1 /*
2  * Copyright (c) 2012-2015 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, S_IRUGO);
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, S_IRUGO);
38 MODULE_PARM_DESC(rx_align_2, " align Rx buffers on 4*n+2, default - no");
39 
40 static inline uint wil_rx_snaplen(void)
41 {
42 	return rx_align_2 ? 6 : 0;
43 }
44 
45 static inline int wil_vring_is_empty(struct vring *vring)
46 {
47 	return vring->swhead == vring->swtail;
48 }
49 
50 static inline u32 wil_vring_next_tail(struct vring *vring)
51 {
52 	return (vring->swtail + 1) % vring->size;
53 }
54 
55 static inline void wil_vring_advance_head(struct vring *vring, int n)
56 {
57 	vring->swhead = (vring->swhead + n) % vring->size;
58 }
59 
60 static inline int wil_vring_is_full(struct vring *vring)
61 {
62 	return wil_vring_next_tail(vring) == vring->swhead;
63 }
64 
65 /* Used space in Tx Vring */
66 static inline int wil_vring_used_tx(struct vring *vring)
67 {
68 	u32 swhead = vring->swhead;
69 	u32 swtail = vring->swtail;
70 	return (vring->size + swhead - swtail) % vring->size;
71 }
72 
73 /* Available space in Tx Vring */
74 static inline int wil_vring_avail_tx(struct vring *vring)
75 {
76 	return vring->size - wil_vring_used_tx(vring) - 1;
77 }
78 
79 /* wil_vring_wmark_low - low watermark for available descriptor space */
80 static inline int wil_vring_wmark_low(struct vring *vring)
81 {
82 	return vring->size/8;
83 }
84 
85 /* wil_vring_wmark_high - high watermark for available descriptor space */
86 static inline int wil_vring_wmark_high(struct vring *vring)
87 {
88 	return vring->size/4;
89 }
90 
91 /* wil_val_in_range - check if value in [min,max) */
92 static inline bool wil_val_in_range(int val, int min, int max)
93 {
94 	return val >= min && val < max;
95 }
96 
97 static int wil_vring_alloc(struct wil6210_priv *wil, struct vring *vring)
98 {
99 	struct device *dev = wil_to_dev(wil);
100 	size_t sz = vring->size * sizeof(vring->va[0]);
101 	uint i;
102 
103 	wil_dbg_misc(wil, "%s()\n", __func__);
104 
105 	BUILD_BUG_ON(sizeof(vring->va[0]) != 32);
106 
107 	vring->swhead = 0;
108 	vring->swtail = 0;
109 	vring->ctx = kcalloc(vring->size, sizeof(vring->ctx[0]), GFP_KERNEL);
110 	if (!vring->ctx) {
111 		vring->va = NULL;
112 		return -ENOMEM;
113 	}
114 	/* vring->va should be aligned on its size rounded up to power of 2
115 	 * This is granted by the dma_alloc_coherent
116 	 */
117 	vring->va = dma_alloc_coherent(dev, sz, &vring->pa, GFP_KERNEL);
118 	if (!vring->va) {
119 		kfree(vring->ctx);
120 		vring->ctx = NULL;
121 		return -ENOMEM;
122 	}
123 	/* initially, all descriptors are SW owned
124 	 * For Tx and Rx, ownership bit is at the same location, thus
125 	 * we can use any
126 	 */
127 	for (i = 0; i < vring->size; i++) {
128 		volatile struct vring_tx_desc *_d = &vring->va[i].tx;
129 
130 		_d->dma.status = TX_DMA_STATUS_DU;
131 	}
132 
133 	wil_dbg_misc(wil, "vring[%d] 0x%p:%pad 0x%p\n", vring->size,
134 		     vring->va, &vring->pa, vring->ctx);
135 
136 	return 0;
137 }
138 
139 static void wil_txdesc_unmap(struct device *dev, struct vring_tx_desc *d,
140 			     struct wil_ctx *ctx)
141 {
142 	dma_addr_t pa = wil_desc_addr(&d->dma.addr);
143 	u16 dmalen = le16_to_cpu(d->dma.length);
144 
145 	switch (ctx->mapped_as) {
146 	case wil_mapped_as_single:
147 		dma_unmap_single(dev, pa, dmalen, DMA_TO_DEVICE);
148 		break;
149 	case wil_mapped_as_page:
150 		dma_unmap_page(dev, pa, dmalen, DMA_TO_DEVICE);
151 		break;
152 	default:
153 		break;
154 	}
155 }
156 
157 static void wil_vring_free(struct wil6210_priv *wil, struct vring *vring,
158 			   int tx)
159 {
160 	struct device *dev = wil_to_dev(wil);
161 	size_t sz = vring->size * sizeof(vring->va[0]);
162 
163 	if (tx) {
164 		int vring_index = vring - wil->vring_tx;
165 
166 		wil_dbg_misc(wil, "free Tx vring %d [%d] 0x%p:%pad 0x%p\n",
167 			     vring_index, vring->size, vring->va,
168 			     &vring->pa, vring->ctx);
169 	} else {
170 		wil_dbg_misc(wil, "free Rx vring [%d] 0x%p:%pad 0x%p\n",
171 			     vring->size, vring->va,
172 			     &vring->pa, vring->ctx);
173 	}
174 
175 	while (!wil_vring_is_empty(vring)) {
176 		dma_addr_t pa;
177 		u16 dmalen;
178 		struct wil_ctx *ctx;
179 
180 		if (tx) {
181 			struct vring_tx_desc dd, *d = &dd;
182 			volatile struct vring_tx_desc *_d =
183 					&vring->va[vring->swtail].tx;
184 
185 			ctx = &vring->ctx[vring->swtail];
186 			*d = *_d;
187 			wil_txdesc_unmap(dev, d, ctx);
188 			if (ctx->skb)
189 				dev_kfree_skb_any(ctx->skb);
190 			vring->swtail = wil_vring_next_tail(vring);
191 		} else { /* rx */
192 			struct vring_rx_desc dd, *d = &dd;
193 			volatile struct vring_rx_desc *_d =
194 					&vring->va[vring->swhead].rx;
195 
196 			ctx = &vring->ctx[vring->swhead];
197 			*d = *_d;
198 			pa = wil_desc_addr(&d->dma.addr);
199 			dmalen = le16_to_cpu(d->dma.length);
200 			dma_unmap_single(dev, pa, dmalen, DMA_FROM_DEVICE);
201 			kfree_skb(ctx->skb);
202 			wil_vring_advance_head(vring, 1);
203 		}
204 	}
205 	dma_free_coherent(dev, sz, (void *)vring->va, vring->pa);
206 	kfree(vring->ctx);
207 	vring->pa = 0;
208 	vring->va = NULL;
209 	vring->ctx = NULL;
210 }
211 
212 /**
213  * Allocate one skb for Rx VRING
214  *
215  * Safe to call from IRQ
216  */
217 static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
218 			       u32 i, int headroom)
219 {
220 	struct device *dev = wil_to_dev(wil);
221 	unsigned int sz = mtu_max + ETH_HLEN + wil_rx_snaplen();
222 	struct vring_rx_desc dd, *d = &dd;
223 	volatile struct vring_rx_desc *_d = &vring->va[i].rx;
224 	dma_addr_t pa;
225 	struct sk_buff *skb = dev_alloc_skb(sz + headroom);
226 
227 	if (unlikely(!skb))
228 		return -ENOMEM;
229 
230 	skb_reserve(skb, headroom);
231 	skb_put(skb, sz);
232 
233 	pa = dma_map_single(dev, skb->data, skb->len, DMA_FROM_DEVICE);
234 	if (unlikely(dma_mapping_error(dev, pa))) {
235 		kfree_skb(skb);
236 		return -ENOMEM;
237 	}
238 
239 	d->dma.d0 = RX_DMA_D0_CMD_DMA_RT | RX_DMA_D0_CMD_DMA_IT;
240 	wil_desc_addr_set(&d->dma.addr, pa);
241 	/* ip_length don't care */
242 	/* b11 don't care */
243 	/* error don't care */
244 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
245 	d->dma.length = cpu_to_le16(sz);
246 	*_d = *d;
247 	vring->ctx[i].skb = skb;
248 
249 	return 0;
250 }
251 
252 /**
253  * Adds radiotap header
254  *
255  * Any error indicated as "Bad FCS"
256  *
257  * Vendor data for 04:ce:14-1 (Wilocity-1) consists of:
258  *  - Rx descriptor: 32 bytes
259  *  - Phy info
260  */
261 static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
262 				       struct sk_buff *skb)
263 {
264 	struct wireless_dev *wdev = wil->wdev;
265 	struct wil6210_rtap {
266 		struct ieee80211_radiotap_header rthdr;
267 		/* fields should be in the order of bits in rthdr.it_present */
268 		/* flags */
269 		u8 flags;
270 		/* channel */
271 		__le16 chnl_freq __aligned(2);
272 		__le16 chnl_flags;
273 		/* MCS */
274 		u8 mcs_present;
275 		u8 mcs_flags;
276 		u8 mcs_index;
277 	} __packed;
278 	struct wil6210_rtap_vendor {
279 		struct wil6210_rtap rtap;
280 		/* vendor */
281 		u8 vendor_oui[3] __aligned(2);
282 		u8 vendor_ns;
283 		__le16 vendor_skip;
284 		u8 vendor_data[0];
285 	} __packed;
286 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
287 	struct wil6210_rtap_vendor *rtap_vendor;
288 	int rtap_len = sizeof(struct wil6210_rtap);
289 	int phy_length = 0; /* phy info header size, bytes */
290 	static char phy_data[128];
291 	struct ieee80211_channel *ch = wdev->preset_chandef.chan;
292 
293 	if (rtap_include_phy_info) {
294 		rtap_len = sizeof(*rtap_vendor) + sizeof(*d);
295 		/* calculate additional length */
296 		if (d->dma.status & RX_DMA_STATUS_PHY_INFO) {
297 			/**
298 			 * PHY info starts from 8-byte boundary
299 			 * there are 8-byte lines, last line may be partially
300 			 * written (HW bug), thus FW configures for last line
301 			 * to be excessive. Driver skips this last line.
