1 /*
2  * Copyright (c) 2012 Qualcomm Atheros, Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
20 #include <linux/hardirq.h>
21 #include <net/ieee80211_radiotap.h>
22 #include <linux/if_arp.h>
23 #include <linux/moduleparam.h>
24 
25 #include "wil6210.h"
26 #include "wmi.h"
27 #include "txrx.h"
28 
29 static bool rtap_include_phy_info;
30 module_param(rtap_include_phy_info, bool, S_IRUGO);
31 MODULE_PARM_DESC(rtap_include_phy_info,
32 		 " Include PHY info in the radiotap header, default - no");
33 
34 static inline int wil_vring_is_empty(struct vring *vring)
35 {
36 	return vring->swhead == vring->swtail;
37 }
38 
39 static inline u32 wil_vring_next_tail(struct vring *vring)
40 {
41 	return (vring->swtail + 1) % vring->size;
42 }
43 
44 static inline void wil_vring_advance_head(struct vring *vring, int n)
45 {
46 	vring->swhead = (vring->swhead + n) % vring->size;
47 }
48 
49 static inline int wil_vring_is_full(struct vring *vring)
50 {
51 	return wil_vring_next_tail(vring) == vring->swhead;
52 }
53 /*
54  * Available space in Tx Vring
55  */
56 static inline int wil_vring_avail_tx(struct vring *vring)
57 {
58 	u32 swhead = vring->swhead;
59 	u32 swtail = vring->swtail;
60 	int used = (vring->size + swhead - swtail) % vring->size;
61 
62 	return vring->size - used - 1;
63 }
64 
65 static int wil_vring_alloc(struct wil6210_priv *wil, struct vring *vring)
66 {
67 	struct device *dev = wil_to_dev(wil);
68 	size_t sz = vring->size * sizeof(vring->va[0]);
69 	uint i;
70 
71 	BUILD_BUG_ON(sizeof(vring->va[0]) != 32);
72 
73 	vring->swhead = 0;
74 	vring->swtail = 0;
75 	vring->ctx = kzalloc(vring->size * sizeof(vring->ctx[0]), GFP_KERNEL);
76 	if (!vring->ctx) {
77 		vring->va = NULL;
78 		return -ENOMEM;
79 	}
80 	/*
81 	 * vring->va should be aligned on its size rounded up to power of 2
82 	 * This is granted by the dma_alloc_coherent
83 	 */
84 	vring->va = dma_alloc_coherent(dev, sz, &vring->pa, GFP_KERNEL);
85 	if (!vring->va) {
86 		wil_err(wil, "vring_alloc [%d] failed to alloc DMA mem\n",
87 			vring->size);
88 		kfree(vring->ctx);
89 		vring->ctx = NULL;
90 		return -ENOMEM;
91 	}
92 	/* initially, all descriptors are SW owned
93 	 * For Tx and Rx, ownership bit is at the same location, thus
94 	 * we can use any
95 	 */
96 	for (i = 0; i < vring->size; i++) {
97 		volatile struct vring_tx_desc *d = &(vring->va[i].tx);
98 		d->dma.status = TX_DMA_STATUS_DU;
99 	}
100 
101 	wil_dbg_misc(wil, "vring[%d] 0x%p:0x%016llx 0x%p\n", vring->size,
102 		     vring->va, (unsigned long long)vring->pa, vring->ctx);
103 
104 	return 0;
105 }
106 
107 static void wil_vring_free(struct wil6210_priv *wil, struct vring *vring,
108 			   int tx)
109 {
110 	struct device *dev = wil_to_dev(wil);
111 	size_t sz = vring->size * sizeof(vring->va[0]);
112 
113 	while (!wil_vring_is_empty(vring)) {
114 		if (tx) {
115 			volatile struct vring_tx_desc *d =
116 					&vring->va[vring->swtail].tx;
117 			dma_addr_t pa = d->dma.addr_low |
118 					((u64)d->dma.addr_high << 32);
119 			struct sk_buff *skb = vring->ctx[vring->swtail];
120 			if (skb) {
121 				dma_unmap_single(dev, pa, d->dma.length,
122 						 DMA_TO_DEVICE);
123 				dev_kfree_skb_any(skb);
124 				vring->ctx[vring->swtail] = NULL;
125 			} else {
126 				dma_unmap_page(dev, pa, d->dma.length,
127 					       DMA_TO_DEVICE);
128 			}
