xref: /openbmc/linux/drivers/net/ethernet/intel/i40e/i40e_txrx.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
1 /*******************************************************************************
2  *
3  * Intel Ethernet Controller XL710 Family Linux Driver
4  * Copyright(c) 2013 - 2014 Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along
16  * with this program.  If not, see <http://www.gnu.org/licenses/>.
17  *
18  * The full GNU General Public License is included in this distribution in
19  * the file called "COPYING".
20  *
21  * Contact Information:
22  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
24  *
25  ******************************************************************************/
26 
27 #include <linux/prefetch.h>
28 #include <net/busy_poll.h>
29 #include "i40e.h"
30 #include "i40e_prototype.h"
31 
32 static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
33 				u32 td_tag)
34 {
35 	return cpu_to_le64(I40E_TX_DESC_DTYPE_DATA |
36 			   ((u64)td_cmd  << I40E_TXD_QW1_CMD_SHIFT) |
37 			   ((u64)td_offset << I40E_TXD_QW1_OFFSET_SHIFT) |
38 			   ((u64)size  << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
39 			   ((u64)td_tag  << I40E_TXD_QW1_L2TAG1_SHIFT));
40 }
41 
42 #define I40E_TXD_CMD (I40E_TX_DESC_CMD_EOP | I40E_TX_DESC_CMD_RS)
43 #define I40E_FD_CLEAN_DELAY 10
44 /**
45  * i40e_program_fdir_filter - Program a Flow Director filter
46  * @fdir_data: Packet data that will be filter parameters
47  * @raw_packet: the pre-allocated packet buffer for FDir
48  * @pf: The PF pointer
49  * @add: True for add/update, False for remove
50  **/
51 int i40e_program_fdir_filter(struct i40e_fdir_filter *fdir_data, u8 *raw_packet,
52 			     struct i40e_pf *pf, bool add)
53 {
54 	struct i40e_filter_program_desc *fdir_desc;
55 	struct i40e_tx_buffer *tx_buf, *first;
56 	struct i40e_tx_desc *tx_desc;
57 	struct i40e_ring *tx_ring;
58 	unsigned int fpt, dcc;
59 	struct i40e_vsi *vsi;
60 	struct device *dev;
61 	dma_addr_t dma;
62 	u32 td_cmd = 0;
63 	u16 delay = 0;
64 	u16 i;
65 
66 	/* find existing FDIR VSI */
67 	vsi = NULL;
68 	for (i = 0; i < pf->num_alloc_vsi; i++)
69 		if (pf->vsi[i] && pf->vsi[i]->type == I40E_VSI_FDIR)
70 			vsi = pf->vsi[i];
71 	if (!vsi)
72 		return -ENOENT;
73 
74 	tx_ring = vsi->tx_rings[0];
75 	dev = tx_ring->dev;
76 
77 	/* we need two descriptors to add/del a filter and we can wait */
78 	do {
79 		if (I40E_DESC_UNUSED(tx_ring) > 1)
80 			break;
81 		msleep_interruptible(1);
82 		delay++;
83 	} while (delay < I40E_FD_CLEAN_DELAY);
84 
85 	if (!(I40E_DESC_UNUSED(tx_ring) > 1))
86 		return -EAGAIN;
87 
88 	dma = dma_map_single(dev, raw_packet,
89 			     I40E_FDIR_MAX_RAW_PACKET_SIZE, DMA_TO_DEVICE);
90 	if (dma_mapping_error(dev, dma))
91 		goto dma_fail;
