Linux 3.9-rc8
[firefly-linux-kernel-4.4.55.git] / drivers / net / wireless / ath / wil6210 / txrx.c
1 /*
2  * Copyright (c) 2012 Qualcomm Atheros, Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16
17 #include <linux/kernel.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
20 #include <linux/hardirq.h>
21 #include <net/ieee80211_radiotap.h>
22 #include <linux/if_arp.h>
23 #include <linux/moduleparam.h>
24
25 #include "wil6210.h"
26 #include "wmi.h"
27 #include "txrx.h"
28
29 static bool rtap_include_phy_info;
30 module_param(rtap_include_phy_info, bool, S_IRUGO);
31 MODULE_PARM_DESC(rtap_include_phy_info,
32                  " Include PHY info in the radiotap header, default - no");
33
34 static inline int wil_vring_is_empty(struct vring *vring)
35 {
36         return vring->swhead == vring->swtail;
37 }
38
39 static inline u32 wil_vring_next_tail(struct vring *vring)
40 {
41         return (vring->swtail + 1) % vring->size;
42 }
43
44 static inline void wil_vring_advance_head(struct vring *vring, int n)
45 {
46         vring->swhead = (vring->swhead + n) % vring->size;
47 }
48
49 static inline int wil_vring_is_full(struct vring *vring)
50 {
51         return wil_vring_next_tail(vring) == vring->swhead;
52 }
53 /*
54  * Available space in Tx Vring
55  */
56 static inline int wil_vring_avail_tx(struct vring *vring)
57 {
58         u32 swhead = vring->swhead;
59         u32 swtail = vring->swtail;
60         int used = (vring->size + swhead - swtail) % vring->size;
61
62         return vring->size - used - 1;
63 }
64
65 static int wil_vring_alloc(struct wil6210_priv *wil, struct vring *vring)
66 {
67         struct device *dev = wil_to_dev(wil);
68         size_t sz = vring->size * sizeof(vring->va[0]);
69         uint i;
70
71         BUILD_BUG_ON(sizeof(vring->va[0]) != 32);
72
73         vring->swhead = 0;
74         vring->swtail = 0;
75         vring->ctx = kzalloc(vring->size * sizeof(vring->ctx[0]), GFP_KERNEL);
76         if (!vring->ctx) {
77                 vring->va = NULL;
78                 return -ENOMEM;
79         }
80         /*
81          * vring->va should be aligned on its size rounded up to power of 2
82          * This is granted by the dma_alloc_coherent
83          */
84         vring->va = dma_alloc_coherent(dev, sz, &vring->pa, GFP_KERNEL);
85         if (!vring->va) {
86                 wil_err(wil, "vring_alloc [%d] failed to alloc DMA mem\n",
87                         vring->size);
88                 kfree(vring->ctx);
89                 vring->ctx = NULL;
90                 return -ENOMEM;
91         }
92         /* initially, all descriptors are SW owned
93          * For Tx and Rx, ownership bit is at the same location, thus
94          * we can use any
95          */
96         for (i = 0; i < vring->size; i++) {
97                 volatile struct vring_tx_desc *d = &(vring->va[i].tx);
98                 d->dma.status = TX_DMA_STATUS_DU;
99         }
100
101         wil_dbg_misc(wil, "vring[%d] 0x%p:0x%016llx 0x%p\n", vring->size,
102                      vring->va, (unsigned long long)vring->pa, vring->ctx);
103
104         return 0;
105 }
106
107 static void wil_vring_free(struct wil6210_priv *wil, struct vring *vring,
108                            int tx)
109 {
110         struct device *dev = wil_to_dev(wil);
111         size_t sz = vring->size * sizeof(vring->va[0]);
112
113         while (!wil_vring_is_empty(vring)) {
114                 if (tx) {
115                         volatile struct vring_tx_desc *d =
116                                         &vring->va[vring->swtail].tx;
117                         dma_addr_t pa = d->dma.addr_low |
118                                         ((u64)d->dma.addr_high << 32);
119                         struct sk_buff *skb = vring->ctx[vring->swtail];
120                         if (skb) {
121                                 dma_unmap_single(dev, pa, d->dma.length,
122                                                  DMA_TO_DEVICE);
123                                 dev_kfree_skb_any(skb);
124                                 vring->ctx[vring->swtail] = NULL;
125                         } else {
126                                 dma_unmap_page(dev, pa, d->dma.length,
127                                                DMA_TO_DEVICE);
128                         }
