]> nv-tegra.nvidia Code Review - linux-2.6.git/blob - drivers/net/wireless/iwlwifi/iwl-rx.c
iwlwifi: fix potential rx buffer loss
[linux-2.6.git] / drivers / net / wireless / iwlwifi / iwl-rx.c
1 /******************************************************************************
2  *
3  * Copyright(c) 2003 - 2009 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 int 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         int ret = 0;
132
133         spin_lock_irqsave(&q->lock, flags);
134
135         if (q->need_update == 0)
136                 goto exit_unlock;
137
138         /* If power-saving is in use, make sure device is awake */
139         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
140                 reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
141
142                 if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
143                         iwl_set_bit(priv, CSR_GP_CNTRL,
144                                     CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
145                         goto exit_unlock;
146                 }
147
148                 q->write_actual = (q->write & ~0x7);
149                 iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
150
151         /* Else device is assumed to be awake */
152         } else {
153                 /* Device expects a multiple of 8 */
154                 q->write_actual = (q->write & ~0x7);
155                 iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
156         }
157
158         q->need_update = 0;
159
160  exit_unlock:
161         spin_unlock_irqrestore(&q->lock, flags);
162         return ret;
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 int 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         int ret = 0;
193
194         spin_lock_irqsave(&rxq->lock, flags);
195         write = rxq->write & ~0x7;
196         while ((iwl_rx_queue_space(rxq) > 0) && (rxq->free_count)) {
197                 /* Get next free Rx buffer, remove from free list */
198                 element = rxq->rx_free.next;
199                 rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
200                 list_del(element);
201
202                 /* Point to Rx buffer via next RBD in circular buffer */
203                 rxq->bd[rxq->write] = iwl_dma_addr2rbd_ptr(priv, rxb->aligned_dma_addr);
204                 rxq->queue[rxq->write] = rxb;
205                 rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
206                 rxq->free_count--;
207         }
208         spin_unlock_irqrestore(&rxq->lock, flags);
209         /* If the pre-allocated buffer pool is dropping low, schedule to
210          * refill it */
211         if (rxq->free_count <= RX_LOW_WATERMARK)
212                 queue_work(priv->workqueue, &priv->rx_replenish);
213
214
215         /* If we've added more space for the firmware to place data, tell it.
216          * Increment device's write pointer in multiples of 8. */
217         if (rxq->write_actual != (rxq->write & ~0x7)) {
218                 spin_lock_irqsave(&rxq->lock, flags);
219                 rxq->need_update = 1;
220                 spin_unlock_irqrestore(&rxq->lock, flags);
221                 ret = iwl_rx_queue_update_write_ptr(priv, rxq);
222         }
223
224         return ret;
225 }
226 EXPORT_SYMBOL(iwl_rx_queue_restock);
227
228
229 /**
230  * iwl_rx_replenish - Move all used packet from rx_used to rx_free
231  *
232  * When moving to rx_free an SKB is allocated for the slot.
233  *
234  * Also restock the Rx queue via iwl_rx_queue_restock.
235  * This is called as a scheduled work item (except for during initialization)
236  */
237 void iwl_rx_allocate(struct iwl_priv *priv, gfp_t priority)
238 {
239         struct iwl_rx_queue *rxq = &priv->rxq;
240         struct list_head *element;
241         struct iwl_rx_mem_buffer *rxb;
242         struct sk_buff *skb;
243         unsigned long flags;
244
245         while (1) {
246                 spin_lock_irqsave(&rxq->lock, flags);
247                 if (list_empty(&rxq->rx_used)) {
248                         spin_unlock_irqrestore(&rxq->lock, flags);
249                         return;
250                 }
251                 spin_unlock_irqrestore(&rxq->lock, flags);
252
253                 /* Alloc a new receive buffer */
254                 skb = alloc_skb(priv->hw_params.rx_buf_size + 256,
255                                                 priority);
256
257                 if (!skb) {
258                         IWL_CRIT(priv, "Can not allocate SKB buffers\n");
259                         /* We don't reschedule replenish work here -- we will
260                          * call the restock method and if it still needs
261                          * more buffers it will schedule replenish */
262                         break;
263                 }
264
265                 spin_lock_irqsave(&rxq->lock, flags);
266
267                 if (list_empty(&rxq->rx_used)) {
268                         spin_unlock_irqrestore(&rxq->lock, flags);
269                         dev_kfree_skb_any(skb);
270                         return;
271                 }
272                 element = rxq->rx_used.next;
