1 /*
2  * Copyright (c) 2012-2014 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 = BIT(9) | 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 
431 	/* use radiotap header only if required */
432 	if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
433 		wil_rx_add_radiotap_header(wil, skb);
434 
435 	/* no extra checks if in sniffer mode */
436 	if (ndev->type != ARPHRD_ETHER)
437 		return skb;
438 	/*
439 	 * Non-data frames may be delivered through Rx DMA channel (ex: BAR)
440 	 * Driver should recognize it by frame type, that is found
441 	 * in Rx descriptor. If type is not data, it is 802.11 frame as is
442 	 */
443 	ftype = wil_rxdesc_ftype(d) << 2;
444 	if (unlikely(ftype != IEEE80211_FTYPE_DATA)) {
445 		wil_dbg_txrx(wil, "Non-data frame ftype 0x%08x\n", ftype);
446 		/* TODO: process it */
447 		kfree_skb(skb);
448 		return NULL;
449 	}
450 
451 	if (unlikely(skb->len < ETH_HLEN + snaplen)) {
452 		wil_err(wil, "Short frame, len = %d\n", skb->len);
453 		/* TODO: process it (i.e. BAR) */
454 		kfree_skb(skb);
455 		return NULL;
456 	}
457 
458 	/* L4 IDENT is on when HW calculated checksum, check status
459 	 * and in case of error drop the packet
460 	 * higher stack layers will handle retransmission (if required)
461 	 */
462 	if (likely(d->dma.status & RX_DMA_STATUS_L4I)) {
463 		/* L4 protocol identified, csum calculated */
464 		if (likely((d->dma.error & RX_DMA_ERROR_L4_ERR) == 0))
465 			skb->ip_summed = CHECKSUM_UNNECESSARY;
466 		/* If HW reports bad checksum, let IP stack re-check it
467 		 * For example, HW don't understand Microsoft IP stack that
468 		 * mis-calculates TCP checksum - if it should be 0x0,
469 		 * it writes 0xffff in violation of RFC 1624
470 		 */
471 	}
472 
473 	if (snaplen) {
474 		/* Packet layout
475 		 * +-------+-------+---------+------------+------+
476 		 * | SA(6) | DA(6) | SNAP(6) | ETHTYPE(2) | DATA |
477 		 * +-------+-------+---------+------------+------+
478 		 * Need to remove SNAP, shifting SA and DA forward
479 		 */
480 		memmove(skb->data + snaplen, skb->data, 2 * ETH_ALEN);
481 		skb_pull(skb, snaplen);
482 	}
483 
484 	return skb;
485 }
486 
487 /**
488  * allocate and fill up to @count buffers in rx ring
489  * buffers posted at @swtail
490  */
491 static int wil_rx_refill(struct wil6210_priv *wil, int count)
492 {
493 	struct net_device *ndev = wil_to_ndev(wil);
494 	struct vring *v = &wil->vring_rx;
495 	u32 next_tail;
496 	int rc = 0;
497 	int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
498 			WIL6210_RTAP_SIZE : 0;
499 
500 	for (; next_tail = wil_vring_next_tail(v),
501 			(next_tail != v->swhead) && (count-- > 0);
502 			v->swtail = next_tail) {
503 		rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
504 		if (unlikely(rc)) {
505 			wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
506 				rc, v->swtail);
507 			break;
508 		}
509 	}
510 	iowrite32(v->swtail, wil->csr + HOSTADDR(v->hwtail));
511 
512 	return rc;
513 }
514 
515 /*
516  * Pass Rx packet to the netif. Update statistics.
517  * Called in softirq context (NAPI poll).
518  */
519 void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
520 {
521 	gro_result_t rc = GRO_NORMAL;
522 	struct wil6210_priv *wil = ndev_to_wil(ndev);
523 	struct wireless_dev *wdev = wil_to_wdev(wil);
524 	unsigned int len = skb->len;
525 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
526 	int cid = wil_rxdesc_cid(d); /* always 0..7, no need to check */
527 	struct ethhdr *eth = (void *)skb->data;
528 	/* here looking for DA, not A1, thus Rxdesc's 'mcast' indication
529 	 * is not suitable, need to look at data
530 	 */
531 	int mcast = is_multicast_ether_addr(eth->h_dest);
532 	struct wil_net_stats *stats = &wil->sta[cid].stats;
533 	struct sk_buff *xmit_skb = NULL;
534 	static const char * const gro_res_str[] = {
535 		[GRO_MERGED]		= "GRO_MERGED",
536 		[GRO_MERGED_FREE]	= "GRO_MERGED_FREE",
537 		[GRO_HELD]		= "GRO_HELD",
538 		[GRO_NORMAL]		= "GRO_NORMAL",
539 		[GRO_DROP]		= "GRO_DROP",
540 	};
541 
542 	skb_orphan(skb);
543 
544 	if (wdev->iftype == NL80211_IFTYPE_AP && !wil->ap_isolate) {
545 		if (mcast) {
546 			/* send multicast frames both to higher layers in
547 			 * local net stack and back to the wireless medium
548 			 */
549 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
550 		} else {
551 			int xmit_cid = wil_find_cid(wil, eth->h_dest);
552 
553 			if (xmit_cid >= 0) {
554 				/* The destination station is associated to
555 				 * this AP (in this VLAN), so send the frame
556 				 * directly to it and do not pass it to local
557 				 * net stack.
