1 /*
2  * Copyright (c) 2012 Qualcomm Atheros, Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/etherdevice.h>
18 #include <net/ieee80211_radiotap.h>
19 #include <linux/if_arp.h>
20 #include <linux/moduleparam.h>
21 
22 #include "wil6210.h"
23 #include "wmi.h"
24 #include "txrx.h"
25 #include "trace.h"
26 
27 static bool rtap_include_phy_info;
28 module_param(rtap_include_phy_info, bool, S_IRUGO);
29 MODULE_PARM_DESC(rtap_include_phy_info,
30 		 " Include PHY info in the radiotap header, default - no");
31 
32 static inline int wil_vring_is_empty(struct vring *vring)
33 {
34 	return vring->swhead == vring->swtail;
35 }
36 
37 static inline u32 wil_vring_next_tail(struct vring *vring)
38 {
39 	return (vring->swtail + 1) % vring->size;
40 }
41 
42 static inline void wil_vring_advance_head(struct vring *vring, int n)
43 {
44 	vring->swhead = (vring->swhead + n) % vring->size;
45 }
46 
47 static inline int wil_vring_is_full(struct vring *vring)
48 {
49 	return wil_vring_next_tail(vring) == vring->swhead;
50 }
51 /*
52  * Available space in Tx Vring
53  */
54 static inline int wil_vring_avail_tx(struct vring *vring)
55 {
56 	u32 swhead = vring->swhead;
57 	u32 swtail = vring->swtail;
58 	int used = (vring->size + swhead - swtail) % vring->size;
59 
60 	return vring->size - used - 1;
61 }
62 
63 static int wil_vring_alloc(struct wil6210_priv *wil, struct vring *vring)
64 {
65 	struct device *dev = wil_to_dev(wil);
66 	size_t sz = vring->size * sizeof(vring->va[0]);
67 	uint i;
68 
69 	BUILD_BUG_ON(sizeof(vring->va[0]) != 32);
70 
71 	vring->swhead = 0;
72 	vring->swtail = 0;
73 	vring->ctx = kzalloc(vring->size * sizeof(vring->ctx[0]), GFP_KERNEL);
74 	if (!vring->ctx) {
75 		vring->va = NULL;
76 		return -ENOMEM;
77 	}
78 	/*
79 	 * vring->va should be aligned on its size rounded up to power of 2
80 	 * This is granted by the dma_alloc_coherent
81 	 */
82 	vring->va = dma_alloc_coherent(dev, sz, &vring->pa, GFP_KERNEL);
83 	if (!vring->va) {
84 		kfree(vring->ctx);
85 		vring->ctx = NULL;
86 		return -ENOMEM;
87 	}
88 	/* initially, all descriptors are SW owned
89 	 * For Tx and Rx, ownership bit is at the same location, thus
90 	 * we can use any
91 	 */
92 	for (i = 0; i < vring->size; i++) {
93 		volatile struct vring_tx_desc *_d = &(vring->va[i].tx);
94 		_d->dma.status = TX_DMA_STATUS_DU;
95 	}
96 
97 	wil_dbg_misc(wil, "vring[%d] 0x%p:0x%016llx 0x%p\n", vring->size,
98 		     vring->va, (unsigned long long)vring->pa, vring->ctx);
99 
100 	return 0;
101 }
102 
103 static void wil_vring_free(struct wil6210_priv *wil, struct vring *vring,
104 			   int tx)
105 {
106 	struct device *dev = wil_to_dev(wil);
107 	size_t sz = vring->size * sizeof(vring->va[0]);
108 
109 	while (!wil_vring_is_empty(vring)) {
110 		dma_addr_t pa;
111 		struct sk_buff *skb;
112 		u16 dmalen;
113 
114 		if (tx) {
115 			struct vring_tx_desc dd, *d = &dd;
116 			volatile struct vring_tx_desc *_d =
117 					&vring->va[vring->swtail].tx;
118 
119 			*d = *_d;
120 			pa = wil_desc_addr(&d->dma.addr);
121 			dmalen = le16_to_cpu(d->dma.length);
122 			skb = vring->ctx[vring->swtail];
123 			if (skb) {
124 				dma_unmap_single(dev, pa, dmalen,
125 						 DMA_TO_DEVICE);
126 				dev_kfree_skb_any(skb);
127 				vring->ctx[vring->swtail] = NULL;
128 			} else {
129 				dma_unmap_page(dev, pa, dmalen,
130 					       DMA_TO_DEVICE);
131 			}