92 
93 	/* grab the next descriptor */
94 	i = tx_ring->next_to_use;
95 	fdir_desc = I40E_TX_FDIRDESC(tx_ring, i);
96 	first = &tx_ring->tx_bi[i];
97 	memset(first, 0, sizeof(struct i40e_tx_buffer));
98 
99 	tx_ring->next_to_use = ((i + 1) < tx_ring->count) ? i + 1 : 0;
100 
101 	fpt = (fdir_data->q_index << I40E_TXD_FLTR_QW0_QINDEX_SHIFT) &
102 	      I40E_TXD_FLTR_QW0_QINDEX_MASK;
103 
104 	fpt |= (fdir_data->flex_off << I40E_TXD_FLTR_QW0_FLEXOFF_SHIFT) &
105 	       I40E_TXD_FLTR_QW0_FLEXOFF_MASK;
106 
107 	fpt |= (fdir_data->pctype << I40E_TXD_FLTR_QW0_PCTYPE_SHIFT) &
108 	       I40E_TXD_FLTR_QW0_PCTYPE_MASK;
109 
110 	/* Use LAN VSI Id if not programmed by user */
111 	if (fdir_data->dest_vsi == 0)
112 		fpt |= (pf->vsi[pf->lan_vsi]->id) <<
113 		       I40E_TXD_FLTR_QW0_DEST_VSI_SHIFT;
114 	else
115 		fpt |= ((u32)fdir_data->dest_vsi <<
116 			I40E_TXD_FLTR_QW0_DEST_VSI_SHIFT) &
117 		       I40E_TXD_FLTR_QW0_DEST_VSI_MASK;
118 
119 	dcc = I40E_TX_DESC_DTYPE_FILTER_PROG;
120 
121 	if (add)
122 		dcc |= I40E_FILTER_PROGRAM_DESC_PCMD_ADD_UPDATE <<
123 		       I40E_TXD_FLTR_QW1_PCMD_SHIFT;
124 	else
125 		dcc |= I40E_FILTER_PROGRAM_DESC_PCMD_REMOVE <<
126 		       I40E_TXD_FLTR_QW1_PCMD_SHIFT;
127 
128 	dcc |= (fdir_data->dest_ctl << I40E_TXD_FLTR_QW1_DEST_SHIFT) &
129 	       I40E_TXD_FLTR_QW1_DEST_MASK;
130 
131 	dcc |= (fdir_data->fd_status << I40E_TXD_FLTR_QW1_FD_STATUS_SHIFT) &
132 	       I40E_TXD_FLTR_QW1_FD_STATUS_MASK;
133 
134 	if (fdir_data->cnt_index != 0) {
135 		dcc |= I40E_TXD_FLTR_QW1_CNT_ENA_MASK;
136 		dcc |= ((u32)fdir_data->cnt_index <<
137 			I40E_TXD_FLTR_QW1_CNTINDEX_SHIFT) &
138 			I40E_TXD_FLTR_QW1_CNTINDEX_MASK;
139 	}
140 
141 	fdir_desc->qindex_flex_ptype_vsi = cpu_to_le32(fpt);
142 	fdir_desc->rsvd = cpu_to_le32(0);
143 	fdir_desc->dtype_cmd_cntindex = cpu_to_le32(dcc);
144 	fdir_desc->fd_id = cpu_to_le32(fdir_data->fd_id);
145 
146 	/* Now program a dummy descriptor */
147 	i = tx_ring->next_to_use;
148 	tx_desc = I40E_TX_DESC(tx_ring, i);
149 	tx_buf = &tx_ring->tx_bi[i];
150 
151 	tx_ring->next_to_use = ((i + 1) < tx_ring->count) ? i + 1 : 0;
152 
153 	memset(tx_buf, 0, sizeof(struct i40e_tx_buffer));
154 
155 	/* record length, and DMA address */
156 	dma_unmap_len_set(tx_buf, len, I40E_FDIR_MAX_RAW_PACKET_SIZE);
157 	dma_unmap_addr_set(tx_buf, dma, dma);
158 
159 	tx_desc->buffer_addr = cpu_to_le64(dma);
160 	td_cmd = I40E_TXD_CMD | I40E_TX_DESC_CMD_DUMMY;
161 
162 	tx_buf->tx_flags = I40E_TX_FLAGS_FD_SB;
163 	tx_buf->raw_buf = (void *)raw_packet;
164 
165 	tx_desc->cmd_type_offset_bsz =
166 		build_ctob(td_cmd, 0, I40E_FDIR_MAX_RAW_PACKET_SIZE, 0);
167 
168 	/* Force memory writes to complete before letting h/w
169 	 * know there are new descriptors to fetch.
