_to_cpu(rx_info->beacon_silence_rssi_b) & IN_BAND_FILTER;
543         int bcn_silence_c =
544                 le32_to_cpu(rx_info->beacon_silence_rssi_c) & IN_BAND_FILTER;
545
546         if (bcn_silence_a) {
547                 total_silence += bcn_silence_a;
548                 num_active_rx++;
549         }
550         if (bcn_silence_b) {
551                 total_silence += bcn_silence_b;
552                 num_active_rx++;
553         }
554         if (bcn_silence_c) {
555                 total_silence += bcn_silence_c;
556                 num_active_rx++;
557         }
558
559         /* Average among active antennas */
560         if (num_active_rx)
561                 priv->last_rx_noise = (total_silence / num_active_rx) - 107;
562         else
563                 priv->last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
564
565         IWL_DEBUG_CALIB(priv, "inband silence a %u, b %u, c %u, dBm %d\n",
566                         bcn_silence_a, bcn_silence_b, bcn_silence_c,
567                         priv->last_rx_noise);
568 }
569
570 #ifdef CONFIG_IWLWIFI_DEBUG
571 /*
572  *  based on the assumption of all statistics counter are in DWORD
573  *  FIXME: This function is for debugging, do not deal with
574  *  the case of counters roll-over.
575  */
576 static void iwl_accumulative_statistics(struct iwl_priv *priv,
577                                         __le32 *stats)
578 {
579         int i;
580         __le32 *prev_stats;
581         u32 *accum_stats;
582         u32 *delta, *max_delta;
583
584         prev_stats = (__le32 *)&priv->statistics;
585         accum_stats = (u32 *)&priv->accum_statistics;
586         delta = (u32 *)&priv->delta_statistics;
587         max_delta = (u32 *)&priv->max_delta;
588
589         for (i = sizeof(__le32); i < sizeof(struct iwl_notif_statistics);
590              i += sizeof(__le32), stats++, prev_stats++, delta++,
591              max_delta++, accum_stats++) {
592                 if (le32_to_cpu(*stats) > le32_to_cpu(*prev_stats)) {
593                         *delta = (le32_to_cpu(*stats) -
594                                 le32_to_cpu(*prev_stats));
595                         *accum_stats += *delta;
596                         if (*delta > *max_delta)
597                                 *max_delta = *delta;
598                 }
599         }
600
601         /* reset accumulative statistics for "no-counter" type statistics */
602         priv->accum_statistics.general.temperature =
603                 priv->statistics.general.temperature;
604         priv->accum_statistics.general.temperature_m =
605                 priv->statistics.general.temperature_m;
606         priv->accum_statistics.general.ttl_timestamp =
607                 priv->statistics.general.ttl_timestamp;
608         priv->accum_statistics.tx.tx_power.ant_a =
609                 priv->statistics.tx.tx_power.ant_a;
610         priv->accum_statistics.tx.tx_power.ant_b =
611                 priv->statistics.tx.tx_power.ant_b;
612         priv->accum_statistics.tx.tx_power.ant_c =
613                 priv->statistics.tx.tx_power.ant_c;
614 }
615 #endif
616
617 #define REG_RECALIB_PERIOD (60)
618
619 /* the threshold ratio of actual_ack_cnt to expected_ack_cnt in percent */
620 #define ACK_CNT_RATIO (50)
621 #define BA_TIMEOUT_CNT (5)
622 #define BA_TIMEOUT_MAX (16)
623
624 /**
625  * iwl_good_ack_health - checks for ACK count ratios, BA timeout retries.
626  *
627  * When the ACK count ratio is 0 and aggregated BA timeout retries exceeding
628  * the BA_TIMEOUT_MAX, reload firmware and bring system back to normal
629  * operation state.