129                         vring->swtail = wil_vring_next_tail(vring);
130                 } else { /* rx */
131                         volatile struct vring_rx_desc *d =
132                                         &vring->va[vring->swtail].rx;
133                         dma_addr_t pa = d->dma.addr_low |
134                                         ((u64)d->dma.addr_high << 32);
135                         struct sk_buff *skb = vring->ctx[vring->swhead];
136                         dma_unmap_single(dev, pa, d->dma.length,
137                                          DMA_FROM_DEVICE);
138                         kfree_skb(skb);
139                         wil_vring_advance_head(vring, 1);
140                 }
141         }
142         dma_free_coherent(dev, sz, (void *)vring->va, vring->pa);
143         kfree(vring->ctx);
144         vring->pa = 0;
145         vring->va = NULL;
146         vring->ctx = NULL;
147 }
148
149 /**
150  * Allocate one skb for Rx VRING
151  *
152  * Safe to call from IRQ
153  */
154 static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
155                                u32 i, int headroom)
156 {
157         struct device *dev = wil_to_dev(wil);
158         unsigned int sz = RX_BUF_LEN;
159         volatile struct vring_rx_desc *d = &(vring->va[i].rx);
160         dma_addr_t pa;
161
162         /* TODO align */
163         struct sk_buff *skb = dev_alloc_skb(sz + headroom);
164         if (unlikely(!skb))
165                 return -ENOMEM;
166
167         skb_reserve(skb, headroom);
168         skb_put(skb, sz);
169
170         pa = dma_map_single(dev, skb->data, skb->len, DMA_FROM_DEVICE);
171         if (unlikely(dma_mapping_error(dev, pa))) {
172                 kfree_skb(skb);
173                 return -ENOMEM;
174         }
175
176         d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
177         d->dma.addr_low = lower_32_bits(pa);
178         d->dma.addr_high = (u16)upper_32_bits(pa);
179         /* ip_length don't care */
180         /* b11 don't care */
181         /* error don't care */
182         d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
183         d->dma.length = sz;
184         vring->ctx[i] = skb;
185
186         return 0;
187 }
188
189 /**
190  * Adds radiotap header
191  *
192  * Any error indicated as "Bad FCS"
193  *
194  * Vendor data for 04:ce:14-1 (Wilocity-1) consists of:
195  *  - Rx descriptor: 32 bytes
196  *  - Phy info
197  */
198 static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
199                                        struct sk_buff *skb,
200                                        volatile struct vring_rx_desc *d)
201 {
202         struct wireless_dev *wdev = wil->wdev;
203         struct wil6210_rtap {
204                 struct ieee80211_radiotap_header rthdr;
205                 /* fields should be in the order of bits in rthdr.it_present */
206                 /* flags */
207                 u8 flags;
208                 /* channel */
209                 __le16 chnl_freq __aligned(2);
210                 __le16 chnl_flags;
211                 /* MCS */
212                 u8 mcs_present;
213                 u8 mcs_flags;
214                 u8 mcs_index;
215         } __packed;
216         struct wil6210_rtap_vendor {
217                 struct wil6210_rtap rtap;
218                 /* vendor */
219                 u8 vendor_oui[3] __aligned(2);
220                 u8 vendor_ns;
221                 __le16 vendor_skip;
222                 u8 vendor_data[0];
223         } __packed;
224         struct wil6210_rtap_vendor *rtap_vendor;
225         int rtap_len = sizeof(struct wil6210_rtap);
226         int phy_length = 0; /* phy info header size, bytes */
227         static char phy_data[128];
228         struct ieee80211_channel *ch = wdev->preset_chandef.chan;
229
230         if (rtap_include_phy_info) {
231                 rtap_len = sizeof(*rtap_vendor) + sizeof(*d);
232                 /* calculate additional length */
233                 if (d->dma.status & RX_DMA_STATUS_PHY_INFO) {
234                         /**
235                          * PHY info starts from 8-byte boundary
236                          * there are 8-byte lines, last line may be partially
237                          * written (HW bug), thus FW configures for last line
238                          * to be excessive. Driver skips this last line.