170 	 */
171 	wmb();
172 
173 	/* Mark the data descriptor to be watched */
174 	first->next_to_watch = tx_desc;
175 
176 	writel(tx_ring->next_to_use, tx_ring->tail);
177 	return 0;
178 
179 dma_fail:
180 	return -1;
181 }
182 
183 #define IP_HEADER_OFFSET 14
184 #define I40E_UDPIP_DUMMY_PACKET_LEN 42
185 /**
186  * i40e_add_del_fdir_udpv4 - Add/Remove UDPv4 filters
187  * @vsi: pointer to the targeted VSI
188  * @fd_data: the flow director data required for the FDir descriptor
189  * @add: true adds a filter, false removes it
190  *
191  * Returns 0 if the filters were successfully added or removed
192  **/
193 static int i40e_add_del_fdir_udpv4(struct i40e_vsi *vsi,
194 				   struct i40e_fdir_filter *fd_data,
195 				   bool add)
196 {
197 	struct i40e_pf *pf = vsi->back;
198 	struct udphdr *udp;
199 	struct iphdr *ip;
200 	bool err = false;
201 	u8 *raw_packet;
202 	int ret;
203 	static char packet[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0,
204 		0x45, 0, 0, 0x1c, 0, 0, 0x40, 0, 0x40, 0x11, 0, 0, 0, 0, 0, 0,
205 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
206 
207 	raw_packet = kzalloc(I40E_FDIR_MAX_RAW_PACKET_SIZE, GFP_KERNEL);
208 	if (!raw_packet)
209 		return -ENOMEM;
210 	memcpy(raw_packet, packet, I40E_UDPIP_DUMMY_PACKET_LEN);
211 
212 	ip = (struct iphdr *)(raw_packet + IP_HEADER_OFFSET);
213 	udp = (struct udphdr *)(raw_packet + IP_HEADER_OFFSET
214 	      + sizeof(struct iphdr));
215 
216 	ip->daddr = fd_data->dst_ip[0];
217 	udp->dest = fd_data->dst_port;
218 	ip->saddr = fd_data->src_ip[0];
219 	udp->source = fd_data->src_port;
220 
221 	fd_data->pctype = I40E_FILTER_PCTYPE_NONF_IPV4_UDP;
222 	ret = i40e_program_fdir_filter(fd_data, raw_packet, pf, add);
223 	if (ret) {
224 		dev_info(&pf->pdev->dev,
225 			 "PCTYPE:%d, Filter command send failed for fd_id:%d (ret = %d)\n",
226 			 fd_data->pctype, fd_data->fd_id, ret);
227 		err = true;
228 	} else if (I40E_DEBUG_FD & pf->hw.debug_mask) {
229 		if (add)
230 			dev_info(&pf->pdev->dev,
231 				 "Filter OK for PCTYPE %d loc = %d\n",
232 				 fd_data->pctype, fd_data->fd_id);
233 		else
234 			dev_info(&pf->pdev->dev,
235 				 "Filter deleted for PCTYPE %d loc = %d\n",
236 				 fd_data->pctype, fd_data->fd_id);
237 	}
238 	return err ? -EOPNOTSUPP : 0;
239 }
240 
241 #define I40E_TCPIP_DUMMY_PACKET_LEN 54
242 /**
243  * i40e_add_del_fdir_tcpv4 - Add/Remove TCPv4 filters
244  * @vsi: pointer to the targeted VSI
245  * @fd_data: the flow director data required for the FDir descriptor
246  * @add: true adds a filter, false removes it
247  *
248  * Returns 0 if the filters were successfully added or removed
249  **/
250 static int i40e_add_del_fdir_tcpv4(struct i40e_vsi *vsi,
251 				   struct i40e_fdir_filter *fd_data,
252 				   bool add)
253 {
254 	struct i40e_pf *pf = vsi->back;
255 	struct tcphdr *tcp;
256 	struct iphdr *ip;
257 	bool err = false;
258 	u8 *raw_packet;
259 	int ret;
260 	/* Dummy packet */
261 	static char packet[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0,
262 		0x45, 0, 0, 0x28, 0, 0, 0x40, 0, 0x40, 0x6, 0, 0, 0, 0, 0, 0,
263 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x80, 0x11,
264 		0x0, 0x72, 0, 0, 0, 0};
265 
266 	raw_packet = kzalloc(I40E_FDIR_MAX_RAW_PACKET_SIZE, GFP_KERNEL);
267 	if (!raw_packet)
268 		return -ENOMEM;
269 	memcpy(raw_packet, packet, I40E_TCPIP_DUMMY_PACKET_LEN);
270 
271 	ip = (struct iphdr *)(raw_packet + IP_HEADER_OFFSET);
272 	tcp = (struct tcphdr *)(raw_packet + IP_HEADER_OFFSET
273 	      + sizeof(struct iphdr));
274 
275 	ip->daddr = fd_data->dst_ip[0];
276 	tcp->dest = fd_data->dst_port;
277 	ip->saddr = fd_data->src_ip[0];
278 	tcp->source = fd_data->src_port;
279 
280 	if (add) {
281 		pf->fd_tcp_rule++;
282 		if (pf->flags & I40E_FLAG_FD_ATR_ENABLED) {
283 			if (I40E_DEBUG_FD & pf->hw.debug_mask)
284 				dev_info(&pf->pdev->dev, "Forcing ATR off, sideband rules for TCP/IPv4 flow being applied\n");
285 			pf->flags &= ~I40E_FLAG_FD_ATR_ENABLED;
286 		}
287 	} else {
288 		pf->fd_tcp_rule = (pf->fd_tcp_rule > 0) ?