129 			vring->swtail = wil_vring_next_tail(vring);
130 		} else { /* rx */
131 			volatile struct vring_rx_desc *d =
132 					&vring->va[vring->swtail].rx;
133 			dma_addr_t pa = d->dma.addr_low |
134 					((u64)d->dma.addr_high << 32);
135 			struct sk_buff *skb = vring->ctx[vring->swhead];
136 			dma_unmap_single(dev, pa, d->dma.length,
137 					 DMA_FROM_DEVICE);
138 			kfree_skb(skb);
139 			wil_vring_advance_head(vring, 1);
140 		}
141 	}
142 	dma_free_coherent(dev, sz, (void *)vring->va, vring->pa);
143 	kfree(vring->ctx);
144 	vring->pa = 0;
145 	vring->va = NULL;
146 	vring->ctx = NULL;
147 }
148 
149 /**
150  * Allocate one skb for Rx VRING
151  *
152  * Safe to call from IRQ
153  */
154 static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
155 			       u32 i, int headroom)
156 {
157 	struct device *dev = wil_to_dev(wil);
158 	unsigned int sz = RX_BUF_LEN;
159 	volatile struct vring_rx_desc *d = &(vring->va[i].rx);
160 	dma_addr_t pa;
161 
162 	/* TODO align */
163 	struct sk_buff *skb = dev_alloc_skb(sz + headroom);
164 	if (unlikely(!skb))
165 		return -ENOMEM;
166 
167 	skb_reserve(skb, headroom);
168 	skb_put(skb, sz);
169 
170 	pa = dma_map_single(dev, skb->data, skb->len, DMA_FROM_DEVICE);
171 	if (unlikely(dma_mapping_error(dev, pa))) {
172 		kfree_skb(skb);
173 		return -ENOMEM;
174 	}
175 
176 	d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
177 	d->dma.addr_low = lower_32_bits(pa);
178 	d->dma.addr_high = (u16)upper_32_bits(pa);
179 	/* ip_length don't care */
180 	/* b11 don't care */
181 	/* error don't care */
182 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
183 	d->dma.length = sz;
184 	vring->ctx[i] = skb;
185 
186 	return 0;
187 }
188 
189 /**
190  * Adds radiotap header
191  *
192  * Any error indicated as "Bad FCS"
193  *
194  * Vendor data for 04:ce:14-1 (Wilocity-1) consists of:
195  *  - Rx descriptor: 32 bytes
196  *  - Phy info
197  */
198 static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
199 				       struct sk_buff *skb,
200 				       volatile struct vring_rx_desc *d)
201 {
202 	struct wireless_dev *wdev = wil->wdev;
203 	struct wil6210_rtap {
204 		struct ieee80211_radiotap_header rthdr;
205 		/* fields should be in the order of bits in rthdr.it_present */
206 		/* flags */
207 		u8 flags;
208 		/* channel */
209 		__le16 chnl_freq __aligned(2);
210 		__le16 chnl_flags;
211 		/* MCS */
212 		u8 mcs_present;
213 		u8 mcs_flags;
214 		u8 mcs_index;
215 	} __packed;
216 	struct wil6210_rtap_vendor {
217 		struct wil6210_rtap rtap;
218 		/* vendor */
219 		u8 vendor_oui[3] __aligned(2);
220 		u8 vendor_ns;
221 		__le16 vendor_skip;
222 		u8 vendor_data[0];
223 	} __packed;
224 	struct wil6210_rtap_vendor *rtap_vendor;
225 	int rtap_len = sizeof(struct wil6210_rtap);
226 	int phy_length = 0; /* phy info header size, bytes */
227 	static char phy_data[128];
228 	struct ieee80211_channel *ch = wdev->preset_chandef.chan;
229 
230 	if (rtap_include_phy_info) {
231 		rtap_len = sizeof(*rtap_vendor) + sizeof(*d);
232 		/* calculate additional length */
233 		if (d->dma.status & RX_DMA_STATUS_PHY_INFO) {
234 			/**
235 			 * PHY info starts from 8-byte boundary
236 			 * there are 8-byte lines, last line may be partially
237 			 * written (HW bug), thus FW configures for last line
238 			 * to be excessive. Driver skips this last line.