558 				 */
559 				xmit_skb = skb;
560 				skb = NULL;
561 			}
562 		}
563 	}
564 	if (xmit_skb) {
565 		/* Send to wireless media and increase priority by 256 to
566 		 * keep the received priority instead of reclassifying
567 		 * the frame (see cfg80211_classify8021d).
568 		 */
569 		xmit_skb->dev = ndev;
570 		xmit_skb->priority += 256;
571 		xmit_skb->protocol = htons(ETH_P_802_3);
572 		skb_reset_network_header(xmit_skb);
573 		skb_reset_mac_header(xmit_skb);
574 		wil_dbg_txrx(wil, "Rx -> Tx %d bytes\n", len);
575 		dev_queue_xmit(xmit_skb);
576 	}
577 
578 	if (skb) { /* deliver to local stack */
579 
580 		skb->protocol = eth_type_trans(skb, ndev);
581 		rc = napi_gro_receive(&wil->napi_rx, skb);
582 		wil_dbg_txrx(wil, "Rx complete %d bytes => %s\n",
583 			     len, gro_res_str[rc]);
584 	}
585 	/* statistics. rc set to GRO_NORMAL for AP bridging */
586 	if (unlikely(rc == GRO_DROP)) {
587 		ndev->stats.rx_dropped++;
588 		stats->rx_dropped++;
589 		wil_dbg_txrx(wil, "Rx drop %d bytes\n", len);
590 	} else {
591 		ndev->stats.rx_packets++;
592 		stats->rx_packets++;
593 		ndev->stats.rx_bytes += len;
594 		stats->rx_bytes += len;
595 		if (mcast)
596 			ndev->stats.multicast++;
597 	}
598 }
599 
600 /**
601  * Proceed all completed skb's from Rx VRING
602  *
603  * Safe to call from NAPI poll, i.e. softirq with interrupts enabled
604  */
605 void wil_rx_handle(struct wil6210_priv *wil, int *quota)
606 {
607 	struct net_device *ndev = wil_to_ndev(wil);
608 	struct vring *v = &wil->vring_rx;
609 	struct sk_buff *skb;
610 
611 	if (unlikely(!v->va)) {
612 		wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
613 		return;
614 	}
615 	wil_dbg_txrx(wil, "%s()\n", __func__);
616 	while ((*quota > 0) && (NULL != (skb = wil_vring_reap_rx(wil, v)))) {
617 		(*quota)--;
618 
619 		if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
620 			skb->dev = ndev;
621 			skb_reset_mac_header(skb);
622 			skb->ip_summed = CHECKSUM_UNNECESSARY;
623 			skb->pkt_type = PACKET_OTHERHOST;
624 			skb->protocol = htons(ETH_P_802_2);
625 			wil_netif_rx_any(skb, ndev);
626 		} else {
627 			wil_rx_reorder(wil, skb);
628 		}
629 	}
630 	wil_rx_refill(wil, v->size);
631 }
632 
633 int wil_rx_init(struct wil6210_priv *wil, u16 size)
634 {
635 	struct vring *vring = &wil->vring_rx;
636 	int rc;
637 
638 	wil_dbg_misc(wil, "%s()\n", __func__);
639 
640 	if (vring->va) {
641 		wil_err(wil, "Rx ring already allocated\n");
642 		return -EINVAL;
643 	}
644 
645 	vring->size = size;
646 	rc = wil_vring_alloc(wil, vring);
647 	if (rc)
648 		return rc;
649 
650 	rc = wmi_rx_chain_add(wil, vring);
651 	if (rc)
652 		goto err_free;
653 
654 	rc = wil_rx_refill(wil, vring->size);
655 	if (rc)
656 		goto err_free;
657 
658 	return 0;
659  err_free:
660 	wil_vring_free(wil, vring, 0);
661 
662 	return rc;
663 }
664 
665 void wil_rx_fini(struct wil6210_priv *wil)
666 {
667 	struct vring *vring = &wil->vring_rx;
668 
669 	wil_dbg_misc(wil, "%s()\n", __func__);
670 
671 	if (vring->va)
672 		wil_vring_free(wil, vring, 0);
673 }
674 
675 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
676 		      int cid, int tid)
677 {
678 	int rc;
679 	struct wmi_vring_cfg_cmd cmd = {
680 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
681 		.vring_cfg = {
682 			.tx_sw_ring = {
683 				.max_mpdu_size =
684 					cpu_to_le16(wil_mtu2macbuf(mtu_max)),
685 				.ring_size = cpu_to_le16(size),
686 			},
687 			.ringid = id,
688 			.cidxtid = mk_cidxtid(cid, tid),
689 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
690 			.mac_ctrl = 0,
691 			.to_resolution = 0,
692 			.agg_max_wsize = 0,
693 			.schd_params = {
694 				.priority = cpu_to_le16(0),
695 				.timeslot_us = cpu_to_le16(0xfff),
696 			},
697 		},
698 	};
699 	struct {
700 		struct wil6210_mbox_hdr_wmi wmi;
701 		struct wmi_vring_cfg_done_event cmd;
