1 /*
2  * Copyright (c) 2012-2017 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/etherdevice.h>
18 #include <net/ieee80211_radiotap.h>
19 #include <linux/if_arp.h>
20 #include <linux/moduleparam.h>
21 #include <linux/ip.h>
22 #include <linux/ipv6.h>
23 #include <net/ipv6.h>
24 #include <linux/prefetch.h>
25 
26 #include "wil6210.h"
27 #include "wmi.h"
28 #include "txrx.h"
29 #include "trace.h"
30 
31 static bool rtap_include_phy_info;
32 module_param(rtap_include_phy_info, bool, 0444);
33 MODULE_PARM_DESC(rtap_include_phy_info,
34 		 " Include PHY info in the radiotap header, default - no");
35 
36 bool rx_align_2;
37 module_param(rx_align_2, bool, 0444);
38 MODULE_PARM_DESC(rx_align_2, " align Rx buffers on 4*n+2, default - no");
39 
40 bool rx_large_buf;
41 module_param(rx_large_buf, bool, 0444);
42 MODULE_PARM_DESC(rx_large_buf, " allocate 8KB RX buffers, default - no");
43 
44 static inline uint wil_rx_snaplen(void)
45 {
46 	return rx_align_2 ? 6 : 0;
47 }
48 
49 static inline int wil_vring_is_empty(struct vring *vring)
50 {
51 	return vring->swhead == vring->swtail;
52 }
53 
54 static inline u32 wil_vring_next_tail(struct vring *vring)
55 {
56 	return (vring->swtail + 1) % vring->size;
57 }
58 
59 static inline void wil_vring_advance_head(struct vring *vring, int n)
60 {
61 	vring->swhead = (vring->swhead + n) % vring->size;
62 }
63 
64 static inline int wil_vring_is_full(struct vring *vring)
65 {
66 	return wil_vring_next_tail(vring) == vring->swhead;
67 }
68 
69 /* Used space in Tx Vring */
70 static inline int wil_vring_used_tx(struct vring *vring)
71 {
72 	u32 swhead = vring->swhead;
73 	u32 swtail = vring->swtail;
74 	return (vring->size + swhead - swtail) % vring->size;
75 }
76 
77 /* Available space in Tx Vring */
78 static inline int wil_vring_avail_tx(struct vring *vring)
79 {
80 	return vring->size - wil_vring_used_tx(vring) - 1;
81 }
82 
83 /* wil_vring_wmark_low - low watermark for available descriptor space */
84 static inline int wil_vring_wmark_low(struct vring *vring)
85 {
86 	return vring->size/8;
87 }
88 
89 /* wil_vring_wmark_high - high watermark for available descriptor space */
90 static inline int wil_vring_wmark_high(struct vring *vring)
91 {
92 	return vring->size/4;
93 }
94 
95 /* returns true if num avail descriptors is lower than wmark_low */
96 static inline int wil_vring_avail_low(struct vring *vring)
97 {
98 	return wil_vring_avail_tx(vring) < wil_vring_wmark_low(vring);
99 }
100 
101 /* returns true if num avail descriptors is higher than wmark_high */
102 static inline int wil_vring_avail_high(struct vring *vring)
103 {
104 	return wil_vring_avail_tx(vring) > wil_vring_wmark_high(vring);
105 }
106 
107 /* returns true when all tx vrings are empty */
108 bool wil_is_tx_idle(struct wil6210_priv *wil)
109 {
110 	int i;
111 	unsigned long data_comp_to;
112 
113 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
114 		struct vring *vring = &wil->vring_tx[i];
115 		int vring_index = vring - wil->vring_tx;
116 		struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
117 
118 		spin_lock(&txdata->lock);
119 
120 		if (!vring->va || !txdata->enabled) {
121 			spin_unlock(&txdata->lock);
122 			continue;
123 		}
124 
125 		data_comp_to = jiffies + msecs_to_jiffies(
126 					WIL_DATA_COMPLETION_TO_MS);
127 		if (test_bit(wil_status_napi_en, wil->status)) {
128 			while (!wil_vring_is_empty(vring)) {
129 				if (time_after(jiffies, data_comp_to)) {
130 					wil_dbg_pm(wil,
131 						   "TO waiting for idle tx\n");
132 					spin_unlock(&txdata->lock);
133 					return false;
134 				}
135 				wil_dbg_ratelimited(wil,
136 						    "tx vring is not empty -> NAPI\n");
137 				spin_unlock(&txdata->lock);
138 				napi_synchronize(&wil->napi_tx);
139 				msleep(20);
140 				spin_lock(&txdata->lock);
141 				if (!vring->va || !txdata->enabled)
142 					break;
143 			}
144 		}
145 
146 		spin_unlock(&txdata->lock);
147 	}
148 
149 	return true;
150 }
151 
152 /* wil_val_in_range - check if value in [min,max) */
153 static inline bool wil_val_in_range(int val, int min, int max)
154 {
155 	return val >= min && val < max;
156 }
157 
158 static int wil_vring_alloc(struct wil6210_priv *wil, struct vring *vring)
159 {
160 	struct device *dev = wil_to_dev(wil);
161 	size_t sz = vring->size * sizeof(vring->va[0]);
162 	uint i;
163 
164 	wil_dbg_misc(wil, "vring_alloc:\n");
165 
166 	BUILD_BUG_ON(sizeof(vring->va[0]) != 32);
167 
168 	vring->swhead = 0;
169 	vring->swtail = 0;
170 	vring->ctx = kcalloc(vring->size, sizeof(vring->ctx[0]), GFP_KERNEL);
171 	if (!vring->ctx) {
172 		vring->va = NULL;
173 		return -ENOMEM;
174 	}
175 
176 	/* vring->va should be aligned on its size rounded up to power of 2
177 	 * This is granted by the dma_alloc_coherent.
178 	 *
179 	 * HW has limitation that all vrings addresses must share the same
180 	 * upper 16 msb bits part of 48 bits address. To workaround that,
181 	 * if we are using 48 bit addresses switch to 32 bit allocation
182 	 * before allocating vring memory.
183 	 *
184 	 * There's no check for the return value of dma_set_mask_and_coherent,
185 	 * since we assume if we were able to set the mask during
186 	 * initialization in this system it will not fail if we set it again
187 	 */
188 	if (wil->use_extended_dma_addr)
189 		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
190 
191 	vring->va = dma_alloc_coherent(dev, sz, &vring->pa, GFP_KERNEL);
192 	if (!vring->va) {
193 		kfree(vring->ctx);
194 		vring->ctx = NULL;
195 		return -ENOMEM;
196 	}
197 
198 	if (wil->use_extended_dma_addr)
199 		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
200 
201 	/* initially, all descriptors are SW owned
202 	 * For Tx and Rx, ownership bit is at the same location, thus
203 	 * we can use any
204 	 */
205 	for (i = 0; i < vring->size; i++) {
206 		volatile struct vring_tx_desc *_d = &vring->va[i].tx;
207 
208 		_d->dma.status = TX_DMA_STATUS_DU;
209 	}
210 
211 	wil_dbg_misc(wil, "vring[%d] 0x%p:%pad 0x%p\n", vring->size,
212 		     vring->va, &vring->pa, vring->ctx);
213 
214 	return 0;
215 }
216 
217 static void wil_txdesc_unmap(struct device *dev, struct vring_tx_desc *d,
218 			     struct wil_ctx *ctx)
219 {
220 	dma_addr_t pa = wil_desc_addr(&d->dma.addr);
221 	u16 dmalen = le16_to_cpu(d->dma.length);
222 
223 	switch (ctx->mapped_as) {
224 	case wil_mapped_as_single:
225 		dma_unmap_single(dev, pa, dmalen, DMA_TO_DEVICE);
226 		break;
227 	case wil_mapped_as_page:
228 		dma_unmap_page(dev, pa, dmalen, DMA_TO_DEVICE);
229 		break;
230 	default:
231 		break;
232 	}
233 }
234 
235 static void wil_vring_free(struct wil6210_priv *wil, struct vring *vring,
236 			   int tx)
237 {
238 	struct device *dev = wil_to_dev(wil);
239 	size_t sz = vring->size * sizeof(vring->va[0]);
240 
241 	lockdep_assert_held(&wil->mutex);
242 	if (tx) {
243 		int vring_index = vring - wil->vring_tx;
244 
245 		wil_dbg_misc(wil, "free Tx vring %d [%d] 0x%p:%pad 0x%p\n",
246 			     vring_index, vring->size, vring->va,
247 			     &vring->pa, vring->ctx);
248 	} else {
249 		wil_dbg_misc(wil, "free Rx vring [%d] 0x%p:%pad 0x%p\n",
250 			     vring->size, vring->va,
251 			     &vring->pa, vring->ctx);
252 	}
253 
254 	while (!wil_vring_is_empty(vring)) {
255 		dma_addr_t pa;
256 		u16 dmalen;
257 		struct wil_ctx *ctx;
258 
259 		if (tx) {
260 			struct vring_tx_desc dd, *d = &dd;
261 			volatile struct vring_tx_desc *_d =
262 					&vring->va[vring->swtail].tx;
263 
264 			ctx = &vring->ctx[vring->swtail];
265 			if (!ctx) {
266 				wil_dbg_txrx(wil,
267 					     "ctx(%d) was already completed\n",
268 					     vring->swtail);
269 				vring->swtail = wil_vring_next_tail(vring);
270 				continue;
271 			}
272 			*d = *_d;
273 			wil_txdesc_unmap(dev, d, ctx);
274 			if (ctx->skb)
275 				dev_kfree_skb_any(ctx->skb);
276 			vring->swtail = wil_vring_next_tail(vring);
277 		} else { /* rx */
278 			struct vring_rx_desc dd, *d = &dd;
279 			volatile struct vring_rx_desc *_d =
280 					&vring->va[vring->swhead].rx;
281 
282 			ctx = &vring->ctx[vring->swhead];
283 			*d = *_d;
284 			pa = wil_desc_addr(&d->dma.addr);
285 			dmalen = le16_to_cpu(d->dma.length);
286 			dma_unmap_single(dev, pa, dmalen, DMA_FROM_DEVICE);
287 			kfree_skb(ctx->skb);
288 			wil_vring_advance_head(vring, 1);
289 		}
290 	}
291 	dma_free_coherent(dev, sz, (void *)vring->va, vring->pa);
292 	kfree(vring->ctx);
293 	vring->pa = 0;
294 	vring->va = NULL;
295 	vring->ctx = NULL;
296 }
297 
298 /**
299  * Allocate one skb for Rx VRING
300  *
301  * Safe to call from IRQ
302  */
303 static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
304 			       u32 i, int headroom)
305 {
306 	struct device *dev = wil_to_dev(wil);
307 	unsigned int sz = wil->rx_buf_len + ETH_HLEN + wil_rx_snaplen();
308 	struct vring_rx_desc dd, *d = &dd;
309 	volatile struct vring_rx_desc *_d = &vring->va[i].rx;
310 	dma_addr_t pa;
311 	struct sk_buff *skb = dev_alloc_skb(sz + headroom);
312 
313 	if (unlikely(!skb))
314 		return -ENOMEM;
315 
316 	skb_reserve(skb, headroom);
317 	skb_put(skb, sz);
318 
319 	pa = dma_map_single(dev, skb->data, skb->len, DMA_FROM_DEVICE);
320 	if (unlikely(dma_mapping_error(dev, pa))) {
321 		kfree_skb(skb);
322 		return -ENOMEM;
323 	}
324 
325 	d->dma.d0 = RX_DMA_D0_CMD_DMA_RT | RX_DMA_D0_CMD_DMA_IT;
326 	wil_desc_addr_set(&d->dma.addr, pa);
327 	/* ip_length don't care */
328 	/* b11 don't care */
329 	/* error don't care */
330 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
331 	d->dma.length = cpu_to_le16(sz);
332 	*_d = *d;
333 	vring->ctx[i].skb = skb;
334 
335 	return 0;
336 }
337 
338 /**
339  * Adds radiotap header
340  *
341  * Any error indicated as "Bad FCS"
342  *
343  * Vendor data for 04:ce:14-1 (Wilocity-1) consists of:
344  *  - Rx descriptor: 32 bytes
345  *  - Phy info
346  */
347 static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
348 				       struct sk_buff *skb)
349 {
350 	struct wireless_dev *wdev = wil->wdev;
351 	struct wil6210_rtap {
352 		struct ieee80211_radiotap_header rthdr;
353 		/* fields should be in the order of bits in rthdr.it_present */
354 		/* flags */
355 		u8 flags;
356 		/* channel */
357 		__le16 chnl_freq __aligned(2);
358 		__le16 chnl_flags;
359 		/* MCS */
360 		u8 mcs_present;
361 		u8 mcs_flags;
362 		u8 mcs_index;
363 	} __packed;
364 	struct wil6210_rtap_vendor {
365 		struct wil6210_rtap rtap;
366 		/* vendor */
367 		u8 vendor_oui[3] __aligned(2);
368 		u8 vendor_ns;
369 		__le16 vendor_skip;
370 		u8 vendor_data[0];
371 	} __packed;
372 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
373 	struct wil6210_rtap_vendor *rtap_vendor;
374 	int rtap_len = sizeof(struct wil6210_rtap);
375 	int phy_length = 0; /* phy info header size, bytes */
376 	static char phy_data[128];
377 	struct ieee80211_channel *ch = wdev->preset_chandef.chan;
378 
379 	if (rtap_include_phy_info) {
380 		rtap_len = sizeof(*rtap_vendor) + sizeof(*d);
381 		/* calculate additional length */
382 		if (d->dma.status & RX_DMA_STATUS_PHY_INFO) {
383 			/**
384 			 * PHY info starts from 8-byte boundary
385 			 * there are 8-byte lines, last line may be partially
386 			 * written (HW bug), thus FW configures for last line
387 			 * to be excessive. Driver skips this last line.