239 			 */
240 			int len = min_t(int, 8 + sizeof(phy_data),
241 					wil_rxdesc_phy_length(d));
242 			if (len > 8) {
243 				void *p = skb_tail_pointer(skb);
244 				void *pa = PTR_ALIGN(p, 8);
245 				if (skb_tailroom(skb) >= len + (pa - p)) {
246 					phy_length = len - 8;
247 					memcpy(phy_data, pa, phy_length);
248 				}
249 			}
250 		}
251 		rtap_len += phy_length;
252 	}
253 
254 	if (skb_headroom(skb) < rtap_len &&
255 	    pskb_expand_head(skb, rtap_len, 0, GFP_ATOMIC)) {
256 		wil_err(wil, "Unable to expand headrom to %d\n", rtap_len);
257 		return;
258 	}
259 
260 	rtap_vendor = (void *)skb_push(skb, rtap_len);
261 	memset(rtap_vendor, 0, rtap_len);
262 
263 	rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;
264 	rtap_vendor->rtap.rthdr.it_len = cpu_to_le16(rtap_len);
265 	rtap_vendor->rtap.rthdr.it_present = cpu_to_le32(
266 			(1 << IEEE80211_RADIOTAP_FLAGS) |
267 			(1 << IEEE80211_RADIOTAP_CHANNEL) |
268 			(1 << IEEE80211_RADIOTAP_MCS));
269 	if (d->dma.status & RX_DMA_STATUS_ERROR)
270 		rtap_vendor->rtap.flags |= IEEE80211_RADIOTAP_F_BADFCS;
271 
272 	rtap_vendor->rtap.chnl_freq = cpu_to_le16(ch ? ch->center_freq : 58320);
273 	rtap_vendor->rtap.chnl_flags = cpu_to_le16(0);
274 
275 	rtap_vendor->rtap.mcs_present = IEEE80211_RADIOTAP_MCS_HAVE_MCS;
276 	rtap_vendor->rtap.mcs_flags = 0;
277 	rtap_vendor->rtap.mcs_index = wil_rxdesc_mcs(d);
278 
279 	if (rtap_include_phy_info) {
280 		rtap_vendor->rtap.rthdr.it_present |= cpu_to_le32(1 <<
281 				IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
282 		/* OUI for Wilocity 04:ce:14 */
283 		rtap_vendor->vendor_oui[0] = 0x04;
284 		rtap_vendor->vendor_oui[1] = 0xce;
285 		rtap_vendor->vendor_oui[2] = 0x14;
286 		rtap_vendor->vendor_ns = 1;
287 		/* Rx descriptor + PHY data  */
288 		rtap_vendor->vendor_skip = cpu_to_le16(sizeof(*d) +
289 						       phy_length);
290 		memcpy(rtap_vendor->vendor_data, (void *)d, sizeof(*d));
291 		memcpy(rtap_vendor->vendor_data + sizeof(*d), phy_data,
292 		       phy_length);
293 	}
294 }
295 
296 /*
297  * Fast swap in place between 2 registers
298  */
299 static void wil_swap_u16(u16 *a, u16 *b)
300 {
301 	*a ^= *b;
302 	*b ^= *a;
303 	*a ^= *b;
304 }
305 
306 static void wil_swap_ethaddr(void *data)
307 {
308 	struct ethhdr *eth = data;
309 	u16 *s = (u16 *)eth->h_source;
310 	u16 *d = (u16 *)eth->h_dest;
311 
312 	wil_swap_u16(s++, d++);
313 	wil_swap_u16(s++, d++);
314 	wil_swap_u16(s, d);
315 }
316 
317 /**
318  * reap 1 frame from @swhead
319  *
320  * Safe to call from IRQ
321  */
322 static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
323 					 struct vring *vring)
324 {
325 	struct device *dev = wil_to_dev(wil);
326 	struct net_device *ndev = wil_to_ndev(wil);
327 	volatile struct vring_rx_desc *d;
328 	struct sk_buff *skb;
329 	dma_addr_t pa;