273                 rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
274                 list_del(element);
275
276                 spin_unlock_irqrestore(&rxq->lock, flags);
277
278                 rxb->skb = skb;
279                 /* Get physical address of RB/SKB */
280                 rxb->real_dma_addr = pci_map_single(
281                                         priv->pci_dev,
282                                         rxb->skb->data,
283                                         priv->hw_params.rx_buf_size + 256,
284                                         PCI_DMA_FROMDEVICE);
285                 /* dma address must be no more than 36 bits */
286                 BUG_ON(rxb->real_dma_addr & ~DMA_BIT_MASK(36));
287                 /* and also 256 byte aligned! */
288                 rxb->aligned_dma_addr = ALIGN(rxb->real_dma_addr, 256);
289                 skb_reserve(rxb->skb, rxb->aligned_dma_addr - rxb->real_dma_addr);
290
291                 spin_lock_irqsave(&rxq->lock, flags);
292
293                 list_add_tail(&rxb->list, &rxq->rx_free);
294                 rxq->free_count++;
295                 priv->alloc_rxb_skb++;
296
297                 spin_unlock_irqrestore(&rxq->lock, flags);
298         }
299 }
300
301 void iwl_rx_replenish(struct iwl_priv *priv)
302 {
303         unsigned long flags;
304
305         iwl_rx_allocate(priv, GFP_KERNEL);
306
307         spin_lock_irqsave(&priv->lock, flags);
308         iwl_rx_queue_restock(priv);
309         spin_unlock_irqrestore(&priv->lock, flags);
310 }
311 EXPORT_SYMBOL(iwl_rx_replenish);
312
313 void iwl_rx_replenish_now(struct iwl_priv *priv)
314 {
315         iwl_rx_allocate(priv, GFP_ATOMIC);
316
317         iwl_rx_queue_restock(priv);
318 }
319 EXPORT_SYMBOL(iwl_rx_replenish_now);
320
321
322 /* Assumes that the skb field of the buffers in 'pool' is kept accurate.
323  * If an SKB has been detached, the POOL needs to have its SKB set to NULL
324  * This free routine walks the list of POOL entries and if SKB is set to
325  * non NULL it is unmapped and freed
326  */
327 void iwl_rx_queue_free(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
328 {
329         int i;
330         for (i = 0; i < RX_QUEUE_SIZE + RX_FREE_BUFFERS; i++) {
331                 if (rxq->pool[i].skb != NULL) {
332                         pci_unmap_single(priv->pci_dev,
333                                          rxq->pool[i].real_dma_addr,
334                                          priv->hw_params.rx_buf_size + 256,
335                                          PCI_DMA_FROMDEVICE);
336                         dev_kfree_skb(rxq->pool[i].skb);
337                 }
338         }
339
340         pci_free_consistent(priv->pci_dev, 4 * RX_QUEUE_SIZE, rxq->bd,
341                             rxq->dma_addr);
342         pci_free_consistent(priv->pci_dev, sizeof(struct iwl_rb_status),
343                             rxq->rb_stts, rxq->rb_stts_dma);
344         rxq->bd = NULL;
345         rxq->rb_stts  = NULL;
346 }
347 EXPORT_SYMBOL(iwl_rx_queue_free);
348
349 int iwl_rx_queue_alloc(struct iwl_priv *priv)
350 {
351         struct iwl_rx_queue *rxq = &priv->rxq;
352         struct pci_dev *dev = priv->pci_dev;
353         int i;
354
355         spin_lock_init(&rxq->lock);
356         INIT_LIST_HEAD(&rxq->rx_free);
357         INIT_LIST_HEAD(&rxq->rx_used);
358
359         /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
360         rxq->bd = pci_alloc_consistent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr);
361         if (!rxq->bd)
362                 goto err_bd;
363
364         rxq->rb_stts = pci_alloc_consistent(dev, sizeof(struct iwl_rb_status),
365                                         &rxq->rb_stts_dma);
366         if (!rxq->rb_stts)
367                 goto err_rb;
368
369         /* Fill the rx_used queue with _all_ of the Rx buffers */
370         for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
371                 list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
372
373         /* Set us so that we have processed and used all buffers, but have
374          * not restocked the Rx queue with fresh buffers */
375         rxq->read = rxq->write = 0;
376         rxq->write_actual = 0;
377         rxq->free_count = 0;
378         rxq->need_update = 0;
379         return 0;
380
381 err_rb:
382         pci_free_consistent(priv->pci_dev, 4 * RX_QUEUE_SIZE, rxq->bd,
383                             rxq->dma_addr);
384 err_bd:
385         return -ENOMEM;
386 }
387 EXPORT_SYMBOL(iwl_rx_queue_alloc);
388
389 void iwl_rx_queue_reset(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
390 {
391         unsigned long flags;
392         int i;
393         spin_lock_irqsave(&rxq->lock, flags);
394         INIT_LIST_HEAD(&rxq->rx_free);
395         INIT_LIST_HEAD(&rxq->rx_used);
396         /* Fill the rx_used queue with _all_ of the Rx buffers */
397         for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) {
398                 /* In the reset function, these buffers may have been allocated
399                  * to an SKB, so we need to unmap and free potential storage */
400                 if (rxq->pool[i].skb != NULL) {