302 			 */
303 			int len = min_t(int, 8 + sizeof(phy_data),
304 					wil_rxdesc_phy_length(d));
305 
306 			if (len > 8) {
307 				void *p = skb_tail_pointer(skb);
308 				void *pa = PTR_ALIGN(p, 8);
309 
310 				if (skb_tailroom(skb) >= len + (pa - p)) {
311 					phy_length = len - 8;
312 					memcpy(phy_data, pa, phy_length);
313 				}
314 			}
315 		}
316 		rtap_len += phy_length;
317 	}
318 
319 	if (skb_headroom(skb) < rtap_len &&
320 	    pskb_expand_head(skb, rtap_len, 0, GFP_ATOMIC)) {
321 		wil_err(wil, "Unable to expand headrom to %d\n", rtap_len);
322 		return;
323 	}
324 
325 	rtap_vendor = (void *)skb_push(skb, rtap_len);
326 	memset(rtap_vendor, 0, rtap_len);
327 
328 	rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;
329 	rtap_vendor->rtap.rthdr.it_len = cpu_to_le16(rtap_len);
330 	rtap_vendor->rtap.rthdr.it_present = cpu_to_le32(
331 			(1 << IEEE80211_RADIOTAP_FLAGS) |
332 			(1 << IEEE80211_RADIOTAP_CHANNEL) |
333 			(1 << IEEE80211_RADIOTAP_MCS));
334 	if (d->dma.status & RX_DMA_STATUS_ERROR)
335 		rtap_vendor->rtap.flags |= IEEE80211_RADIOTAP_F_BADFCS;
336 
337 	rtap_vendor->rtap.chnl_freq = cpu_to_le16(ch ? ch->center_freq : 58320);
338 	rtap_vendor->rtap.chnl_flags = cpu_to_le16(0);
339 
340 	rtap_vendor->rtap.mcs_present = IEEE80211_RADIOTAP_MCS_HAVE_MCS;
341 	rtap_vendor->rtap.mcs_flags = 0;
342 	rtap_vendor->rtap.mcs_index = wil_rxdesc_mcs(d);
343 
344 	if (rtap_include_phy_info) {
345 		rtap_vendor->rtap.rthdr.it_present |= cpu_to_le32(1 <<
346 				IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
347 		/* OUI for Wilocity 04:ce:14 */
348 		rtap_vendor->vendor_oui[0] = 0x04;
349 		rtap_vendor->vendor_oui[1] = 0xce;
350 		rtap_vendor->vendor_oui[2] = 0x14;
351 		rtap_vendor->vendor_ns = 1;
352 		/* Rx descriptor + PHY data  */
353 		rtap_vendor->vendor_skip = cpu_to_le16(sizeof(*d) +
354 						       phy_length);
355 		memcpy(rtap_vendor->vendor_data, (void *)d, sizeof(*d));
356 		memcpy(rtap_vendor->vendor_data + sizeof(*d), phy_data,
357 		       phy_length);
358 	}
359 }
360 
361 /**
362  * reap 1 frame from @swhead
363  *
364  * Rx descriptor copied to skb->cb
365  *
366  * Safe to call from IRQ
367  */
368 static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
369 					 struct vring *vring)
370 {
371 	struct device *dev = wil_to_dev(wil);
372 	struct net_device *ndev = wil_to_ndev(wil);
373 	volatile struct vring_rx_desc *_d;
374 	struct vring_rx_desc *d;
375 	struct sk_buff *skb;
376 	dma_addr_t pa;
377 	unsigned int snaplen = wil_rx_snaplen();
378 	unsigned int sz = mtu_max + ETH_HLEN + snaplen;
379 	u16 dmalen;
380 	u8 ftype;
381 	int cid;
382 	int i = (int)vring->swhead;
383 	struct wil_net_stats *stats;
384 
385 	BUILD_BUG_ON(sizeof(struct vring_rx_desc) > sizeof(skb->cb));
386 
387 	if (unlikely(wil_vring_is_empty(vring)))
388 		return NULL;
389 
390 	_d = &vring->va[i].rx;
391 	if (unlikely(!(_d->dma.status & RX_DMA_STATUS_DU))) {
392 		/* it is not error, we just reached end of Rx done area */
393 		return NULL;
394 	}
395 
396 	skb = vring->ctx[i].skb;
397 	vring->ctx[i].skb = NULL;
398 	wil_vring_advance_head(vring, 1);
399 	if (!skb) {
400 		wil_err(wil, "No Rx skb at [%d]\n", i);
401 		return NULL;
402 	}
403 	d = wil_skb_rxdesc(skb);
404 	*d = *_d;
405 	pa = wil_desc_addr(&d->dma.addr);
406 
407 	dma_unmap_single(dev, pa, sz, DMA_FROM_DEVICE);
408 	dmalen = le16_to_cpu(d->dma.length);
409 
410 	trace_wil6210_rx(i, d);
411 	wil_dbg_txrx(wil, "Rx[%3d] : %d bytes\n", i, dmalen);
412 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_NONE, 32, 4,
413 			  (const void *)d, sizeof(*d), false);
414 
415 	if (unlikely(dmalen > sz)) {
416 		wil_err(wil, "Rx size too large: %d bytes!\n", dmalen);
417 		kfree_skb(skb);
418 		return NULL;
419 	}
420 	skb_trim(skb, dmalen);
421 
422 	prefetch(skb->data);
423 
424 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
425 			  skb->data, skb_headlen(skb), false);
426 
427 	cid = wil_rxdesc_cid(d);
428 	stats = &wil->sta[cid].stats;
429 	stats->last_mcs_rx = wil_rxdesc_mcs(d);
430 	if (stats->last_mcs_rx < ARRAY_SIZE(stats->rx_per_mcs))
431 		stats->rx_per_mcs[stats->last_mcs_rx]++;
432 
433 	/* use radiotap header only if required */
434 	if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
435 		wil_rx_add_radiotap_header(wil, skb);
436 
437 	/* no extra checks if in sniffer mode */
438 	if (ndev->type != ARPHRD_ETHER)
439 		return skb;
440 	/*
441 	 * Non-data frames may be delivered through Rx DMA channel (ex: BAR)
442 	 * Driver should recognize it by frame type, that is found
443 	 * in Rx descriptor. If type is not data, it is 802.11 frame as is
444 	 */
445 	ftype = wil_rxdesc_ftype(d) << 2;
446 	if (unlikely(ftype != IEEE80211_FTYPE_DATA)) {
447 		wil_dbg_txrx(wil, "Non-data frame ftype 0x%08x\n", ftype);
448 		/* TODO: process it */
449 		kfree_skb(skb);
450 		return NULL;
451 	}
452 
453 	if (unlikely(skb->len < ETH_HLEN + snaplen)) {
454 		wil_err(wil, "Short frame, len = %d\n", skb->len);
455 		/* TODO: process it (i.e. BAR) */
456 		kfree_skb(skb);
457 		return NULL;
458 	}
459 
460 	/* L4 IDENT is on when HW calculated checksum, check status
461 	 * and in case of error drop the packet
462 	 * higher stack layers will handle retransmission (if required)
463 	 */
464 	if (likely(d->dma.status & RX_DMA_STATUS_L4I)) {
465 		/* L4 protocol identified, csum calculated */
466 		if (likely((d->dma.error & RX_DMA_ERROR_L4_ERR) == 0))
467 			skb->ip_summed = CHECKSUM_UNNECESSARY;
468 		/* If HW reports bad checksum, let IP stack re-check it
469 		 * For example, HW don't understand Microsoft IP stack that
470 		 * mis-calculates TCP checksum - if it should be 0x0,
471 		 * it writes 0xffff in violation of RFC 1624
472 		 */
473 	}
474 
475 	if (snaplen) {
476 		/* Packet layout
477 		 * +-------+-------+---------+------------+------+
478 		 * | SA(6) | DA(6) | SNAP(6) | ETHTYPE(2) | DATA |
479 		 * +-------+-------+---------+------------+------+
480 		 * Need to remove SNAP, shifting SA and DA forward
481 		 */
482 		memmove(skb->data + snaplen, skb->data, 2 * ETH_ALEN);
483 		skb_pull(skb, snaplen);
484 	}
485 
486 	return skb;
487 }
488 
489 /**
490  * allocate and fill up to @count buffers in rx ring
491  * buffers posted at @swtail
492  */
493 static int wil_rx_refill(struct wil6210_priv *wil, int count)
494 {
495 	struct net_device *ndev = wil_to_ndev(wil);
496 	struct vring *v = &wil->vring_rx;
497 	u32 next_tail;
498 	int rc = 0;
499 	int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
500 			WIL6210_RTAP_SIZE : 0;
501 
502 	for (; next_tail = wil_vring_next_tail(v),
503 			(next_tail != v->swhead) && (count-- > 0);
504 			v->swtail = next_tail) {
505 		rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
506 		if (unlikely(rc)) {
507 			wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
508 				rc, v->swtail);
509 			break;
510 		}
511 	}
512 	wil_w(wil, v->hwtail, v->swtail);
513 
514 	return rc;
515 }
516 
517 /*
518  * Pass Rx packet to the netif. Update statistics.