132 			vring->swtail = wil_vring_next_tail(vring);
133 		} else { /* rx */
134 			struct vring_rx_desc dd, *d = &dd;
135 			volatile struct vring_rx_desc *_d =
136 					&vring->va[vring->swtail].rx;
137 
138 			*d = *_d;
139 			pa = wil_desc_addr(&d->dma.addr);
140 			dmalen = le16_to_cpu(d->dma.length);
141 			skb = vring->ctx[vring->swhead];
142 			dma_unmap_single(dev, pa, dmalen, DMA_FROM_DEVICE);
143 			kfree_skb(skb);
144 			wil_vring_advance_head(vring, 1);
145 		}
146 	}
147 	dma_free_coherent(dev, sz, (void *)vring->va, vring->pa);
148 	kfree(vring->ctx);
149 	vring->pa = 0;
150 	vring->va = NULL;
151 	vring->ctx = NULL;
152 }
153 
154 /**
155  * Allocate one skb for Rx VRING
156  *
157  * Safe to call from IRQ
158  */
159 static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
160 			       u32 i, int headroom)
161 {
162 	struct device *dev = wil_to_dev(wil);
163 	unsigned int sz = RX_BUF_LEN;
164 	struct vring_rx_desc dd, *d = &dd;
165 	volatile struct vring_rx_desc *_d = &(vring->va[i].rx);
166 	dma_addr_t pa;
167 
168 	/* TODO align */
169 	struct sk_buff *skb = dev_alloc_skb(sz + headroom);
170 	if (unlikely(!skb))
171 		return -ENOMEM;
172 
173 	skb_reserve(skb, headroom);
174 	skb_put(skb, sz);
175 
176 	pa = dma_map_single(dev, skb->data, skb->len, DMA_FROM_DEVICE);
177 	if (unlikely(dma_mapping_error(dev, pa))) {
178 		kfree_skb(skb);
179 		return -ENOMEM;
180 	}
181 
182 	d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
183 	wil_desc_addr_set(&d->dma.addr, pa);
184 	/* ip_length don't care */
185 	/* b11 don't care */
186 	/* error don't care */
187 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
188 	d->dma.length = cpu_to_le16(sz);
189 	*_d = *d;
190 	vring->ctx[i] = skb;
191 
192 	return 0;
193 }
194 
195 /**
196  * Adds radiotap header
197  *
198  * Any error indicated as "Bad FCS"
199  *
200  * Vendor data for 04:ce:14-1 (Wilocity-1) consists of:
201  *  - Rx descriptor: 32 bytes
202  *  - Phy info
203  */
204 static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
205 				       struct sk_buff *skb)
206 {
207 	struct wireless_dev *wdev = wil->wdev;
208 	struct wil6210_rtap {
209 		struct ieee80211_radiotap_header rthdr;
210 		/* fields should be in the order of bits in rthdr.it_present */
211 		/* flags */
212 		u8 flags;
213 		/* channel */
214 		__le16 chnl_freq __aligned(2);
215 		__le16 chnl_flags;
216 		/* MCS */
217 		u8 mcs_present;
218 		u8 mcs_flags;
219 		u8 mcs_index;
220 	} __packed;
221 	struct wil6210_rtap_vendor {
222 		struct wil6210_rtap rtap;
223 		/* vendor */
224 		u8 vendor_oui[3] __aligned(2);
225 		u8 vendor_ns;
226 		__le16 vendor_skip;
227 		u8 vendor_data[0];
228 	} __packed;
229 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
230 	struct wil6210_rtap_vendor *rtap_vendor;
231 	int rtap_len = sizeof(struct wil6210_rtap);
232 	int phy_length = 0; /* phy info header size, bytes */
233 	static char phy_data[128];
234 	struct ieee80211_channel *ch = wdev->preset_chandef.chan;
235 
236 	if (rtap_include_phy_info) {
237 		rtap_len = sizeof(*rtap_vendor) + sizeof(*d);
238 		/* calculate additional length */
239 		if (d->dma.status & RX_DMA_STATUS_PHY_INFO) {
240 			/**
241 			 * PHY info starts from 8-byte boundary
242 			 * there are 8-byte lines, last line may be partially
243 			 * written (HW bug), thus FW configures for last line
244 			 * to be excessive. Driver skips this last line.