388 			 */
389 			int len = min_t(int, 8 + sizeof(phy_data),
390 					wil_rxdesc_phy_length(d));
391 
392 			if (len > 8) {
393 				void *p = skb_tail_pointer(skb);
394 				void *pa = PTR_ALIGN(p, 8);
395 
396 				if (skb_tailroom(skb) >= len + (pa - p)) {
397 					phy_length = len - 8;
398 					memcpy(phy_data, pa, phy_length);
399 				}
400 			}
401 		}
402 		rtap_len += phy_length;
403 	}
404 
405 	if (skb_headroom(skb) < rtap_len &&
406 	    pskb_expand_head(skb, rtap_len, 0, GFP_ATOMIC)) {
407 		wil_err(wil, "Unable to expand headroom to %d\n", rtap_len);
408 		return;
409 	}
410 
411 	rtap_vendor = skb_push(skb, rtap_len);
412 	memset(rtap_vendor, 0, rtap_len);
413 
414 	rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;
415 	rtap_vendor->rtap.rthdr.it_len = cpu_to_le16(rtap_len);
416 	rtap_vendor->rtap.rthdr.it_present = cpu_to_le32(
417 			(1 << IEEE80211_RADIOTAP_FLAGS) |
418 			(1 << IEEE80211_RADIOTAP_CHANNEL) |
419 			(1 << IEEE80211_RADIOTAP_MCS));
420 	if (d->dma.status & RX_DMA_STATUS_ERROR)
421 		rtap_vendor->rtap.flags |= IEEE80211_RADIOTAP_F_BADFCS;
422 
423 	rtap_vendor->rtap.chnl_freq = cpu_to_le16(ch ? ch->center_freq : 58320);
424 	rtap_vendor->rtap.chnl_flags = cpu_to_le16(0);
425 
426 	rtap_vendor->rtap.mcs_present = IEEE80211_RADIOTAP_MCS_HAVE_MCS;
427 	rtap_vendor->rtap.mcs_flags = 0;
428 	rtap_vendor->rtap.mcs_index = wil_rxdesc_mcs(d);
429 
430 	if (rtap_include_phy_info) {
431 		rtap_vendor->rtap.rthdr.it_present |= cpu_to_le32(1 <<
432 				IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
433 		/* OUI for Wilocity 04:ce:14 */
434 		rtap_vendor->vendor_oui[0] = 0x04;
435 		rtap_vendor->vendor_oui[1] = 0xce;
436 		rtap_vendor->vendor_oui[2] = 0x14;
437 		rtap_vendor->vendor_ns = 1;
438 		/* Rx descriptor + PHY data  */
439 		rtap_vendor->vendor_skip = cpu_to_le16(sizeof(*d) +
440 						       phy_length);
441 		memcpy(rtap_vendor->vendor_data, (void *)d, sizeof(*d));
442 		memcpy(rtap_vendor->vendor_data + sizeof(*d), phy_data,
443 		       phy_length);
444 	}
445 }
446 
447 /* similar to ieee80211_ version, but FC contain only 1-st byte */
448 static inline int wil_is_back_req(u8 fc)
449 {
450 	return (fc & (IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
451 	       (IEEE80211_FTYPE_CTL | IEEE80211_STYPE_BACK_REQ);
452 }
453 
454 bool wil_is_rx_idle(struct wil6210_priv *wil)
455 {
456 	struct vring_rx_desc *_d;
457 	struct vring *vring = &wil->vring_rx;
458 
459 	_d = (struct vring_rx_desc *)&vring->va[vring->swhead].rx;
460 	if (_d->dma.status & RX_DMA_STATUS_DU)
461 		return false;
462 
463 	return true;
464 }
465 
466 /**
467  * reap 1 frame from @swhead
468  *
469  * Rx descriptor copied to skb->cb
470  *
471  * Safe to call from IRQ
472  */
473 static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
474 					 struct vring *vring)
475 {
476 	struct device *dev = wil_to_dev(wil);
477 	struct net_device *ndev = wil_to_ndev(wil);
478 	volatile struct vring_rx_desc *_d;
479 	struct vring_rx_desc *d;
480 	struct sk_buff *skb;
481 	dma_addr_t pa;
482 	unsigned int snaplen = wil_rx_snaplen();
483 	unsigned int sz = wil->rx_buf_len + ETH_HLEN + snaplen;
484 	u16 dmalen;
485 	u8 ftype;
486 	int cid;
487 	int i;
488 	struct wil_net_stats *stats;
489 
490 	BUILD_BUG_ON(sizeof(struct vring_rx_desc) > sizeof(skb->cb));
491 
492 again:
493 	if (unlikely(wil_vring_is_empty(vring)))
494 		return NULL;
495 
496 	i = (int)vring->swhead;
497 	_d = &vring->va[i].rx;
498 	if (unlikely(!(_d->dma.status & RX_DMA_STATUS_DU))) {
499 		/* it is not error, we just reached end of Rx done area */
500 		return NULL;
501 	}
502 
503 	skb = vring->ctx[i].skb;
504 	vring->ctx[i].skb = NULL;
505 	wil_vring_advance_head(vring, 1);
506 	if (!skb) {
507 		wil_err(wil, "No Rx skb at [%d]\n", i);
508 		goto again;
509 	}
510 	d = wil_skb_rxdesc(skb);
511 	*d = *_d;
512 	pa = wil_desc_addr(&d->dma.addr);
513 
514 	dma_unmap_single(dev, pa, sz, DMA_FROM_DEVICE);
515 	dmalen = le16_to_cpu(d->dma.length);
516 
517 	trace_wil6210_rx(i, d);
518 	wil_dbg_txrx(wil, "Rx[%3d] : %d bytes\n", i, dmalen);
519 	wil_hex_dump_txrx("RxD ", DUMP_PREFIX_NONE, 32, 4,
520 			  (const void *)d, sizeof(*d), false);
521 
522 	cid = wil_rxdesc_cid(d);
523 	stats = &wil->sta[cid].stats;
524 
525 	if (unlikely(dmalen > sz)) {
526 		wil_err(wil, "Rx size too large: %d bytes!\n", dmalen);
527 		stats->rx_large_frame++;
528 		kfree_skb(skb);
529 		goto again;
530 	}
531 	skb_trim(skb, dmalen);
532 
533 	prefetch(skb->data);
534 
535 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
536 			  skb->data, skb_headlen(skb), false);
537 
538 	stats->last_mcs_rx = wil_rxdesc_mcs(d);
539 	if (stats->last_mcs_rx < ARRAY_SIZE(stats->rx_per_mcs))
540 		stats->rx_per_mcs[stats->last_mcs_rx]++;
541 
542 	/* use radiotap header only if required */
543 	if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
544 		wil_rx_add_radiotap_header(wil, skb);
545 
546 	/* no extra checks if in sniffer mode */
547 	if (ndev->type != ARPHRD_ETHER)
548 		return skb;
549 	/* Non-data frames may be delivered through Rx DMA channel (ex: BAR)
550 	 * Driver should recognize it by frame type, that is found
551 	 * in Rx descriptor. If type is not data, it is 802.11 frame as is
552 	 */
553 	ftype = wil_rxdesc_ftype(d) << 2;
554 	if (unlikely(ftype != IEEE80211_FTYPE_DATA)) {
555 		u8 fc1 = wil_rxdesc_fc1(d);
556 		int mid = wil_rxdesc_mid(d);
557 		int tid = wil_rxdesc_tid(d);
558 		u16 seq = wil_rxdesc_seq(d);
559 
560 		wil_dbg_txrx(wil,
561 			     "Non-data frame FC[7:0] 0x%02x MID %d CID %d TID %d Seq 0x%03x\n",
562 			     fc1, mid, cid, tid, seq);
563 		stats->rx_non_data_frame++;
564 		if (wil_is_back_req(fc1)) {
565 			wil_dbg_txrx(wil,
566 				     "BAR: MID %d CID %d TID %d Seq 0x%03x\n",
567 				     mid, cid, tid, seq);
568 			wil_rx_bar(wil, cid, tid, seq);
569 		} else {
570 			/* print again all info. One can enable only this
571 			 * without overhead for printing every Rx frame
572 			 */
573 			wil_dbg_txrx(wil,
574 				     "Unhandled non-data frame FC[7:0] 0x%02x MID %d CID %d TID %d Seq 0x%03x\n",
575 				     fc1, mid, cid, tid, seq);
576 			wil_hex_dump_txrx("RxD ", DUMP_PREFIX_NONE, 32, 4,
577 					  (const void *)d, sizeof(*d), false);
578 			wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
579 					  skb->data, skb_headlen(skb), false);
580 		}
581 		kfree_skb(skb);
582 		goto again;
583 	}
584 
585 	if (unlikely(skb->len < ETH_HLEN + snaplen)) {
586 		wil_err(wil, "Short frame, len = %d\n", skb->len);
587 		stats->rx_short_frame++;
588 		kfree_skb(skb);
589 		goto again;
590 	}
591 
592 	/* L4 IDENT is on when HW calculated checksum, check status
593 	 * and in case of error drop the packet
594 	 * higher stack layers will handle retransmission (if required)
595 	 */
596 	if (likely(d->dma.status & RX_DMA_STATUS_L4I)) {
597 		/* L4 protocol identified, csum calculated */
598 		if (likely((d->dma.error & RX_DMA_ERROR_L4_ERR) == 0))
599 			skb->ip_summed = CHECKSUM_UNNECESSARY;
600 		/* If HW reports bad checksum, let IP stack re-check it
601 		 * For example, HW don't understand Microsoft IP stack that
602 		 * mis-calculates TCP checksum - if it should be 0x0,
603 		 * it writes 0xffff in violation of RFC 1624
604 		 */
605 	}
606 
607 	if (snaplen) {
608 		/* Packet layout
609 		 * +-------+-------+---------+------------+------+