330 	unsigned int sz = RX_BUF_LEN;
331 	u8 ftype;
332 	u8 ds_bits;
333 
334 	if (wil_vring_is_empty(vring))
335 		return NULL;
336 
337 	d = &(vring->va[vring->swhead].rx);
338 	if (!(d->dma.status & RX_DMA_STATUS_DU)) {
339 		/* it is not error, we just reached end of Rx done area */
340 		return NULL;
341 	}
342 
343 	pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
344 	skb = vring->ctx[vring->swhead];
345 	dma_unmap_single(dev, pa, sz, DMA_FROM_DEVICE);
346 	skb_trim(skb, d->dma.length);
347 
348 	wil->stats.last_mcs_rx = wil_rxdesc_mcs(d);
349 
350 	/* use radiotap header only if required */
351 	if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
352 		wil_rx_add_radiotap_header(wil, skb, d);
353 
354 	wil_dbg_txrx(wil, "Rx[%3d] : %d bytes\n", vring->swhead, d->dma.length);
355 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_NONE, 32, 4,
356 			  (const void *)d, sizeof(*d), false);
357 
358 	wil_vring_advance_head(vring, 1);
359 
360 	/* no extra checks if in sniffer mode */
361 	if (ndev->type != ARPHRD_ETHER)
362 		return skb;
363 	/*
364 	 * Non-data frames may be delivered through Rx DMA channel (ex: BAR)
365 	 * Driver should recognize it by frame type, that is found
366 	 * in Rx descriptor. If type is not data, it is 802.11 frame as is
367 	 */
368 	ftype = wil_rxdesc_ftype(d) << 2;
369 	if (ftype != IEEE80211_FTYPE_DATA) {
370 		wil_dbg_txrx(wil, "Non-data frame ftype 0x%08x\n", ftype);
371 		/* TODO: process it */
372 		kfree_skb(skb);
373 		return NULL;
374 	}
375 
376 	if (skb->len < ETH_HLEN) {
377 		wil_err(wil, "Short frame, len = %d\n", skb->len);
378 		/* TODO: process it (i.e. BAR) */
379 		kfree_skb(skb);
380 		return NULL;
381 	}
382 
383 	ds_bits = wil_rxdesc_ds_bits(d);
384 	if (ds_bits == 1) {
385 		/*
386 		 * HW bug - in ToDS mode, i.e. Rx on AP side,
387 		 * addresses get swapped
388 		 */
389 		wil_swap_ethaddr(skb->data);
390 	}
391 
392 	return skb;
393 }
394 
395 /**
396  * allocate and fill up to @count buffers in rx ring
397  * buffers posted at @swtail
398  */
399 static int wil_rx_refill(struct wil6210_priv *wil, int count)
400 {
401 	struct net_device *ndev = wil_to_ndev(wil);
402 	struct vring *v = &wil->vring_rx;
403 	u32 next_tail;
404 	int rc = 0;
405 	int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
406 			WIL6210_RTAP_SIZE : 0;
407 
408 	for (; next_tail = wil_vring_next_tail(v),
409 			(next_tail != v->swhead) && (count-- > 0);
410 			v->swtail = next_tail) {
411 		rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
412 		if (rc) {
413 			wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
414 				rc, v->swtail);
415 			break;
416 		}
417 	}
418 	iowrite32(v->swtail, wil->csr + HOSTADDR(v->hwtail));
419 
420 	return rc;
421 }
422 
423 /*
424  * Pass Rx packet to the netif. Update statistics.