702 	} __packed reply;
703 	struct vring *vring = &wil->vring_tx[id];
704 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
705 
706 	wil_dbg_misc(wil, "%s() max_mpdu_size %d\n", __func__,
707 		     cmd.vring_cfg.tx_sw_ring.max_mpdu_size);
708 
709 	if (vring->va) {
710 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
711 		rc = -EINVAL;
712 		goto out;
713 	}
714 
715 	memset(txdata, 0, sizeof(*txdata));
716 	spin_lock_init(&txdata->lock);
717 	vring->size = size;
718 	rc = wil_vring_alloc(wil, vring);
719 	if (rc)
720 		goto out;
721 
722 	wil->vring2cid_tid[id][0] = cid;
723 	wil->vring2cid_tid[id][1] = tid;
724 
725 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
726 
727 	rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
728 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
729 	if (rc)
730 		goto out_free;
731 
732 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
733 		wil_err(wil, "Tx config failed, status 0x%02x\n",
734 			reply.cmd.status);
735 		rc = -EINVAL;
736 		goto out_free;
737 	}
738 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
739 
740 	txdata->enabled = 1;
741 	if (wil->sta[cid].data_port_open && (agg_wsize >= 0))
742 		wil_addba_tx_request(wil, id, agg_wsize);
743 
744 	return 0;
745  out_free:
746 	wil_vring_free(wil, vring, 1);
747  out:
748 
749 	return rc;
750 }
751 
752 int wil_vring_init_bcast(struct wil6210_priv *wil, int id, int size)
753 {
754 	int rc;
755 	struct wmi_bcast_vring_cfg_cmd cmd = {
756 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
757 		.vring_cfg = {
758 			.tx_sw_ring = {
759 				.max_mpdu_size =
760 					cpu_to_le16(wil_mtu2macbuf(mtu_max)),
761 				.ring_size = cpu_to_le16(size),
762 			},
763 			.ringid = id,
764 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
765 		},
766 	};
767 	struct {
768 		struct wil6210_mbox_hdr_wmi wmi;
769 		struct wmi_vring_cfg_done_event cmd;
770 	} __packed reply;
771 	struct vring *vring = &wil->vring_tx[id];
772 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
773 
774 	wil_dbg_misc(wil, "%s() max_mpdu_size %d\n", __func__,
775 		     cmd.vring_cfg.tx_sw_ring.max_mpdu_size);
776 
777 	if (vring->va) {
778 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
779 		rc = -EINVAL;
780 		goto out;
781 	}
782 
783 	memset(txdata, 0, sizeof(*txdata));
784 	spin_lock_init(&txdata->lock);
785 	vring->size = size;
786 	rc = wil_vring_alloc(wil, vring);
787 	if (rc)
788 		goto out;
789 
790 	wil->vring2cid_tid[id][0] = WIL6210_MAX_CID; /* CID */
791 	wil->vring2cid_tid[id][1] = 0; /* TID */
792 
793 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
794 
795 	rc = wmi_call(wil, WMI_BCAST_VRING_CFG_CMDID, &cmd, sizeof(cmd),
796 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
797 	if (rc)
798 		goto out_free;
799 
800 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
801 		wil_err(wil, "Tx config failed, status 0x%02x\n",
802 			reply.cmd.status);
803 		rc = -EINVAL;
804 		goto out_free;
805 	}
806 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
807 
808 	txdata->enabled = 1;
809 
810 	return 0;
811  out_free:
812 	wil_vring_free(wil, vring, 1);
813  out:
814 
815 	return rc;
816 }
817 
818 void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
819 {
820 	struct vring *vring = &wil->vring_tx[id];
821 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
822 
823 	WARN_ON(!mutex_is_locked(&wil->mutex));
824 
825 	if (!vring->va)
826 		return;
827 
828 	wil_dbg_misc(wil, "%s() id=%d\n", __func__, id);
829 
830 	spin_lock_bh(&txdata->lock);
831 	txdata->enabled = 0; /* no Tx can be in progress or start anew */
832 	spin_unlock_bh(&txdata->lock);
833 	/* make sure NAPI won't touch this vring */
834 	if (test_bit(wil_status_napi_en, wil->status))
835 		napi_synchronize(&wil->napi_tx);
836 