630  */
631 bool iwl_good_ack_health(struct iwl_priv *priv,
632                                 struct iwl_rx_packet *pkt)
633 {
634         bool rc = true;
635         int actual_ack_cnt_delta, expected_ack_cnt_delta;
636         int ba_timeout_delta;
637
638         actual_ack_cnt_delta =
639                 le32_to_cpu(pkt->u.stats.tx.actual_ack_cnt) -
640                 le32_to_cpu(priv->statistics.tx.actual_ack_cnt);
641         expected_ack_cnt_delta =
642                 le32_to_cpu(pkt->u.stats.tx.expected_ack_cnt) -
643                 le32_to_cpu(priv->statistics.tx.expected_ack_cnt);
644         ba_timeout_delta =
645                 le32_to_cpu(pkt->u.stats.tx.agg.ba_timeout) -
646                 le32_to_cpu(priv->statistics.tx.agg.ba_timeout);
647         if ((priv->_agn.agg_tids_count > 0) &&
648             (expected_ack_cnt_delta > 0) &&
649             (((actual_ack_cnt_delta * 100) / expected_ack_cnt_delta)
650                 < ACK_CNT_RATIO) &&
651             (ba_timeout_delta > BA_TIMEOUT_CNT)) {
652                 IWL_DEBUG_RADIO(priv, "actual_ack_cnt delta = %d,"
653                                 " expected_ack_cnt = %d\n",
654                                 actual_ack_cnt_delta, expected_ack_cnt_delta);
655
656 #ifdef CONFIG_IWLWIFI_DEBUG
657                 IWL_DEBUG_RADIO(priv, "rx_detected_cnt delta = %d\n",
658                                 priv->delta_statistics.tx.rx_detected_cnt);
659                 IWL_DEBUG_RADIO(priv,
660                                 "ack_or_ba_timeout_collision delta = %d\n",
661                                 priv->delta_statistics.tx.
662                                 ack_or_ba_timeout_collision);
663 #endif
664                 IWL_DEBUG_RADIO(priv, "agg ba_timeout delta = %d\n",
665                                 ba_timeout_delta);
666                 if (!actual_ack_cnt_delta &&
667                     (ba_timeout_delta >= BA_TIMEOUT_MAX))
668                         rc = false;
669         }
670         return rc;
671 }
672 EXPORT_SYMBOL(iwl_good_ack_health);
673
674 /**
675  * iwl_good_plcp_health - checks for plcp error.
676  *
677  * When the plcp error is exceeding the thresholds, reset the radio
678  * to improve the throughput.
679  */
680 bool iwl_good_plcp_health(struct iwl_priv *priv,
681                                 struct iwl_rx_packet *pkt)
682 {
683         bool rc = true;
684         int combined_plcp_delta;
685         unsigned int plcp_msec;
686         unsigned long plcp_received_jiffies;
687
688         /*
689          * check for plcp_err and trigger radio reset if it exceeds
690          * the plcp error threshold plcp_delta.
691          */
692         plcp_received_jiffies = jiffies;
693         plcp_msec = jiffies_to_msecs((long) plcp_received_jiffies -
694                                         (long) priv->plcp_jiffies);
695         priv->plcp_jiffies = plcp_received_jiffies;
696         /*
697          * check to make sure plcp_msec is not 0 to prevent division
698          * by zero.