401                         pci_unmap_single(priv->pci_dev,
402                                          rxq->pool[i].real_dma_addr,
403                                          priv->hw_params.rx_buf_size + 256,
404                                          PCI_DMA_FROMDEVICE);
405                         priv->alloc_rxb_skb--;
406                         dev_kfree_skb(rxq->pool[i].skb);
407                         rxq->pool[i].skb = NULL;
408                 }
409                 list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
410         }
411
412         /* Set us so that we have processed and used all buffers, but have
413          * not restocked the Rx queue with fresh buffers */
414         rxq->read = rxq->write = 0;
415         rxq->write_actual = 0;
416         rxq->free_count = 0;
417         spin_unlock_irqrestore(&rxq->lock, flags);
418 }
419
420 int iwl_rx_init(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
421 {
422         u32 rb_size;
423         const u32 rfdnlog = RX_QUEUE_SIZE_LOG; /* 256 RBDs */
424         u32 rb_timeout = 0; /* FIXME: RX_RB_TIMEOUT for all devices? */
425
426         if (!priv->cfg->use_isr_legacy)
427                 rb_timeout = RX_RB_TIMEOUT;
428
429         if (priv->cfg->mod_params->amsdu_size_8K)
430                 rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_8K;
431         else
432                 rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K;
433
434         /* Stop Rx DMA */
435         iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
436
437         /* Reset driver's Rx queue write index */
438         iwl_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_WPTR_REG, 0);
439
440         /* Tell device where to find RBD circular buffer in DRAM */
441         iwl_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_BASE_REG,
442                            (u32)(rxq->dma_addr >> 8));
443
444         /* Tell device where in DRAM to update its Rx status */
445         iwl_write_direct32(priv, FH_RSCSR_CHNL0_STTS_WPTR_REG,
446                            rxq->rb_stts_dma >> 4);
447
448         /* Enable Rx DMA
449          * FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY is set because of HW bug in
450          *      the credit mechanism in 5000 HW RX FIFO
451          * Direct rx interrupts to hosts
452          * Rx buffer size 4 or 8k
453          * RB timeout 0x10
454          * 256 RBDs
455          */
456         iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG,
457                            FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL |
458                            FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY |
459                            FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL |
460                            FH_RCSR_CHNL0_RX_CONFIG_SINGLE_FRAME_MSK |
461                            rb_size|
462                            (rb_timeout << FH_RCSR_RX_CONFIG_REG_IRQ_RBTH_POS)|
463                            (rfdnlog << FH_RCSR_RX_CONFIG_RBDCB_SIZE_POS));
464
465         iwl_write32(priv, CSR_INT_COALESCING, 0x40);
466
467         return 0;
468 }
469
470 int iwl_rxq_stop(struct iwl_priv *priv)
471 {
472
473         /* stop Rx DMA */
474         iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
475         iwl_poll_direct_bit(priv, FH_MEM_RSSR_RX_STATUS_REG,
476                             FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE, 1000);
477
478         return 0;
479 }
480 EXPORT_SYMBOL(iwl_rxq_stop);
481
482 void iwl_rx_missed_beacon_notif(struct iwl_priv *priv,
483                                 struct iwl_rx_mem_buffer *rxb)
484
485 {
486         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
487         struct iwl_missed_beacon_notif *missed_beacon;
488
489         missed_beacon = &pkt->u.missed_beacon;
490         if (le32_to_cpu(missed_beacon->consequtive_missed_beacons) > 5) {
491                 IWL_DEBUG_CALIB(priv, "missed bcn cnsq %d totl %d rcd %d expctd %d\n",
492                     le32_to_cpu(missed_beacon->consequtive_missed_beacons),
493                     le32_to_cpu(missed_beacon->total_missed_becons),
494                     le32_to_cpu(missed_beacon->num_recvd_beacons),
495                     le32_to_cpu(missed_beacon->num_expected_beacons));
496                 if (!test_bit(STATUS_SCANNING, &priv->status))
497                         iwl_init_sensitivity(priv);
498         }
499 }
500 EXPORT_SYMBOL(iwl_rx_missed_beacon_notif);
501
502
503 /* Calculate noise level, based on measurements during network silence just
504  *   before arriving beacon.  This measurement can be done only if we know
505  *   exactly when to expect beacons, therefore only when we're associated. */
506 static void iwl_rx_calc_noise(struct iwl_priv *priv)
507 {
508         struct statistics_rx_non_phy *rx_info
509                                 = &(priv->statistics.rx.general);
510         int num_active_rx = 0;
511         int total_silence = 0;
512         int bcn_silence_a =
513                 le32_to_cpu(rx_info->beacon_silence_rssi_a) & IN_BAND_FILTER;
514         int bcn_silence_b =
515                 le32_to_cpu(rx_info->beacon_silence_rssi_b) & IN_BAND_FILTER;