289 				  (pf->fd_tcp_rule - 1) : 0;
290 		if (pf->fd_tcp_rule == 0) {
291 			pf->flags |= I40E_FLAG_FD_ATR_ENABLED;
292 			if (I40E_DEBUG_FD & pf->hw.debug_mask)
293 				dev_info(&pf->pdev->dev, "ATR re-enabled due to no sideband TCP/IPv4 rules\n");
294 		}
295 	}
296 
297 	fd_data->pctype = I40E_FILTER_PCTYPE_NONF_IPV4_TCP;
298 	ret = i40e_program_fdir_filter(fd_data, raw_packet, pf, add);
299 
300 	if (ret) {
301 		dev_info(&pf->pdev->dev,
302 			 "PCTYPE:%d, Filter command send failed for fd_id:%d (ret = %d)\n",
303 			 fd_data->pctype, fd_data->fd_id, ret);
304 		err = true;
305 	} else if (I40E_DEBUG_FD & pf->hw.debug_mask) {
306 		if (add)
307 			dev_info(&pf->pdev->dev, "Filter OK for PCTYPE %d loc = %d)\n",
308 				 fd_data->pctype, fd_data->fd_id);
309 		else
310 			dev_info(&pf->pdev->dev,
311 				 "Filter deleted for PCTYPE %d loc = %d\n",
312 				 fd_data->pctype, fd_data->fd_id);
313 	}
314 
315 	return err ? -EOPNOTSUPP : 0;
316 }
317 
318 /**
319  * i40e_add_del_fdir_sctpv4 - Add/Remove SCTPv4 Flow Director filters for
320  * a specific flow spec
321  * @vsi: pointer to the targeted VSI
322  * @fd_data: the flow director data required for the FDir descriptor
323  * @add: true adds a filter, false removes it
324  *
325  * Always returns -EOPNOTSUPP
326  **/
327 static int i40e_add_del_fdir_sctpv4(struct i40e_vsi *vsi,
328 				    struct i40e_fdir_filter *fd_data,
329 				    bool add)
330 {
331 	return -EOPNOTSUPP;
332 }
333 
334 #define I40E_IP_DUMMY_PACKET_LEN 34
335 /**
336  * i40e_add_del_fdir_ipv4 - Add/Remove IPv4 Flow Director filters for
337  * a specific flow spec
338  * @vsi: pointer to the targeted VSI
339  * @fd_data: the flow director data required for the FDir descriptor
340  * @add: true adds a filter, false removes it
341  *
342  * Returns 0 if the filters were successfully added or removed
343  **/
344 static int i40e_add_del_fdir_ipv4(struct i40e_vsi *vsi,
345 				  struct i40e_fdir_filter *fd_data,
346 				  bool add)
347 {
348 	struct i40e_pf *pf = vsi->back;
349 	struct iphdr *ip;
350 	bool err = false;
351 	u8 *raw_packet;
352 	int ret;
353 	int i;
354 	static char packet[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x08, 0,
355 		0x45, 0, 0, 0x14, 0, 0, 0x40, 0, 0x40, 0x10, 0, 0, 0, 0, 0, 0,
356 		0, 0, 0, 0};
357 
358 	for (i = I40E_FILTER_PCTYPE_NONF_IPV4_OTHER;
359 	     i <= I40E_FILTER_PCTYPE_FRAG_IPV4;	i++) {
360 		raw_packet = kzalloc(I40E_FDIR_MAX_RAW_PACKET_SIZE, GFP_KERNEL);
361 		if (!raw_packet)
362 			return -ENOMEM;
363 		memcpy(raw_packet, packet, I40E_IP_DUMMY_PACKET_LEN);
364 		ip = (struct iphdr *)(raw_packet + IP_HEADER_OFFSET);
365 
366 		ip->saddr = fd_data->src_ip[0];