610 		 * | SA(6) | DA(6) | SNAP(6) | ETHTYPE(2) | DATA |
611 		 * +-------+-------+---------+------------+------+
612 		 * Need to remove SNAP, shifting SA and DA forward
613 		 */
614 		memmove(skb->data + snaplen, skb->data, 2 * ETH_ALEN);
615 		skb_pull(skb, snaplen);
616 	}
617 
618 	return skb;
619 }
620 
621 /**
622  * allocate and fill up to @count buffers in rx ring
623  * buffers posted at @swtail
624  */
625 static int wil_rx_refill(struct wil6210_priv *wil, int count)
626 {
627 	struct net_device *ndev = wil_to_ndev(wil);
628 	struct vring *v = &wil->vring_rx;
629 	u32 next_tail;
630 	int rc = 0;
631 	int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
632 			WIL6210_RTAP_SIZE : 0;
633 
634 	for (; next_tail = wil_vring_next_tail(v),
635 			(next_tail != v->swhead) && (count-- > 0);
636 			v->swtail = next_tail) {
637 		rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
638 		if (unlikely(rc)) {
639 			wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
640 				rc, v->swtail);
641 			break;
642 		}
643 	}
644 
645 	/* make sure all writes to descriptors (shared memory) are done before
646 	 * committing them to HW
647 	 */
648 	wmb();
649 
650 	wil_w(wil, v->hwtail, v->swtail);
651 
652 	return rc;
653 }
654 
655 /**
656  * reverse_memcmp - Compare two areas of memory, in reverse order
657  * @cs: One area of memory
658  * @ct: Another area of memory
659  * @count: The size of the area.
660  *
661  * Cut'n'paste from original memcmp (see lib/string.c)
662  * with minimal modifications
663  */
664 static int reverse_memcmp(const void *cs, const void *ct, size_t count)
665 {
666 	const unsigned char *su1, *su2;
667 	int res = 0;
668 
669 	for (su1 = cs + count - 1, su2 = ct + count - 1; count > 0;
670 	     --su1, --su2, count--) {
671 		res = *su1 - *su2;
672 		if (res)
673 			break;
674 	}
675 	return res;
676 }
677 
678 static int wil_rx_crypto_check(struct wil6210_priv *wil, struct sk_buff *skb)
679 {
680 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
681 	int cid = wil_rxdesc_cid(d);
682 	int tid = wil_rxdesc_tid(d);
683 	int key_id = wil_rxdesc_key_id(d);
684 	int mc = wil_rxdesc_mcast(d);
685 	struct wil_sta_info *s = &wil->sta[cid];
686 	struct wil_tid_crypto_rx *c = mc ? &s->group_crypto_rx :
687 				      &s->tid_crypto_rx[tid];
688 	struct wil_tid_crypto_rx_single *cc = &c->key_id[key_id];
689 	const u8 *pn = (u8 *)&d->mac.pn_15_0;
690 
691 	if (!cc->key_set) {
692 		wil_err_ratelimited(wil,
693 				    "Key missing. CID %d TID %d MCast %d KEY_ID %d\n",
694 				    cid, tid, mc, key_id);
695 		return -EINVAL;
696 	}
697 
698 	if (reverse_memcmp(pn, cc->pn, IEEE80211_GCMP_PN_LEN) <= 0) {
699 		wil_err_ratelimited(wil,
700 				    "Replay attack. CID %d TID %d MCast %d KEY_ID %d PN %6phN last %6phN\n",
701 				    cid, tid, mc, key_id, pn, cc->pn);
702 		return -EINVAL;
703 	}
704 	memcpy(cc->pn, pn, IEEE80211_GCMP_PN_LEN);
705 
706 	return 0;
707 }
708 
709 /*
710  * Pass Rx packet to the netif. Update statistics.
711  * Called in softirq context (NAPI poll).
712  */
713 void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
714 {
715 	gro_result_t rc = GRO_NORMAL;
716 	struct wil6210_priv *wil = ndev_to_wil(ndev);
717 	struct wireless_dev *wdev = wil_to_wdev(wil);
718 	unsigned int len = skb->len;
719 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
720 	int cid = wil_rxdesc_cid(d); /* always 0..7, no need to check */
721 	int security = wil_rxdesc_security(d);
722 	struct ethhdr *eth = (void *)skb->data;
723 	/* here looking for DA, not A1, thus Rxdesc's 'mcast' indication
724 	 * is not suitable, need to look at data
725 	 */
726 	int mcast = is_multicast_ether_addr(eth->h_dest);
727 	struct wil_net_stats *stats = &wil->sta[cid].stats;
728 	struct sk_buff *xmit_skb = NULL;
729 	static const char * const gro_res_str[] = {
730 		[GRO_MERGED]		= "GRO_MERGED",
731 		[GRO_MERGED_FREE]	= "GRO_MERGED_FREE",
732 		[GRO_HELD]		= "GRO_HELD",
733 		[GRO_NORMAL]		= "GRO_NORMAL",
734 		[GRO_DROP]		= "GRO_DROP",
735 	};
736 
737 	if (ndev->features & NETIF_F_RXHASH)
738 		/* fake L4 to ensure it won't be re-calculated later
739 		 * set hash to any non-zero value to activate rps
740 		 * mechanism, core will be chosen according
741 		 * to user-level rps configuration.
742 		 */
743 		skb_set_hash(skb, 1, PKT_HASH_TYPE_L4);
744 
745 	skb_orphan(skb);
746 
747 	if (security && (wil_rx_crypto_check(wil, skb) != 0)) {
748 		rc = GRO_DROP;
749 		dev_kfree_skb(skb);
750 		stats->rx_replay++;
751 		goto stats;
752 	}
753 
754 	if (wdev->iftype == NL80211_IFTYPE_AP && !wil->ap_isolate) {
755 		if (mcast) {
756 			/* send multicast frames both to higher layers in
757 			 * local net stack and back to the wireless medium
758 			 */
759 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
760 		} else {
761 			int xmit_cid = wil_find_cid(wil, eth->h_dest);
762 
763 			if (xmit_cid >= 0) {
764 				/* The destination station is associated to
765 				 * this AP (in this VLAN), so send the frame
766 				 * directly to it and do not pass it to local
767 				 * net stack.
768 				 */
769 				xmit_skb = skb;
770 				skb = NULL;
771 			}
772 		}
773 	}
774 	if (xmit_skb) {
775 		/* Send to wireless media and increase priority by 256 to
776 		 * keep the received priority instead of reclassifying
777 		 * the frame (see cfg80211_classify8021d).
778 		 */
779 		xmit_skb->dev = ndev;
780 		xmit_skb->priority += 256;
781 		xmit_skb->protocol = htons(ETH_P_802_3);
782 		skb_reset_network_header(xmit_skb);
783 		skb_reset_mac_header(xmit_skb);
784 		wil_dbg_txrx(wil, "Rx -> Tx %d bytes\n", len);
785 		dev_queue_xmit(xmit_skb);
786 	}
787 
788 	if (skb) { /* deliver to local stack */
789 
790 		skb->protocol = eth_type_trans(skb, ndev);
791 		rc = napi_gro_receive(&wil->napi_rx, skb);
792 		wil_dbg_txrx(wil, "Rx complete %d bytes => %s\n",
793 			     len, gro_res_str[rc]);
794 	}
795 stats:
796 	/* statistics. rc set to GRO_NORMAL for AP bridging */
797 	if (unlikely(rc == GRO_DROP)) {
798 		ndev->stats.rx_dropped++;
799 		stats->rx_dropped++;
800 		wil_dbg_txrx(wil, "Rx drop %d bytes\n", len);
801 	} else {
802 		ndev->stats.rx_packets++;
803 		stats->rx_packets++;
804 		ndev->stats.rx_bytes += len;
805 		stats->rx_bytes += len;
806 		if (mcast)
807 			ndev->stats.multicast++;
808 	}
809 }
810 
811 /**
812  * Proceed all completed skb's from Rx VRING
813  *
814  * Safe to call from NAPI poll, i.e. softirq with interrupts enabled
815  */
816 void wil_rx_handle(struct wil6210_priv *wil, int *quota)
817 {
818 	struct net_device *ndev = wil_to_ndev(wil);
819 	struct vring *v = &wil->vring_rx;
820 	struct sk_buff *skb;
821 
822 	if (unlikely(!v->va)) {
823 		wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
824 		return;
825 	}
826 	wil_dbg_txrx(wil, "rx_handle\n");
827 	while ((*quota > 0) && (NULL != (skb = wil_vring_reap_rx(wil, v)))) {
828 		(*quota)--;
829 
830 		if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
831 			skb->dev = ndev;
832 			skb_reset_mac_header(skb);
833 			skb->ip_summed = CHECKSUM_UNNECESSARY;
834 			skb->pkt_type = PACKET_OTHERHOST;
835 			skb->protocol = htons(ETH_P_802_2);
836 			wil_netif_rx_any(skb, ndev);
837 		} else {
838 			wil_rx_reorder(wil, skb);
839 		}
840 	}
841 	wil_rx_refill(wil, v->size);
842 }
843 
844 static void wil_rx_buf_len_init(struct wil6210_priv *wil)
845 {
846 	wil->rx_buf_len = rx_large_buf ?