519  * Called in softirq context (NAPI poll).
520  */
521 void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
522 {
523 	gro_result_t rc = GRO_NORMAL;
524 	struct wil6210_priv *wil = ndev_to_wil(ndev);
525 	struct wireless_dev *wdev = wil_to_wdev(wil);
526 	unsigned int len = skb->len;
527 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
528 	int cid = wil_rxdesc_cid(d); /* always 0..7, no need to check */
529 	struct ethhdr *eth = (void *)skb->data;
530 	/* here looking for DA, not A1, thus Rxdesc's 'mcast' indication
531 	 * is not suitable, need to look at data
532 	 */
533 	int mcast = is_multicast_ether_addr(eth->h_dest);
534 	struct wil_net_stats *stats = &wil->sta[cid].stats;
535 	struct sk_buff *xmit_skb = NULL;
536 	static const char * const gro_res_str[] = {
537 		[GRO_MERGED]		= "GRO_MERGED",
538 		[GRO_MERGED_FREE]	= "GRO_MERGED_FREE",
539 		[GRO_HELD]		= "GRO_HELD",
540 		[GRO_NORMAL]		= "GRO_NORMAL",
541 		[GRO_DROP]		= "GRO_DROP",
542 	};
543 
544 	if (ndev->features & NETIF_F_RXHASH)
545 		/* fake L4 to ensure it won't be re-calculated later
546 		 * set hash to any non-zero value to activate rps
547 		 * mechanism, core will be chosen according
548 		 * to user-level rps configuration.
549 		 */
550 		skb_set_hash(skb, 1, PKT_HASH_TYPE_L4);
551 
552 	skb_orphan(skb);
553 
554 	if (wdev->iftype == NL80211_IFTYPE_AP && !wil->ap_isolate) {
555 		if (mcast) {
556 			/* send multicast frames both to higher layers in
557 			 * local net stack and back to the wireless medium
558 			 */
559 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
560 		} else {
561 			int xmit_cid = wil_find_cid(wil, eth->h_dest);
562 
563 			if (xmit_cid >= 0) {
564 				/* The destination station is associated to
565 				 * this AP (in this VLAN), so send the frame
566 				 * directly to it and do not pass it to local
567 				 * net stack.
568 				 */
569 				xmit_skb = skb;
570 				skb = NULL;
571 			}
572 		}
573 	}
574 	if (xmit_skb) {
575 		/* Send to wireless media and increase priority by 256 to
576 		 * keep the received priority instead of reclassifying
577 		 * the frame (see cfg80211_classify8021d).
578 		 */
579 		xmit_skb->dev = ndev;
580 		xmit_skb->priority += 256;
581 		xmit_skb->protocol = htons(ETH_P_802_3);
582 		skb_reset_network_header(xmit_skb);
583 		skb_reset_mac_header(xmit_skb);
584 		wil_dbg_txrx(wil, "Rx -> Tx %d bytes\n", len);
585 		dev_queue_xmit(xmit_skb);
586 	}
587 
588 	if (skb) { /* deliver to local stack */
589 
590 		skb->protocol = eth_type_trans(skb, ndev);
591 		rc = napi_gro_receive(&wil->napi_rx, skb);
592 		wil_dbg_txrx(wil, "Rx complete %d bytes => %s\n",
593 			     len, gro_res_str[rc]);
594 	}
595 	/* statistics. rc set to GRO_NORMAL for AP bridging */
596 	if (unlikely(rc == GRO_DROP)) {
597 		ndev->stats.rx_dropped++;
598 		stats->rx_dropped++;
599 		wil_dbg_txrx(wil, "Rx drop %d bytes\n", len);
600 	} else {
601 		ndev->stats.rx_packets++;
602 		stats->rx_packets++;
603 		ndev->stats.rx_bytes += len;
604 		stats->rx_bytes += len;
605 		if (mcast)
606 			ndev->stats.multicast++;
607 	}
608 }
609 
610 /**
611  * Proceed all completed skb's from Rx VRING
612  *
613  * Safe to call from NAPI poll, i.e. softirq with interrupts enabled
614  */
615 void wil_rx_handle(struct wil6210_priv *wil, int *quota)
616 {
617 	struct net_device *ndev = wil_to_ndev(wil);
618 	struct vring *v = &wil->vring_rx;
619 	struct sk_buff *skb;
620 
621 	if (unlikely(!v->va)) {
622 		wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
623 		return;
624 	}
625 	wil_dbg_txrx(wil, "%s()\n", __func__);
626 	while ((*quota > 0) && (NULL != (skb = wil_vring_reap_rx(wil, v)))) {
627 		(*quota)--;
628 
629 		if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
630 			skb->dev = ndev;
631 			skb_reset_mac_header(skb);
632 			skb->ip_summed = CHECKSUM_UNNECESSARY;
633 			skb->pkt_type = PACKET_OTHERHOST;
634 			skb->protocol = htons(ETH_P_802_2);
635 			wil_netif_rx_any(skb, ndev);
636 		} else {
637 			wil_rx_reorder(wil, skb);
638 		}
639 	}
640 	wil_rx_refill(wil, v->size);
641 }
642 
643 int wil_rx_init(struct wil6210_priv *wil, u16 size)
644 {
645 	struct vring *vring = &wil->vring_rx;
646 	int rc;
647 
648 	wil_dbg_misc(wil, "%s()\n", __func__);
649 
650 	if (vring->va) {
651 		wil_err(wil, "Rx ring already allocated\n");
652 		return -EINVAL;
653 	}
654 
655 	vring->size = size;
656 	rc = wil_vring_alloc(wil, vring);
657 	if (rc)
658 		return rc;
659 
660 	rc = wmi_rx_chain_add(wil, vring);
661 	if (rc)
662 		goto err_free;
663 
664 	rc = wil_rx_refill(wil, vring->size);
665 	if (rc)
666 		goto err_free;
667 
668 	return 0;
669  err_free:
670 	wil_vring_free(wil, vring, 0);
671 
672 	return rc;
673 }
674 
675 void wil_rx_fini(struct wil6210_priv *wil)
676 {
677 	struct vring *vring = &wil->vring_rx;
678 
679 	wil_dbg_misc(wil, "%s()\n", __func__);
680 
681 	if (vring->va)
682 		wil_vring_free(wil, vring, 0);
683 }
684 
685 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
686 		      int cid, int tid)
687 {
688 	int rc;
689 	struct wmi_vring_cfg_cmd cmd = {
690 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
691 		.vring_cfg = {
692 			.tx_sw_ring = {
693 				.max_mpdu_size =
694 					cpu_to_le16(wil_mtu2macbuf(mtu_max)),
695 				.ring_size = cpu_to_le16(size),
696 			},
697 			.ringid = id,
698 			.cidxtid = mk_cidxtid(cid, tid),
699 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
700 			.mac_ctrl = 0,
701 			.to_resolution = 0,
702 			.agg_max_wsize = 0,
703 			.schd_params = {
704 				.priority = cpu_to_le16(0),