699          */
700         if (plcp_msec) {
701                 combined_plcp_delta =
702                         (le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err) -
703                         le32_to_cpu(priv->statistics.rx.ofdm.plcp_err)) +
704                         (le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err) -
705                         le32_to_cpu(priv->statistics.rx.ofdm_ht.plcp_err));
706
707                 if ((combined_plcp_delta > 0) &&
708                     ((combined_plcp_delta * 100) / plcp_msec) >
709                         priv->cfg->plcp_delta_threshold) {
710                         /*
711                          * if plcp_err exceed the threshold,
712                          * the following data is printed in csv format:
713                          *    Text: plcp_err exceeded %d,
714                          *    Received ofdm.plcp_err,
715                          *    Current ofdm.plcp_err,
716                          *    Received ofdm_ht.plcp_err,
717                          *    Current ofdm_ht.plcp_err,
718                          *    combined_plcp_delta,
719                          *    plcp_msec
720                          */
721                         IWL_DEBUG_RADIO(priv, "plcp_err exceeded %u, "
722                                 "%u, %u, %u, %u, %d, %u mSecs\n",
723                                 priv->cfg->plcp_delta_threshold,
724                                 le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err),
725                                 le32_to_cpu(priv->statistics.rx.ofdm.plcp_err),
726                                 le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err),
727                                 le32_to_cpu(
728                                   priv->statistics.rx.ofdm_ht.plcp_err),
729                                 combined_plcp_delta, plcp_msec);
730                         rc = false;
731                 }
732         }
733         return rc;
734 }
735 EXPORT_SYMBOL(iwl_good_plcp_health);
736
737 static void iwl_recover_from_statistics(struct iwl_priv *priv,
738                                 struct iwl_rx_packet *pkt)
739 {
740         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
741                 return;
742         if (iwl_is_associated(priv)) {
743                 if (priv->cfg->ops->lib->check_ack_health) {
744                         if (!priv->cfg->ops->lib->check_ack_health(
745                             priv, pkt)) {
746                                 /*
747                                  * low ack count detected
748                                  * restart Firmware
749                                  */
750                                 IWL_ERR(priv, "low ack count detected, "
751                                         "restart firmware\n");
752                                 iwl_force_reset(priv, IWL_FW_RESET);
753                         }
754                 } else if (priv->cfg->ops->lib->check_plcp_health) {
755                         if (!priv->cfg->ops->lib->check_plcp_health(
756                             priv, pkt)) {
757                                 /*
758                                  * high plcp error detected
759                                  * reset Radio
760                                  */
761                                 iwl_force_reset(priv, IWL_RF_RESET);
762                         }
763                 }
764         }
765 }
766
767 void iwl_rx_statistics(struct iwl_priv *priv,
768                               struct iwl_rx_mem_buffer *rxb)
769 {
770         int change;
771         struct iwl_rx_packet *pkt = rxb_addr(rxb);
772
773
774         IWL_DEBUG_RX(priv, "Statistics notification received (%d vs %d).\n",
775                      (int)sizeof(priv->statistics),
776                      le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK);
777
778         change = ((priv->statistics.general.temperature !=
779                    pkt->u.stats.general.temperature) ||
780                   ((priv->statistics.flag &
781                     STATISTICS_REPLY_FLG_HT40_MODE_MSK) !=
782                    (pkt->u.stats.flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK)));
783
784 #ifdef CONFIG_IWLWIFI_DEBUG
785         iwl_accumulative_statistics(priv, (__le32 *)&pkt->u.stats);
786 #endif
787         iwl_recover_from_statistics(priv, pkt);
788
789         memcpy(&priv->statistics, &pkt->u.stats, sizeof(priv->statistics));
790
791         set_bit(STATUS_STATISTICS, &priv->status);
792
793         /* Reschedule the statistics timer to occur in
794          * REG_RECALIB_PERIOD seconds to ensure we get a
795          * thermal update even if the uCode doesn't give
796          * us one */
797         mod_timer(&priv->statistics_periodic, jiffies +
798                   msecs_to_jiffies(REG_RECALIB_PERIOD * 1000));
799
800         if (unlikely(!test_bit(STATUS_SCANNING, &priv->status)) &&
801             (pkt->hdr.cmd == STATISTICS_NOTIFICATION)) {
802                 iwl_rx_calc_noise(priv);
803                 queue_work(priv->workqueue, &priv->run_time_calib_work);
804         }
805         if (priv->cfg->ops->lib->temp_ops.temperature && change)
806                 priv->cfg->ops->lib->temp_ops.temperature(priv);
807 }
808 EXPORT_SYMBOL(iwl_rx_statistics);
809
810 void iwl_reply_statistics(struct iwl_priv *priv,
811                               struct iwl_rx_mem_buffer *rxb)
812 {
813         struct iwl_rx_packet *pkt = rxb_addr(rxb);
814
815         if (le32_to_cpu(pkt->u.stats.flag) & UCODE_STATISTICS_CLEAR_MSK) {
816 #ifdef CONFIG_IWLWIFI_DEBUG
817                 memset(&priv->accum_statistics, 0,
818                         sizeof(struct iwl_notif_statistics));
819                 memset(&priv->delta_statistics, 0,
820                         sizeof(struct iwl_notif_statistics));
821                 memset(&priv->max_delta, 0,
822                         sizeof(struct iwl_notif_statistics));
823 #endif
824                 IWL_DEBUG_RX(priv, "Statistics have been cleared\n");
825         }
826         iwl_rx_statistics(priv, rxb);
827 }
828 EXPORT_SYMBOL(iwl_reply_statistics);
829
830 /* Calc max signal level (dBm) among 3 possible receivers */
831 static inline int iwl_calc_rssi(struct iwl_priv *priv,
832                                 struct iwl_rx_phy_res *rx_resp)
833 {
834         return priv->cfg->ops->utils->calc_rssi(priv, rx_resp);
835 }
836
837 #ifdef CONFIG_IWLWIFI_DEBUG
838 /**
839  * iwl_dbg_report_frame - dump frame to syslog during debug sessions
840  *
841  * You may hack this function to show different aspects of received frames,
842  * including selective frame dumps.