425  */
426 static void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
427 {
428 	int rc;
429 	unsigned int len = skb->len;
430 
431 	skb_orphan(skb);
432 
433 	if (in_interrupt())
434 		rc = netif_rx(skb);
435 	else
436 		rc = netif_rx_ni(skb);
437 
438 	if (likely(rc == NET_RX_SUCCESS)) {
439 		ndev->stats.rx_packets++;
440 		ndev->stats.rx_bytes += len;
441 
442 	} else {
443 		ndev->stats.rx_dropped++;
444 	}
445 }
446 
447 /**
448  * Proceed all completed skb's from Rx VRING
449  *
450  * Safe to call from IRQ
451  */
452 void wil_rx_handle(struct wil6210_priv *wil)
453 {
454 	struct net_device *ndev = wil_to_ndev(wil);
455 	struct vring *v = &wil->vring_rx;
456 	struct sk_buff *skb;
457 
458 	if (!v->va) {
459 		wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
460 		return;
461 	}
462 	wil_dbg_txrx(wil, "%s()\n", __func__);
463 	while (NULL != (skb = wil_vring_reap_rx(wil, v))) {
464 		wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
465 				  skb->data, skb_headlen(skb), false);
466 
467 		if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
468 			skb->dev = ndev;
469 			skb_reset_mac_header(skb);
470 			skb->ip_summed = CHECKSUM_UNNECESSARY;
471 			skb->pkt_type = PACKET_OTHERHOST;
472 			skb->protocol = htons(ETH_P_802_2);
473 
474 		} else {
475 			skb->protocol = eth_type_trans(skb, ndev);
476 		}
477 
478 		wil_netif_rx_any(skb, ndev);
479 	}
480 	wil_rx_refill(wil, v->size);
481 }
482 
483 int wil_rx_init(struct wil6210_priv *wil)
484 {
485 	struct vring *vring = &wil->vring_rx;
486 	int rc;
487 
488 	vring->size = WIL6210_RX_RING_SIZE;
489 	rc = wil_vring_alloc(wil, vring);
490 	if (rc)
491 		return rc;
492 
493 	rc = wmi_rx_chain_add(wil, vring);
494 	if (rc)
495 		goto err_free;
496 
497 	rc = wil_rx_refill(wil, vring->size);
498 	if (rc)
499 		goto err_free;
500 
501 	return 0;
502  err_free:
503 	wil_vring_free(wil, vring, 0);
504 
505 	return rc;
506 }
507 
508 void wil_rx_fini(struct wil6210_priv *wil)
509 {
510 	struct vring *vring = &wil->vring_rx;
511 
512 	if (vring->va)
513 		wil_vring_free(wil, vring, 0);
514 }
515 
516 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
517 		      int cid, int tid)
518 {
519 	int rc;
520 	struct wmi_vring_cfg_cmd cmd = {
521 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
522 		.vring_cfg = {
523 			.tx_sw_ring = {
524 				.max_mpdu_size = cpu_to_le16(TX_BUF_LEN),
525 			},
526 			.ringid = id,
527 			.cidxtid = (cid & 0xf) | ((tid & 0xf) << 4),
528 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
529 			.mac_ctrl = 0,
530 			.to_resolution = 0,
531 			.agg_max_wsize = 16,
532 			.schd_params = {
533 				.priority = cpu_to_le16(0),
534 				.timeslot_us = cpu_to_le16(0xfff),
535 			},
536 		},
537 	};
538 	struct {
539 		struct wil6210_mbox_hdr_wmi wmi;
540 		struct wmi_vring_cfg_done_event cmd;
541 	} __packed reply;
542 	struct vring *vring = &wil->vring_tx[id];
543 
544 	if (vring->va) {
545 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
546 		rc = -EINVAL;
547 		goto out;
548 	}
549 
550 	vring->size = size;
551 	rc = wil_vring_alloc(wil, vring);
552 	if (rc)
553 		goto out;
554 
555 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
556 	cmd.vring_cfg.tx_sw_ring.ring_size = cpu_to_le16(vring->size);
557 
558 	rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
559 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
560 	if (rc)
561 		goto out_free;
562 
563 	if (reply.cmd.status != WMI_VRING_CFG_SUCCESS) {
564 		wil_err(wil, "Tx config failed, status 0x%02x\n",
565 			reply.cmd.status);
566 		rc = -EINVAL;
567 		goto out_free;
568 	}
569 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
570 
571 	return 0;
572  out_free:
573 	wil_vring_free(wil, vring, 1);
574  out:
575 
576 	return rc;
577 }
578 
579 void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