245 			 */
246 			int len = min_t(int, 8 + sizeof(phy_data),
247 					wil_rxdesc_phy_length(d));
248 			if (len > 8) {
249 				void *p = skb_tail_pointer(skb);
250 				void *pa = PTR_ALIGN(p, 8);
251 				if (skb_tailroom(skb) >= len + (pa - p)) {
252 					phy_length = len - 8;
253 					memcpy(phy_data, pa, phy_length);
254 				}
255 			}
256 		}
257 		rtap_len += phy_length;
258 	}
259 
260 	if (skb_headroom(skb) < rtap_len &&
261 	    pskb_expand_head(skb, rtap_len, 0, GFP_ATOMIC)) {
262 		wil_err(wil, "Unable to expand headrom to %d\n", rtap_len);
263 		return;
264 	}
265 
266 	rtap_vendor = (void *)skb_push(skb, rtap_len);
267 	memset(rtap_vendor, 0, rtap_len);
268 
269 	rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;
270 	rtap_vendor->rtap.rthdr.it_len = cpu_to_le16(rtap_len);
271 	rtap_vendor->rtap.rthdr.it_present = cpu_to_le32(
272 			(1 << IEEE80211_RADIOTAP_FLAGS) |
273 			(1 << IEEE80211_RADIOTAP_CHANNEL) |
274 			(1 << IEEE80211_RADIOTAP_MCS));
275 	if (d->dma.status & RX_DMA_STATUS_ERROR)
276 		rtap_vendor->rtap.flags |= IEEE80211_RADIOTAP_F_BADFCS;
277 
278 	rtap_vendor->rtap.chnl_freq = cpu_to_le16(ch ? ch->center_freq : 58320);
279 	rtap_vendor->rtap.chnl_flags = cpu_to_le16(0);
280 
281 	rtap_vendor->rtap.mcs_present = IEEE80211_RADIOTAP_MCS_HAVE_MCS;
282 	rtap_vendor->rtap.mcs_flags = 0;
283 	rtap_vendor->rtap.mcs_index = wil_rxdesc_mcs(d);
284 
285 	if (rtap_include_phy_info) {
286 		rtap_vendor->rtap.rthdr.it_present |= cpu_to_le32(1 <<
287 				IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
288 		/* OUI for Wilocity 04:ce:14 */
289 		rtap_vendor->vendor_oui[0] = 0x04;
290 		rtap_vendor->vendor_oui[1] = 0xce;
291 		rtap_vendor->vendor_oui[2] = 0x14;
292 		rtap_vendor->vendor_ns = 1;
293 		/* Rx descriptor + PHY data  */
294 		rtap_vendor->vendor_skip = cpu_to_le16(sizeof(*d) +
295 						       phy_length);
296 		memcpy(rtap_vendor->vendor_data, (void *)d, sizeof(*d));
297 		memcpy(rtap_vendor->vendor_data + sizeof(*d), phy_data,
298 		       phy_length);
299 	}
300 }
301 
302 /*
303  * Fast swap in place between 2 registers
304  */
305 static void wil_swap_u16(u16 *a, u16 *b)
306 {
307 	*a ^= *b;
308 	*b ^= *a;
309 	*a ^= *b;
310 }
311 
312 static void wil_swap_ethaddr(void *data)
313 {
314 	struct ethhdr *eth = data;
315 	u16 *s = (u16 *)eth->h_source;
316 	u16 *d = (u16 *)eth->h_dest;
317 
318 	wil_swap_u16(s++, d++);
319 	wil_swap_u16(s++, d++);
320 	wil_swap_u16(s, d);
321 }
322 
323 /**
324  * reap 1 frame from @swhead
325  *
326  * Rx descriptor copied to skb->cb
327  *
328  * Safe to call from IRQ
329  */
330 static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
331 					 struct vring *vring)
332 {
333 	struct device *dev = wil_to_dev(wil);
334 	struct net_device *ndev = wil_to_ndev(wil);
335 	volatile struct vring_rx_desc *_d;
336 	struct vring_rx_desc *d;
337 	struct sk_buff *skb;
338 	dma_addr_t pa;
339 	unsigned int sz = RX_BUF_LEN;
340 	u16 dmalen;
341 	u8 ftype;
342 	u8 ds_bits;
343 