239                          */
240                         int len = min_t(int, 8 + sizeof(phy_data),
241                                         wil_rxdesc_phy_length(d));
242                         if (len > 8) {
243                                 void *p = skb_tail_pointer(skb);
244                                 void *pa = PTR_ALIGN(p, 8);
245                                 if (skb_tailroom(skb) >= len + (pa - p)) {
246                                         phy_length = len - 8;
247                                         memcpy(phy_data, pa, phy_length);
248                                 }
249                         }
250                 }
251                 rtap_len += phy_length;
252         }
253
254         if (skb_headroom(skb) < rtap_len &&
255             pskb_expand_head(skb, rtap_len, 0, GFP_ATOMIC)) {
256                 wil_err(wil, "Unable to expand headrom to %d\n", rtap_len);
257                 return;
258         }
259
260         rtap_vendor = (void *)skb_push(skb, rtap_len);
261         memset(rtap_vendor, 0, rtap_len);
262
263         rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;
264         rtap_vendor->rtap.rthdr.it_len = cpu_to_le16(rtap_len);
265         rtap_vendor->rtap.rthdr.it_present = cpu_to_le32(
266                         (1 << IEEE80211_RADIOTAP_FLAGS) |
267                         (1 << IEEE80211_RADIOTAP_CHANNEL) |
268                         (1 << IEEE80211_RADIOTAP_MCS));
269         if (d->dma.status & RX_DMA_STATUS_ERROR)
270                 rtap_vendor->rtap.flags |= IEEE80211_RADIOTAP_F_BADFCS;
271
272         rtap_vendor->rtap.chnl_freq = cpu_to_le16(ch ? ch->center_freq : 58320);
273         rtap_vendor->rtap.chnl_flags = cpu_to_le16(0);
274
275         rtap_vendor->rtap.mcs_present = IEEE80211_RADIOTAP_MCS_HAVE_MCS;
276         rtap_vendor->rtap.mcs_flags = 0;
277         rtap_vendor->rtap.mcs_index = wil_rxdesc_mcs(d);
278
279         if (rtap_include_phy_info) {
280                 rtap_vendor->rtap.rthdr.it_present |= cpu_to_le32(1 <<
281                                 IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
282                 /* OUI for Wilocity 04:ce:14 */
283                 rtap_vendor->vendor_oui[0] = 0x04;
284                 rtap_vendor->vendor_oui[1] = 0xce;
285                 rtap_vendor->vendor_oui[2] = 0x14;
286                 rtap_vendor->vendor_ns = 1;
287                 /* Rx descriptor + PHY data  */
288                 rtap_vendor->vendor_skip = cpu_to_le16(sizeof(*d) +
289                                                        phy_length);
290                 memcpy(rtap_vendor->vendor_data, (void *)d, sizeof(*d));
291                 memcpy(rtap_vendor->vendor_data + sizeof(*d), phy_data,
292                        phy_length);
293         }
294 }
295
296 /*
297  * Fast swap in place between 2 registers
298  */
299 static void wil_swap_u16(u16 *a, u16 *b)
300 {
301         *a ^= *b;
302         *b ^= *a;
303         *a ^= *b;
304 }
305
306 static void wil_swap_ethaddr(void *data)
307 {
308         struct ethhdr *eth = data;
309         u16 *s = (u16 *)eth->h_source;
310         u16 *d = (u16 *)eth->h_dest;
311
312         wil_swap_u16(s++, d++);
313         wil_swap_u16(s++, d++);
314         wil_swap_u16(s, d);
315 }
316
317 /**
318  * reap 1 frame from @swhead
319  *
320  * Safe to call from IRQ
321  */
322 static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
323                                          struct vring *vring)
324 {
325         struct device *dev = wil_to_dev(wil);
326         struct net_device *ndev = wil_to_ndev(wil);