705 				.timeslot_us = cpu_to_le16(0xfff),
706 			},
707 		},
708 	};
709 	struct {
710 		struct wil6210_mbox_hdr_wmi wmi;
711 		struct wmi_vring_cfg_done_event cmd;
712 	} __packed reply;
713 	struct vring *vring = &wil->vring_tx[id];
714 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
715 
716 	wil_dbg_misc(wil, "%s() max_mpdu_size %d\n", __func__,
717 		     cmd.vring_cfg.tx_sw_ring.max_mpdu_size);
718 
719 	if (vring->va) {
720 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
721 		rc = -EINVAL;
722 		goto out;
723 	}
724 
725 	memset(txdata, 0, sizeof(*txdata));
726 	spin_lock_init(&txdata->lock);
727 	vring->size = size;
728 	rc = wil_vring_alloc(wil, vring);
729 	if (rc)
730 		goto out;
731 
732 	wil->vring2cid_tid[id][0] = cid;
733 	wil->vring2cid_tid[id][1] = tid;
734 
735 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
736 
737 	if (!wil->privacy)
738 		txdata->dot1x_open = true;
739 	rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
740 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
741 	if (rc)
742 		goto out_free;
743 
744 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
745 		wil_err(wil, "Tx config failed, status 0x%02x\n",
746 			reply.cmd.status);
747 		rc = -EINVAL;
748 		goto out_free;
749 	}
750 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
751 
752 	txdata->enabled = 1;
753 	if (txdata->dot1x_open && (agg_wsize >= 0))
754 		wil_addba_tx_request(wil, id, agg_wsize);
755 
756 	return 0;
757  out_free:
758 	txdata->dot1x_open = false;
759 	txdata->enabled = 0;
760 	wil_vring_free(wil, vring, 1);
761  out:
762 
763 	return rc;
764 }
765 
766 int wil_vring_init_bcast(struct wil6210_priv *wil, int id, int size)
767 {
768 	int rc;
769 	struct wmi_bcast_vring_cfg_cmd cmd = {
770 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
771 		.vring_cfg = {
772 			.tx_sw_ring = {
773 				.max_mpdu_size =
774 					cpu_to_le16(wil_mtu2macbuf(mtu_max)),
775 				.ring_size = cpu_to_le16(size),
776 			},
777 			.ringid = id,
778 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
779 		},
780 	};
781 	struct {
782 		struct wil6210_mbox_hdr_wmi wmi;
783 		struct wmi_vring_cfg_done_event cmd;
784 	} __packed reply;
785 	struct vring *vring = &wil->vring_tx[id];
786 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
787 
788 	wil_dbg_misc(wil, "%s() max_mpdu_size %d\n", __func__,
789 		     cmd.vring_cfg.tx_sw_ring.max_mpdu_size);
790 
791 	if (vring->va) {
792 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
793 		rc = -EINVAL;
794 		goto out;
795 	}
796 
797 	memset(txdata, 0, sizeof(*txdata));
798 	spin_lock_init(&txdata->lock);
799 	vring->size = size;
800 	rc = wil_vring_alloc(wil, vring);
801 	if (rc)
802 		goto out;
803 
804 	wil->vring2cid_tid[id][0] = WIL6210_MAX_CID; /* CID */
805 	wil->vring2cid_tid[id][1] = 0; /* TID */
806 
807 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
808 
809 	if (!wil->privacy)
810 		txdata->dot1x_open = true;
811 	rc = wmi_call(wil, WMI_BCAST_VRING_CFG_CMDID, &cmd, sizeof(cmd),
812 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
813 	if (rc)
814 		goto out_free;
815 
816 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
817 		wil_err(wil, "Tx config failed, status 0x%02x\n",
818 			reply.cmd.status);
819 		rc = -EINVAL;
820 		goto out_free;
821 	}
822 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
823 
824 	txdata->enabled = 1;
825 
826 	return 0;
827  out_free:
828 	txdata->enabled = 0;
829 	txdata->dot1x_open = false;
830 	wil_vring_free(wil, vring, 1);
831  out:
832 
833 	return rc;
834 }
835 
836 void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
837 {
838 	struct vring *vring = &wil->vring_tx[id];
839 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
840 
841 	WARN_ON(!mutex_is_locked(&wil->mutex));
842 
843 	if (!vring->va)
844 		return;
845 
846 	wil_dbg_misc(wil, "%s() id=%d\n", __func__, id);
847 
848 	spin_lock_bh(&txdata->lock);
849 	txdata->dot1x_open = false;
850 	txdata->enabled = 0; /* no Tx can be in progress or start anew */
851 	spin_unlock_bh(&txdata->lock);
852 	/* make sure NAPI won't touch this vring */
853 	if (test_bit(wil_status_napi_en, wil->status))
854 		napi_synchronize(&wil->napi_tx);
855 
856 	wil_vring_free(wil, vring, 1);
857 	memset(txdata, 0, sizeof(*txdata));
858 }
859 
860 static struct vring *wil_find_tx_ucast(struct wil6210_priv *wil,
861 				       struct sk_buff *skb)
862 {
863 	int i;
864 	struct ethhdr *eth = (void *)skb->data;
865 	int cid = wil_find_cid(wil, eth->h_dest);
866 
867 	if (cid < 0)
868 		return NULL;
869 
870 	/* TODO: fix for multiple TID */
871 	for (i = 0; i < ARRAY_SIZE(wil->vring2cid_tid); i++) {
872 		if (!wil->vring_tx_data[i].dot1x_open &&
873 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
874 			continue;
875 		if (wil->vring2cid_tid[i][0] == cid) {
876 			struct vring *v = &wil->vring_tx[i];
877 
878 			wil_dbg_txrx(wil, "%s(%pM) -> [%d]\n",
879 				     __func__, eth->h_dest, i);
880 			if (v->va) {
881 				return v;
882 			} else {
883 				wil_dbg_txrx(wil, "vring[%d] not valid\n", i);
884 				return NULL;
885 			}
886 		}
887 	}
888 
889 	return NULL;
890 }
891 
892 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
893 			struct sk_buff *skb);
894 
895 static struct vring *wil_find_tx_vring_sta(struct wil6210_priv *wil,
896 					   struct sk_buff *skb)
897 {
898 	struct vring *v;
899 	int i;
900 	u8 cid;
901 
902 	/* In the STA mode, it is expected to have only 1 VRING
903 	 * for the AP we connected to.
904 	 * find 1-st vring eligible for this skb and use it.