344 	BUILD_BUG_ON(sizeof(struct vring_rx_desc) > sizeof(skb->cb));
345 
346 	if (wil_vring_is_empty(vring))
347 		return NULL;
348 
349 	_d = &(vring->va[vring->swhead].rx);
350 	if (!(_d->dma.status & RX_DMA_STATUS_DU)) {
351 		/* it is not error, we just reached end of Rx done area */
352 		return NULL;
353 	}
354 
355 	skb = vring->ctx[vring->swhead];
356 	d = wil_skb_rxdesc(skb);
357 	*d = *_d;
358 	pa = wil_desc_addr(&d->dma.addr);
359 	vring->ctx[vring->swhead] = NULL;
360 	wil_vring_advance_head(vring, 1);
361 
362 	dma_unmap_single(dev, pa, sz, DMA_FROM_DEVICE);
363 	dmalen = le16_to_cpu(d->dma.length);
364 
365 	trace_wil6210_rx(vring->swhead, d);
366 	wil_dbg_txrx(wil, "Rx[%3d] : %d bytes\n", vring->swhead, dmalen);
367 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_NONE, 32, 4,
368 			  (const void *)d, sizeof(*d), false);
369 
370 	if (dmalen > sz) {
371 		wil_err(wil, "Rx size too large: %d bytes!\n", dmalen);
372 		kfree_skb(skb);
373 		return NULL;
374 	}
375 	skb_trim(skb, dmalen);
376 
377 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
378 			  skb->data, skb_headlen(skb), false);
379 
380 
381 	wil->stats.last_mcs_rx = wil_rxdesc_mcs(d);
382 
383 	/* use radiotap header only if required */
384 	if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
385 		wil_rx_add_radiotap_header(wil, skb);
386 
387 	/* no extra checks if in sniffer mode */
388 	if (ndev->type != ARPHRD_ETHER)
389 		return skb;
390 	/*
391 	 * Non-data frames may be delivered through Rx DMA channel (ex: BAR)
392 	 * Driver should recognize it by frame type, that is found
393 	 * in Rx descriptor. If type is not data, it is 802.11 frame as is
394 	 */
395 	ftype = wil_rxdesc_ftype(d) << 2;
396 	if (ftype != IEEE80211_FTYPE_DATA) {
397 		wil_dbg_txrx(wil, "Non-data frame ftype 0x%08x\n", ftype);
398 		/* TODO: process it */
399 		kfree_skb(skb);
400 		return NULL;
401 	}
402 
403 	if (skb->len < ETH_HLEN) {
404 		wil_err(wil, "Short frame, len = %d\n", skb->len);
405 		/* TODO: process it (i.e. BAR) */
406 		kfree_skb(skb);
407 		return NULL;
408 	}
409 
410 	ds_bits = wil_rxdesc_ds_bits(d);
411 	if (ds_bits == 1) {
412 		/*
413 		 * HW bug - in ToDS mode, i.e. Rx on AP side,
414 		 * addresses get swapped
415 		 */
416 		wil_swap_ethaddr(skb->data);
417 	}
418 
419 	return skb;
420 }
421 
422 /**
423  * allocate and fill up to @count buffers in rx ring
424  * buffers posted at @swtail
425  */
426 static int wil_rx_refill(struct wil6210_priv *wil, int count)
427 {
428 	struct net_device *ndev = wil_to_ndev(wil);
429 	struct vring *v = &wil->vring_rx;
430 	u32 next_tail;
431 	int rc = 0;
432 	int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
433 			WIL6210_RTAP_SIZE : 0;
434 
435 	for (; next_tail = wil_vring_next_tail(v),
436 			(next_tail != v->swhead) && (count-- > 0);
437 			v->swtail = next_tail) {
438 		rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
439 		if (rc) {
440 			wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