847 		WIL_MAX_ETH_MTU : TXRX_BUF_LEN_DEFAULT - WIL_MAX_MPDU_OVERHEAD;
848 	if (mtu_max > wil->rx_buf_len) {
849 		/* do not allow RX buffers to be smaller than mtu_max, for
850 		 * backward compatibility (mtu_max parameter was also used
851 		 * to support receiving large packets)
852 		 */
853 		wil_info(wil, "Override RX buffer to mtu_max(%d)\n", mtu_max);
854 		wil->rx_buf_len = mtu_max;
855 	}
856 }
857 
858 int wil_rx_init(struct wil6210_priv *wil, u16 size)
859 {
860 	struct vring *vring = &wil->vring_rx;
861 	int rc;
862 
863 	wil_dbg_misc(wil, "rx_init\n");
864 
865 	if (vring->va) {
866 		wil_err(wil, "Rx ring already allocated\n");
867 		return -EINVAL;
868 	}
869 
870 	wil_rx_buf_len_init(wil);
871 
872 	vring->size = size;
873 	rc = wil_vring_alloc(wil, vring);
874 	if (rc)
875 		return rc;
876 
877 	rc = wmi_rx_chain_add(wil, vring);
878 	if (rc)
879 		goto err_free;
880 
881 	rc = wil_rx_refill(wil, vring->size);
882 	if (rc)
883 		goto err_free;
884 
885 	return 0;
886  err_free:
887 	wil_vring_free(wil, vring, 0);
888 
889 	return rc;
890 }
891 
892 void wil_rx_fini(struct wil6210_priv *wil)
893 {
894 	struct vring *vring = &wil->vring_rx;
895 
896 	wil_dbg_misc(wil, "rx_fini\n");
897 
898 	if (vring->va)
899 		wil_vring_free(wil, vring, 0);
900 }
901 
902 static inline void wil_tx_data_init(struct vring_tx_data *txdata)
903 {
904 	spin_lock_bh(&txdata->lock);
905 	txdata->dot1x_open = 0;
906 	txdata->enabled = 0;
907 	txdata->idle = 0;
908 	txdata->last_idle = 0;
909 	txdata->begin = 0;
910 	txdata->agg_wsize = 0;
911 	txdata->agg_timeout = 0;
912 	txdata->agg_amsdu = 0;
913 	txdata->addba_in_progress = false;
914 	spin_unlock_bh(&txdata->lock);
915 }
916 
917 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
918 		      int cid, int tid)
919 {
920 	int rc;
921 	struct wmi_vring_cfg_cmd cmd = {
922 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
923 		.vring_cfg = {
924 			.tx_sw_ring = {
925 				.max_mpdu_size =
926 					cpu_to_le16(wil_mtu2macbuf(mtu_max)),
927 				.ring_size = cpu_to_le16(size),
928 			},
929 			.ringid = id,
930 			.cidxtid = mk_cidxtid(cid, tid),
931 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
932 			.mac_ctrl = 0,
933 			.to_resolution = 0,
934 			.agg_max_wsize = 0,
935 			.schd_params = {
936 				.priority = cpu_to_le16(0),
937 				.timeslot_us = cpu_to_le16(0xfff),
938 			},
939 		},
940 	};
941 	struct {
942 		struct wmi_cmd_hdr wmi;
943 		struct wmi_vring_cfg_done_event cmd;
944 	} __packed reply;
945 	struct vring *vring = &wil->vring_tx[id];
946 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
947 
948 	wil_dbg_misc(wil, "vring_init_tx: max_mpdu_size %d\n",
949 		     cmd.vring_cfg.tx_sw_ring.max_mpdu_size);
950 	lockdep_assert_held(&wil->mutex);
951 
952 	if (vring->va) {
953 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
954 		rc = -EINVAL;
955 		goto out;
956 	}
957 
958 	wil_tx_data_init(txdata);
959 	vring->size = size;
960 	rc = wil_vring_alloc(wil, vring);
961 	if (rc)
962 		goto out;
963 
964 	wil->vring2cid_tid[id][0] = cid;
965 	wil->vring2cid_tid[id][1] = tid;
966 
967 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
968 
969 	if (!wil->privacy)
970 		txdata->dot1x_open = true;
971 	rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
972 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
973 	if (rc)
974 		goto out_free;
975 
976 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
977 		wil_err(wil, "Tx config failed, status 0x%02x\n",
978 			reply.cmd.status);
979 		rc = -EINVAL;
980 		goto out_free;
981 	}
982 
983 	spin_lock_bh(&txdata->lock);
984 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
985 	txdata->enabled = 1;
986 	spin_unlock_bh(&txdata->lock);
987 
988 	if (txdata->dot1x_open && (agg_wsize >= 0))
989 		wil_addba_tx_request(wil, id, agg_wsize);
990 
991 	return 0;
992  out_free:
993 	spin_lock_bh(&txdata->lock);
994 	txdata->dot1x_open = false;
995 	txdata->enabled = 0;
996 	spin_unlock_bh(&txdata->lock);
997 	wil_vring_free(wil, vring, 1);
998 	wil->vring2cid_tid[id][0] = WIL6210_MAX_CID;
999 	wil->vring2cid_tid[id][1] = 0;
1000 
1001  out:
1002 
1003 	return rc;
1004 }
1005 
1006 int wil_vring_init_bcast(struct wil6210_priv *wil, int id, int size)
1007 {
1008 	int rc;
1009 	struct wmi_bcast_vring_cfg_cmd cmd = {
1010 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
1011 		.vring_cfg = {
1012 			.tx_sw_ring = {
1013 				.max_mpdu_size =
1014 					cpu_to_le16(wil_mtu2macbuf(mtu_max)),
1015 				.ring_size = cpu_to_le16(size),
1016 			},
1017 			.ringid = id,
1018 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
1019 		},
1020 	};
1021 	struct {
1022 		struct wmi_cmd_hdr wmi;
1023 		struct wmi_vring_cfg_done_event cmd;
1024 	} __packed reply;
1025 	struct vring *vring = &wil->vring_tx[id];
1026 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
1027 
1028 	wil_dbg_misc(wil, "vring_init_bcast: max_mpdu_size %d\n",
1029 		     cmd.vring_cfg.tx_sw_ring.max_mpdu_size);
1030 	lockdep_assert_held(&wil->mutex);
1031 
1032 	if (vring->va) {
1033 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
1034 		rc = -EINVAL;
1035 		goto out;
1036 	}
1037 
1038 	wil_tx_data_init(txdata);
1039 	vring->size = size;
1040 	rc = wil_vring_alloc(wil, vring);
1041 	if (rc)
1042 		goto out;
1043 
1044 	wil->vring2cid_tid[id][0] = WIL6210_MAX_CID; /* CID */
1045 	wil->vring2cid_tid[id][1] = 0; /* TID */
1046 
1047 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
1048 
1049 	if (!wil->privacy)
1050 		txdata->dot1x_open = true;
1051 	rc = wmi_call(wil, WMI_BCAST_VRING_CFG_CMDID, &cmd, sizeof(cmd),
1052 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
1053 	if (rc)
1054 		goto out_free;
1055 
1056 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
1057 		wil_err(wil, "Tx config failed, status 0x%02x\n",
1058 			reply.cmd.status);
1059 		rc = -EINVAL;
1060 		goto out_free;
1061 	}
1062 
1063 	spin_lock_bh(&txdata->lock);
1064 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
1065 	txdata->enabled = 1;
1066 	spin_unlock_bh(&txdata->lock);
1067 
1068 	return 0;
1069  out_free:
1070 	spin_lock_bh(&txdata->lock);
1071 	txdata->enabled = 0;
1072 	txdata->dot1x_open = false;
1073 	spin_unlock_bh(&txdata->lock);
1074 	wil_vring_free(wil, vring, 1);
1075  out:
1076 
1077 	return rc;
1078 }
1079 
1080 void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
1081 {
1082 	struct vring *vring = &wil->vring_tx[id];
1083 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
1084 
1085 	lockdep_assert_held(&wil->mutex);
1086 
1087 	if (!vring->va)
1088 		return;
1089 
1090 	wil_dbg_misc(wil, "vring_fini_tx: id=%d\n", id);
1091 
1092 	spin_lock_bh(&txdata->lock);
1093 	txdata->dot1x_open = false;
1094 	txdata->enabled = 0; /* no Tx can be in progress or start anew */
1095 	spin_unlock_bh(&txdata->lock);
1096 	/* napi_synchronize waits for completion of the current NAPI but will
1097 	 * not prevent the next NAPI run.
1098 	 * Add a memory barrier to guarantee that txdata->enabled is zeroed
1099 	 * before napi_synchronize so that the next scheduled NAPI will not
1100 	 * handle this vring
1101 	 */
1102 	wmb();
1103 	/* make sure NAPI won't touch this vring */
1104 	if (test_bit(wil_status_napi_en, wil->status))
1105 		napi_synchronize(&wil->napi_tx);
1106 
1107 	wil_vring_free(wil, vring, 1);
1108 }
1109 
1110 static struct vring *wil_find_tx_ucast(struct wil6210_priv *wil,
1111 				       struct sk_buff *skb)
1112 {
1113 	int i;
1114 	struct ethhdr *eth = (void *)skb->data;
1115 	int cid = wil_find_cid(wil, eth->h_dest);
1116 
1117 	if (cid < 0)
1118 		return NULL;
1119 
1120 	/* TODO: fix for multiple TID */
1121 	for (i = 0; i < ARRAY_SIZE(wil->vring2cid_tid); i++) {
1122 		if (!wil->vring_tx_data[i].dot1x_open &&
1123 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
1124 			continue;
1125 		if (wil->vring2cid_tid[i][0] == cid) {
1126 			struct vring *v = &wil->vring_tx[i];
1127 			struct vring_tx_data *txdata = &wil->vring_tx_data[i];
1128 
1129 			wil_dbg_txrx(wil, "find_tx_ucast: (%pM) -> [%d]\n",
1130 				     eth->h_dest, i);
1131 			if (v->va && txdata->enabled) {
1132 				return v;
1133 			} else {
1134 				wil_dbg_txrx(wil,
1135 					     "find_tx_ucast: vring[%d] not valid\n",
1136 					     i);
1137 				return NULL;
1138 			}
1139 		}
1140 	}
1141 
1142 	return NULL;
1143 }
1144 
1145 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
1146 			struct sk_buff *skb);
1147 
1148 static struct vring *wil_find_tx_vring_sta(struct wil6210_priv *wil,
1149 					   struct sk_buff *skb)
1150 {
1151 	struct vring *v;
1152 	int i;
1153 	u8 cid;
1154 	struct vring_tx_data *txdata;
1155 
1156 	/* In the STA mode, it is expected to have only 1 VRING
1157 	 * for the AP we connected to.