905 	 */
906 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
907 		v = &wil->vring_tx[i];
908 		if (!v->va)
909 			continue;
910 
911 		cid = wil->vring2cid_tid[i][0];
912 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
913 			continue;
914 
915 		if (!wil->vring_tx_data[i].dot1x_open &&
916 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
917 			continue;
918 
919 		wil_dbg_txrx(wil, "Tx -> ring %d\n", i);
920 
921 		return v;
922 	}
923 
924 	wil_dbg_txrx(wil, "Tx while no vrings active?\n");
925 
926 	return NULL;
927 }
928 
929 /* Use one of 2 strategies:
930  *
931  * 1. New (real broadcast):
932  *    use dedicated broadcast vring
933  * 2. Old (pseudo-DMS):
934  *    Find 1-st vring and return it;
935  *    duplicate skb and send it to other active vrings;
936  *    in all cases override dest address to unicast peer's address
937  * Use old strategy when new is not supported yet:
938  *  - for PBSS
939  */
940 static struct vring *wil_find_tx_bcast_1(struct wil6210_priv *wil,
941 					 struct sk_buff *skb)
942 {
943 	struct vring *v;
944 	int i = wil->bcast_vring;
945 
946 	if (i < 0)
947 		return NULL;
948 	v = &wil->vring_tx[i];
949 	if (!v->va)
950 		return NULL;
951 	if (!wil->vring_tx_data[i].dot1x_open &&
952 	    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
953 		return NULL;
954 
955 	return v;
956 }
957 
958 static void wil_set_da_for_vring(struct wil6210_priv *wil,
959 				 struct sk_buff *skb, int vring_index)
960 {
961 	struct ethhdr *eth = (void *)skb->data;
962 	int cid = wil->vring2cid_tid[vring_index][0];
963 
964 	ether_addr_copy(eth->h_dest, wil->sta[cid].addr);
965 }
966 
967 static struct vring *wil_find_tx_bcast_2(struct wil6210_priv *wil,
968 					 struct sk_buff *skb)
969 {
970 	struct vring *v, *v2;
971 	struct sk_buff *skb2;
972 	int i;
973 	u8 cid;
974 	struct ethhdr *eth = (void *)skb->data;
975 	char *src = eth->h_source;
976 
977 	/* find 1-st vring eligible for data */
978 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
979 		v = &wil->vring_tx[i];
980 		if (!v->va)
981 			continue;
982 
983 		cid = wil->vring2cid_tid[i][0];
984 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
985 			continue;
986 		if (!wil->vring_tx_data[i].dot1x_open &&
987 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
988 			continue;
989 
990 		/* don't Tx back to source when re-routing Rx->Tx at the AP */
991 		if (0 == memcmp(wil->sta[cid].addr, src, ETH_ALEN))
992 			continue;
993 
994 		goto found;
995 	}
996 
997 	wil_dbg_txrx(wil, "Tx while no vrings active?\n");
998 
999 	return NULL;
1000 
1001 found:
1002 	wil_dbg_txrx(wil, "BCAST -> ring %d\n", i);
1003 	wil_set_da_for_vring(wil, skb, i);
1004 
1005 	/* find other active vrings and duplicate skb for each */
1006 	for (i++; i < WIL6210_MAX_TX_RINGS; i++) {
1007 		v2 = &wil->vring_tx[i];
1008 		if (!v2->va)
1009 			continue;
1010 		cid = wil->vring2cid_tid[i][0];
1011 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
1012 			continue;
1013 		if (!wil->vring_tx_data[i].dot1x_open &&
1014 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
1015 			continue;
1016 
1017 		if (0 == memcmp(wil->sta[cid].addr, src, ETH_ALEN))
1018 			continue;
1019 
1020 		skb2 = skb_copy(skb, GFP_ATOMIC);
1021 		if (skb2) {
1022 			wil_dbg_txrx(wil, "BCAST DUP -> ring %d\n", i);
1023 			wil_set_da_for_vring(wil, skb2, i);
1024 			wil_tx_vring(wil, v2, skb2);
1025 		} else {
1026 			wil_err(wil, "skb_copy failed\n");
1027 		}
1028 	}
1029 
1030 	return v;
1031 }
1032 
1033 static struct vring *wil_find_tx_bcast(struct wil6210_priv *wil,
1034 				       struct sk_buff *skb)
1035 {
1036 	struct wireless_dev *wdev = wil->wdev;
1037 
1038 	if (wdev->iftype != NL80211_IFTYPE_AP)
1039 		return wil_find_tx_bcast_2(wil, skb);
1040 
1041 	return wil_find_tx_bcast_1(wil, skb);
1042 }
1043 
1044 static int wil_tx_desc_map(struct vring_tx_desc *d, dma_addr_t pa, u32 len,
1045 			   int vring_index)
1046 {
1047 	wil_desc_addr_set(&d->dma.addr, pa);
1048 	d->dma.ip_length = 0;
1049 	/* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
1050 	d->dma.b11 = 0/*14 | BIT(7)*/;
1051 	d->dma.error = 0;
1052 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
1053 	d->dma.length = cpu_to_le16((u16)len);
1054 	d->dma.d0 = (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
1055 	d->mac.d[0] = 0;
1056 	d->mac.d[1] = 0;
1057 	d->mac.d[2] = 0;
1058 	d->mac.ucode_cmd = 0;
1059 	/* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
1060 	d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
1061 		      (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
1062 
1063 	return 0;
1064 }
1065 
1066 static inline
1067 void wil_tx_desc_set_nr_frags(struct vring_tx_desc *d, int nr_frags)
1068 {
1069 	d->mac.d[2] |= (nr_frags << MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
1070 }
1071 
1072 /**
1073  * Sets the descriptor @d up for csum and/or TSO offloading. The corresponding
1074  * @skb is used to obtain the protocol and headers length.
1075  * @tso_desc_type is a descriptor type for TSO: 0 - a header, 1 - first data,
1076  * 2 - middle, 3 - last descriptor.
1077  */
1078 
1079 static void wil_tx_desc_offload_setup_tso(struct vring_tx_desc *d,
1080 					  struct sk_buff *skb,
1081 					  int tso_desc_type, bool is_ipv4,
1082 					  int tcp_hdr_len, int skb_net_hdr_len)
1083 {
1084 	d->dma.b11 = ETH_HLEN; /* MAC header length */
1085 	d->dma.b11 |= is_ipv4 << DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS;
1086 
1087 	d->dma.d0 |= (2 << DMA_CFG_DESC_TX_0_L4_TYPE_POS);
1088 	/* L4 header len: TCP header length */
1089 	d->dma.d0 |= (tcp_hdr_len & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1090 
1091 	/* Setup TSO: bit and desc type */
1092 	d->dma.d0 |= (BIT(DMA_CFG_DESC_TX_0_TCP_SEG_EN_POS)) |
1093 		(tso_desc_type << DMA_CFG_DESC_TX_0_SEGMENT_BUF_DETAILS_POS);
1094 	d->dma.d0 |= (is_ipv4 << DMA_CFG_DESC_TX_0_IPV4_CHECKSUM_EN_POS);
1095 
1096 	d->dma.ip_length = skb_net_hdr_len;
1097 	/* Enable TCP/UDP checksum */
1098 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_TCP_UDP_CHECKSUM_EN_POS);
1099 	/* Calculate pseudo-header */
1100 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_PSEUDO_HEADER_CALC_EN_POS);
1101 }
1102 
1103 /**
1104  * Sets the descriptor @d up for csum. The corresponding
1105  * @skb is used to obtain the protocol and headers length.
1106  * Returns the protocol: 0 - not TCP, 1 - TCPv4, 2 - TCPv6.
1107  * Note, if d==NULL, the function only returns the protocol result.
1108  *
1109  * It is very similar to previous wil_tx_desc_offload_setup_tso. This
1110  * is "if unrolling" to optimize the critical path.
1111  */
1112 
1113 static int wil_tx_desc_offload_setup(struct vring_tx_desc *d,
1114 				     struct sk_buff *skb){
1115 	int protocol;
1116 
1117 	if (skb->ip_summed != CHECKSUM_PARTIAL)
1118 		return 0;
1119 
1120 	d->dma.b11 = ETH_HLEN; /* MAC header length */
1121 
1122 	switch (skb->protocol) {
1123 	case cpu_to_be16(ETH_P_IP):
1124 		protocol = ip_hdr(skb)->protocol;
1125 		d->dma.b11 |= BIT(DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS);
1126 		break;
1127 	case cpu_to_be16(ETH_P_IPV6):
1128 		protocol = ipv6_hdr(skb)->nexthdr;
1129 		break;
1130 	default:
1131 		return -EINVAL;
1132 	}
1133 
1134 	switch (protocol) {
1135 	case IPPROTO_TCP:
1136 		d->dma.d0 |= (2 << DMA_CFG_DESC_TX_0_L4_TYPE_POS);
1137 		/* L4 header len: TCP header length */
1138 		d->dma.d0 |=
1139 		(tcp_hdrlen(skb) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1140 		break;
1141 	case IPPROTO_UDP:
1142 		/* L4 header len: UDP header length */
1143 		d->dma.d0 |=
1144 		(sizeof(struct udphdr) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1145 		break;
1146 	default:
1147 		return -EINVAL;
1148 	}
1149 
1150 	d->dma.ip_length = skb_network_header_len(skb);
1151 	/* Enable TCP/UDP checksum */
1152 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_TCP_UDP_CHECKSUM_EN_POS);
1153 	/* Calculate pseudo-header */
1154 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_PSEUDO_HEADER_CALC_EN_POS);
1155 
1156 	return 0;
1157 }
1158 
1159 static inline void wil_tx_last_desc(struct vring_tx_desc *d)
1160 {
1161 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS) |
1162 	      BIT(DMA_CFG_DESC_TX_0_CMD_MARK_WB_POS) |
1163 	      BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
1164 }
1165 
1166 static inline void wil_set_tx_desc_last_tso(volatile struct vring_tx_desc *d)
1167 {
1168 	d->dma.d0 |= wil_tso_type_lst <<
1169 		  DMA_CFG_DESC_TX_0_SEGMENT_BUF_DETAILS_POS;
1170 }
1171 
1172 static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
1173 			      struct sk_buff *skb)
1174 {
1175 	struct device *dev = wil_to_dev(wil);
1176 
1177 	/* point to descriptors in shared memory */
1178 	volatile struct vring_tx_desc *_desc = NULL, *_hdr_desc,
1179 				      *_first_desc = NULL;
1180 
1181 	/* pointers to shadow descriptors */
1182 	struct vring_tx_desc desc_mem, hdr_desc_mem, first_desc_mem,
1183 			     *d = &hdr_desc_mem, *hdr_desc = &hdr_desc_mem,
1184 			     *first_desc = &first_desc_mem;
1185 
1186 	/* pointer to shadow descriptors' context */
1187 	struct wil_ctx *hdr_ctx, *first_ctx = NULL;
1188 
1189 	int descs_used = 0; /* total number of used descriptors */
1190 	int sg_desc_cnt = 0; /* number of descriptors for current mss*/
1191 
1192 	u32 swhead = vring->swhead;
1193 	int used, avail = wil_vring_avail_tx(vring);
1194 	int nr_frags = skb_shinfo(skb)->nr_frags;
1195 	int min_desc_required = nr_frags + 1;
1196 	int mss = skb_shinfo(skb)->gso_size;	/* payload size w/o headers */
1197 	int f, len, hdrlen, headlen;
1198 	int vring_index = vring - wil->vring_tx;
1199 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1200 	uint i = swhead;
1201 	dma_addr_t pa;
1202 	const skb_frag_t *frag = NULL;
1203 	int rem_data = mss;
1204 	int lenmss;
1205 	int hdr_compensation_need = true;
1206 	int desc_tso_type = wil_tso_type_first;
1207 	bool is_ipv4;
1208 	int tcp_hdr_len;
1209 	int skb_net_hdr_len;
1210 	int gso_type;
1211 
1212 	wil_dbg_txrx(wil, "%s() %d bytes to vring %d\n",
1213 		     __func__, skb->len, vring_index);
1214 
1215 	if (unlikely(!txdata->enabled))
1216 		return -EINVAL;
1217 
1218 	/* A typical page 4K is 3-4 payloads, we assume each fragment
1219 	 * is a full payload, that's how min_desc_required has been
1220 	 * calculated. In real we might need more or less descriptors,
1221 	 * this is the initial check only.