837 	wil_vring_free(wil, vring, 1);
838 	memset(txdata, 0, sizeof(*txdata));
839 }
840 
841 static struct vring *wil_find_tx_ucast(struct wil6210_priv *wil,
842 				       struct sk_buff *skb)
843 {
844 	int i;
845 	struct ethhdr *eth = (void *)skb->data;
846 	int cid = wil_find_cid(wil, eth->h_dest);
847 
848 	if (cid < 0)
849 		return NULL;
850 
851 	if (!wil->sta[cid].data_port_open &&
852 	    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
853 		return NULL;
854 
855 	/* TODO: fix for multiple TID */
856 	for (i = 0; i < ARRAY_SIZE(wil->vring2cid_tid); i++) {
857 		if (wil->vring2cid_tid[i][0] == cid) {
858 			struct vring *v = &wil->vring_tx[i];
859 
860 			wil_dbg_txrx(wil, "%s(%pM) -> [%d]\n",
861 				     __func__, eth->h_dest, i);
862 			if (v->va) {
863 				return v;
864 			} else {
865 				wil_dbg_txrx(wil, "vring[%d] not valid\n", i);
866 				return NULL;
867 			}
868 		}
869 	}
870 
871 	return NULL;
872 }
873 
874 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
875 			struct sk_buff *skb);
876 
877 static struct vring *wil_find_tx_vring_sta(struct wil6210_priv *wil,
878 					   struct sk_buff *skb)
879 {
880 	struct vring *v;
881 	int i;
882 	u8 cid;
883 
884 	/* In the STA mode, it is expected to have only 1 VRING
885 	 * for the AP we connected to.
886 	 * find 1-st vring and see whether it is eligible for data
887 	 */
888 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
889 		v = &wil->vring_tx[i];
890 		if (!v->va)
891 			continue;
892 
893 		cid = wil->vring2cid_tid[i][0];
894 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
895 			continue;
896 
897 		if (!wil->sta[cid].data_port_open &&
898 		    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
899 			break;
900 
901 		wil_dbg_txrx(wil, "Tx -> ring %d\n", i);
902 
903 		return v;
904 	}
905 
906 	wil_dbg_txrx(wil, "Tx while no vrings active?\n");
907 
908 	return NULL;
909 }
910 
911 /* Use one of 2 strategies:
912  *
913  * 1. New (real broadcast):
914  *    use dedicated broadcast vring
915  * 2. Old (pseudo-DMS):
916  *    Find 1-st vring and return it;
917  *    duplicate skb and send it to other active vrings;
918  *    in all cases override dest address to unicast peer's address
919  * Use old strategy when new is not supported yet:
920  *  - for PBSS
921  *  - for secure link
922  */
923 static struct vring *wil_find_tx_bcast_1(struct wil6210_priv *wil,
924 					 struct sk_buff *skb)
925 {
926 	struct vring *v;
927 	int i = wil->bcast_vring;
928 
929 	if (i < 0)
930 		return NULL;
931 	v = &wil->vring_tx[i];
932 	if (!v->va)
933 		return NULL;
934 
935 	return v;
936 }
937 
938 static void wil_set_da_for_vring(struct wil6210_priv *wil,
939 				 struct sk_buff *skb, int vring_index)
940 {
941 	struct ethhdr *eth = (void *)skb->data;
942 	int cid = wil->vring2cid_tid[vring_index][0];
943 
944 	ether_addr_copy(eth->h_dest, wil->sta[cid].addr);
945 }
946 
947 static struct vring *wil_find_tx_bcast_2(struct wil6210_priv *wil,
948 					 struct sk_buff *skb)
949 {
950 	struct vring *v, *v2;
951 	struct sk_buff *skb2;
952 	int i;
953 	u8 cid;
954 	struct ethhdr *eth = (void *)skb->data;
955 	char *src = eth->h_source;
956 
957 	/* find 1-st vring eligible for data */
958 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
959 		v = &wil->vring_tx[i];
960 		if (!v->va)
961 			continue;
962 
963 		cid = wil->vring2cid_tid[i][0];
964 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
965 			continue;
966 		if (!wil->sta[cid].data_port_open)
967 			continue;
968 
969 		/* don't Tx back to source when re-routing Rx->Tx at the AP */
970 		if (0 == memcmp(wil->sta[cid].addr, src, ETH_ALEN))
971 			continue;
972 
973 		goto found;
974 	}
975 
976 	wil_dbg_txrx(wil, "Tx while no vrings active?\n");
977 
978 	return NULL;
979 
980 found:
981 	wil_dbg_txrx(wil, "BCAST -> ring %d\n", i);