516         int bcn_silence_c =
517                 le32_to_cpu(rx_info->beacon_silence_rssi_c) & IN_BAND_FILTER;
518
519         if (bcn_silence_a) {
520                 total_silence += bcn_silence_a;
521                 num_active_rx++;
522         }
523         if (bcn_silence_b) {
524                 total_silence += bcn_silence_b;
525                 num_active_rx++;
526         }
527         if (bcn_silence_c) {
528                 total_silence += bcn_silence_c;
529                 num_active_rx++;
530         }
531
532         /* Average among active antennas */
533         if (num_active_rx)
534                 priv->last_rx_noise = (total_silence / num_active_rx) - 107;
535         else
536                 priv->last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
537
538         IWL_DEBUG_CALIB(priv, "inband silence a %u, b %u, c %u, dBm %d\n",
539                         bcn_silence_a, bcn_silence_b, bcn_silence_c,
540                         priv->last_rx_noise);
541 }
542
543 #define REG_RECALIB_PERIOD (60)
544
545 void iwl_rx_statistics(struct iwl_priv *priv,
546                               struct iwl_rx_mem_buffer *rxb)
547 {
548         int change;
549         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
550
551         IWL_DEBUG_RX(priv, "Statistics notification received (%d vs %d).\n",
552                      (int)sizeof(priv->statistics),
553                      le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK);
554
555         change = ((priv->statistics.general.temperature !=
556                    pkt->u.stats.general.temperature) ||
557                   ((priv->statistics.flag &
558                     STATISTICS_REPLY_FLG_HT40_MODE_MSK) !=
559                    (pkt->u.stats.flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK)));
560
561         memcpy(&priv->statistics, &pkt->u.stats, sizeof(priv->statistics));
562
563         set_bit(STATUS_STATISTICS, &priv->status);
564
565         /* Reschedule the statistics timer to occur in
566          * REG_RECALIB_PERIOD seconds to ensure we get a
567          * thermal update even if the uCode doesn't give
568          * us one */
569         mod_timer(&priv->statistics_periodic, jiffies +
570                   msecs_to_jiffies(REG_RECALIB_PERIOD * 1000));
571
572         if (unlikely(!test_bit(STATUS_SCANNING, &priv->status)) &&
573             (pkt->hdr.cmd == STATISTICS_NOTIFICATION)) {
574                 iwl_rx_calc_noise(priv);
575                 queue_work(priv->workqueue, &priv->run_time_calib_work);
576         }
577
578         iwl_leds_background(priv);
579
580         if (priv->cfg->ops->lib->temp_ops.temperature && change)
581                 priv->cfg->ops->lib->temp_ops.temperature(priv);
582 }
583 EXPORT_SYMBOL(iwl_rx_statistics);
584
585 #define PERFECT_RSSI (-20) /* dBm */
586 #define WORST_RSSI (-95)   /* dBm */
587 #define RSSI_RANGE (PERFECT_RSSI - WORST_RSSI)
588
589 /* Calculate an indication of rx signal quality (a percentage, not dBm!).
590  * See http://www.ces.clemson.edu/linux/signal_quality.shtml for info
591  *   about formulas used below. */
592 static int iwl_calc_sig_qual(int rssi_dbm, int noise_dbm)
593 {
594         int sig_qual;
595         int degradation = PERFECT_RSSI - rssi_dbm;
596
597         /* If we get a noise measurement, use signal-to-noise ratio (SNR)
598          * as indicator; formula is (signal dbm - noise dbm).
599          * SNR at or above 40 is a great signal (100%).
600          * Below that, scale to fit SNR of 0 - 40 dB within 0 - 100% indicator.
601          * Weakest usable signal is usually 10 - 15 dB SNR. */
602         if (noise_dbm) {
603                 if (rssi_dbm - noise_dbm >= 40)
604                         return 100;
605                 else if (rssi_dbm < noise_dbm)
606                         return 0;
607                 sig_qual = ((rssi_dbm - noise_dbm) * 5) / 2;
608
609         /* Else use just the signal level.
610          * This formula is a least squares fit of data points collected and
611          *   compared with a reference system that had a percentage (%) display
612          *   for signal quality. */
613         } else
614                 sig_qual = (100 * (RSSI_RANGE * RSSI_RANGE) - degradation *
615                             (15 * RSSI_RANGE + 62 * degradation)) /
616                            (RSSI_RANGE * RSSI_RANGE);
617
618         if (sig_qual > 100)
619                 sig_qual = 100;
620         else if (sig_qual < 1)
621                 sig_qual = 0;
622
623         return sig_qual;
624 }
625
626 /* Calc max signal level (dBm) among 3 possible receivers */
627 static inline int iwl_calc_rssi(struct iwl_priv *priv,
628                                 struct iwl_rx_phy_res *rx_resp)
629 {
630         return priv->cfg->ops->utils->calc_rssi(priv, rx_resp);
631 }
632
633 #ifdef CONFIG_IWLWIFI_DEBUG
634 /**
635  * iwl_dbg_report_frame - dump frame to syslog during debug sessions
636  *
637  * You may hack this function to show different aspects of received frames,
638  * including selective frame dumps.
639  * group100 parameter selects whether to show 1 out of 100 good data frames.