580 {
581 	struct vring *vring = &wil->vring_tx[id];
582 
583 	if (!vring->va)
584 		return;
585 
586 	wil_vring_free(wil, vring, 1);
587 }
588 
589 static struct vring *wil_find_tx_vring(struct wil6210_priv *wil,
590 				       struct sk_buff *skb)
591 {
592 	struct vring *v = &wil->vring_tx[0];
593 
594 	if (v->va)
595 		return v;
596 
597 	return NULL;
598 }
599 
600 static int wil_tx_desc_map(volatile struct vring_tx_desc *d,
601 			   dma_addr_t pa, u32 len)
602 {
603 	d->dma.addr_low = lower_32_bits(pa);
604 	d->dma.addr_high = (u16)upper_32_bits(pa);
605 	d->dma.ip_length = 0;
606 	/* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
607 	d->dma.b11 = 0/*14 | BIT(7)*/;
608 	d->dma.error = 0;
609 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
610 	d->dma.length = len;
611 	d->dma.d0 = 0;
612 	d->mac.d[0] = 0;
613 	d->mac.d[1] = 0;
614 	d->mac.d[2] = 0;
615 	d->mac.ucode_cmd = 0;
616 	/* use dst index 0 */
617 	d->mac.d[1] |= BIT(MAC_CFG_DESC_TX_1_DST_INDEX_EN_POS) |
618 		       (0 << MAC_CFG_DESC_TX_1_DST_INDEX_POS);
619 	/* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
620 	d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
621 		      (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
622 
623 	return 0;
624 }
625 
626 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
627 			struct sk_buff *skb)
628 {
629 	struct device *dev = wil_to_dev(wil);
630 	volatile struct vring_tx_desc *d;
631 	u32 swhead = vring->swhead;
632 	int avail = wil_vring_avail_tx(vring);
633 	int nr_frags = skb_shinfo(skb)->nr_frags;
634 	uint f;
635 	int vring_index = vring - wil->vring_tx;
636 	uint i = swhead;
637 	dma_addr_t pa;
638 
639 	wil_dbg_txrx(wil, "%s()\n", __func__);
640 
641 	if (avail < vring->size/8)
642 		netif_tx_stop_all_queues(wil_to_ndev(wil));
643 	if (avail < 1 + nr_frags) {
644 		wil_err(wil, "Tx ring full. No space for %d fragments\n",
645 			1 + nr_frags);
646 		return -ENOMEM;
647 	}
648 	d = &(vring->va[i].tx);
649 
650 	/* FIXME FW can accept only unicast frames for the peer */
651 	memcpy(skb->data, wil->dst_addr[vring_index], ETH_ALEN);
652 
653 	pa = dma_map_single(dev, skb->data,
654 			skb_headlen(skb), DMA_TO_DEVICE);
655 
656 	wil_dbg_txrx(wil, "Tx skb %d bytes %p -> %#08llx\n", skb_headlen(skb),
657 		     skb->data, (unsigned long long)pa);
658 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
659 			  skb->data, skb_headlen(skb), false);
660 
661 	if (unlikely(dma_mapping_error(dev, pa)))
662 		return -EINVAL;
663 	/* 1-st segment */
664 	wil_tx_desc_map(d, pa, skb_headlen(skb));
665 	d->mac.d[2] |= ((nr_frags + 1) <<
666 		       MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
667 	/* middle segments */
668 	for (f = 0; f < nr_frags; f++) {
669 		const struct skb_frag_struct *frag =
670 				&skb_shinfo(skb)->frags[f];
671 		int len = skb_frag_size(frag);
672 		i = (swhead + f + 1) % vring->size;
673 		d = &(vring->va[i].tx);
674 		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
675 				DMA_TO_DEVICE);
676 		if (unlikely(dma_mapping_error(dev, pa)))
677 			goto dma_error;
678 		wil_tx_desc_map(d, pa, len);
679 		vring->ctx[i] = NULL;
680 	}
681 	/* for the last seg only */
682 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
683 	d->dma.d0 |= BIT(9); /* BUG: undocumented bit */
684 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
685 	d->dma.d0 |= (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
686 
687 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_NONE, 32, 4,
688 			  (const void *)d, sizeof(*d), false);
689 
690 	/* advance swhead */
691 	wil_vring_advance_head(vring, nr_frags + 1);
692 	wil_dbg_txrx(wil, "Tx swhead %d -> %d\n", swhead, vring->swhead);
693 	iowrite32(vring->swhead, wil->csr + HOSTADDR(vring->hwtail));