327         volatile struct vring_rx_desc *d;
328         struct sk_buff *skb;
329         dma_addr_t pa;
330         unsigned int sz = RX_BUF_LEN;
331         u8 ftype;
332         u8 ds_bits;
333
334         if (wil_vring_is_empty(vring))
335                 return NULL;
336
337         d = &(vring->va[vring->swhead].rx);
338         if (!(d->dma.status & RX_DMA_STATUS_DU)) {
339                 /* it is not error, we just reached end of Rx done area */
340                 return NULL;
341         }
342
343         pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
344         skb = vring->ctx[vring->swhead];
345         dma_unmap_single(dev, pa, sz, DMA_FROM_DEVICE);
346         skb_trim(skb, d->dma.length);
347
348         wil->stats.last_mcs_rx = wil_rxdesc_mcs(d);
349
350         /* use radiotap header only if required */
351         if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
352                 wil_rx_add_radiotap_header(wil, skb, d);
353
354         wil_dbg_txrx(wil, "Rx[%3d] : %d bytes\n", vring->swhead, d->dma.length);
355         wil_hex_dump_txrx("Rx ", DUMP_PREFIX_NONE, 32, 4,
356                           (const void *)d, sizeof(*d), false);
357
358         wil_vring_advance_head(vring, 1);
359
360         /* no extra checks if in sniffer mode */
361         if (ndev->type != ARPHRD_ETHER)
362                 return skb;
363         /*
364          * Non-data frames may be delivered through Rx DMA channel (ex: BAR)
365          * Driver should recognize it by frame type, that is found
366          * in Rx descriptor. If type is not data, it is 802.11 frame as is
367          */
368         ftype = wil_rxdesc_ftype(d) << 2;
369         if (ftype != IEEE80211_FTYPE_DATA) {
370                 wil_dbg_txrx(wil, "Non-data frame ftype 0x%08x\n", ftype);
371                 /* TODO: process it */
372                 kfree_skb(skb);
373                 return NULL;
374         }
375
376         if (skb->len < ETH_HLEN) {
377                 wil_err(wil, "Short frame, len = %d\n", skb->len);
378                 /* TODO: process it (i.e. BAR) */
379                 kfree_skb(skb);
380                 return NULL;
381         }
382
383         ds_bits = wil_rxdesc_ds_bits(d);
384         if (ds_bits == 1) {
385                 /*
386                  * HW bug - in ToDS mode, i.e. Rx on AP side,
387                  * addresses get swapped
388                  */
389                 wil_swap_ethaddr(skb->data);
390         }
391
392         return skb;
393 }
394
395 /**
396  * allocate and fill up to @count buffers in rx ring
397  * buffers posted at @swtail
398  */
399 static int wil_rx_refill(struct wil6210_priv *wil, int count)
400 {
401         struct net_device *ndev = wil_to_ndev(wil);
402         struct vring *v = &wil->vring_rx;
403         u32 next_tail;
404         int rc = 0;
405         int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
406                         WIL6210_RTAP_SIZE : 0;
407
408         for (; next_tail = wil_vring_next_tail(v),
409                         (next_tail != v->swhead) && (count-- > 0);
410                         v->swtail = next_tail) {
411                 rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
412                 if (rc) {
413                         wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
414                                 rc, v->swtail);
415                         break;
416                 }
417         }
418         iowrite32(v->swtail, wil->csr + HOSTADDR(v->hwtail));
419
420         return rc;
421 }
422
423 /*
424  * Pass Rx packet to the netif. Update statistics.