843  * group100 parameter selects whether to show 1 out of 100 good data frames.
844  *    All beacon and probe response frames are printed.
845  */
846 static void iwl_dbg_report_frame(struct iwl_priv *priv,
847                       struct iwl_rx_phy_res *phy_res, u16 length,
848                       struct ieee80211_hdr *header, int group100)
849 {
850         u32 to_us;
851         u32 print_summary = 0;
852         u32 print_dump = 0;     /* set to 1 to dump all frames' contents */
853         u32 hundred = 0;
854         u32 dataframe = 0;
855         __le16 fc;
856         u16 seq_ctl;
857         u16 channel;
858         u16 phy_flags;
859         u32 rate_n_flags;
860         u32 tsf_low;
861         int rssi;
862
863         if (likely(!(iwl_get_debug_level(priv) & IWL_DL_RX)))
864                 return;
865
866         /* MAC header */
867         fc = header->frame_control;
868         seq_ctl = le16_to_cpu(header->seq_ctrl);
869
870         /* metadata */
871         channel = le16_to_cpu(phy_res->channel);
872         phy_flags = le16_to_cpu(phy_res->phy_flags);
873         rate_n_flags = le32_to_cpu(phy_res->rate_n_flags);
874
875         /* signal statistics */
876         rssi = iwl_calc_rssi(priv, phy_res);
877         tsf_low = le64_to_cpu(phy_res->timestamp) & 0x0ffffffff;
878
879         to_us = !compare_ether_addr(header->addr1, priv->mac_addr);
880
881         /* if data frame is to us and all is good,
882          *   (optionally) print summary for only 1 out of every 100 */
883         if (to_us && (fc & ~cpu_to_le16(IEEE80211_FCTL_PROTECTED)) ==
884             cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FTYPE_DATA)) {
885                 dataframe = 1;
886                 if (!group100)
887                         print_summary = 1;      /* print each frame */
888                 else if (priv->framecnt_to_us < 100) {
889                         priv->framecnt_to_us++;
890                         print_summary = 0;
891                 } else {
892                         priv->framecnt_to_us = 0;
893                         print_summary = 1;
894                         hundred = 1;
895                 }
896         } else {
897                 /* print summary for all other frames */
898                 print_summary = 1;
899         }
900
901         if (print_summary) {
902                 char *title;
903                 int rate_idx;
904                 u32 bitrate;
905
906                 if (hundred)
907                         title = "100Frames";
908                 else if (ieee80211_has_retry(fc))
909                         title = "Retry";
910                 else if (ieee80211_is_assoc_resp(fc))
911                         title = "AscRsp";
912                 else if (ieee80211_is_reassoc_resp(fc))
913                         title = "RasRsp";
914                 else if (ieee80211_is_probe_resp(fc)) {
915                         title = "PrbRsp";
916                         print_dump = 1; /* dump frame contents */
917                 } else if (ieee80211_is_beacon(fc)) {
918                         title = "Beacon";
919                         print_dump = 1; /* dump frame contents */
920                 } else if (ieee80211_is_atim(fc))
921                         title = "ATIM";
922                 else if (ieee80211_is_auth(fc))
923                         title = "Auth";
924                 else if (ieee80211_is_deauth(fc))
925                         title = "DeAuth";
926                 else if (ieee80211_is_disassoc(fc))
927                         title = "DisAssoc";
928                 else
929                         title = "Frame";
930
931                 rate_idx = iwl_hwrate_to_plcp_idx(rate_n_flags);
932                 if (unlikely((rate_idx < 0) || (rate_idx >= IWL_RATE_COUNT))) {
933                         bitrate = 0;
934                         WARN_ON_ONCE(1);
935                 } else {
936                         bitrate = iwl_rates[rate_idx].ieee / 2;
937                 }
938
939                 /* print frame summary.