1158 	 * find 1-st vring eligible for this skb and use it.
1159 	 */
1160 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
1161 		v = &wil->vring_tx[i];
1162 		txdata = &wil->vring_tx_data[i];
1163 		if (!v->va || !txdata->enabled)
1164 			continue;
1165 
1166 		cid = wil->vring2cid_tid[i][0];
1167 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
1168 			continue;
1169 
1170 		if (!wil->vring_tx_data[i].dot1x_open &&
1171 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
1172 			continue;
1173 
1174 		wil_dbg_txrx(wil, "Tx -> ring %d\n", i);
1175 
1176 		return v;
1177 	}
1178 
1179 	wil_dbg_txrx(wil, "Tx while no vrings active?\n");
1180 
1181 	return NULL;
1182 }
1183 
1184 /* Use one of 2 strategies:
1185  *
1186  * 1. New (real broadcast):
1187  *    use dedicated broadcast vring
1188  * 2. Old (pseudo-DMS):
1189  *    Find 1-st vring and return it;
1190  *    duplicate skb and send it to other active vrings;
1191  *    in all cases override dest address to unicast peer's address
1192  * Use old strategy when new is not supported yet:
1193  *  - for PBSS
1194  */
1195 static struct vring *wil_find_tx_bcast_1(struct wil6210_priv *wil,
1196 					 struct sk_buff *skb)
1197 {
1198 	struct vring *v;
1199 	struct vring_tx_data *txdata;
1200 	int i = wil->bcast_vring;
1201 
1202 	if (i < 0)
1203 		return NULL;
1204 	v = &wil->vring_tx[i];
1205 	txdata = &wil->vring_tx_data[i];
1206 	if (!v->va || !txdata->enabled)
1207 		return NULL;
1208 	if (!wil->vring_tx_data[i].dot1x_open &&
1209 	    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
1210 		return NULL;
1211 
1212 	return v;
1213 }
1214 
1215 static void wil_set_da_for_vring(struct wil6210_priv *wil,
1216 				 struct sk_buff *skb, int vring_index)
1217 {
1218 	struct ethhdr *eth = (void *)skb->data;
1219 	int cid = wil->vring2cid_tid[vring_index][0];
1220 
1221 	ether_addr_copy(eth->h_dest, wil->sta[cid].addr);
1222 }
1223 
1224 static struct vring *wil_find_tx_bcast_2(struct wil6210_priv *wil,
1225 					 struct sk_buff *skb)
1226 {
1227 	struct vring *v, *v2;
1228 	struct sk_buff *skb2;
1229 	int i;
1230 	u8 cid;
1231 	struct ethhdr *eth = (void *)skb->data;
1232 	char *src = eth->h_source;
1233 	struct vring_tx_data *txdata;
1234 
1235 	/* find 1-st vring eligible for data */
1236 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
1237 		v = &wil->vring_tx[i];
1238 		txdata = &wil->vring_tx_data[i];
1239 		if (!v->va || !txdata->enabled)
1240 			continue;
1241 
1242 		cid = wil->vring2cid_tid[i][0];
1243 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
1244 			continue;
1245 		if (!wil->vring_tx_data[i].dot1x_open &&
1246 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
1247 			continue;
1248 
1249 		/* don't Tx back to source when re-routing Rx->Tx at the AP */
1250 		if (0 == memcmp(wil->sta[cid].addr, src, ETH_ALEN))
1251 			continue;
1252 
1253 		goto found;
1254 	}
1255 
1256 	wil_dbg_txrx(wil, "Tx while no vrings active?\n");
1257 
1258 	return NULL;
1259 
1260 found:
1261 	wil_dbg_txrx(wil, "BCAST -> ring %d\n", i);
1262 	wil_set_da_for_vring(wil, skb, i);
1263 
1264 	/* find other active vrings and duplicate skb for each */
1265 	for (i++; i < WIL6210_MAX_TX_RINGS; i++) {
1266 		v2 = &wil->vring_tx[i];
1267 		if (!v2->va)
1268 			continue;
1269 		cid = wil->vring2cid_tid[i][0];
1270 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
1271 			continue;
1272 		if (!wil->vring_tx_data[i].dot1x_open &&
1273 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
1274 			continue;
1275 
1276 		if (0 == memcmp(wil->sta[cid].addr, src, ETH_ALEN))
1277 			continue;
1278 
1279 		skb2 = skb_copy(skb, GFP_ATOMIC);
1280 		if (skb2) {
1281 			wil_dbg_txrx(wil, "BCAST DUP -> ring %d\n", i);
1282 			wil_set_da_for_vring(wil, skb2, i);
1283 			wil_tx_vring(wil, v2, skb2);
1284 		} else {
1285 			wil_err(wil, "skb_copy failed\n");
1286 		}
1287 	}
1288 
1289 	return v;
1290 }
1291 
1292 static int wil_tx_desc_map(struct vring_tx_desc *d, dma_addr_t pa, u32 len,
1293 			   int vring_index)
1294 {
1295 	wil_desc_addr_set(&d->dma.addr, pa);
1296 	d->dma.ip_length = 0;
1297 	/* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
1298 	d->dma.b11 = 0/*14 | BIT(7)*/;
1299 	d->dma.error = 0;
1300 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
1301 	d->dma.length = cpu_to_le16((u16)len);
1302 	d->dma.d0 = (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
1303 	d->mac.d[0] = 0;
1304 	d->mac.d[1] = 0;
1305 	d->mac.d[2] = 0;
1306 	d->mac.ucode_cmd = 0;
1307 	/* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
1308 	d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
1309 		      (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
1310 
1311 	return 0;
1312 }
1313 
1314 static inline
1315 void wil_tx_desc_set_nr_frags(struct vring_tx_desc *d, int nr_frags)
1316 {
1317 	d->mac.d[2] |= (nr_frags << MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
1318 }
1319 
1320 /**
1321  * Sets the descriptor @d up for csum and/or TSO offloading. The corresponding
1322  * @skb is used to obtain the protocol and headers length.
1323  * @tso_desc_type is a descriptor type for TSO: 0 - a header, 1 - first data,
1324  * 2 - middle, 3 - last descriptor.
1325  */
1326 
1327 static void wil_tx_desc_offload_setup_tso(struct vring_tx_desc *d,
1328 					  struct sk_buff *skb,
1329 					  int tso_desc_type, bool is_ipv4,
1330 					  int tcp_hdr_len, int skb_net_hdr_len)
1331 {
1332 	d->dma.b11 = ETH_HLEN; /* MAC header length */
1333 	d->dma.b11 |= is_ipv4 << DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS;
1334 
1335 	d->dma.d0 |= (2 << DMA_CFG_DESC_TX_0_L4_TYPE_POS);
1336 	/* L4 header len: TCP header length */
1337 	d->dma.d0 |= (tcp_hdr_len & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1338 
1339 	/* Setup TSO: bit and desc type */
1340 	d->dma.d0 |= (BIT(DMA_CFG_DESC_TX_0_TCP_SEG_EN_POS)) |
1341 		(tso_desc_type << DMA_CFG_DESC_TX_0_SEGMENT_BUF_DETAILS_POS);
1342 	d->dma.d0 |= (is_ipv4 << DMA_CFG_DESC_TX_0_IPV4_CHECKSUM_EN_POS);
1343 
1344 	d->dma.ip_length = skb_net_hdr_len;
1345 	/* Enable TCP/UDP checksum */
1346 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_TCP_UDP_CHECKSUM_EN_POS);
1347 	/* Calculate pseudo-header */
1348 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_PSEUDO_HEADER_CALC_EN_POS);
1349 }
1350 
1351 /**
1352  * Sets the descriptor @d up for csum. The corresponding
1353  * @skb is used to obtain the protocol and headers length.
1354  * Returns the protocol: 0 - not TCP, 1 - TCPv4, 2 - TCPv6.
1355  * Note, if d==NULL, the function only returns the protocol result.
1356  *
1357  * It is very similar to previous wil_tx_desc_offload_setup_tso. This
1358  * is "if unrolling" to optimize the critical path.