640  *    All beacon and probe response frames are printed.
641  */
642 static void iwl_dbg_report_frame(struct iwl_priv *priv,
643                       struct iwl_rx_phy_res *phy_res, u16 length,
644                       struct ieee80211_hdr *header, int group100)
645 {
646         u32 to_us;
647         u32 print_summary = 0;
648         u32 print_dump = 0;     /* set to 1 to dump all frames' contents */
649         u32 hundred = 0;
650         u32 dataframe = 0;
651         __le16 fc;
652         u16 seq_ctl;
653         u16 channel;
654         u16 phy_flags;
655         u32 rate_n_flags;
656         u32 tsf_low;
657         int rssi;
658
659         if (likely(!(iwl_get_debug_level(priv) & IWL_DL_RX)))
660                 return;
661
662         /* MAC header */
663         fc = header->frame_control;
664         seq_ctl = le16_to_cpu(header->seq_ctrl);
665
666         /* metadata */
667         channel = le16_to_cpu(phy_res->channel);
668         phy_flags = le16_to_cpu(phy_res->phy_flags);
669         rate_n_flags = le32_to_cpu(phy_res->rate_n_flags);
670
671         /* signal statistics */
672         rssi = iwl_calc_rssi(priv, phy_res);
673         tsf_low = le64_to_cpu(phy_res->timestamp) & 0x0ffffffff;
674
675         to_us = !compare_ether_addr(header->addr1, priv->mac_addr);
676
677         /* if data frame is to us and all is good,
678          *   (optionally) print summary for only 1 out of every 100 */
679         if (to_us && (fc & ~cpu_to_le16(IEEE80211_FCTL_PROTECTED)) ==
680             cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FTYPE_DATA)) {
681                 dataframe = 1;
682                 if (!group100)
683                         print_summary = 1;      /* print each frame */
684                 else if (priv->framecnt_to_us < 100) {
685                         priv->framecnt_to_us++;
686                         print_summary = 0;
687                 } else {
688                         priv->framecnt_to_us = 0;
689                         print_summary = 1;
690                         hundred = 1;
691                 }
692         } else {
693                 /* print summary for all other frames */
694                 print_summary = 1;
695         }
696
697         if (print_summary) {
698                 char *title;
699                 int rate_idx;
700                 u32 bitrate;
701
702                 if (hundred)
703                         title = "100Frames";
704                 else if (ieee80211_has_retry(fc))
705                         title = "Retry";
706                 else if (ieee80211_is_assoc_resp(fc))
707                         title = "AscRsp";
708                 else if (ieee80211_is_reassoc_resp(fc))
709                         title = "RasRsp";
710                 else if (ieee80211_is_probe_resp(fc)) {
711                         title = "PrbRsp";
712                         print_dump = 1; /* dump frame contents */
713                 } else if (ieee80211_is_beacon(fc)) {
714                         title = "Beacon";
715                         print_dump = 1; /* dump frame contents */
716                 } else if (ieee80211_is_atim(fc))
717                         title = "ATIM";
718                 else if (ieee80211_is_auth(fc))
719                         title = "Auth";
720                 else if (ieee80211_is_deauth(fc))
721                         title = "DeAuth";
722                 else if (ieee80211_is_disassoc(fc))
723                         title = "DisAssoc";
724                 else
725                         title = "Frame";
726
727                 rate_idx = iwl_hwrate_to_plcp_idx(rate_n_flags);
728                 if (unlikely((rate_idx < 0) || (rate_idx >= IWL_RATE_COUNT))) {
729                         bitrate = 0;
730                         WARN_ON_ONCE(1);
731                 } else {
732                         bitrate = iwl_rates[rate_idx].ieee / 2;
733                 }
734
735                 /* print frame summary.
736                  * MAC addresses show just the last byte (for brevity),
737                  *    but you can hack it to show more, if you'd like to. */
738                 if (dataframe)
739                         IWL_DEBUG_RX(priv, "%s: mhd=0x%04x, dst=0x%02x, "
740                                      "len=%u, rssi=%d, chnl=%d, rate=%u, \n",
741                                      title, le16_to_cpu(fc), header->addr1[5],
742                                      length, rssi, channel, bitrate);
743                 else {
744                         /* src/dst addresses assume managed mode */
745                         IWL_DEBUG_RX(priv, "%s: 0x%04x, dst=0x%02x, src=0x%02x, "
746                                      "len=%u, rssi=%d, tim=%lu usec, "
747                                      "phy=0x%02x, chnl=%d\n",
748                                      title, le16_to_cpu(fc), header->addr1[5],
749                                      header->addr3[5], length, rssi,
750                                      tsf_low - priv->scan_start_tsf,
751                                      phy_flags, channel);
752                 }
753         }
754         if (print_dump)
755                 iwl_print_hex_dump(priv, IWL_DL_RX, header, length);
756 }
757 #endif
758
759 /*
760  * returns non-zero if packet should be dropped
761  */
762 int iwl_set_decrypted_flag(struct iwl_priv *priv,
763                            struct ieee80211_hdr *hdr,
764                            u32 decrypt_res,
765                            struct ieee80211_rx_status *stats)
766 {
767         u16 fc = le16_to_cpu(hdr->frame_control);
768
769         if (priv->active_rxon.filter_flags & RXON_FILTER_DIS_DECRYPT_MSK)
770                 return 0;
771
772         if (!(fc & IEEE80211_FCTL_PROTECTED))
773                 return 0;
774
775         IWL_DEBUG_RX(priv, "decrypt_res:0x%x\n", decrypt_res);
776         switch (decrypt_res & RX_RES_STATUS_SEC_TYPE_MSK) {
777         case RX_RES_STATUS_SEC_TYPE_TKIP:
778                 /* The uCode has got a bad phase 1 Key, pushes the packet.