940                  * MAC addresses show just the last byte (for brevity),
941                  *    but you can hack it to show more, if you'd like to. */
942                 if (dataframe)
943                         IWL_DEBUG_RX(priv, "%s: mhd=0x%04x, dst=0x%02x, "
944                                      "len=%u, rssi=%d, chnl=%d, rate=%u, \n",
945                                      title, le16_to_cpu(fc), header->addr1[5],
946                                      length, rssi, channel, bitrate);
947                 else {
948                         /* src/dst addresses assume managed mode */
949                         IWL_DEBUG_RX(priv, "%s: 0x%04x, dst=0x%02x, src=0x%02x, "
950                                      "len=%u, rssi=%d, tim=%lu usec, "
951                                      "phy=0x%02x, chnl=%d\n",
952                                      title, le16_to_cpu(fc), header->addr1[5],
953                                      header->addr3[5], length, rssi,
954                                      tsf_low - priv->scan_start_tsf,
955                                      phy_flags, channel);
956                 }
957         }
958         if (print_dump)
959                 iwl_print_hex_dump(priv, IWL_DL_RX, header, length);
960 }
961 #endif
962
963 /*
964  * returns non-zero if packet should be dropped
965  */
966 int iwl_set_decrypted_flag(struct iwl_priv *priv,
967                            struct ieee80211_hdr *hdr,
968                            u32 decrypt_res,
969                            struct ieee80211_rx_status *stats)
970 {
971         u16 fc = le16_to_cpu(hdr->frame_control);
972
973         if (priv->active_rxon.filter_flags & RXON_FILTER_DIS_DECRYPT_MSK)
974                 return 0;
975
976         if (!(fc & IEEE80211_FCTL_PROTECTED))
977                 return 0;
978
979         IWL_DEBUG_RX(priv, "decrypt_res:0x%x\n", decrypt_res);
980         switch (decrypt_res & RX_RES_STATUS_SEC_TYPE_MSK) {
981         case RX_RES_STATUS_SEC_TYPE_TKIP:
982                 /* The uCode has got a bad phase 1 Key, pushes the packet.
983                  * Decryption will be done in SW. */
984                 if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
985                     RX_RES_STATUS_BAD_KEY_TTAK)
986                         break;
987
988         case RX_RES_STATUS_SEC_TYPE_WEP:
989                 if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
990                     RX_RES_STATUS_BAD_ICV_MIC) {
991                         /* bad ICV, the packet is destroyed since the
992                          * decryption is inplace, drop it */
993                         IWL_DEBUG_RX(priv, "Packet destroyed\n");
994                         return -1;
995                 }
996         case RX_RES_STATUS_SEC_TYPE_CCMP:
997                 if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
998                     RX_RES_STATUS_DECRYPT_OK) {
999                         IWL_DEBUG_RX(priv, "hw decrypt successfully!!!\n");
1000                         stats->flag |= RX_FLAG_DECRYPTED;
1001                 }
1002                 break;
1003
1004         default:
1005                 break;
1006         }
1007         return 0;
1008 }
1009 EXPORT_SYMBOL(iwl_set_decrypted_flag);
1010
1011 static u32 iwl_translate_rx_status(struct iwl_priv *priv, u32 decrypt_in)
1012 {
1013         u32 decrypt_out = 0;
1014
1015         if ((decrypt_in & RX_RES_STATUS_STATION_FOUND) ==
1016                                         RX_RES_STATUS_STATION_FOUND)
1017                 decrypt_out |= (RX_RES_STATUS_STATION_FOUND |
1018                                 RX_RES_STATUS_NO_STATION_INFO_MISMATCH);
1019
1020         decrypt_out |= (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK);
1021
1022         /* packet was not encrypted */
1023         if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
1024                                         RX_RES_STATUS_SEC_TYPE_NONE)
1025                 return decrypt_out;
1026
1027         /* packet was encrypted with unknown alg */
1028         if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
1029                                         RX_RES_STATUS_SEC_TYPE_ERR)