1359  */
1360 
1361 static int wil_tx_desc_offload_setup(struct vring_tx_desc *d,
1362 				     struct sk_buff *skb){
1363 	int protocol;
1364 
1365 	if (skb->ip_summed != CHECKSUM_PARTIAL)
1366 		return 0;
1367 
1368 	d->dma.b11 = ETH_HLEN; /* MAC header length */
1369 
1370 	switch (skb->protocol) {
1371 	case cpu_to_be16(ETH_P_IP):
1372 		protocol = ip_hdr(skb)->protocol;
1373 		d->dma.b11 |= BIT(DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS);
1374 		break;
1375 	case cpu_to_be16(ETH_P_IPV6):
1376 		protocol = ipv6_hdr(skb)->nexthdr;
1377 		break;
1378 	default:
1379 		return -EINVAL;
1380 	}
1381 
1382 	switch (protocol) {
1383 	case IPPROTO_TCP:
1384 		d->dma.d0 |= (2 << DMA_CFG_DESC_TX_0_L4_TYPE_POS);
1385 		/* L4 header len: TCP header length */
1386 		d->dma.d0 |=
1387 		(tcp_hdrlen(skb) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1388 		break;
1389 	case IPPROTO_UDP:
1390 		/* L4 header len: UDP header length */
1391 		d->dma.d0 |=
1392 		(sizeof(struct udphdr) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1393 		break;
1394 	default:
1395 		return -EINVAL;
1396 	}
1397 
1398 	d->dma.ip_length = skb_network_header_len(skb);
1399 	/* Enable TCP/UDP checksum */
1400 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_TCP_UDP_CHECKSUM_EN_POS);
1401 	/* Calculate pseudo-header */
1402 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_PSEUDO_HEADER_CALC_EN_POS);
1403 
1404 	return 0;
1405 }
1406 
1407 static inline void wil_tx_last_desc(struct vring_tx_desc *d)
1408 {
1409 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS) |
1410 	      BIT(DMA_CFG_DESC_TX_0_CMD_MARK_WB_POS) |
1411 	      BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
1412 }
1413 
1414 static inline void wil_set_tx_desc_last_tso(volatile struct vring_tx_desc *d)
1415 {
1416 	d->dma.d0 |= wil_tso_type_lst <<
1417 		  DMA_CFG_DESC_TX_0_SEGMENT_BUF_DETAILS_POS;
1418 }
1419 
1420 static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
1421 			      struct sk_buff *skb)
1422 {
1423 	struct device *dev = wil_to_dev(wil);
1424 
1425 	/* point to descriptors in shared memory */
1426 	volatile struct vring_tx_desc *_desc = NULL, *_hdr_desc,
1427 				      *_first_desc = NULL;
1428 
1429 	/* pointers to shadow descriptors */
1430 	struct vring_tx_desc desc_mem, hdr_desc_mem, first_desc_mem,
1431 			     *d = &hdr_desc_mem, *hdr_desc = &hdr_desc_mem,
1432 			     *first_desc = &first_desc_mem;
1433 
1434 	/* pointer to shadow descriptors' context */
1435 	struct wil_ctx *hdr_ctx, *first_ctx = NULL;
1436 
1437 	int descs_used = 0; /* total number of used descriptors */
1438 	int sg_desc_cnt = 0; /* number of descriptors for current mss*/
1439 
1440 	u32 swhead = vring->swhead;
1441 	int used, avail = wil_vring_avail_tx(vring);
1442 	int nr_frags = skb_shinfo(skb)->nr_frags;
1443 	int min_desc_required = nr_frags + 1;
1444 	int mss = skb_shinfo(skb)->gso_size;	/* payload size w/o headers */
1445 	int f, len, hdrlen, headlen;
1446 	int vring_index = vring - wil->vring_tx;
1447 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1448 	uint i = swhead;
1449 	dma_addr_t pa;
1450 	const skb_frag_t *frag = NULL;
1451 	int rem_data = mss;
1452 	int lenmss;
1453 	int hdr_compensation_need = true;
1454 	int desc_tso_type = wil_tso_type_first;
1455 	bool is_ipv4;
1456 	int tcp_hdr_len;
1457 	int skb_net_hdr_len;
1458 	int gso_type;
1459 	int rc = -EINVAL;
1460 
1461 	wil_dbg_txrx(wil, "tx_vring_tso: %d bytes to vring %d\n", skb->len,
1462 		     vring_index);
1463 
1464 	if (unlikely(!txdata->enabled))
1465 		return -EINVAL;
1466 
1467 	/* A typical page 4K is 3-4 payloads, we assume each fragment
1468 	 * is a full payload, that's how min_desc_required has been
1469 	 * calculated. In real we might need more or less descriptors,
1470 	 * this is the initial check only.
1471 	 */
1472 	if (unlikely(avail < min_desc_required)) {
1473 		wil_err_ratelimited(wil,
1474 				    "TSO: Tx ring[%2d] full. No space for %d fragments\n",
1475 				    vring_index, min_desc_required);
1476 		return -ENOMEM;
1477 	}
1478 
1479 	/* Header Length = MAC header len + IP header len + TCP header len*/
1480 	hdrlen = ETH_HLEN +
1481 		(int)skb_network_header_len(skb) +
1482 		tcp_hdrlen(skb);
1483 
1484 	gso_type = skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV6 | SKB_GSO_TCPV4);
1485 	switch (gso_type) {
1486 	case SKB_GSO_TCPV4:
1487 		/* TCP v4, zero out the IP length and IPv4 checksum fields
1488 		 * as required by the offloading doc
1489 		 */
1490 		ip_hdr(skb)->tot_len = 0;
1491 		ip_hdr(skb)->check = 0;
1492 		is_ipv4 = true;
1493 		break;
1494 	case SKB_GSO_TCPV6:
1495 		/* TCP v6, zero out the payload length */
1496 		ipv6_hdr(skb)->payload_len = 0;
1497 		is_ipv4 = false;
1498 		break;
1499 	default:
1500 		/* other than TCPv4 or TCPv6 types are not supported for TSO.
1501 		 * It is also illegal for both to be set simultaneously
1502 		 */
1503 		return -EINVAL;
1504 	}
1505 
1506 	if (skb->ip_summed != CHECKSUM_PARTIAL)
1507 		return -EINVAL;
1508 
1509 	/* tcp header length and skb network header length are fixed for all
1510 	 * packet's descriptors - read then once here
1511 	 */
1512 	tcp_hdr_len = tcp_hdrlen(skb);
1513 	skb_net_hdr_len = skb_network_header_len(skb);
1514 
1515 	_hdr_desc = &vring->va[i].tx;
1516 
1517 	pa = dma_map_single(dev, skb->data, hdrlen, DMA_TO_DEVICE);
1518 	if (unlikely(dma_mapping_error(dev, pa))) {
1519 		wil_err(wil, "TSO: Skb head DMA map error\n");
1520 		goto err_exit;
1521 	}
1522 
1523 	wil_tx_desc_map(hdr_desc, pa, hdrlen, vring_index);
1524 	wil_tx_desc_offload_setup_tso(hdr_desc, skb, wil_tso_type_hdr, is_ipv4,
1525 				      tcp_hdr_len, skb_net_hdr_len);
1526 	wil_tx_last_desc(hdr_desc);
1527 
1528 	vring->ctx[i].mapped_as = wil_mapped_as_single;
1529 	hdr_ctx = &vring->ctx[i];
1530 
1531 	descs_used++;
1532 	headlen = skb_headlen(skb) - hdrlen;
1533 
1534 	for (f = headlen ? -1 : 0; f < nr_frags; f++)  {
1535 		if (headlen) {
1536 			len = headlen;
1537 			wil_dbg_txrx(wil, "TSO: process skb head, len %u\n",
1538 				     len);
1539 		} else {
1540 			frag = &skb_shinfo(skb)->frags[f];
1541 			len = frag->size;
1542 			wil_dbg_txrx(wil, "TSO: frag[%d]: len %u\n", f, len);
1543 		}
1544 
1545 		while (len) {
1546 			wil_dbg_txrx(wil,
1547 				     "TSO: len %d, rem_data %d, descs_used %d\n",
1548 				     len, rem_data, descs_used);
1549 
1550 			if (descs_used == avail)  {
1551 				wil_err_ratelimited(wil, "TSO: ring overflow\n");
1552 				rc = -ENOMEM;
1553 				goto mem_error;
1554 			}
1555 
1556 			lenmss = min_t(int, rem_data, len);
1557 			i = (swhead + descs_used) % vring->size;
1558 			wil_dbg_txrx(wil, "TSO: lenmss %d, i %d\n", lenmss, i);
1559 
1560 			if (!headlen) {
1561 				pa = skb_frag_dma_map(dev, frag,
1562 						      frag->size - len, lenmss,
1563 						      DMA_TO_DEVICE);
1564 				vring->ctx[i].mapped_as = wil_mapped_as_page;
1565 			} else {
1566 				pa = dma_map_single(dev,
1567 						    skb->data +
1568 						    skb_headlen(skb) - headlen,
1569 						    lenmss,
1570 						    DMA_TO_DEVICE);
1571 				vring->ctx[i].mapped_as = wil_mapped_as_single;
1572 				headlen -= lenmss;
1573 			}
1574 
1575 			if (unlikely(dma_mapping_error(dev, pa))) {
1576 				wil_err(wil, "TSO: DMA map page error\n");
1577 				goto mem_error;
1578 			}
1579 
1580 			_desc = &vring->va[i].tx;
1581 
1582 			if (!_first_desc) {
1583 				_first_desc = _desc;
1584 				first_ctx = &vring->ctx[i];
1585 				d = first_desc;
1586 			} else {
1587 				d = &desc_mem;
1588 			}
1589 
1590 			wil_tx_desc_map(d, pa, lenmss, vring_index);
1591 			wil_tx_desc_offload_setup_tso(d, skb, desc_tso_type,
1592 						      is_ipv4, tcp_hdr_len,
1593 						      skb_net_hdr_len);
1594 
1595 			/* use tso_type_first only once */
1596 			desc_tso_type = wil_tso_type_mid;
1597 
1598 			descs_used++;  /* desc used so far */
1599 			sg_desc_cnt++; /* desc used for this segment */
1600 			len -= lenmss;
1601 			rem_data -= lenmss;
1602 
1603 			wil_dbg_txrx(wil,
1604 				     "TSO: len %d, rem_data %d, descs_used %d, sg_desc_cnt %d,\n",
1605 				     len, rem_data, descs_used, sg_desc_cnt);
1606 
1607 			/* Close the segment if reached mss size or last frag*/
1608 			if (rem_data == 0 || (f == nr_frags - 1 && len == 0)) {
1609 				if (hdr_compensation_need) {
1610 					/* first segment include hdr desc for
1611 					 * release
1612 					 */
1613 					hdr_ctx->nr_frags = sg_desc_cnt;
1614 					wil_tx_desc_set_nr_frags(first_desc,
1615 								 sg_desc_cnt +
1616 								 1);
1617 					hdr_compensation_need = false;
1618 				} else {
1619 					wil_tx_desc_set_nr_frags(first_desc,
1620 								 sg_desc_cnt);
1621 				}
1622 				first_ctx->nr_frags = sg_desc_cnt - 1;
1623 
1624 				wil_tx_last_desc(d);
1625 
1626 				/* first descriptor may also be the last
1627 				 * for this mss - make sure not to copy
1628 				 * it twice
1629 				 */
1630 				if (first_desc != d)
1631 					*_first_desc = *first_desc;
1632 
1633 				/*last descriptor will be copied at the end
1634 				 * of this TS processing
1635 				 */
1636 				if (f < nr_frags - 1 || len > 0)
1637 					*_desc = *d;
1638 
1639 				rem_data = mss;
1640 				_first_desc = NULL;
1641 				sg_desc_cnt = 0;
1642 			} else if (first_desc != d) /* update mid descriptor */
1643 					*_desc = *d;
1644 		}
1645 	}
1646 
1647 	/* first descriptor may also be the last.
1648 	 * in this case d pointer is invalid
1649 	 */
1650 	if (_first_desc == _desc)
1651 		d = first_desc;
1652 
1653 	/* Last data descriptor */
1654 	wil_set_tx_desc_last_tso(d);
1655 	*_desc = *d;
1656 
1657 	/* Fill the total number of descriptors in first desc (hdr)*/
1658 	wil_tx_desc_set_nr_frags(hdr_desc, descs_used);
1659 	*_hdr_desc = *hdr_desc;
1660 
1661 	/* hold reference to skb
1662 	 * to prevent skb release before accounting
1663 	 * in case of immediate "tx done"
1664 	 */
1665 	vring->ctx[i].skb = skb_get(skb);
1666 
1667 	/* performance monitoring */
1668 	used = wil_vring_used_tx(vring);
1669 	if (wil_val_in_range(wil->vring_idle_trsh,
1670 			     used, used + descs_used)) {
1671 		txdata->idle += get_cycles() - txdata->last_idle;
1672 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
1673 			     vring_index, used, used + descs_used);
1674 	}
1675 
1676 	/* Make sure to advance the head only after descriptor update is done.