1222 	 */
1223 	if (unlikely(avail < min_desc_required)) {
1224 		wil_err_ratelimited(wil,
1225 				    "TSO: Tx ring[%2d] full. No space for %d fragments\n",
1226 				    vring_index, min_desc_required);
1227 		return -ENOMEM;
1228 	}
1229 
1230 	/* Header Length = MAC header len + IP header len + TCP header len*/
1231 	hdrlen = ETH_HLEN +
1232 		(int)skb_network_header_len(skb) +
1233 		tcp_hdrlen(skb);
1234 
1235 	gso_type = skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV6 | SKB_GSO_TCPV4);
1236 	switch (gso_type) {
1237 	case SKB_GSO_TCPV4:
1238 		/* TCP v4, zero out the IP length and IPv4 checksum fields
1239 		 * as required by the offloading doc
1240 		 */
1241 		ip_hdr(skb)->tot_len = 0;
1242 		ip_hdr(skb)->check = 0;
1243 		is_ipv4 = true;
1244 		break;
1245 	case SKB_GSO_TCPV6:
1246 		/* TCP v6, zero out the payload length */
1247 		ipv6_hdr(skb)->payload_len = 0;
1248 		is_ipv4 = false;
1249 		break;
1250 	default:
1251 		/* other than TCPv4 or TCPv6 types are not supported for TSO.
1252 		 * It is also illegal for both to be set simultaneously
1253 		 */
1254 		return -EINVAL;
1255 	}
1256 
1257 	if (skb->ip_summed != CHECKSUM_PARTIAL)
1258 		return -EINVAL;
1259 
1260 	/* tcp header length and skb network header length are fixed for all
1261 	 * packet's descriptors - read then once here
1262 	 */
1263 	tcp_hdr_len = tcp_hdrlen(skb);
1264 	skb_net_hdr_len = skb_network_header_len(skb);
1265 
1266 	_hdr_desc = &vring->va[i].tx;
1267 
1268 	pa = dma_map_single(dev, skb->data, hdrlen, DMA_TO_DEVICE);
1269 	if (unlikely(dma_mapping_error(dev, pa))) {
1270 		wil_err(wil, "TSO: Skb head DMA map error\n");
1271 		goto err_exit;
1272 	}
1273 
1274 	wil_tx_desc_map(hdr_desc, pa, hdrlen, vring_index);
1275 	wil_tx_desc_offload_setup_tso(hdr_desc, skb, wil_tso_type_hdr, is_ipv4,
1276 				      tcp_hdr_len, skb_net_hdr_len);
1277 	wil_tx_last_desc(hdr_desc);
1278 
1279 	vring->ctx[i].mapped_as = wil_mapped_as_single;
1280 	hdr_ctx = &vring->ctx[i];
1281 
1282 	descs_used++;
1283 	headlen = skb_headlen(skb) - hdrlen;
1284 
1285 	for (f = headlen ? -1 : 0; f < nr_frags; f++)  {
1286 		if (headlen) {
1287 			len = headlen;
1288 			wil_dbg_txrx(wil, "TSO: process skb head, len %u\n",
1289 				     len);
1290 		} else {
1291 			frag = &skb_shinfo(skb)->frags[f];
1292 			len = frag->size;
1293 			wil_dbg_txrx(wil, "TSO: frag[%d]: len %u\n", f, len);
1294 		}
1295 
1296 		while (len) {
1297 			wil_dbg_txrx(wil,
1298 				     "TSO: len %d, rem_data %d, descs_used %d\n",
1299 				     len, rem_data, descs_used);
1300 
1301 			if (descs_used == avail)  {
1302 				wil_err(wil, "TSO: ring overflow\n");
1303 				goto dma_error;
1304 			}
1305 
1306 			lenmss = min_t(int, rem_data, len);
1307 			i = (swhead + descs_used) % vring->size;
1308 			wil_dbg_txrx(wil, "TSO: lenmss %d, i %d\n", lenmss, i);
1309 
1310 			if (!headlen) {
1311 				pa = skb_frag_dma_map(dev, frag,
1312 						      frag->size - len, lenmss,
1313 						      DMA_TO_DEVICE);
1314 				vring->ctx[i].mapped_as = wil_mapped_as_page;
1315 			} else {
1316 				pa = dma_map_single(dev,
1317 						    skb->data +
1318 						    skb_headlen(skb) - headlen,
1319 						    lenmss,
1320 						    DMA_TO_DEVICE);
1321 				vring->ctx[i].mapped_as = wil_mapped_as_single;
1322 				headlen -= lenmss;
1323 			}
1324 
1325 			if (unlikely(dma_mapping_error(dev, pa)))
1326 				goto dma_error;
1327 
1328 			_desc = &vring->va[i].tx;
1329 
1330 			if (!_first_desc) {
1331 				_first_desc = _desc;
1332 				first_ctx = &vring->ctx[i];
1333 				d = first_desc;
1334 			} else {
1335 				d = &desc_mem;
1336 			}
1337 
1338 			wil_tx_desc_map(d, pa, lenmss, vring_index);
1339 			wil_tx_desc_offload_setup_tso(d, skb, desc_tso_type,
1340 						      is_ipv4, tcp_hdr_len,
1341 						      skb_net_hdr_len);
1342 
1343 			/* use tso_type_first only once */
1344 			desc_tso_type = wil_tso_type_mid;
1345 
1346 			descs_used++;  /* desc used so far */
1347 			sg_desc_cnt++; /* desc used for this segment */
1348 			len -= lenmss;
1349 			rem_data -= lenmss;
1350 
1351 			wil_dbg_txrx(wil,
1352 				     "TSO: len %d, rem_data %d, descs_used %d, sg_desc_cnt %d,\n",
1353 				     len, rem_data, descs_used, sg_desc_cnt);
1354 
1355 			/* Close the segment if reached mss size or last frag*/
1356 			if (rem_data == 0 || (f == nr_frags - 1 && len == 0)) {
1357 				if (hdr_compensation_need) {
1358 					/* first segment include hdr desc for
1359 					 * release
1360 					 */
1361 					hdr_ctx->nr_frags = sg_desc_cnt;
1362 					wil_tx_desc_set_nr_frags(first_desc,
1363 								 sg_desc_cnt +
1364 								 1);
1365 					hdr_compensation_need = false;
1366 				} else {
1367 					wil_tx_desc_set_nr_frags(first_desc,
1368 								 sg_desc_cnt);
1369 				}
1370 				first_ctx->nr_frags = sg_desc_cnt - 1;
1371 
1372 				wil_tx_last_desc(d);
1373 
1374 				/* first descriptor may also be the last
1375 				 * for this mss - make sure not to copy
1376 				 * it twice
1377 				 */
1378 				if (first_desc != d)
1379 					*_first_desc = *first_desc;
1380 
1381 				/*last descriptor will be copied at the end
1382 				 * of this TS processing
1383 				 */
1384 				if (f < nr_frags - 1 || len > 0)
1385 					*_desc = *d;
1386 
1387 				rem_data = mss;
1388 				_first_desc = NULL;
1389 				sg_desc_cnt = 0;
1390 			} else if (first_desc != d) /* update mid descriptor */
1391 					*_desc = *d;
1392 		}
1393 	}
1394 
1395 	/* first descriptor may also be the last.