1030                 return decrypt_out;
1031
1032         /* decryption was not done in HW */
1033         if ((decrypt_in & RX_MPDU_RES_STATUS_DEC_DONE_MSK) !=
1034                                         RX_MPDU_RES_STATUS_DEC_DONE_MSK)
1035                 return decrypt_out;
1036
1037         switch (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) {
1038
1039         case RX_RES_STATUS_SEC_TYPE_CCMP:
1040                 /* alg is CCM: check MIC only */
1041                 if (!(decrypt_in & RX_MPDU_RES_STATUS_MIC_OK))
1042                         /* Bad MIC */
1043                         decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
1044                 else
1045                         decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
1046
1047                 break;
1048
1049         case RX_RES_STATUS_SEC_TYPE_TKIP:
1050                 if (!(decrypt_in & RX_MPDU_RES_STATUS_TTAK_OK)) {
1051                         /* Bad TTAK */
1052                         decrypt_out |= RX_RES_STATUS_BAD_KEY_TTAK;
1053                         break;
1054                 }
1055                 /* fall through if TTAK OK */
1056         default:
1057                 if (!(decrypt_in & RX_MPDU_RES_STATUS_ICV_OK))
1058                         decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
1059                 else
1060                         decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
1061                 break;
1062         };
1063
1064         IWL_DEBUG_RX(priv, "decrypt_in:0x%x  decrypt_out = 0x%x\n",
1065                                         decrypt_in, decrypt_out);
1066
1067         return decrypt_out;
1068 }
1069
1070 static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
1071                                         struct ieee80211_hdr *hdr,
1072                                         u16 len,
1073                                         u32 ampdu_status,
1074                                         struct iwl_rx_mem_buffer *rxb,
1075                                         struct ieee80211_rx_status *stats)
1076 {
1077         struct sk_buff *skb;
1078         int ret = 0;
1079         __le16 fc = hdr->frame_control;
1080
1081         /* We only process data packets if the interface is open */
1082         if (unlikely(!priv->is_open)) {
1083                 IWL_DEBUG_DROP_LIMIT(priv,
1084                     "Dropping packet while interface is not open.\n");
1085                 return;
1086         }
1087
1088         /* In case of HW accelerated crypto and bad decryption, drop */
1089         if (!priv->cfg->mod_params->sw_crypto &&
1090             iwl_set_decrypted_flag(priv, hdr, ampdu_status, stats))
1091                 return;
1092
1093         skb = alloc_skb(IWL_LINK_HDR_MAX * 2, GFP_ATOMIC);
1094         if (!skb) {
1095                 IWL_ERR(priv, "alloc_skb failed\n");
1096                 return;
1097         }
1098
1099         skb_reserve(skb, IWL_LINK_HDR_MAX);
1100         skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len);
1101
1102         /* mac80211 currently doesn't support paged SKB. Convert it to
1103          * linear SKB for management frame and data frame requires
1104          * software decryption or software defragementation. */
1105         if (ieee80211_is_mgmt(fc) ||
1106             ieee80211_has_protected(fc) ||
1107             ieee80211_has_morefrags(fc) ||
1108             le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG ||
1109             (ieee80211_is_data_qos(fc) &&
1110              *ieee80211_get_qos_ctl(hdr) &
1111              IEEE80211_QOS_CONTROL_A_MSDU_PRESENT))
1112                 ret = skb_linearize(skb);
1113         else
1114                 ret = __pskb_pull_tail(skb, min_t(u16, IWL_LINK_HDR_MAX, len)) ?
1115                          0 : -ENOMEM;
1116
1117         if (ret) {
1118                 kfree_skb(skb);
1119                 goto out;
1120         }
1121
1122         /*
1123          * XXX: We cannot touch the page and its virtual memory (hdr) after
1124          * here. It might have already been freed by the above skb change.