367 		ip->daddr = fd_data->dst_ip[0];
368 		ip->protocol = 0;
369 
370 		fd_data->pctype = i;
371 		ret = i40e_program_fdir_filter(fd_data, raw_packet, pf, add);
372 
373 		if (ret) {
374 			dev_info(&pf->pdev->dev,
375 				 "PCTYPE:%d, Filter command send failed for fd_id:%d (ret = %d)\n",
376 				 fd_data->pctype, fd_data->fd_id, ret);
377 			err = true;
378 		} else if (I40E_DEBUG_FD & pf->hw.debug_mask) {
379 			if (add)
380 				dev_info(&pf->pdev->dev,
381 					 "Filter OK for PCTYPE %d loc = %d\n",
382 					 fd_data->pctype, fd_data->fd_id);
383 			else
384 				dev_info(&pf->pdev->dev,
385 					 "Filter deleted for PCTYPE %d loc = %d\n",
386 					 fd_data->pctype, fd_data->fd_id);
387 		}
388 	}
389 
390 	return err ? -EOPNOTSUPP : 0;
391 }
392 
393 /**
394  * i40e_add_del_fdir - Build raw packets to add/del fdir filter
395  * @vsi: pointer to the targeted VSI
396  * @cmd: command to get or set RX flow classification rules
397  * @add: true adds a filter, false removes it
398  *
399  **/
400 int i40e_add_del_fdir(struct i40e_vsi *vsi,
401 		      struct i40e_fdir_filter *input, bool add)
402 {
403 	struct i40e_pf *pf = vsi->back;
404 	int ret;
405 
406 	switch (input->flow_type & ~FLOW_EXT) {
407 	case TCP_V4_FLOW:
408 		ret = i40e_add_del_fdir_tcpv4(vsi, input, add);
409 		break;
410 	case UDP_V4_FLOW:
411 		ret = i40e_add_del_fdir_udpv4(vsi, input, add);
412 		break;
413 	case SCTP_V4_FLOW:
414 		ret = i40e_add_del_fdir_sctpv4(vsi, input, add);
415 		break;
416 	case IPV4_FLOW:
417 		ret = i40e_add_del_fdir_ipv4(vsi, input, add);
418 		break;
419 	case IP_USER_FLOW:
420 		switch (input->ip4_proto) {
421 		case IPPROTO_TCP:
422 			ret = i40e_add_del_fdir_tcpv4(vsi, input, add);
423 			break;
424 		case IPPROTO_UDP:
425 			ret = i40e_add_del_fdir_udpv4(vsi, input, add);
426 			break;
427 		case IPPROTO_SCTP:
428 			ret = i40e_add_del_fdir_sctpv4(vsi, input, add);
429 			break;
430 		default:
431 			ret = i40e_add_del_fdir_ipv4(vsi, input, add);
432 			break;
433 		}
434 		break;
435 	default:
436 		dev_info(&pf->pdev->dev, "Could not specify spec type %d\n",
437 			 input->flow_type);
438 		ret = -EINVAL;
439 	}
440 
441 	/* The buffer allocated here is freed by the i40e_clean_tx_ring() */
442 	return ret;
443 }
444 
445 /**
446  * i40e_fd_handle_status - check the Programming Status for FD
447  * @rx_ring: the Rx ring for this descriptor
448  * @rx_desc: the Rx descriptor for programming Status, not a packet descriptor.
449  * @prog_id: the id originally used for programming
450  *
451  * This is used to verify if the FD programming or invalidation
452  * requested by SW to the HW is successful or not and take actions accordingly.