1396 	 * in this case d pointer is invalid
1397 	 */
1398 	if (_first_desc == _desc)
1399 		d = first_desc;
1400 
1401 	/* Last data descriptor */
1402 	wil_set_tx_desc_last_tso(d);
1403 	*_desc = *d;
1404 
1405 	/* Fill the total number of descriptors in first desc (hdr)*/
1406 	wil_tx_desc_set_nr_frags(hdr_desc, descs_used);
1407 	*_hdr_desc = *hdr_desc;
1408 
1409 	/* hold reference to skb
1410 	 * to prevent skb release before accounting
1411 	 * in case of immediate "tx done"
1412 	 */
1413 	vring->ctx[i].skb = skb_get(skb);
1414 
1415 	/* performance monitoring */
1416 	used = wil_vring_used_tx(vring);
1417 	if (wil_val_in_range(vring_idle_trsh,
1418 			     used, used + descs_used)) {
1419 		txdata->idle += get_cycles() - txdata->last_idle;
1420 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
1421 			     vring_index, used, used + descs_used);
1422 	}
1423 
1424 	/* advance swhead */
1425 	wil_dbg_txrx(wil, "TSO: Tx swhead %d -> %d\n", swhead, vring->swhead);
1426 	wil_vring_advance_head(vring, descs_used);
1427 
1428 	/* make sure all writes to descriptors (shared memory) are done before
1429 	 * committing them to HW
1430 	 */
1431 	wmb();
1432 
1433 	wil_w(wil, vring->hwtail, vring->swhead);
1434 	return 0;
1435 
1436 dma_error:
1437 	wil_err(wil, "TSO: DMA map page error\n");
1438 	while (descs_used > 0) {
1439 		struct wil_ctx *ctx;
1440 
1441 		i = (swhead + descs_used) % vring->size;
1442 		d = (struct vring_tx_desc *)&vring->va[i].tx;
1443 		_desc = &vring->va[i].tx;
1444 		*d = *_desc;
1445 		_desc->dma.status = TX_DMA_STATUS_DU;
1446 		ctx = &vring->ctx[i];
1447 		wil_txdesc_unmap(dev, d, ctx);
1448 		if (ctx->skb)
1449 			dev_kfree_skb_any(ctx->skb);
1450 		memset(ctx, 0, sizeof(*ctx));
1451 		descs_used--;
1452 	}
1453 
1454 err_exit:
1455 	return -EINVAL;
1456 }
1457 
1458 static int __wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
1459 			  struct sk_buff *skb)
1460 {
1461 	struct device *dev = wil_to_dev(wil);
1462 	struct vring_tx_desc dd, *d = &dd;
1463 	volatile struct vring_tx_desc *_d;
1464 	u32 swhead = vring->swhead;
1465 	int avail = wil_vring_avail_tx(vring);
1466 	int nr_frags = skb_shinfo(skb)->nr_frags;
1467 	uint f = 0;
1468 	int vring_index = vring - wil->vring_tx;
1469 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1470 	uint i = swhead;
1471 	dma_addr_t pa;
1472 	int used;
1473 	bool mcast = (vring_index == wil->bcast_vring);
1474 	uint len = skb_headlen(skb);
1475 
1476 	wil_dbg_txrx(wil, "%s() %d bytes to vring %d\n",
1477 		     __func__, skb->len, vring_index);
1478 
1479 	if (unlikely(!txdata->enabled))
1480 		return -EINVAL;
1481 
1482 	if (unlikely(avail < 1 + nr_frags)) {
1483 		wil_err_ratelimited(wil,
1484 				    "Tx ring[%2d] full. No space for %d fragments\n",
1485 				    vring_index, 1 + nr_frags);
1486 		return -ENOMEM;
1487 	}
1488 	_d = &vring->va[i].tx;
1489 
1490 	pa = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
1491 
1492 	wil_dbg_txrx(wil, "Tx[%2d] skb %d bytes 0x%p -> %pad\n", vring_index,
1493 		     skb_headlen(skb), skb->data, &pa);
1494 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
1495 			  skb->data, skb_headlen(skb), false);
1496 
1497 	if (unlikely(dma_mapping_error(dev, pa)))
1498 		return -EINVAL;
1499 	vring->ctx[i].mapped_as = wil_mapped_as_single;
1500 	/* 1-st segment */
1501 	wil_tx_desc_map(d, pa, len, vring_index);
1502 	if (unlikely(mcast)) {
1503 		d->mac.d[0] |= BIT(MAC_CFG_DESC_TX_0_MCS_EN_POS); /* MCS 0 */
1504 		if (unlikely(len > WIL_BCAST_MCS0_LIMIT)) /* set MCS 1 */
1505 			d->mac.d[0] |= (1 << MAC_CFG_DESC_TX_0_MCS_INDEX_POS);
1506 	}
1507 	/* Process TCP/UDP checksum offloading */
1508 	if (unlikely(wil_tx_desc_offload_setup(d, skb))) {
1509 		wil_err(wil, "Tx[%2d] Failed to set cksum, drop packet\n",
1510 			vring_index);
1511 		goto dma_error;
1512 	}
1513 
1514 	vring->ctx[i].nr_frags = nr_frags;
1515 	wil_tx_desc_set_nr_frags(d, nr_frags + 1);
1516 
1517 	/* middle segments */
1518 	for (; f < nr_frags; f++) {
1519 		const struct skb_frag_struct *frag =
1520 				&skb_shinfo(skb)->frags[f];
1521 		int len = skb_frag_size(frag);
1522 
1523 		*_d = *d;
1524 		wil_dbg_txrx(wil, "Tx[%2d] desc[%4d]\n", vring_index, i);
1525 		wil_hex_dump_txrx("TxD ", DUMP_PREFIX_NONE, 32, 4,
1526 				  (const void *)d, sizeof(*d), false);
1527 		i = (swhead + f + 1) % vring->size;
1528 		_d = &vring->va[i].tx;
1529 		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
1530 				      DMA_TO_DEVICE);
1531 		if (unlikely(dma_mapping_error(dev, pa)))
1532 			goto dma_error;
1533 		vring->ctx[i].mapped_as = wil_mapped_as_page;
1534 		wil_tx_desc_map(d, pa, len, vring_index);
1535 		/* no need to check return code -
1536 		 * if it succeeded for 1-st descriptor,
1537 		 * it will succeed here too
1538 		 */
1539 		wil_tx_desc_offload_setup(d, skb);
1540 	}
1541 	/* for the last seg only */
1542 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
1543 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_MARK_WB_POS);
1544 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
1545 	*_d = *d;
1546 	wil_dbg_txrx(wil, "Tx[%2d] desc[%4d]\n", vring_index, i);
1547 	wil_hex_dump_txrx("TxD ", DUMP_PREFIX_NONE, 32, 4,
1548 			  (const void *)d, sizeof(*d), false);
1549 
1550 	/* hold reference to skb
1551 	 * to prevent skb release before accounting
1552 	 * in case of immediate "tx done"
1553 	 */
1554 	vring->ctx[i].skb = skb_get(skb);
1555 
1556 	/* performance monitoring */
1557 	used = wil_vring_used_tx(vring);
1558 	if (wil_val_in_range(vring_idle_trsh,
1559 			     used, used + nr_frags + 1)) {
1560 		txdata->idle += get_cycles() - txdata->last_idle;
1561 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
1562 			     vring_index, used, used + nr_frags + 1);
1563 	}
1564 
1565 	/* advance swhead */
1566 	wil_vring_advance_head(vring, nr_frags + 1);
1567 	wil_dbg_txrx(wil, "Tx[%2d] swhead %d -> %d\n", vring_index, swhead,
1568 		     vring->swhead);
1569 	trace_wil6210_tx(vring_index, swhead, skb->len, nr_frags);
1570 
1571 	/* make sure all writes to descriptors (shared memory) are done before
1572 	 * committing them to HW
1573 	 */
1574 	wmb();
1575 
1576 	wil_w(wil, vring->hwtail, vring->swhead);
1577 
1578 	return 0;
1579  dma_error:
1580 	/* unmap what we have mapped */
1581 	nr_frags = f + 1; /* frags mapped + one for skb head */
1582 	for (f = 0; f < nr_frags; f++) {
1583 		struct wil_ctx *ctx;
1584 
1585 		i = (swhead + f) % vring->size;
1586 		ctx = &vring->ctx[i];
1587 		_d = &vring->va[i].tx;
1588 		*d = *_d;
1589 		_d->dma.status = TX_DMA_STATUS_DU;
1590 		wil_txdesc_unmap(dev, d, ctx);
1591 
1592 		if (ctx->skb)
1593 			dev_kfree_skb_any(ctx->skb);
1594 
1595 		memset(ctx, 0, sizeof(*ctx));
1596 	}
1597 
1598 	return -EINVAL;
1599 }
1600 