982 	wil_set_da_for_vring(wil, skb, i);
983 
984 	/* find other active vrings and duplicate skb for each */
985 	for (i++; i < WIL6210_MAX_TX_RINGS; i++) {
986 		v2 = &wil->vring_tx[i];
987 		if (!v2->va)
988 			continue;
989 		cid = wil->vring2cid_tid[i][0];
990 		if (cid >= WIL6210_MAX_CID) /* skip BCAST */
991 			continue;
992 		if (!wil->sta[cid].data_port_open)
993 			continue;
994 
995 		if (0 == memcmp(wil->sta[cid].addr, src, ETH_ALEN))
996 			continue;
997 
998 		skb2 = skb_copy(skb, GFP_ATOMIC);
999 		if (skb2) {
1000 			wil_dbg_txrx(wil, "BCAST DUP -> ring %d\n", i);
1001 			wil_set_da_for_vring(wil, skb2, i);
1002 			wil_tx_vring(wil, v2, skb2);
1003 		} else {
1004 			wil_err(wil, "skb_copy failed\n");
1005 		}
1006 	}
1007 
1008 	return v;
1009 }
1010 
1011 static struct vring *wil_find_tx_bcast(struct wil6210_priv *wil,
1012 				       struct sk_buff *skb)
1013 {
1014 	struct wireless_dev *wdev = wil->wdev;
1015 
1016 	if (wdev->iftype != NL80211_IFTYPE_AP)
1017 		return wil_find_tx_bcast_2(wil, skb);
1018 
1019 	if (wil->privacy)
1020 		return wil_find_tx_bcast_2(wil, skb);
1021 
1022 	return wil_find_tx_bcast_1(wil, skb);
1023 }
1024 
1025 static int wil_tx_desc_map(struct vring_tx_desc *d, dma_addr_t pa, u32 len,
1026 			   int vring_index)
1027 {
1028 	wil_desc_addr_set(&d->dma.addr, pa);
1029 	d->dma.ip_length = 0;
1030 	/* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
1031 	d->dma.b11 = 0/*14 | BIT(7)*/;
1032 	d->dma.error = 0;
1033 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
1034 	d->dma.length = cpu_to_le16((u16)len);
1035 	d->dma.d0 = (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
1036 	d->mac.d[0] = 0;
1037 	d->mac.d[1] = 0;
1038 	d->mac.d[2] = 0;
1039 	d->mac.ucode_cmd = 0;
1040 	/* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
1041 	d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
1042 		      (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
1043 
1044 	return 0;
1045 }
1046 
1047 static inline
1048 void wil_tx_desc_set_nr_frags(struct vring_tx_desc *d, int nr_frags)
1049 {
1050 	d->mac.d[2] |= ((nr_frags + 1) <<
1051 		       MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
1052 }
1053 
1054 static int wil_tx_desc_offload_cksum_set(struct wil6210_priv *wil,
1055 					 struct vring_tx_desc *d,
1056 					 struct sk_buff *skb)
1057 {
1058 	int protocol;
1059 
1060 	if (skb->ip_summed != CHECKSUM_PARTIAL)
1061 		return 0;
1062 
1063 	d->dma.b11 = ETH_HLEN; /* MAC header length */
1064 
1065 	switch (skb->protocol) {
1066 	case cpu_to_be16(ETH_P_IP):
1067 		protocol = ip_hdr(skb)->protocol;
1068 		d->dma.b11 |= BIT(DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS);
1069 		break;
1070 	case cpu_to_be16(ETH_P_IPV6):
1071 		protocol = ipv6_hdr(skb)->nexthdr;
1072 		break;
1073 	default:
1074 		return -EINVAL;
1075 	}
1076 
1077 	switch (protocol) {
1078 	case IPPROTO_TCP:
1079 		d->dma.d0 |= (2 << DMA_CFG_DESC_TX_0_L4_TYPE_POS);
1080 		/* L4 header len: TCP header length */
1081 		d->dma.d0 |=
1082 		(tcp_hdrlen(skb) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1083 		break;
1084 	case IPPROTO_UDP:
1085 		/* L4 header len: UDP header length */
1086 		d->dma.d0 |=
1087 		(sizeof(struct udphdr) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
1088 		break;
1089 	default:
1090 		return -EINVAL;
1091 	}
1092 
1093 	d->dma.ip_length = skb_network_header_len(skb);
1094 	/* Enable TCP/UDP checksum */
1095 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_TCP_UDP_CHECKSUM_EN_POS);
1096 	/* Calculate pseudo-header */
1097 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_PSEUDO_HEADER_CALC_EN_POS);
1098 
1099 	return 0;
1100 }
1101 
1102 static int __wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
1103 			  struct sk_buff *skb)
1104 {
1105 	struct device *dev = wil_to_dev(wil);