425  */
426 static void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
427 {
428         int rc;
429         unsigned int len = skb->len;
430
431         skb_orphan(skb);
432
433         if (in_interrupt())
434                 rc = netif_rx(skb);
435         else
436                 rc = netif_rx_ni(skb);
437
438         if (likely(rc == NET_RX_SUCCESS)) {
439                 ndev->stats.rx_packets++;
440                 ndev->stats.rx_bytes += len;
441
442         } else {
443                 ndev->stats.rx_dropped++;
444         }
445 }
446
447 /**
448  * Proceed all completed skb's from Rx VRING
449  *
450  * Safe to call from IRQ
451  */
452 void wil_rx_handle(struct wil6210_priv *wil)
453 {
454         struct net_device *ndev = wil_to_ndev(wil);
455         struct vring *v = &wil->vring_rx;
456         struct sk_buff *skb;
457
458         if (!v->va) {
459                 wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
460                 return;
461         }
462         wil_dbg_txrx(wil, "%s()\n", __func__);
463         while (NULL != (skb = wil_vring_reap_rx(wil, v))) {
464                 wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
465                                   skb->data, skb_headlen(skb), false);
466
467                 if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
468                         skb->dev = ndev;
469                         skb_reset_mac_header(skb);
470                         skb->ip_summed = CHECKSUM_UNNECESSARY;
471                         skb->pkt_type = PACKET_OTHERHOST;
472                         skb->protocol = htons(ETH_P_802_2);
473
474                 } else {
475                         skb->protocol = eth_type_trans(skb, ndev);
476                 }
477
478                 wil_netif_rx_any(skb, ndev);
479         }
480         wil_rx_refill(wil, v->size);
481 }
482
483 int wil_rx_init(struct wil6210_priv *wil)
484 {
485         struct vring *vring = &wil->vring_rx;
486         int rc;
487
488         vring->size = WIL6210_RX_RING_SIZE;
489         rc = wil_vring_alloc(wil, vring);
490         if (rc)
491                 return rc;
492
493         rc = wmi_rx_chain_add(wil, vring);
494         if (rc)
495                 goto err_free;
496
497         rc = wil_rx_refill(wil, vring->size);
498         if (rc)
499                 goto err_free;
500
501         return 0;
502  err_free:
503         wil_vring_free(wil, vring, 0);
504
505         return rc;
506 }
507
508 void wil_rx_fini(struct wil6210_priv *wil)
509 {
510         struct vring *vring = &wil->vring_rx;
511
512         if (vring->va)
513                 wil_vring_free(wil, vring, 0);
514 }
515
516 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
517                       int cid, int tid)
518 {
519         int rc;
520         struct wmi_vring_cfg_cmd cmd = {
521                 .action = cpu_to_le32(WMI_VRING_CMD_ADD),
522                 .vring_cfg = {
523                         .tx_sw_ring = {
524                                 .max_mpdu_size = cpu_to_le16(TX_BUF_LEN),
525                         },
526                         .ringid = id,
527                         .cidxtid = (cid & 0xf) | ((tid & 0xf) << 4),
528                         .encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
529                         .mac_ctrl = 0,
530                         .to_resolution = 0,
531                         .agg_max_wsize = 16,
532                         .schd_params = {
533                                 .priority = cpu_to_le16(0),
534                                 .timeslot_us = cpu_to_le16(0xfff),
535                         },
536                 },
537         };
538         struct {
539                 struct wil6210_mbox_hdr_wmi wmi;
540                 struct wmi_vring_cfg_done_event cmd;
541         } __packed reply;
542         struct vring *vring = &wil->vring_tx[id];
543
544         if (vring->va) {
545                 wil_err(wil, "Tx ring [%d] already allocated\n", id);
546                 rc = -EINVAL;
547                 goto out;
548         }
549
550         vring->size = size;
551         rc = wil_vring_alloc(wil, vring);
552         if (rc)
553                 goto out;
554
555         cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
556         cmd.vring_cfg.tx_sw_ring.ring_size = cpu_to_le16(vring->size);
557
558         rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
559                       WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
560         if (rc)
561                 goto out_free;
562
563         if (reply.cmd.status != WMI_VRING_CFG_SUCCESS) {
564                 wil_err(wil, "Tx config failed, status 0x%02x\n",
565                         reply.cmd.status);
566                 rc = -EINVAL;
567                 goto out_free;
568         }
569         vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
570
571         return 0;
572  out_free:
573         wil_vring_free(wil, vring, 1);