1601 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
1602 			struct sk_buff *skb)
1603 {
1604 	int vring_index = vring - wil->vring_tx;
1605 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1606 	int rc;
1607 
1608 	spin_lock(&txdata->lock);
1609 
1610 	rc = (skb_is_gso(skb) ? __wil_tx_vring_tso : __wil_tx_vring)
1611 	     (wil, vring, skb);
1612 
1613 	spin_unlock(&txdata->lock);
1614 
1615 	return rc;
1616 }
1617 
1618 netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
1619 {
1620 	struct wil6210_priv *wil = ndev_to_wil(ndev);
1621 	struct ethhdr *eth = (void *)skb->data;
1622 	bool bcast = is_multicast_ether_addr(eth->h_dest);
1623 	struct vring *vring;
1624 	static bool pr_once_fw;
1625 	int rc;
1626 
1627 	wil_dbg_txrx(wil, "%s()\n", __func__);
1628 	if (unlikely(!test_bit(wil_status_fwready, wil->status))) {
1629 		if (!pr_once_fw) {
1630 			wil_err(wil, "FW not ready\n");
1631 			pr_once_fw = true;
1632 		}
1633 		goto drop;
1634 	}
1635 	if (unlikely(!test_bit(wil_status_fwconnected, wil->status))) {
1636 		wil_err(wil, "FW not connected\n");
1637 		goto drop;
1638 	}
1639 	if (unlikely(wil->wdev->iftype == NL80211_IFTYPE_MONITOR)) {
1640 		wil_err(wil, "Xmit in monitor mode not supported\n");
1641 		goto drop;
1642 	}
1643 	pr_once_fw = false;
1644 
1645 	/* find vring */
1646 	if (wil->wdev->iftype == NL80211_IFTYPE_STATION) {
1647 		/* in STA mode (ESS), all to same VRING */
1648 		vring = wil_find_tx_vring_sta(wil, skb);
1649 	} else { /* direct communication, find matching VRING */
1650 		vring = bcast ? wil_find_tx_bcast(wil, skb) :
1651 				wil_find_tx_ucast(wil, skb);
1652 	}
1653 	if (unlikely(!vring)) {
1654 		wil_dbg_txrx(wil, "No Tx VRING found for %pM\n", eth->h_dest);
1655 		goto drop;
1656 	}
1657 	/* set up vring entry */
1658 	rc = wil_tx_vring(wil, vring, skb);
1659 
1660 	/* do we still have enough room in the vring? */
1661 	if (unlikely(wil_vring_avail_tx(vring) < wil_vring_wmark_low(vring))) {
1662 		netif_tx_stop_all_queues(wil_to_ndev(wil));
1663 		wil_dbg_txrx(wil, "netif_tx_stop : ring full\n");
1664 	}
1665 
1666 	switch (rc) {
1667 	case 0:
1668 		/* statistics will be updated on the tx_complete */
1669 		dev_kfree_skb_any(skb);
1670 		return NETDEV_TX_OK;
1671 	case -ENOMEM:
1672 		return NETDEV_TX_BUSY;
1673 	default:
1674 		break; /* goto drop; */
1675 	}
1676  drop:
1677 	ndev->stats.tx_dropped++;
1678 	dev_kfree_skb_any(skb);
1679 
1680 	return NET_XMIT_DROP;
1681 }
1682 
1683 static inline bool wil_need_txstat(struct sk_buff *skb)
1684 {
1685 	struct ethhdr *eth = (void *)skb->data;
1686 
1687 	return is_unicast_ether_addr(eth->h_dest) && skb->sk &&
1688 	       (skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS);
1689 }
1690 
1691 static inline void wil_consume_skb(struct sk_buff *skb, bool acked)
1692 {
1693 	if (unlikely(wil_need_txstat(skb)))
1694 		skb_complete_wifi_ack(skb, acked);
1695 	else
1696 		acked ? dev_consume_skb_any(skb) : dev_kfree_skb_any(skb);
1697 }
1698 
1699 /**
1700  * Clean up transmitted skb's from the Tx VRING
1701  *
1702  * Return number of descriptors cleared
1703  *
1704  * Safe to call from IRQ
1705  */
1706 int wil_tx_complete(struct wil6210_priv *wil, int ringid)
1707 {
1708 	struct net_device *ndev = wil_to_ndev(wil);
1709 	struct device *dev = wil_to_dev(wil);
1710 	struct vring *vring = &wil->vring_tx[ringid];
1711 	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
1712 	int done = 0;
1713 	int cid = wil->vring2cid_tid[ringid][0];
1714 	struct wil_net_stats *stats = NULL;
1715 	volatile struct vring_tx_desc *_d;
1716 	int used_before_complete;
1717 	int used_new;
1718 
1719 	if (unlikely(!vring->va)) {
1720 		wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
1721 		return 0;
1722 	}
1723 
1724 	if (unlikely(!txdata->enabled)) {
1725 		wil_info(wil, "Tx irq[%d]: vring disabled\n", ringid);
1726 		return 0;
1727 	}
1728 
1729 	wil_dbg_txrx(wil, "%s(%d)\n", __func__, ringid);
1730 
1731 	used_before_complete = wil_vring_used_tx(vring);
1732 
1733 	if (cid < WIL6210_MAX_CID)
1734 		stats = &wil->sta[cid].stats;
1735 
1736 	while (!wil_vring_is_empty(vring)) {
1737 		int new_swtail;
1738 		struct wil_ctx *ctx = &vring->ctx[vring->swtail];
1739 		/**
1740 		 * For the fragmented skb, HW will set DU bit only for the
1741 		 * last fragment. look for it.
1742 		 * In TSO the first DU will include hdr desc
1743 		 */
1744 		int lf = (vring->swtail + ctx->nr_frags) % vring->size;
1745 		/* TODO: check we are not past head */
1746 
1747 		_d = &vring->va[lf].tx;
1748 		if (unlikely(!(_d->dma.status & TX_DMA_STATUS_DU)))
1749 			break;
1750 
1751 		new_swtail = (lf + 1) % vring->size;
1752 		while (vring->swtail != new_swtail) {
1753 			struct vring_tx_desc dd, *d = &dd;
1754 			u16 dmalen;
1755 			struct sk_buff *skb;
1756 
1757 			ctx = &vring->ctx[vring->swtail];
1758 			skb = ctx->skb;
1759 			_d = &vring->va[vring->swtail].tx;
1760 
1761 			*d = *_d;
1762 
1763 			dmalen = le16_to_cpu(d->dma.length);
1764 			trace_wil6210_tx_done(ringid, vring->swtail, dmalen,
1765 					      d->dma.error);
1766 			wil_dbg_txrx(wil,
1767 				     "TxC[%2d][%3d] : %d bytes, status 0x%02x err 0x%02x\n",
1768 				     ringid, vring->swtail, dmalen,
1769 				     d->dma.status, d->dma.error);
1770 			wil_hex_dump_txrx("TxCD ", DUMP_PREFIX_NONE, 32, 4,
1771 					  (const void *)d, sizeof(*d), false);
1772 
1773 			wil_txdesc_unmap(dev, d, ctx);
1774 
1775 			if (skb) {
1776 				if (likely(d->dma.error == 0)) {
1777 					ndev->stats.tx_packets++;
1778 					ndev->stats.tx_bytes += skb->len;
1779 					if (stats) {
1780 						stats->tx_packets++;
1781 						stats->tx_bytes += skb->len;
1782 					}
1783 				} else {
1784 					ndev->stats.tx_errors++;
1785 					if (stats)
1786 						stats->tx_errors++;
1787 				}
1788 				wil_consume_skb(skb, d->dma.error == 0);
1789 			}
1790 			memset(ctx, 0, sizeof(*ctx));
1791 			/* There is no need to touch HW descriptor:
1792 			 * - ststus bit TX_DMA_STATUS_DU is set by design,
1793 			 *   so hardware will not try to process this desc.,
1794 			 * - rest of descriptor will be initialized on Tx.
1795 			 */
1796 			vring->swtail = wil_vring_next_tail(vring);
1797 			done++;
1798 		}
1799 	}
1800 
1801 	/* performance monitoring */
1802 	used_new = wil_vring_used_tx(vring);
1803 	if (wil_val_in_range(vring_idle_trsh,
1804 			     used_new, used_before_complete)) {
1805 		wil_dbg_txrx(wil, "Ring[%2d] idle %d -> %d\n",
1806 			     ringid, used_before_complete, used_new);
1807 		txdata->last_idle = get_cycles();
1808 	}
1809 
1810 	if (wil_vring_avail_tx(vring) > wil_vring_wmark_high(vring)) {
1811 		wil_dbg_txrx(wil, "netif_tx_wake : ring not full\n");
1812 		netif_tx_wake_all_queues(wil_to_ndev(wil));
1813 	}
1814 
1815 	return done;
1816 }
1817