779                  * Decryption will be done in SW. */
780                 if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
781                     RX_RES_STATUS_BAD_KEY_TTAK)
782                         break;
783
784         case RX_RES_STATUS_SEC_TYPE_WEP:
785                 if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
786                     RX_RES_STATUS_BAD_ICV_MIC) {
787                         /* bad ICV, the packet is destroyed since the
788                          * decryption is inplace, drop it */
789                         IWL_DEBUG_RX(priv, "Packet destroyed\n");
790                         return -1;
791                 }
792         case RX_RES_STATUS_SEC_TYPE_CCMP:
793                 if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
794                     RX_RES_STATUS_DECRYPT_OK) {
795                         IWL_DEBUG_RX(priv, "hw decrypt successfully!!!\n");
796                         stats->flag |= RX_FLAG_DECRYPTED;
797                 }
798                 break;
799
800         default:
801                 break;
802         }
803         return 0;
804 }
805 EXPORT_SYMBOL(iwl_set_decrypted_flag);
806
807 static u32 iwl_translate_rx_status(struct iwl_priv *priv, u32 decrypt_in)
808 {
809         u32 decrypt_out = 0;
810
811         if ((decrypt_in & RX_RES_STATUS_STATION_FOUND) ==
812                                         RX_RES_STATUS_STATION_FOUND)
813                 decrypt_out |= (RX_RES_STATUS_STATION_FOUND |
814                                 RX_RES_STATUS_NO_STATION_INFO_MISMATCH);
815
816         decrypt_out |= (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK);
817
818         /* packet was not encrypted */
819         if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
820                                         RX_RES_STATUS_SEC_TYPE_NONE)
821                 return decrypt_out;
822
823         /* packet was encrypted with unknown alg */
824         if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
825                                         RX_RES_STATUS_SEC_TYPE_ERR)
826                 return decrypt_out;
827
828         /* decryption was not done in HW */
829         if ((decrypt_in & RX_MPDU_RES_STATUS_DEC_DONE_MSK) !=
830                                         RX_MPDU_RES_STATUS_DEC_DONE_MSK)
831                 return decrypt_out;
832
833         switch (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) {
834
835         case RX_RES_STATUS_SEC_TYPE_CCMP:
836                 /* alg is CCM: check MIC only */
837                 if (!(decrypt_in & RX_MPDU_RES_STATUS_MIC_OK))
838                         /* Bad MIC */
839                         decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
840                 else
841                         decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
842
843                 break;
844
845         case RX_RES_STATUS_SEC_TYPE_TKIP:
846                 if (!(decrypt_in & RX_MPDU_RES_STATUS_TTAK_OK)) {
847                         /* Bad TTAK */
848                         decrypt_out |= RX_RES_STATUS_BAD_KEY_TTAK;
849                         break;
850                 }
851                 /* fall through if TTAK OK */
852         default:
853                 if (!(decrypt_in & RX_MPDU_RES_STATUS_ICV_OK))
854                         decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
855                 else
856                         decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
857                 break;
858         };
859
860         IWL_DEBUG_RX(priv, "decrypt_in:0x%x  decrypt_out = 0x%x\n",
861                                         decrypt_in, decrypt_out);
862
863         return decrypt_out;
864 }
865
866 static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
867                                         struct ieee80211_hdr *hdr,
868                                         u16 len,
869                                         u32 ampdu_status,
870                                         struct iwl_rx_mem_buffer *rxb,
871                                         struct ieee80211_rx_status *stats)
872 {
873         /* We only process data packets if the interface is open */
874         if (unlikely(!priv->is_open)) {
875                 IWL_DEBUG_DROP_LIMIT(priv,
876                     "Dropping packet while interface is not open.\n");
877                 return;
878         }
879
880         /* In case of HW accelerated crypto and bad decryption, drop */
881         if (!priv->cfg->mod_params->sw_crypto &&
882             iwl_set_decrypted_flag(priv, hdr, ampdu_status, stats))
883                 return;
884