1106 	struct vring_tx_desc dd, *d = &dd;
1107 	volatile struct vring_tx_desc *_d;
1108 	u32 swhead = vring->swhead;
1109 	int avail = wil_vring_avail_tx(vring);
1110 	int nr_frags = skb_shinfo(skb)->nr_frags;
1111 	uint f = 0;
1112 	int vring_index = vring - wil->vring_tx;
1113 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1114 	uint i = swhead;
1115 	dma_addr_t pa;
1116 	int used;
1117 	bool mcast = (vring_index == wil->bcast_vring);
1118 	uint len = skb_headlen(skb);
1119 
1120 	wil_dbg_txrx(wil, "%s()\n", __func__);
1121 
1122 	if (unlikely(!txdata->enabled))
1123 		return -EINVAL;
1124 
1125 	if (unlikely(avail < 1 + nr_frags)) {
1126 		wil_err_ratelimited(wil,
1127 				    "Tx ring[%2d] full. No space for %d fragments\n",
1128 				    vring_index, 1 + nr_frags);
1129 		return -ENOMEM;
1130 	}
1131 	_d = &vring->va[i].tx;
1132 
1133 	pa = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
1134 
1135 	wil_dbg_txrx(wil, "Tx[%2d] skb %d bytes 0x%p -> %pad\n", vring_index,
1136 		     skb_headlen(skb), skb->data, &pa);
1137 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
1138 			  skb->data, skb_headlen(skb), false);
1139 
1140 	if (unlikely(dma_mapping_error(dev, pa)))
1141 		return -EINVAL;
1142 	vring->ctx[i].mapped_as = wil_mapped_as_single;
1143 	/* 1-st segment */
1144 	wil_tx_desc_map(d, pa, len, vring_index);
1145 	if (unlikely(mcast)) {
1146 		d->mac.d[0] |= BIT(MAC_CFG_DESC_TX_0_MCS_EN_POS); /* MCS 0 */
1147 		if (unlikely(len > WIL_BCAST_MCS0_LIMIT)) {
1148 			/* set MCS 1 */
1149 			d->mac.d[0] |= (1 << MAC_CFG_DESC_TX_0_MCS_INDEX_POS);
1150 			/* packet mode 2 */
1151 			d->mac.d[1] |= BIT(MAC_CFG_DESC_TX_1_PKT_MODE_EN_POS) |
1152 				       (2 << MAC_CFG_DESC_TX_1_PKT_MODE_POS);
1153 		}
1154 	}
1155 	/* Process TCP/UDP checksum offloading */
1156 	if (unlikely(wil_tx_desc_offload_cksum_set(wil, d, skb))) {
1157 		wil_err(wil, "Tx[%2d] Failed to set cksum, drop packet\n",
1158 			vring_index);
1159 		goto dma_error;
1160 	}
1161 
1162 	vring->ctx[i].nr_frags = nr_frags;
1163 	wil_tx_desc_set_nr_frags(d, nr_frags);
1164 
1165 	/* middle segments */
1166 	for (; f < nr_frags; f++) {
1167 		const struct skb_frag_struct *frag =
1168 				&skb_shinfo(skb)->frags[f];
1169 		int len = skb_frag_size(frag);
1170 
1171 		*_d = *d;
1172 		wil_dbg_txrx(wil, "Tx[%2d] desc[%4d]\n", vring_index, i);
1173 		wil_hex_dump_txrx("TxD ", DUMP_PREFIX_NONE, 32, 4,
1174 				  (const void *)d, sizeof(*d), false);
1175 		i = (swhead + f + 1) % vring->size;
1176 		_d = &vring->va[i].tx;
1177 		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
1178 				      DMA_TO_DEVICE);
1179 		if (unlikely(dma_mapping_error(dev, pa)))
1180 			goto dma_error;
1181 		vring->ctx[i].mapped_as = wil_mapped_as_page;
1182 		wil_tx_desc_map(d, pa, len, vring_index);
1183 		/* no need to check return code -
1184 		 * if it succeeded for 1-st descriptor,
1185 		 * it will succeed here too
1186 		 */
1187 		wil_tx_desc_offload_cksum_set(wil, d, skb);
1188 	}
1189 	/* for the last seg only */
1190 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
1191 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_MARK_WB_POS);
1192 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
1193 	*_d = *d;
1194 	wil_dbg_txrx(wil, "Tx[%2d] desc[%4d]\n", vring_index, i);
1195 	wil_hex_dump_txrx("TxD ", DUMP_PREFIX_NONE, 32, 4,
1196 			  (const void *)d, sizeof(*d), false);
1197 
1198 	/* hold reference to skb
1199 	 * to prevent skb release before accounting
1200 	 * in case of immediate "tx done"
1201 	 */
1202 	vring->ctx[i].skb = skb_get(skb);
1203 
1204 	/* performance monitoring */
1205 	used = wil_vring_used_tx(vring);
1206 	if (wil_val_in_range(vring_idle_trsh,
1207 			     used, used + nr_frags + 1)) {
1208 		txdata->idle += get_cycles() - txdata->last_idle;