441 				rc, v->swtail);
442 			break;
443 		}
444 	}
445 	iowrite32(v->swtail, wil->csr + HOSTADDR(v->hwtail));
446 
447 	return rc;
448 }
449 
450 /*
451  * Pass Rx packet to the netif. Update statistics.
452  * Called in softirq context (NAPI poll).
453  */
454 static void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
455 {
456 	int rc;
457 	unsigned int len = skb->len;
458 
459 	skb_orphan(skb);
460 
461 	rc = netif_receive_skb(skb);
462 
463 	if (likely(rc == NET_RX_SUCCESS)) {
464 		ndev->stats.rx_packets++;
465 		ndev->stats.rx_bytes += len;
466 
467 	} else {
468 		ndev->stats.rx_dropped++;
469 	}
470 }
471 
472 /**
473  * Proceed all completed skb's from Rx VRING
474  *
475  * Safe to call from NAPI poll, i.e. softirq with interrupts enabled
476  */
477 void wil_rx_handle(struct wil6210_priv *wil, int *quota)
478 {
479 	struct net_device *ndev = wil_to_ndev(wil);
480 	struct vring *v = &wil->vring_rx;
481 	struct sk_buff *skb;
482 
483 	if (!v->va) {
484 		wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
485 		return;
486 	}
487 	wil_dbg_txrx(wil, "%s()\n", __func__);
488 	while ((*quota > 0) && (NULL != (skb = wil_vring_reap_rx(wil, v)))) {
489 		(*quota)--;
490 
491 		if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
492 			skb->dev = ndev;
493 			skb_reset_mac_header(skb);
494 			skb->ip_summed = CHECKSUM_UNNECESSARY;
495 			skb->pkt_type = PACKET_OTHERHOST;
496 			skb->protocol = htons(ETH_P_802_2);
497 
498 		} else {
499 			skb->protocol = eth_type_trans(skb, ndev);
500 		}
501 
502 		wil_netif_rx_any(skb, ndev);
503 	}
504 	wil_rx_refill(wil, v->size);
505 }
506 
507 int wil_rx_init(struct wil6210_priv *wil)
508 {
509 	struct vring *vring = &wil->vring_rx;
510 	int rc;
511 
512 	vring->size = WIL6210_RX_RING_SIZE;
513 	rc = wil_vring_alloc(wil, vring);
514 	if (rc)
515 		return rc;
516 
517 	rc = wmi_rx_chain_add(wil, vring);
518 	if (rc)
519 		goto err_free;
520 
521 	rc = wil_rx_refill(wil, vring->size);
522 	if (rc)
523 		goto err_free;
524 
525 	return 0;
526  err_free:
527 	wil_vring_free(wil, vring, 0);
528 
529 	return rc;
530 }
531 
532 void wil_rx_fini(struct wil6210_priv *wil)
533 {
534 	struct vring *vring = &wil->vring_rx;
535 
536 	if (vring->va)
537 		wil_vring_free(wil, vring, 0);
538 }
539 
540 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
541 		      int cid, int tid)
542 {
543 	int rc;
544 	struct wmi_vring_cfg_cmd cmd = {
545 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
546 		.vring_cfg = {
547 			.tx_sw_ring = {
548 				.max_mpdu_size = cpu_to_le16(TX_BUF_LEN),
549 				.ring_size = cpu_to_le16(size),
550 			},
551 			.ringid = id,
552 			.cidxtid = (cid & 0xf) | ((tid & 0xf) << 4),
553 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
554 			.mac_ctrl = 0,
555 			.to_resolution = 0,
556 			.agg_max_wsize = 16,
557 			.schd_params = {
558 				.priority = cpu_to_le16(0),
559 				.timeslot_us = cpu_to_le16(0xfff),
560 			},
561 		},
562 	};
563 	struct {
564 		struct wil6210_mbox_hdr_wmi wmi;