1125          */
1126
1127         iwl_update_stats(priv, false, fc, len);
1128         memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
1129
1130         ieee80211_rx(priv->hw, skb);
1131  out:
1132         priv->alloc_rxb_page--;
1133         rxb->page = NULL;
1134 }
1135
1136 /* Called for REPLY_RX (legacy ABG frames), or
1137  * REPLY_RX_MPDU_CMD (HT high-throughput N frames). */
1138 void iwl_rx_reply_rx(struct iwl_priv *priv,
1139                                 struct iwl_rx_mem_buffer *rxb)
1140 {
1141         struct ieee80211_hdr *header;
1142         struct ieee80211_rx_status rx_status;
1143         struct iwl_rx_packet *pkt = rxb_addr(rxb);
1144         struct iwl_rx_phy_res *phy_res;
1145         __le32 rx_pkt_status;
1146         struct iwl4965_rx_mpdu_res_start *amsdu;
1147         u32 len;
1148         u32 ampdu_status;
1149         u32 rate_n_flags;
1150
1151         /**
1152          * REPLY_RX and REPLY_RX_MPDU_CMD are handled differently.
1153          *      REPLY_RX: physical layer info is in this buffer
1154          *      REPLY_RX_MPDU_CMD: physical layer info was sent in separate
1155          *              command and cached in priv->last_phy_res
1156          *
1157          * Here we set up local variables depending on which command is
1158          * received.
1159          */
1160         if (pkt->hdr.cmd == REPLY_RX) {
1161                 phy_res = (struct iwl_rx_phy_res *)pkt->u.raw;
1162                 header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*phy_res)
1163                                 + phy_res->cfg_phy_cnt);
1164
1165                 len = le16_to_cpu(phy_res->byte_count);
1166                 rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*phy_res) +
1167                                 phy_res->cfg_phy_cnt + len);
1168                 ampdu_status = le32_to_cpu(rx_pkt_status);
1169         } else {
1170                 if (!priv->last_phy_res[0]) {
1171                         IWL_ERR(priv, "MPDU frame without cached PHY data\n");
1172                         return;
1173                 }
1174                 phy_res = (struct iwl_rx_phy_res *)&priv->last_phy_res[1];
1175                 amsdu = (struct iwl4965_rx_mpdu_res_start *)pkt->u.raw;
1176                 header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*amsdu));
1177                 len = le16_to_cpu(amsdu->byte_count);
1178                 rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*amsdu) + len);
1179                 ampdu_status = iwl_translate_rx_status(priv,
1180                                 le32_to_cpu(rx_pkt_status));
1181         }
1182
1183         if ((unlikely(phy_res->cfg_phy_cnt > 20))) {
1184                 IWL_DEBUG_DROP(priv, "dsp size out of range [0,20]: %d/n",
1185                                 phy_res->cfg_phy_cnt);
1186                 return;
1187         }
1188
1189         if (!(rx_pkt_status & RX_RES_STATUS_NO_CRC32_ERROR) ||
1190             !(rx_pkt_status & RX_RES_STATUS_NO_RXE_OVERFLOW)) {
1191                 IWL_DEBUG_RX(priv, "Bad CRC or FIFO: 0x%08X.\n",
1192                                 le32_to_cpu(rx_pkt_status));
1193                 return;
1194         }
1195
1196         /* This will be used in several places later */
1197         rate_n_flags = le32_to_cpu(phy_res->rate_n_flags);
1198
1199         /* rx_status carries information about the packet to mac80211 */
1200         rx_status.mactime = le64_to_cpu(phy_res->timestamp);
1201         rx_status.freq =
1202                 ieee80211_channel_to_frequency(le16_to_cpu(phy_res->channel));
1203         rx_status.band = (phy_res->phy_flags & RX_RES_PHY_FLAGS_BAND_24_MSK) ?