1209 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
1210 			     vring_index, used, used + nr_frags + 1);
1211 	}
1212 
1213 	/* advance swhead */
1214 	wil_vring_advance_head(vring, nr_frags + 1);
1215 	wil_dbg_txrx(wil, "Tx[%2d] swhead %d -> %d\n", vring_index, swhead,
1216 		     vring->swhead);
1217 	trace_wil6210_tx(vring_index, swhead, skb->len, nr_frags);
1218 	iowrite32(vring->swhead, wil->csr + HOSTADDR(vring->hwtail));
1219 
1220 	return 0;
1221  dma_error:
1222 	/* unmap what we have mapped */
1223 	nr_frags = f + 1; /* frags mapped + one for skb head */
1224 	for (f = 0; f < nr_frags; f++) {
1225 		struct wil_ctx *ctx;
1226 
1227 		i = (swhead + f) % vring->size;
1228 		ctx = &vring->ctx[i];
1229 		_d = &vring->va[i].tx;
1230 		*d = *_d;
1231 		_d->dma.status = TX_DMA_STATUS_DU;
1232 		wil_txdesc_unmap(dev, d, ctx);
1233 
1234 		if (ctx->skb)
1235 			dev_kfree_skb_any(ctx->skb);
1236 
1237 		memset(ctx, 0, sizeof(*ctx));
1238 	}
1239 
1240 	return -EINVAL;
1241 }
1242 
1243 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
1244 			struct sk_buff *skb)
1245 {
1246 	int vring_index = vring - wil->vring_tx;
1247 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
1248 	int rc;
1249 
1250 	spin_lock(&txdata->lock);
1251 	rc = __wil_tx_vring(wil, vring, skb);
1252 	spin_unlock(&txdata->lock);
1253 	return rc;
1254 }
1255 
1256 netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
1257 {
1258 	struct wil6210_priv *wil = ndev_to_wil(ndev);
1259 	struct ethhdr *eth = (void *)skb->data;
1260 	bool bcast = is_multicast_ether_addr(eth->h_dest);
1261 	struct vring *vring;
1262 	static bool pr_once_fw;
1263 	int rc;
1264 
1265 	wil_dbg_txrx(wil, "%s()\n", __func__);
1266 	if (unlikely(!test_bit(wil_status_fwready, wil->status))) {
1267 		if (!pr_once_fw) {
1268 			wil_err(wil, "FW not ready\n");
1269 			pr_once_fw = true;
1270 		}
1271 		goto drop;
1272 	}
1273 	if (unlikely(!test_bit(wil_status_fwconnected, wil->status))) {
1274 		wil_err(wil, "FW not connected\n");
1275 		goto drop;
1276 	}
1277 	if (unlikely(wil->wdev->iftype == NL80211_IFTYPE_MONITOR)) {
1278 		wil_err(wil, "Xmit in monitor mode not supported\n");
1279 		goto drop;
1280 	}
1281 	pr_once_fw = false;
1282 
1283 	/* find vring */
1284 	if (wil->wdev->iftype == NL80211_IFTYPE_STATION) {
1285 		/* in STA mode (ESS), all to same VRING */
1286 		vring = wil_find_tx_vring_sta(wil, skb);
1287 	} else { /* direct communication, find matching VRING */
1288 		vring = bcast ? wil_find_tx_bcast(wil, skb) :
1289 				wil_find_tx_ucast(wil, skb);
1290 	}
1291 	if (unlikely(!vring)) {
1292 		wil_dbg_txrx(wil, "No Tx VRING found for %pM\n", eth->h_dest);
1293 		goto drop;
1294 	}
1295 	/* set up vring entry */
1296 	rc = wil_tx_vring(wil, vring, skb);
1297 
1298 	/* do we still have enough room in the vring? */
1299 	if (unlikely(wil_vring_avail_tx(vring) < wil_vring_wmark_low(vring))) {
1300 		netif_tx_stop_all_queues(wil_to_ndev(wil));
1301 		wil_dbg_txrx(wil, "netif_tx_stop : ring full\n");
1302 	}
1303 
1304 	switch (rc) {
1305 	case 0:
1306 		/* statistics will be updated on the tx_complete */
1307 		dev_kfree_skb_any(skb);
1308 		return NETDEV_TX_OK;
1309 	case -ENOMEM:
1310 		return NETDEV_TX_BUSY;
1311 	default:
1312 		break; /* goto drop; */
1313 	}
1314  drop:
1315 	ndev->stats.tx_dropped++;
1316 	dev_kfree_skb_any(skb);
1317 
1318 	return NET_XMIT_DROP;
1319 }
1320 
1321 static inline bool wil_need_txstat(struct sk_buff *skb)
1322 {
1323 	struct ethhdr *eth = (void *)skb->data;
1324 
1325 	return is_unicast_ether_addr(eth->h_dest) && skb->sk &&
1326 	       (skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS);
1327 }
1328 
1329 static inline void wil_consume_skb(struct sk_buff *skb, bool acked)
1330 {
1331 	if (unlikely(wil_need_txstat(skb)))
1332 		skb_complete_wifi_ack(skb, acked);