1677 	 * This will prevent a race condition where the completion thread
1678 	 * will see the DU bit set from previous run and will handle the
1679 	 * skb before it was completed.
1680 	 */
1681 	wmb();
1682 
1683 	/* advance swhead */
1684 	wil_vring_advance_head(vring, descs_used);
1685 	wil_dbg_txrx(wil, "TSO: Tx swhead %d -> %d\n", swhead, vring->swhead);
1686 
1687 	/* make sure all writes to descriptors (shared memory) are done before
1688 	 * committing them to HW
1689 	 */
1690 	wmb();
1691 
1692 	wil_w(wil, vring->hwtail, vring->swhead);
1693 	return 0;
1694 
1695 mem_error:
1696 	while (descs_used > 0) {
1697 		struct wil_ctx *ctx;
1698 
1699 		i = (swhead + descs_used - 1) % vring->size;
1700 		d = (struct vring_tx_desc *)&vring->va[i].tx;
1701 		_desc = &vring->va[i].tx;
1702 		*d = *_desc;
1703 		_desc->dma.status = TX_DMA_STATUS_DU;
1704 		ctx = &vring->ctx[i];
1705 		wil_txdesc_unmap(dev, d, ctx);
1706 		memset(ctx, 0, sizeof(*ctx));
1707 		descs_used--;
1708 	}
1709 err_exit:
1710 	return rc;
1711 }
1712 
1713 static int __wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
1714 			  struct sk_buff *skb)
1715 {
1716 	struct device *dev = wil_to_dev(wil);
1717 	struct vring_tx_desc dd, *d = &dd;
1718 	volatile struct vring_tx_desc *_d;
1719 	u32 swhead = vring->swhead;
1720 	int avail = wil_vring_avail_tx(vring);
1721 	int nr_frags = skb_shinfo(skb)->nr_frags;
1722 	uint f = 0;
1723 	int vring_index = vring - wil->vring_tx;
1724 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1725 	uint i = swhead;
1726 	dma_addr_t pa;
1727 	int used;
1728 	bool mcast = (vring_index == wil->bcast_vring);
1729 	uint len = skb_headlen(skb);
1730 
1731 	wil_dbg_txrx(wil, "tx_vring: %d bytes to vring %d\n", skb->len,
1732 		     vring_index);
1733 
1734 	if (unlikely(!txdata->enabled))
1735 		return -EINVAL;
1736 
1737 	if (unlikely(avail < 1 + nr_frags)) {
1738 		wil_err_ratelimited(wil,
1739 				    "Tx ring[%2d] full. No space for %d fragments\n",
1740 				    vring_index, 1 + nr_frags);
1741 		return -ENOMEM;
1742 	}
1743 	_d = &vring->va[i].tx;
1744 
1745 	pa = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
1746 
1747 	wil_dbg_txrx(wil, "Tx[%2d] skb %d bytes 0x%p -> %pad\n", vring_index,
1748 		     skb_headlen(skb), skb->data, &pa);
1749 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
1750 			  skb->data, skb_headlen(skb), false);
1751 
1752 	if (unlikely(dma_mapping_error(dev, pa)))
1753 		return -EINVAL;
1754 	vring->ctx[i].mapped_as = wil_mapped_as_single;
1755 	/* 1-st segment */
1756 	wil_tx_desc_map(d, pa, len, vring_index);
1757 	if (unlikely(mcast)) {
1758 		d->mac.d[0] |= BIT(MAC_CFG_DESC_TX_0_MCS_EN_POS); /* MCS 0 */
1759 		if (unlikely(len > WIL_BCAST_MCS0_LIMIT)) /* set MCS 1 */
1760 			d->mac.d[0] |= (1 << MAC_CFG_DESC_TX_0_MCS_INDEX_POS);
1761 	}
1762 	/* Process TCP/UDP checksum offloading */
1763 	if (unlikely(wil_tx_desc_offload_setup(d, skb))) {
1764 		wil_err(wil, "Tx[%2d] Failed to set cksum, drop packet\n",
1765 			vring_index);
1766 		goto dma_error;
1767 	}
1768 
1769 	vring->ctx[i].nr_frags = nr_frags;
1770 	wil_tx_desc_set_nr_frags(d, nr_frags + 1);
1771 
1772 	/* middle segments */
1773 	for (; f < nr_frags; f++) {
1774 		const struct skb_frag_struct *frag =
1775 				&skb_shinfo(skb)->frags[f];
1776 		int len = skb_frag_size(frag);
1777 
1778 		*_d = *d;
1779 		wil_dbg_txrx(wil, "Tx[%2d] desc[%4d]\n", vring_index, i);
1780 		wil_hex_dump_txrx("TxD ", DUMP_PREFIX_NONE, 32, 4,
1781 				  (const void *)d, sizeof(*d), false);
1782 		i = (swhead + f + 1) % vring->size;
1783 		_d = &vring->va[i].tx;
1784 		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
1785 				      DMA_TO_DEVICE);
1786 		if (unlikely(dma_mapping_error(dev, pa))) {
1787 			wil_err(wil, "Tx[%2d] failed to map fragment\n",
1788 				vring_index);
1789 			goto dma_error;
1790 		}
1791 		vring->ctx[i].mapped_as = wil_mapped_as_page;
1792 		wil_tx_desc_map(d, pa, len, vring_index);
1793 		/* no need to check return code -
1794 		 * if it succeeded for 1-st descriptor,
1795 		 * it will succeed here too
1796 		 */
1797 		wil_tx_desc_offload_setup(d, skb);
1798 	}
1799 	/* for the last seg only */
1800 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
1801 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_MARK_WB_POS);
1802 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
1803 	*_d = *d;
1804 	wil_dbg_txrx(wil, "Tx[%2d] desc[%4d]\n", vring_index, i);
1805 	wil_hex_dump_txrx("TxD ", DUMP_PREFIX_NONE, 32, 4,
1806 			  (const void *)d, sizeof(*d), false);
1807 
1808 	/* hold reference to skb
1809 	 * to prevent skb release before accounting
1810 	 * in case of immediate "tx done"
1811 	 */
1812 	vring->ctx[i].skb = skb_get(skb);
1813 
1814 	/* performance monitoring */
1815 	used = wil_vring_used_tx(vring);
1816 	if (wil_val_in_range(wil->vring_idle_trsh,
1817 			     used, used + nr_frags + 1)) {
1818 		txdata->idle += get_cycles() - txdata->last_idle;
1819 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
1820 			     vring_index, used, used + nr_frags + 1);
1821 	}
1822 
1823 	/* Make sure to advance the head only after descriptor update is done.
1824 	 * This will prevent a race condition where the completion thread
1825 	 * will see the DU bit set from previous run and will handle the
1826 	 * skb before it was completed.
1827 	 */
1828 	wmb();
1829 
1830 	/* advance swhead */
1831 	wil_vring_advance_head(vring, nr_frags + 1);
1832 	wil_dbg_txrx(wil, "Tx[%2d] swhead %d -> %d\n", vring_index, swhead,
1833 		     vring->swhead);
1834 	trace_wil6210_tx(vring_index, swhead, skb->len, nr_frags);
1835 
1836 	/* make sure all writes to descriptors (shared memory) are done before
1837 	 * committing them to HW
1838 	 */
1839 	wmb();
1840 
1841 	wil_w(wil, vring->hwtail, vring->swhead);
1842 
1843 	return 0;
1844  dma_error:
1845 	/* unmap what we have mapped */
1846 	nr_frags = f + 1; /* frags mapped + one for skb head */
1847 	for (f = 0; f < nr_frags; f++) {
1848 		struct wil_ctx *ctx;
1849 
1850 		i = (swhead + f) % vring->size;
1851 		ctx = &vring->ctx[i];
1852 		_d = &vring->va[i].tx;
1853 		*d = *_d;
1854 		_d->dma.status = TX_DMA_STATUS_DU;
1855 		wil_txdesc_unmap(dev, d, ctx);
1856 
1857 		memset(ctx, 0, sizeof(*ctx));
1858 	}
1859 
1860 	return -EINVAL;
1861 }
1862 
1863 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
1864 			struct sk_buff *skb)
1865 {
1866 	int vring_index = vring - wil->vring_tx;
1867 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1868 	int rc;
1869 
1870 	spin_lock(&txdata->lock);
1871 
1872 	if (test_bit(wil_status_suspending, wil->status) ||
1873 	    test_bit(wil_status_suspended, wil->status) ||
1874 	    test_bit(wil_status_resuming, wil->status)) {
1875 		wil_dbg_txrx(wil,
1876 			     "suspend/resume in progress. drop packet\n");
1877 		spin_unlock(&txdata->lock);
1878 		return -EINVAL;
1879 	}
1880 
1881 	rc = (skb_is_gso(skb) ? __wil_tx_vring_tso : __wil_tx_vring)
1882 	     (wil, vring, skb);
1883 
1884 	spin_unlock(&txdata->lock);
1885 
1886 	return rc;
1887 }
1888 
1889 /**
1890  * Check status of tx vrings and stop/wake net queues if needed
1891  *
1892  * This function does one of two checks:
1893  * In case check_stop is true, will check if net queues need to be stopped. If
1894  * the conditions for stopping are met, netif_tx_stop_all_queues() is called.
1895  * In case check_stop is false, will check if net queues need to be waked. If
1896  * the conditions for waking are met, netif_tx_wake_all_queues() is called.
1897  * vring is the vring which is currently being modified by either adding
1898  * descriptors (tx) into it or removing descriptors (tx complete) from it. Can
1899  * be null when irrelevant (e.g. connect/disconnect events).
1900  *
1901  * The implementation is to stop net queues if modified vring has low
1902  * descriptor availability. Wake if all vrings are not in low descriptor
1903  * availability and modified vring has high descriptor availability.