1204                                 IEEE80211_BAND_2GHZ : IEEE80211_BAND_5GHZ;
1205         rx_status.rate_idx =
1206                 iwl_hwrate_to_mac80211_idx(rate_n_flags, rx_status.band);
1207         rx_status.flag = 0;
1208
1209         /* TSF isn't reliable. In order to allow smooth user experience,
1210          * this W/A doesn't propagate it to the mac80211 */
1211         /*rx_status.flag |= RX_FLAG_TSFT;*/
1212
1213         priv->ucode_beacon_time = le32_to_cpu(phy_res->beacon_time_stamp);
1214
1215         /* Find max signal strength (dBm) among 3 antenna/receiver chains */
1216         rx_status.signal = iwl_calc_rssi(priv, phy_res);
1217
1218         /* Meaningful noise values are available only from beacon statistics,
1219          *   which are gathered only when associated, and indicate noise
1220          *   only for the associated network channel ...
1221          * Ignore these noise values while scanning (other channels) */
1222         if (iwl_is_associated(priv) &&
1223             !test_bit(STATUS_SCANNING, &priv->status)) {
1224                 rx_status.noise = priv->last_rx_noise;
1225         } else {
1226                 rx_status.noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
1227         }
1228
1229         /* Reset beacon noise level if not associated. */
1230         if (!iwl_is_associated(priv))
1231                 priv->last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
1232
1233 #ifdef CONFIG_IWLWIFI_DEBUG
1234         /* Set "1" to report good data frames in groups of 100 */
1235         if (unlikely(iwl_get_debug_level(priv) & IWL_DL_RX))
1236                 iwl_dbg_report_frame(priv, phy_res, len, header, 1);
1237 #endif
1238         iwl_dbg_log_rx_data_frame(priv, len, header);
1239         IWL_DEBUG_STATS_LIMIT(priv, "Rssi %d, noise %d, TSF %llu\n",
1240                 rx_status.signal, rx_status.noise,
1241                 (unsigned long long)rx_status.mactime);
1242
1243         /*
1244          * "antenna number"
1245          *
1246          * It seems that the antenna field in the phy flags value
1247          * is actually a bit field. This is undefined by radiotap,
1248          * it wants an actual antenna number but I always get "7"
1249          * for most legacy frames I receive indicating that the
1250          * same frame was received on all three RX chains.
1251          *
1252          * I think this field should be removed in favor of a
1253          * new 802.11n radiotap field "RX chains" that is defined
1254          * as a bitmask.
1255          */
1256         rx_status.antenna =
1257                 (le16_to_cpu(phy_res->phy_flags) & RX_RES_PHY_FLAGS_ANTENNA_MSK)
1258                 >> RX_RES_PHY_FLAGS_ANTENNA_POS;
1259
1260         /* set the preamble flag if appropriate */
1261         if (phy_res->phy_flags & RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK)
1262                 rx_status.flag |= RX_FLAG_SHORTPRE;
1263
1264         /* Set up the HT phy flags */
1265         if (rate_n_flags & RATE_MCS_HT_MSK)
1266                 rx_status.flag |= RX_FLAG_HT;
1267         if (rate_n_flags & RATE_MCS_HT40_MSK)
1268                 rx_status.flag |= RX_FLAG_40MHZ;
1269         if (rate_n_flags & RATE_MCS_SGI_MSK)
1270                 rx_status.flag |= RX_FLAG_SHORT_GI;
1271
1272         iwl_pass_packet_to_mac80211(priv, header, len, ampdu_status,
1273                                     rxb, &rx_status);
1274 }
1275 EXPORT_SYMBOL(iwl_rx_reply_rx);
1276
1277 /* Cache phy data (Rx signal strength, etc) for HT frame (REPLY_RX_PHY_CMD).
1278  * This will be used later in iwl_rx_reply_rx() for REPLY_RX_MPDU_CMD. */
1279 void iwl_rx_reply_rx_phy(struct iwl_priv *priv,
1280                                     struct iwl_rx_mem_buffer *rxb)
1281 {
1282         struct iwl_rx_packet *pkt = rxb_addr(rxb);
1283         priv->last_phy_res[0] = 1;
1284         memcpy(&priv->last_phy_res[1], &(pkt->u.raw[0]),
1285                sizeof(struct iwl_rx_phy_res));
1286 }
1287 EXPORT_SYMBOL(iwl_rx_reply_rx_phy);