565 		struct wmi_vring_cfg_done_event cmd;
566 	} __packed reply;
567 	struct vring *vring = &wil->vring_tx[id];
568 
569 	if (vring->va) {
570 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
571 		rc = -EINVAL;
572 		goto out;
573 	}
574 
575 	vring->size = size;
576 	rc = wil_vring_alloc(wil, vring);
577 	if (rc)
578 		goto out;
579 
580 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
581 
582 	rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
583 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
584 	if (rc)
585 		goto out_free;
586 
587 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
588 		wil_err(wil, "Tx config failed, status 0x%02x\n",
589 			reply.cmd.status);
590 		rc = -EINVAL;
591 		goto out_free;
592 	}
593 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
594 
595 	return 0;
596  out_free:
597 	wil_vring_free(wil, vring, 1);
598  out:
599 
600 	return rc;
601 }
602 
603 void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
604 {
605 	struct vring *vring = &wil->vring_tx[id];
606 
607 	if (!vring->va)
608 		return;
609 
610 	wil_vring_free(wil, vring, 1);
611 }
612 
613 static struct vring *wil_find_tx_vring(struct wil6210_priv *wil,
614 				       struct sk_buff *skb)
615 {
616 	struct vring *v = &wil->vring_tx[0];
617 
618 	if (v->va)
619 		return v;
620 
621 	return NULL;
622 }
623 
624 static int wil_tx_desc_map(struct vring_tx_desc *d, dma_addr_t pa, u32 len,
625 			   int vring_index)
626 {
627 	wil_desc_addr_set(&d->dma.addr, pa);
628 	d->dma.ip_length = 0;
629 	/* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
630 	d->dma.b11 = 0/*14 | BIT(7)*/;
631 	d->dma.error = 0;
632 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
633 	d->dma.length = cpu_to_le16((u16)len);
634 	d->dma.d0 = (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
635 	d->mac.d[0] = 0;
636 	d->mac.d[1] = 0;
637 	d->mac.d[2] = 0;
638 	d->mac.ucode_cmd = 0;
639 	/* use dst index 0 */
640 	d->mac.d[1] |= BIT(MAC_CFG_DESC_TX_1_DST_INDEX_EN_POS) |
641 		       (0 << MAC_CFG_DESC_TX_1_DST_INDEX_POS);
642 	/* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
643 	d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
644 		      (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
645 
646 	return 0;
647 }
648 
649 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
650 			struct sk_buff *skb)
651 {
652 	struct device *dev = wil_to_dev(wil);
653 	struct vring_tx_desc dd, *d = &dd;
654 	volatile struct vring_tx_desc *_d;
655 	u32 swhead = vring->swhead;
656 	int avail = wil_vring_avail_tx(vring);
657 	int nr_frags = skb_shinfo(skb)->nr_frags;
658 	uint f;
659 	int vring_index = vring - wil->vring_tx;
660 	uint i = swhead;
661 	dma_addr_t pa;
662 
663 	wil_dbg_txrx(wil, "%s()\n", __func__);
664 
665 	if (avail < vring->size/8)
666 		netif_tx_stop_all_queues(wil_to_ndev(wil));
667 	if (avail < 1 + nr_frags) {
668 		wil_err(wil, "Tx ring full. No space for %d fragments\n",
669 			1 + nr_frags);