1333 	else
1334 		acked ? dev_consume_skb_any(skb) : dev_kfree_skb_any(skb);
1335 }
1336 
1337 /**
1338  * Clean up transmitted skb's from the Tx VRING
1339  *
1340  * Return number of descriptors cleared
1341  *
1342  * Safe to call from IRQ
1343  */
1344 int wil_tx_complete(struct wil6210_priv *wil, int ringid)
1345 {
1346 	struct net_device *ndev = wil_to_ndev(wil);
1347 	struct device *dev = wil_to_dev(wil);
1348 	struct vring *vring = &wil->vring_tx[ringid];
1349 	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
1350 	int done = 0;
1351 	int cid = wil->vring2cid_tid[ringid][0];
1352 	struct wil_net_stats *stats = NULL;
1353 	volatile struct vring_tx_desc *_d;
1354 	int used_before_complete;
1355 	int used_new;
1356 
1357 	if (unlikely(!vring->va)) {
1358 		wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
1359 		return 0;
1360 	}
1361 
1362 	if (unlikely(!txdata->enabled)) {
1363 		wil_info(wil, "Tx irq[%d]: vring disabled\n", ringid);
1364 		return 0;
1365 	}
1366 
1367 	wil_dbg_txrx(wil, "%s(%d)\n", __func__, ringid);
1368 
1369 	used_before_complete = wil_vring_used_tx(vring);
1370 
1371 	if (cid < WIL6210_MAX_CID)
1372 		stats = &wil->sta[cid].stats;
1373 
1374 	while (!wil_vring_is_empty(vring)) {
1375 		int new_swtail;
1376 		struct wil_ctx *ctx = &vring->ctx[vring->swtail];
1377 		/**
1378 		 * For the fragmented skb, HW will set DU bit only for the
1379 		 * last fragment. look for it
1380 		 */
1381 		int lf = (vring->swtail + ctx->nr_frags) % vring->size;
1382 		/* TODO: check we are not past head */
1383 
1384 		_d = &vring->va[lf].tx;
1385 		if (unlikely(!(_d->dma.status & TX_DMA_STATUS_DU)))
1386 			break;
1387 
1388 		new_swtail = (lf + 1) % vring->size;
1389 		while (vring->swtail != new_swtail) {
1390 			struct vring_tx_desc dd, *d = &dd;
1391 			u16 dmalen;
1392 			struct sk_buff *skb;
1393 
1394 			ctx = &vring->ctx[vring->swtail];
1395 			skb = ctx->skb;
1396 			_d = &vring->va[vring->swtail].tx;
1397 
1398 			*d = *_d;
1399 
1400 			dmalen = le16_to_cpu(d->dma.length);
1401 			trace_wil6210_tx_done(ringid, vring->swtail, dmalen,
1402 					      d->dma.error);
1403 			wil_dbg_txrx(wil,
1404 				     "TxC[%2d][%3d] : %d bytes, status 0x%02x err 0x%02x\n",
1405 				     ringid, vring->swtail, dmalen,
1406 				     d->dma.status, d->dma.error);
1407 			wil_hex_dump_txrx("TxCD ", DUMP_PREFIX_NONE, 32, 4,
1408 					  (const void *)d, sizeof(*d), false);
1409 
1410 			wil_txdesc_unmap(dev, d, ctx);
1411 
1412 			if (skb) {
1413 				if (likely(d->dma.error == 0)) {
1414 					ndev->stats.tx_packets++;
1415 					ndev->stats.tx_bytes += skb->len;
1416 					if (stats) {
1417 						stats->tx_packets++;
1418 						stats->tx_bytes += skb->len;
1419 					}
1420 				} else {
1421 					ndev->stats.tx_errors++;
1422 					if (stats)
1423 						stats->tx_errors++;
1424 				}
1425 				wil_consume_skb(skb, d->dma.error == 0);
1426 			}
1427 			memset(ctx, 0, sizeof(*ctx));
1428 			/* There is no need to touch HW descriptor:
1429 			 * - ststus bit TX_DMA_STATUS_DU is set by design,
1430 			 *   so hardware will not try to process this desc.,
1431 			 * - rest of descriptor will be initialized on Tx.
1432 			 */
1433 			vring->swtail = wil_vring_next_tail(vring);
1434 			done++;
1435 		}
1436 	}
1437 
1438 	/* performance monitoring */
1439 	used_new = wil_vring_used_tx(vring);
1440 	if (wil_val_in_range(vring_idle_trsh,
1441 			     used_new, used_before_complete)) {
1442 		wil_dbg_txrx(wil, "Ring[%2d] idle %d -> %d\n",
1443 			     ringid, used_before_complete, used_new);
1444 		txdata->last_idle = get_cycles();
1445 	}
1446 
1447 	if (wil_vring_avail_tx(vring) > wil_vring_wmark_high(vring)) {
1448 		wil_dbg_txrx(wil, "netif_tx_wake : ring not full\n");
1449 		netif_tx_wake_all_queues(wil_to_ndev(wil));
1450 	}
1451 
1452 	return done;
1453 }
1454