574  out:
575
576         return rc;
577 }
578
579 void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
580 {
581         struct vring *vring = &wil->vring_tx[id];
582
583         if (!vring->va)
584                 return;
585
586         wil_vring_free(wil, vring, 1);
587 }
588
589 static struct vring *wil_find_tx_vring(struct wil6210_priv *wil,
590                                        struct sk_buff *skb)
591 {
592         struct vring *v = &wil->vring_tx[0];
593
594         if (v->va)
595                 return v;
596
597         return NULL;
598 }
599
600 static int wil_tx_desc_map(volatile struct vring_tx_desc *d,
601                            dma_addr_t pa, u32 len)
602 {
603         d->dma.addr_low = lower_32_bits(pa);
604         d->dma.addr_high = (u16)upper_32_bits(pa);
605         d->dma.ip_length = 0;
606         /* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
607         d->dma.b11 = 0/*14 | BIT(7)*/;
608         d->dma.error = 0;
609         d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
610         d->dma.length = len;
611         d->dma.d0 = 0;
612         d->mac.d[0] = 0;
613         d->mac.d[1] = 0;
614         d->mac.d[2] = 0;
615         d->mac.ucode_cmd = 0;
616         /* use dst index 0 */
617         d->mac.d[1] |= BIT(MAC_CFG_DESC_TX_1_DST_INDEX_EN_POS) |
618                        (0 << MAC_CFG_DESC_TX_1_DST_INDEX_POS);
619         /* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
620         d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
621                       (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
622
623         return 0;
624 }
625
626 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
627                         struct sk_buff *skb)
628 {
629         struct device *dev = wil_to_dev(wil);
630         volatile struct vring_tx_desc *d;
631         u32 swhead = vring->swhead;
632         int avail = wil_vring_avail_tx(vring);
633         int nr_frags = skb_shinfo(skb)->nr_frags;
634         uint f;
635         int vring_index = vring - wil->vring_tx;
636         uint i = swhead;
637         dma_addr_t pa;
638
639         wil_dbg_txrx(wil, "%s()\n", __func__);
640
641         if (avail < vring->size/8)
642                 netif_tx_stop_all_queues(wil_to_ndev(wil));
643         if (avail < 1 + nr_frags) {
644                 wil_err(wil, "Tx ring full. No space for %d fragments\n",
645                         1 + nr_frags);
646                 return -ENOMEM;
647         }
648         d = &(vring->va[i].tx);
649
650         /* FIXME FW can accept only unicast frames for the peer */
651         memcpy(skb->data, wil->dst_addr[vring_index], ETH_ALEN);
652
653         pa = dma_map_single(dev, skb->data,
654                         skb_headlen(skb), DMA_TO_DEVICE);
655
656         wil_dbg_txrx(wil, "Tx skb %d bytes %p -> %#08llx\n", skb_headlen(skb),
657                      skb->data, (unsigned long long)pa);
658         wil_hex_dump_txrx("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
659                           skb->data, skb_headlen(skb), false);
660
661         if (unlikely(dma_mapping_error(dev, pa)))
662                 return -EINVAL;
663         /* 1-st segment */
664         wil_tx_desc_map(d, pa, skb_headlen(skb));
665         d->mac.d[2] |= ((nr_frags + 1) <<
666                        MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
667         /* middle segments */
668         for (f = 0; f < nr_frags; f++) {
669                 const struct skb_frag_struct *frag =
670                                 &skb_shinfo(skb)->frags[f];
671                 int len = skb_frag_size(frag);
672                 i = (swhead + f + 1) % vring->size;
673                 d = &(vring->va[i].tx);
674                 pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
675                                 DMA_TO_DEVICE);
676                 if (unlikely(dma_mapping_error(dev, pa)))
677                         goto dma_error;
678                 wil_tx_desc_map(d, pa, len);
679                 vring->ctx[i] = NULL;
680         }
681         /* for the last seg only */
682         d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
683         d->dma.d0 |= BIT(9); /* BUG: undocumented bit */
684         d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
685         d->dma.d0 |= (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
686
687         wil_hex_dump_txrx("Tx ", DUMP_PREFIX_NONE, 32, 4,
688                           (const void *)d, sizeof(*d), false);
689
690         /* advance swhead */
691         wil_vring_advance_head(vring, nr_frags + 1);
692         wil_dbg_txrx(wil, "Tx swhead %d -> %d\n", swhead, vring->swhead);
693         iowrite32(vring->swhead, wil->csr + HOSTADDR(vring->hwtail));
694         /* hold reference to skb
695          * to prevent skb release before accounting
696          * in case of immediate "tx done"
697          */