670 		return -ENOMEM;
671 	}
672 	_d = &(vring->va[i].tx);
673 
674 	/* FIXME FW can accept only unicast frames for the peer */
675 	memcpy(skb->data, wil->dst_addr[vring_index], ETH_ALEN);
676 
677 	pa = dma_map_single(dev, skb->data,
678 			skb_headlen(skb), DMA_TO_DEVICE);
679 
680 	wil_dbg_txrx(wil, "Tx skb %d bytes %p -> %#08llx\n", skb_headlen(skb),
681 		     skb->data, (unsigned long long)pa);
682 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
683 			  skb->data, skb_headlen(skb), false);
684 
685 	if (unlikely(dma_mapping_error(dev, pa)))
686 		return -EINVAL;
687 	/* 1-st segment */
688 	wil_tx_desc_map(d, pa, skb_headlen(skb), vring_index);
689 	d->mac.d[2] |= ((nr_frags + 1) <<
690 		       MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
691 	if (nr_frags)
692 		*_d = *d;
693 
694 	/* middle segments */
695 	for (f = 0; f < nr_frags; f++) {
696 		const struct skb_frag_struct *frag =
697 				&skb_shinfo(skb)->frags[f];
698 		int len = skb_frag_size(frag);
699 		i = (swhead + f + 1) % vring->size;
700 		_d = &(vring->va[i].tx);
701 		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
702 				DMA_TO_DEVICE);
703 		if (unlikely(dma_mapping_error(dev, pa)))
704 			goto dma_error;
705 		wil_tx_desc_map(d, pa, len, vring_index);
706 		vring->ctx[i] = NULL;
707 		*_d = *d;
708 	}
709 	/* for the last seg only */
710 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
711 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_MARK_WB_POS);
712 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
713 	*_d = *d;
714 
715 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_NONE, 32, 4,
716 			  (const void *)d, sizeof(*d), false);
717 
718 	/* advance swhead */
719 	wil_vring_advance_head(vring, nr_frags + 1);
720 	wil_dbg_txrx(wil, "Tx swhead %d -> %d\n", swhead, vring->swhead);
721 	trace_wil6210_tx(vring_index, swhead, skb->len, nr_frags);
722 	iowrite32(vring->swhead, wil->csr + HOSTADDR(vring->hwtail));
723 	/* hold reference to skb
724 	 * to prevent skb release before accounting
725 	 * in case of immediate "tx done"
726 	 */
727 	vring->ctx[i] = skb_get(skb);
728 
729 	return 0;
730  dma_error:
731 	/* unmap what we have mapped */
732 	/* Note: increment @f to operate with positive index */
733 	for (f++; f > 0; f--) {
734 		u16 dmalen;
735 
736 		i = (swhead + f) % vring->size;
737 		_d = &(vring->va[i].tx);
738 		*d = *_d;
739 		_d->dma.status = TX_DMA_STATUS_DU;
740 		pa = wil_desc_addr(&d->dma.addr);
741 		dmalen = le16_to_cpu(d->dma.length);
742 		if (vring->ctx[i])
743 			dma_unmap_single(dev, pa, dmalen, DMA_TO_DEVICE);
744 		else
745 			dma_unmap_page(dev, pa, dmalen, DMA_TO_DEVICE);
746 	}
747 
748 	return -EINVAL;
749 }
750 
751 
752 netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
753 {
754 	struct wil6210_priv *wil = ndev_to_wil(ndev);
755 	struct vring *vring;
756 	int rc;
757 
758 	wil_dbg_txrx(wil, "%s()\n", __func__);
759 	if (!test_bit(wil_status_fwready, &wil->status)) {
760 		wil_err(wil, "FW not ready\n");