885         /* Resize SKB from mac header to end of packet */
886         skb_reserve(rxb->skb, (void *)hdr - (void *)rxb->skb->data);
887         skb_put(rxb->skb, len);
888
889         iwl_update_stats(priv, false, hdr->frame_control, len);
890         memcpy(IEEE80211_SKB_RXCB(rxb->skb), stats, sizeof(*stats));
891         ieee80211_rx_irqsafe(priv->hw, rxb->skb);
892         priv->alloc_rxb_skb--;
893         rxb->skb = NULL;
894 }
895
896 /* This is necessary only for a number of statistics, see the caller. */
897 static int iwl_is_network_packet(struct iwl_priv *priv,
898                 struct ieee80211_hdr *header)
899 {
900         /* Filter incoming packets to determine if they are targeted toward
901          * this network, discarding packets coming from ourselves */
902         switch (priv->iw_mode) {
903         case NL80211_IFTYPE_ADHOC: /* Header: Dest. | Source    | BSSID */
904                 /* packets to our IBSS update information */
905                 return !compare_ether_addr(header->addr3, priv->bssid);
906         case NL80211_IFTYPE_STATION: /* Header: Dest. | AP{BSSID} | Source */
907                 /* packets to our IBSS update information */
908                 return !compare_ether_addr(header->addr2, priv->bssid);
909         default:
910                 return 1;
911         }
912 }
913
914 /* Called for REPLY_RX (legacy ABG frames), or
915  * REPLY_RX_MPDU_CMD (HT high-throughput N frames). */
916 void iwl_rx_reply_rx(struct iwl_priv *priv,
917                                 struct iwl_rx_mem_buffer *rxb)
918 {
919         struct ieee80211_hdr *header;
920         struct ieee80211_rx_status rx_status;
921         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
922         struct iwl_rx_phy_res *phy_res;
923         __le32 rx_pkt_status;
924         struct iwl4965_rx_mpdu_res_start *amsdu;
925         u32 len;
926         u32 ampdu_status;
927         u16 fc;
928         u32 rate_n_flags;
929
930         /**
931          * REPLY_RX and REPLY_RX_MPDU_CMD are handled differently.
932          *      REPLY_RX: physical layer info is in this buffer
933          *      REPLY_RX_MPDU_CMD: physical layer info was sent in separate
934          *              command and cached in priv->last_phy_res
935          *
936          * Here we set up local variables depending on which command is
937          * received.
938          */
939         if (pkt->hdr.cmd == REPLY_RX) {
940                 phy_res = (struct iwl_rx_phy_res *)pkt->u.raw;
941                 header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*phy_res)
942                                 + phy_res->cfg_phy_cnt);
943
944                 len = le16_to_cpu(phy_res->byte_count);
945                 rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*phy_res) +
946                                 phy_res->cfg_phy_cnt + len);
947                 ampdu_status = le32_to_cpu(rx_pkt_status);
948         } else {
949                 if (!priv->last_phy_res[0]) {
950                         IWL_ERR(priv, "MPDU frame without cached PHY data\n");
951                         return;
952                 }
953                 phy_res = (struct iwl_rx_phy_res *)&priv->last_phy_res[1];
954                 amsdu = (struct iwl4965_rx_mpdu_res_start *)pkt->u.raw;
955                 header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*amsdu));
956                 len = le16_to_cpu(amsdu->byte_count);
957                 rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*amsdu) + len);
958                 ampdu_status = iwl_translate_rx_status(priv,
959                                 le32_to_cpu(rx_pkt_status));
960         }
961
962         if ((unlikely(phy_res->cfg_phy_cnt > 20))) {
963                 IWL_DEBUG_DROP(priv, "dsp size out of range [0,20]: %d/n",
964                                 phy_res->cfg_phy_cnt);
965                 return;
966         }
967
968         if (!(rx_pkt_status & RX_RES_STATUS_NO_CRC32_ERROR) ||
969             !(rx_pkt_status & RX_RES_STATUS_NO_RXE_OVERFLOW)) {
970                 IWL_DEBUG_RX(priv, "Bad CRC or FIFO: 0x%08X.\n",
971                                 le32_to_cpu(rx_pkt_status));
972                 return;
973         }
974
975         /* This will be used in several places later */
976         rate_n_flags = le32_to_cpu(phy_res->rate_n_flags);
977
978         /* rx_status carries information about the packet to mac80211 */
979         rx_status.mactime = le64_to_cpu(phy_res->timestamp);
980         rx_status.freq =
981                 ieee80211_channel_to_frequency(le16_to_cpu(phy_res->channel));
982         rx_status.band = (phy_res->phy_flags & RX_RES_PHY_FLAGS_BAND_24_MSK) ?