698         vring->ctx[i] = skb_get(skb);
699
700         return 0;
701  dma_error:
702         /* unmap what we have mapped */
703         /* Note: increment @f to operate with positive index */
704         for (f++; f > 0; f--) {
705                 i = (swhead + f) % vring->size;
706                 d = &(vring->va[i].tx);
707                 d->dma.status = TX_DMA_STATUS_DU;
708                 pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
709                 if (vring->ctx[i])
710                         dma_unmap_single(dev, pa, d->dma.length, DMA_TO_DEVICE);
711                 else
712                         dma_unmap_page(dev, pa, d->dma.length, DMA_TO_DEVICE);
713         }
714
715         return -EINVAL;
716 }
717
718
719 netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
720 {
721         struct wil6210_priv *wil = ndev_to_wil(ndev);
722         struct vring *vring;
723         int rc;
724
725         wil_dbg_txrx(wil, "%s()\n", __func__);
726         if (!test_bit(wil_status_fwready, &wil->status)) {
727                 wil_err(wil, "FW not ready\n");
728                 goto drop;
729         }
730         if (!test_bit(wil_status_fwconnected, &wil->status)) {
731                 wil_err(wil, "FW not connected\n");
732                 goto drop;
733         }
734         if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
735                 wil_err(wil, "Xmit in monitor mode not supported\n");
736                 goto drop;
737         }
738         if (skb->protocol == cpu_to_be16(ETH_P_PAE)) {
739                 rc = wmi_tx_eapol(wil, skb);
740         } else {
741                 /* find vring */
742                 vring = wil_find_tx_vring(wil, skb);
743                 if (!vring) {
744                         wil_err(wil, "No Tx VRING available\n");
745                         goto drop;
746                 }
747                 /* set up vring entry */
748                 rc = wil_tx_vring(wil, vring, skb);
749         }
750         switch (rc) {
751         case 0:
752                 /* statistics will be updated on the tx_complete */
753                 dev_kfree_skb_any(skb);
754                 return NETDEV_TX_OK;
755         case -ENOMEM:
756                 return NETDEV_TX_BUSY;
757         default:
758                 break; /* goto drop; */
759         }
760  drop:
761         netif_tx_stop_all_queues(ndev);
762         ndev->stats.tx_dropped++;
763         dev_kfree_skb_any(skb);
764
765         return NET_XMIT_DROP;
766 }
767
768 /**
769  * Clean up transmitted skb's from the Tx VRING
770  *
771  * Safe to call from IRQ
772  */
773 void wil_tx_complete(struct wil6210_priv *wil, int ringid)
774 {
775         struct net_device *ndev = wil_to_ndev(wil);
776         struct device *dev = wil_to_dev(wil);
777         struct vring *vring = &wil->vring_tx[ringid];
778
779         if (!vring->va) {
780                 wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
781                 return;
782         }
783
784         wil_dbg_txrx(wil, "%s(%d)\n", __func__, ringid);
785
786         while (!wil_vring_is_empty(vring)) {
787                 volatile struct vring_tx_desc *d = &vring->va[vring->swtail].tx;
788                 dma_addr_t pa;
789                 struct sk_buff *skb;
790                 if (!(d->dma.status & TX_DMA_STATUS_DU))
791                         break;
792
793                 wil_dbg_txrx(wil,
794                              "Tx[%3d] : %d bytes, status 0x%02x err 0x%02x\n",
795                              vring->swtail, d->dma.length, d->dma.status,
796                              d->dma.error);
797                 wil_hex_dump_txrx("TxC ", DUMP_PREFIX_NONE, 32, 4,
798                                   (const void *)d, sizeof(*d), false);
799
800                 pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
801                 skb = vring->ctx[vring->swtail];
802                 if (skb) {
803                         if (d->dma.error == 0) {
804                                 ndev->stats.tx_packets++;
805                                 ndev->stats.tx_bytes += skb->len;
806                         } else {
807                                 ndev->stats.tx_errors++;
808                         }
809
810                         dma_unmap_single(dev, pa, d->dma.length, DMA_TO_DEVICE);
811                         dev_kfree_skb_any(skb);
812                         vring->ctx[vring->swtail] = NULL;
813                 } else {
814                         dma_unmap_page(dev, pa, d->dma.length, DMA_TO_DEVICE);
815                 }
816                 d->dma.addr_low = 0;
817                 d->dma.addr_high = 0;
818                 d->dma.length = 0;
819                 d->dma.status = TX_DMA_STATUS_DU;
820                 vring->swtail = wil_vring_next_tail(vring);
821         }
822         if (wil_vring_avail_tx(vring) > vring->size/4)
823                 netif_tx_wake_all_queues(wil_to_ndev(wil));
824 }