761 		goto drop;
762 	}
763 	if (!test_bit(wil_status_fwconnected, &wil->status)) {
764 		wil_err(wil, "FW not connected\n");
765 		goto drop;
766 	}
767 	if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
768 		wil_err(wil, "Xmit in monitor mode not supported\n");
769 		goto drop;
770 	}
771 
772 	/* find vring */
773 	vring = wil_find_tx_vring(wil, skb);
774 	if (!vring) {
775 		wil_err(wil, "No Tx VRING available\n");
776 		goto drop;
777 	}
778 	/* set up vring entry */
779 	rc = wil_tx_vring(wil, vring, skb);
780 
781 	switch (rc) {
782 	case 0:
783 		/* statistics will be updated on the tx_complete */
784 		dev_kfree_skb_any(skb);
785 		return NETDEV_TX_OK;
786 	case -ENOMEM:
787 		return NETDEV_TX_BUSY;
788 	default:
789 		break; /* goto drop; */
790 	}
791  drop:
792 	ndev->stats.tx_dropped++;
793 	dev_kfree_skb_any(skb);
794 
795 	return NET_XMIT_DROP;
796 }
797 
798 /**
799  * Clean up transmitted skb's from the Tx VRING
800  *
801  * Return number of descriptors cleared
802  *
803  * Safe to call from IRQ
804  */
805 int wil_tx_complete(struct wil6210_priv *wil, int ringid)
806 {
807 	struct net_device *ndev = wil_to_ndev(wil);
808 	struct device *dev = wil_to_dev(wil);
809 	struct vring *vring = &wil->vring_tx[ringid];
810 	int done = 0;
811 
812 	if (!vring->va) {
813 		wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
814 		return 0;
815 	}
816 
817 	wil_dbg_txrx(wil, "%s(%d)\n", __func__, ringid);
818 
819 	while (!wil_vring_is_empty(vring)) {
820 		volatile struct vring_tx_desc *_d =
821 					      &vring->va[vring->swtail].tx;
822 		struct vring_tx_desc dd, *d = &dd;
823 		dma_addr_t pa;
824 		struct sk_buff *skb;
825 		u16 dmalen;
826 
827 		*d = *_d;
828 
829 		if (!(d->dma.status & TX_DMA_STATUS_DU))
830 			break;
831 
832 		dmalen = le16_to_cpu(d->dma.length);
833 		trace_wil6210_tx_done(ringid, vring->swtail, dmalen,
834 				      d->dma.error);
835 		wil_dbg_txrx(wil,
836 			     "Tx[%3d] : %d bytes, status 0x%02x err 0x%02x\n",
837 			     vring->swtail, dmalen, d->dma.status,
838 			     d->dma.error);
839 		wil_hex_dump_txrx("TxC ", DUMP_PREFIX_NONE, 32, 4,
840 				  (const void *)d, sizeof(*d), false);
841 
842 		pa = wil_desc_addr(&d->dma.addr);
843 		skb = vring->ctx[vring->swtail];
844 		if (skb) {
845 			if (d->dma.error == 0) {
846 				ndev->stats.tx_packets++;
847 				ndev->stats.tx_bytes += skb->len;
848 			} else {
849 				ndev->stats.tx_errors++;
850 			}
851 
852 			dma_unmap_single(dev, pa, dmalen, DMA_TO_DEVICE);
853 			dev_kfree_skb_any(skb);
854 			vring->ctx[vring->swtail] = NULL;
855 		} else {
856 			dma_unmap_page(dev, pa, dmalen, DMA_TO_DEVICE);
857 		}
858 		d->dma.addr.addr_low = 0;
859 		d->dma.addr.addr_high = 0;
860 		d->dma.length = 0;
861 		d->dma.status = TX_DMA_STATUS_DU;
862 		vring->swtail = wil_vring_next_tail(vring);
863 		done++;
864 	}
865 	if (wil_vring_avail_tx(vring) > vring->size/4)
866 		netif_tx_wake_all_queues(wil_to_ndev(wil));
867 
868 	return done;
869 }
870