694 	/* hold reference to skb
695 	 * to prevent skb release before accounting
696 	 * in case of immediate "tx done"
697 	 */
698 	vring->ctx[i] = skb_get(skb);
699 
700 	return 0;
701  dma_error:
702 	/* unmap what we have mapped */
703 	/* Note: increment @f to operate with positive index */
704 	for (f++; f > 0; f--) {
705 		i = (swhead + f) % vring->size;
706 		d = &(vring->va[i].tx);
707 		d->dma.status = TX_DMA_STATUS_DU;
708 		pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
709 		if (vring->ctx[i])
710 			dma_unmap_single(dev, pa, d->dma.length, DMA_TO_DEVICE);
711 		else
712 			dma_unmap_page(dev, pa, d->dma.length, DMA_TO_DEVICE);
713 	}
714 
715 	return -EINVAL;
716 }
717 
718 
719 netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
720 {
721 	struct wil6210_priv *wil = ndev_to_wil(ndev);
722 	struct vring *vring;
723 	int rc;
724 
725 	wil_dbg_txrx(wil, "%s()\n", __func__);
726 	if (!test_bit(wil_status_fwready, &wil->status)) {
727 		wil_err(wil, "FW not ready\n");
728 		goto drop;
729 	}
730 	if (!test_bit(wil_status_fwconnected, &wil->status)) {
731 		wil_err(wil, "FW not connected\n");
732 		goto drop;
733 	}
734 	if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
735 		wil_err(wil, "Xmit in monitor mode not supported\n");
736 		goto drop;
737 	}
738 	if (skb->protocol == cpu_to_be16(ETH_P_PAE)) {
739 		rc = wmi_tx_eapol(wil, skb);
740 	} else {
741 		/* find vring */
742 		vring = wil_find_tx_vring(wil, skb);
743 		if (!vring) {
744 			wil_err(wil, "No Tx VRING available\n");
745 			goto drop;
746 		}
747 		/* set up vring entry */
748 		rc = wil_tx_vring(wil, vring, skb);
749 	}
750 	switch (rc) {
751 	case 0:
752 		/* statistics will be updated on the tx_complete */
753 		dev_kfree_skb_any(skb);
754 		return NETDEV_TX_OK;
755 	case -ENOMEM:
756 		return NETDEV_TX_BUSY;
757 	default:
758 		break; /* goto drop; */
759 	}
760  drop:
761 	netif_tx_stop_all_queues(ndev);
762 	ndev->stats.tx_dropped++;
763 	dev_kfree_skb_any(skb);
764 
765 	return NET_XMIT_DROP;
766 }
767 
768 /**
769  * Clean up transmitted skb's from the Tx VRING
770  *
771  * Safe to call from IRQ
772  */
773 void wil_tx_complete(struct wil6210_priv *wil, int ringid)
774 {
775 	struct net_device *ndev = wil_to_ndev(wil);
776 	struct device *dev = wil_to_dev(wil);
777 	struct vring *vring = &wil->vring_tx[ringid];
778 
779 	if (!vring->va) {
780 		wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
781 		return;
782 	}
783 
784 	wil_dbg_txrx(wil, "%s(%d)\n", __func__, ringid);
785 
786 	while (!wil_vring_is_empty(vring)) {
787 		volatile struct vring_tx_desc *d = &vring->va[vring->swtail].tx;
788 		dma_addr_t pa;
789 		struct sk_buff *skb;
790 		if (!(d->dma.status & TX_DMA_STATUS_DU))
791 			break;
792 
793 		wil_dbg_txrx(wil,
794 			     "Tx[%3d] : %d bytes, status 0x%02x err 0x%02x\n",
795 			     vring->swtail, d->dma.length, d->dma.status,
796 			     d->dma.error);
797 		wil_hex_dump_txrx("TxC ", DUMP_PREFIX_NONE, 32, 4,
798 				  (const void *)d, sizeof(*d), false);
799 
800 		pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
801 		skb = vring->ctx[vring->swtail];
802 		if (skb) {
803 			if (d->dma.error == 0) {
804 				ndev->stats.tx_packets++;
805 				ndev->stats.tx_bytes += skb->len;
806 			} else {
807 				ndev->stats.tx_errors++;
808 			}
809 
810 			dma_unmap_single(dev, pa, d->dma.length, DMA_TO_DEVICE);
811 			dev_kfree_skb_any(skb);
812 			vring->ctx[vring->swtail] = NULL;
813 		} else {
814 			dma_unmap_page(dev, pa, d->dma.length, DMA_TO_DEVICE);
815 		}
816 		d->dma.addr_low = 0;
817 		d->dma.addr_high = 0;
818 		d->dma.length = 0;
819 		d->dma.status = TX_DMA_STATUS_DU;
820 		vring->swtail = wil_vring_next_tail(vring);
821 	}
822 	if (wil_vring_avail_tx(vring) > vring->size/4)
823 		netif_tx_wake_all_queues(wil_to_ndev(wil));
824 }
825