983                                 IEEE80211_BAND_2GHZ : IEEE80211_BAND_5GHZ;
984         rx_status.rate_idx =
985                 iwl_hwrate_to_mac80211_idx(rate_n_flags, rx_status.band);
986         rx_status.flag = 0;
987
988         /* TSF isn't reliable. In order to allow smooth user experience,
989          * this W/A doesn't propagate it to the mac80211 */
990         /*rx_status.flag |= RX_FLAG_TSFT;*/
991
992         priv->ucode_beacon_time = le32_to_cpu(phy_res->beacon_time_stamp);
993
994         /* Find max signal strength (dBm) among 3 antenna/receiver chains */
995         rx_status.signal = iwl_calc_rssi(priv, phy_res);
996
997         /* Meaningful noise values are available only from beacon statistics,
998          *   which are gathered only when associated, and indicate noise
999          *   only for the associated network channel ...
1000          * Ignore these noise values while scanning (other channels) */
1001         if (iwl_is_associated(priv) &&
1002             !test_bit(STATUS_SCANNING, &priv->status)) {
1003                 rx_status.noise = priv->last_rx_noise;
1004                 rx_status.qual = iwl_calc_sig_qual(rx_status.signal,
1005                                                          rx_status.noise);
1006         } else {
1007                 rx_status.noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
1008                 rx_status.qual = iwl_calc_sig_qual(rx_status.signal, 0);
1009         }
1010
1011         /* Reset beacon noise level if not associated. */
1012         if (!iwl_is_associated(priv))
1013                 priv->last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
1014
1015 #ifdef CONFIG_IWLWIFI_DEBUG
1016         /* Set "1" to report good data frames in groups of 100 */
1017         if (unlikely(iwl_get_debug_level(priv) & IWL_DL_RX))
1018                 iwl_dbg_report_frame(priv, phy_res, len, header, 1);
1019 #endif
1020         iwl_dbg_log_rx_data_frame(priv, len, header);
1021         IWL_DEBUG_STATS_LIMIT(priv, "Rssi %d, noise %d, qual %d, TSF %llu\n",
1022                 rx_status.signal, rx_status.noise, rx_status.qual,
1023                 (unsigned long long)rx_status.mactime);
1024
1025         /*
1026          * "antenna number"
1027          *
1028          * It seems that the antenna field in the phy flags value
1029          * is actually a bit field. This is undefined by radiotap,
1030          * it wants an actual antenna number but I always get "7"
1031          * for most legacy frames I receive indicating that the
1032          * same frame was received on all three RX chains.
1033          *
1034          * I think this field should be removed in favor of a
1035          * new 802.11n radiotap field "RX chains" that is defined
1036          * as a bitmask.
1037          */
1038         rx_status.antenna =
1039                 le16_to_cpu(phy_res->phy_flags & RX_RES_PHY_FLAGS_ANTENNA_MSK)
1040                 >> RX_RES_PHY_FLAGS_ANTENNA_POS;
1041
1042         /* set the preamble flag if appropriate */
1043         if (phy_res->phy_flags & RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK)
1044                 rx_status.flag |= RX_FLAG_SHORTPRE;
1045
1046         /* Set up the HT phy flags */
1047         if (rate_n_flags & RATE_MCS_HT_MSK)
1048                 rx_status.flag |= RX_FLAG_HT;
1049         if (rate_n_flags & RATE_MCS_HT40_MSK)
1050                 rx_status.flag |= RX_FLAG_40MHZ;
1051         if (rate_n_flags & RATE_MCS_SGI_MSK)
1052                 rx_status.flag |= RX_FLAG_SHORT_GI;
1053
1054         if (iwl_is_network_packet(priv, header)) {
1055                 priv->last_rx_rssi = rx_status.signal;
1056                 priv->last_beacon_time =  priv->ucode_beacon_time;
1057                 priv->last_tsf = le64_to_cpu(phy_res->timestamp);
1058         }
1059
1060         fc = le16_to_cpu(header->frame_control);
1061         switch (fc & IEEE80211_FCTL_FTYPE) {
1062         case IEEE80211_FTYPE_MGMT:
1063         case IEEE80211_FTYPE_DATA:
1064                 if (priv->iw_mode == NL80211_IFTYPE_AP)
1065                         iwl_update_ps_mode(priv, fc  & IEEE80211_FCTL_PM,
1066                                                 header->addr2);
1067                 /* fall through */
1068         default:
1069                 iwl_pass_packet_to_mac80211(priv, header, len, ampdu_status,
1070                                 rxb, &rx_status);
1071                 break;
1072
1073         }
1074 }
1075 EXPORT_SYMBOL(iwl_rx_reply_rx);
1076
1077 /* Cache phy data (Rx signal strength, etc) for HT frame (REPLY_RX_PHY_CMD).
1078  * This will be used later in iwl_rx_reply_rx() for REPLY_RX_MPDU_CMD. */
1079 void iwl_rx_reply_rx_phy(struct iwl_priv *priv,
1080                                     struct iwl_rx_mem_buffer *rxb)
1081 {
1082         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
1083         priv->last_phy_res[0] = 1;
1084         memcpy(&priv->last_phy_res[1], &(pkt->u.raw[0]),
1085                sizeof(struct iwl_rx_phy_res));
1086 }
1087 EXPORT_SYMBOL(iwl_rx_reply_rx_phy);