1904  */
1905 static inline void __wil_update_net_queues(struct wil6210_priv *wil,
1906 					   struct vring *vring,
1907 					   bool check_stop)
1908 {
1909 	int i;
1910 
1911 	if (vring)
1912 		wil_dbg_txrx(wil, "vring %d, check_stop=%d, stopped=%d",
1913 			     (int)(vring - wil->vring_tx), check_stop,
1914 			     wil->net_queue_stopped);
1915 	else
1916 		wil_dbg_txrx(wil, "check_stop=%d, stopped=%d",
1917 			     check_stop, wil->net_queue_stopped);
1918 
1919 	if (check_stop == wil->net_queue_stopped)
1920 		/* net queues already in desired state */
1921 		return;
1922 
1923 	if (check_stop) {
1924 		if (!vring || unlikely(wil_vring_avail_low(vring))) {
1925 			/* not enough room in the vring */
1926 			netif_tx_stop_all_queues(wil_to_ndev(wil));
1927 			wil->net_queue_stopped = true;
1928 			wil_dbg_txrx(wil, "netif_tx_stop called\n");
1929 		}
1930 		return;
1931 	}
1932 
1933 	/* Do not wake the queues in suspend flow */
1934 	if (test_bit(wil_status_suspending, wil->status) ||
1935 	    test_bit(wil_status_suspended, wil->status))
1936 		return;
1937 
1938 	/* check wake */
1939 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
1940 		struct vring *cur_vring = &wil->vring_tx[i];
1941 		struct vring_tx_data *txdata = &wil->vring_tx_data[i];
1942 
1943 		if (!cur_vring->va || !txdata->enabled || cur_vring == vring)
1944 			continue;
1945 
1946 		if (wil_vring_avail_low(cur_vring)) {
1947 			wil_dbg_txrx(wil, "vring %d full, can't wake\n",
1948 				     (int)(cur_vring - wil->vring_tx));
1949 			return;
1950 		}
1951 	}
1952 
1953 	if (!vring || wil_vring_avail_high(vring)) {
1954 		/* enough room in the vring */
1955 		wil_dbg_txrx(wil, "calling netif_tx_wake\n");
1956 		netif_tx_wake_all_queues(wil_to_ndev(wil));
1957 		wil->net_queue_stopped = false;
1958 	}
1959 }
1960 
1961 void wil_update_net_queues(struct wil6210_priv *wil, struct vring *vring,
1962 			   bool check_stop)
1963 {
1964 	spin_lock(&wil->net_queue_lock);
1965 	__wil_update_net_queues(wil, vring, check_stop);
1966 	spin_unlock(&wil->net_queue_lock);
1967 }
1968 
1969 void wil_update_net_queues_bh(struct wil6210_priv *wil, struct vring *vring,
1970 			      bool check_stop)
1971 {
1972 	spin_lock_bh(&wil->net_queue_lock);
1973 	__wil_update_net_queues(wil, vring, check_stop);
1974 	spin_unlock_bh(&wil->net_queue_lock);
1975 }
1976 
1977 netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
1978 {
1979 	struct wil6210_priv *wil = ndev_to_wil(ndev);
1980 	struct ethhdr *eth = (void *)skb->data;
1981 	bool bcast = is_multicast_ether_addr(eth->h_dest);
1982 	struct vring *vring;
1983 	static bool pr_once_fw;
1984 	int rc;
1985 
1986 	wil_dbg_txrx(wil, "start_xmit\n");
1987 	if (unlikely(!test_bit(wil_status_fwready, wil->status))) {
1988 		if (!pr_once_fw) {
1989 			wil_err(wil, "FW not ready\n");
1990 			pr_once_fw = true;
1991 		}
1992 		goto drop;
1993 	}
1994 	if (unlikely(!test_bit(wil_status_fwconnected, wil->status))) {
1995 		wil_dbg_ratelimited(wil, "FW not connected, packet dropped\n");
1996 		goto drop;
1997 	}
1998 	if (unlikely(wil->wdev->iftype == NL80211_IFTYPE_MONITOR)) {
1999 		wil_err(wil, "Xmit in monitor mode not supported\n");
2000 		goto drop;
2001 	}
2002 	pr_once_fw = false;
2003 
2004 	/* find vring */
2005 	if (wil->wdev->iftype == NL80211_IFTYPE_STATION && !wil->pbss) {
2006 		/* in STA mode (ESS), all to same VRING (to AP) */
2007 		vring = wil_find_tx_vring_sta(wil, skb);
2008 	} else if (bcast) {
2009 		if (wil->pbss)
2010 			/* in pbss, no bcast VRING - duplicate skb in
2011 			 * all stations VRINGs
2012 			 */
2013 			vring = wil_find_tx_bcast_2(wil, skb);
2014 		else if (wil->wdev->iftype == NL80211_IFTYPE_AP)
2015 			/* AP has a dedicated bcast VRING */
2016 			vring = wil_find_tx_bcast_1(wil, skb);
2017 		else
2018 			/* unexpected combination, fallback to duplicating
2019 			 * the skb in all stations VRINGs
2020 			 */
2021 			vring = wil_find_tx_bcast_2(wil, skb);
2022 	} else {
2023 		/* unicast, find specific VRING by dest. address */
2024 		vring = wil_find_tx_ucast(wil, skb);
2025 	}
2026 	if (unlikely(!vring)) {
2027 		wil_dbg_txrx(wil, "No Tx VRING found for %pM\n", eth->h_dest);
2028 		goto drop;
2029 	}
2030 	/* set up vring entry */
2031 	rc = wil_tx_vring(wil, vring, skb);
2032 
2033 	switch (rc) {
2034 	case 0:
2035 		/* shall we stop net queues? */
2036 		wil_update_net_queues_bh(wil, vring, true);
2037 		/* statistics will be updated on the tx_complete */
2038 		dev_kfree_skb_any(skb);
2039 		return NETDEV_TX_OK;
2040 	case -ENOMEM:
2041 		return NETDEV_TX_BUSY;
2042 	default:
2043 		break; /* goto drop; */
2044 	}
2045  drop:
2046 	ndev->stats.tx_dropped++;
2047 	dev_kfree_skb_any(skb);
2048 
2049 	return NET_XMIT_DROP;
2050 }
2051 
2052 static inline bool wil_need_txstat(struct sk_buff *skb)
2053 {
2054 	struct ethhdr *eth = (void *)skb->data;
2055 
2056 	return is_unicast_ether_addr(eth->h_dest) && skb->sk &&
2057 	       (skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS);
2058 }
2059 
2060 static inline void wil_consume_skb(struct sk_buff *skb, bool acked)
2061 {
2062 	if (unlikely(wil_need_txstat(skb)))
2063 		skb_complete_wifi_ack(skb, acked);
2064 	else
2065 		acked ? dev_consume_skb_any(skb) : dev_kfree_skb_any(skb);
2066 }
2067 
2068 /**
2069  * Clean up transmitted skb's from the Tx VRING
2070  *
2071  * Return number of descriptors cleared
2072  *
2073  * Safe to call from IRQ
2074  */
2075 int wil_tx_complete(struct wil6210_priv *wil, int ringid)
2076 {
2077 	struct net_device *ndev = wil_to_ndev(wil);
2078 	struct device *dev = wil_to_dev(wil);
2079 	struct vring *vring = &wil->vring_tx[ringid];
2080 	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
2081 	int done = 0;
2082 	int cid = wil->vring2cid_tid[ringid][0];
2083 	struct wil_net_stats *stats = NULL;
2084 	volatile struct vring_tx_desc *_d;
2085 	int used_before_complete;
2086 	int used_new;
2087 
2088 	if (unlikely(!vring->va)) {
2089 		wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
2090 		return 0;
2091 	}
2092 
2093 	if (unlikely(!txdata->enabled)) {
2094 		wil_info(wil, "Tx irq[%d]: vring disabled\n", ringid);
2095 		return 0;
2096 	}
2097 
2098 	wil_dbg_txrx(wil, "tx_complete: (%d)\n", ringid);
2099 
2100 	used_before_complete = wil_vring_used_tx(vring);
2101 
2102 	if (cid < WIL6210_MAX_CID)
2103 		stats = &wil->sta[cid].stats;
2104 
2105 	while (!wil_vring_is_empty(vring)) {
2106 		int new_swtail;
2107 		struct wil_ctx *ctx = &vring->ctx[vring->swtail];
2108 		/**
2109 		 * For the fragmented skb, HW will set DU bit only for the
2110 		 * last fragment. look for it.
2111 		 * In TSO the first DU will include hdr desc
2112 		 */
2113 		int lf = (vring->swtail + ctx->nr_frags) % vring->size;
2114 		/* TODO: check we are not past head */
2115 
2116 		_d = &vring->va[lf].tx;
2117 		if (unlikely(!(_d->dma.status & TX_DMA_STATUS_DU)))
2118 			break;
2119 
2120 		new_swtail = (lf + 1) % vring->size;
2121 		while (vring->swtail != new_swtail) {
2122 			struct vring_tx_desc dd, *d = &dd;
2123 			u16 dmalen;
2124 			struct sk_buff *skb;
2125 
2126 			ctx = &vring->ctx[vring->swtail];
2127 			skb = ctx->skb;
2128 			_d = &vring->va[vring->swtail].tx;
2129 
2130 			*d = *_d;
2131 
2132 			dmalen = le16_to_cpu(d->dma.length);
2133 			trace_wil6210_tx_done(ringid, vring->swtail, dmalen,
2134 					      d->dma.error);
2135 			wil_dbg_txrx(wil,
2136 				     "TxC[%2d][%3d] : %d bytes, status 0x%02x err 0x%02x\n",
2137 				     ringid, vring->swtail, dmalen,
2138 				     d->dma.status, d->dma.error);
2139 			wil_hex_dump_txrx("TxCD ", DUMP_PREFIX_NONE, 32, 4,
2140 					  (const void *)d, sizeof(*d), false);
2141 
2142 			wil_txdesc_unmap(dev, d, ctx);
2143 
2144 			if (skb) {
2145 				if (likely(d->dma.error == 0)) {
2146 					ndev->stats.tx_packets++;
2147 					ndev->stats.tx_bytes += skb->len;
2148 					if (stats) {
2149 						stats->tx_packets++;
2150 						stats->tx_bytes += skb->len;
2151 					}
2152 				} else {
2153 					ndev->stats.tx_errors++;
2154 					if (stats)
2155 						stats->tx_errors++;
2156 				}
2157 				wil_consume_skb(skb, d->dma.error == 0);
2158 			}
2159 			memset(ctx, 0, sizeof(*ctx));
2160 			/* Make sure the ctx is zeroed before updating the tail
2161 			 * to prevent a case where wil_tx_vring will see
2162 			 * this descriptor as used and handle it before ctx zero
2163 			 * is completed.
2164 			 */
2165 			wmb();
2166 			/* There is no need to touch HW descriptor:
2167 			 * - ststus bit TX_DMA_STATUS_DU is set by design,
2168 			 *   so hardware will not try to process this desc.,
2169 			 * - rest of descriptor will be initialized on Tx.
2170 			 */
2171 			vring->swtail = wil_vring_next_tail(vring);
2172 			done++;
2173 		}
2174 	}
2175 
2176 	/* performance monitoring */
2177 	used_new = wil_vring_used_tx(vring);
2178 	if (wil_val_in_range(wil->vring_idle_trsh,
2179 			     used_new, used_before_complete)) {
2180 		wil_dbg_txrx(wil, "Ring[%2d] idle %d -> %d\n",
2181 			     ringid, used_before_complete, used_new);
2182 		txdata->last_idle = get_cycles();
2183 	}
2184 
2185 	/* shall we wake net queues? */
2186 	if (done)
2187 		wil_update_net_queues(wil, vring, false);
2188 
2189 	return done;
2190 }
2191