453  **/
454 static void i40e_fd_handle_status(struct i40e_ring *rx_ring,
455 				  union i40e_rx_desc *rx_desc, u8 prog_id)
456 {
457 	struct i40e_pf *pf = rx_ring->vsi->back;
458 	struct pci_dev *pdev = pf->pdev;
459 	u32 fcnt_prog, fcnt_avail;
460 	u32 error;
461 	u64 qw;
462 
463 	qw = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
464 	error = (qw & I40E_RX_PROG_STATUS_DESC_QW1_ERROR_MASK) >>
465 		I40E_RX_PROG_STATUS_DESC_QW1_ERROR_SHIFT;
466 
467 	if (error == BIT(I40E_RX_PROG_STATUS_DESC_FD_TBL_FULL_SHIFT)) {
468 		if ((rx_desc->wb.qword0.hi_dword.fd_id != 0) ||
469 		    (I40E_DEBUG_FD & pf->hw.debug_mask))
470 			dev_warn(&pdev->dev, "ntuple filter loc = %d, could not be added\n",
471 				 rx_desc->wb.qword0.hi_dword.fd_id);
472 
473 		/* Check if the programming error is for ATR.
474 		 * If so, auto disable ATR and set a state for
475 		 * flush in progress. Next time we come here if flush is in
476 		 * progress do nothing, once flush is complete the state will
477 		 * be cleared.
478 		 */
479 		if (test_bit(__I40E_FD_FLUSH_REQUESTED, &pf->state))
480 			return;
481 
482 		pf->fd_add_err++;
483 		/* store the current atr filter count */
484 		pf->fd_atr_cnt = i40e_get_current_atr_cnt(pf);
485 
486 		if ((rx_desc->wb.qword0.hi_dword.fd_id == 0) &&
487 		    (pf->auto_disable_flags & I40E_FLAG_FD_SB_ENABLED)) {
488 			pf->auto_disable_flags |= I40E_FLAG_FD_ATR_ENABLED;
489 			set_bit(__I40E_FD_FLUSH_REQUESTED, &pf->state);
490 		}
491 
492 		/* filter programming failed most likely due to table full */
493 		fcnt_prog = i40e_get_global_fd_count(pf);
494 		fcnt_avail = pf->fdir_pf_filter_count;
495 		/* If ATR is running fcnt_prog can quickly change,
496 		 * if we are very close to full, it makes sense to disable
497 		 * FD ATR/SB and then re-enable it when there is room.
498 		 */
499 		if (fcnt_prog >= (fcnt_avail - I40E_FDIR_BUFFER_FULL_MARGIN)) {
500 			if ((pf->flags & I40E_FLAG_FD_SB_ENABLED) &&
501 			    !(pf->auto_disable_flags &
502 				     I40E_FLAG_FD_SB_ENABLED)) {
503 				if (I40E_DEBUG_FD & pf->hw.debug_mask)
504 					dev_warn(&pdev->dev, "FD filter space full, new ntuple rules will not be added\n");
505 				pf->auto_disable_flags |=
506 							I40E_FLAG_FD_SB_ENABLED;
507 			}
508 		} else {
509 			dev_info(&pdev->dev,
510 				"FD filter programming failed due to incorrect filter parameters\n");
511 		}
512 	} else if (error == BIT(I40E_RX_PROG_STATUS_DESC_NO_FD_ENTRY_SHIFT)) {
513 		if (I40E_DEBUG_FD & pf->hw.debug_mask)
514 			dev_info(&pdev->dev, "ntuple filter fd_id = %d, could not be removed\n",
515 				 rx_desc->wb.qword0.hi_dword.fd_id);
516 	}
517 }
518 
519 /**
520  * i40e_unmap_and_free_tx_resource - Release a Tx buffer
521  * @ring:      the ring that owns the buffer
522  * @tx_buffer: the buffer to free
523  **/
524 static void i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
525 					    struct i40e_tx_buffer *tx_buffer)
526 {
527 	if (tx_buffer->skb) {
528 		if (tx_buffer->tx_flags & I40E_TX_FLAGS_FD_SB)
529 			kfree(tx_buffer->raw_buf);
530 		else
531 			dev_kfree_skb_any(tx_buffer->skb);
532 
533 		if (dma_unmap_len(tx_buffer, len))
534 			dma_unmap_single(ring->dev,
535 					 dma_unmap_addr(tx_buffer, dma),
536 					 dma_unmap_len(tx_buffer, len),
537 					 DMA_TO_DEVICE);
538 	} else if (dma_unmap_len(tx_buffer, len)) {
539 		dma_unmap_page(ring->dev,
540 			       dma_unmap_addr(tx_buffer, dma),
541 			       dma_unmap_len(tx_buffer, len),
542 			       DMA_TO_DEVICE);
543 	}
544 	tx_buffer->next_to_watch = NULL;
545 	tx_buffer->skb = NULL;
546 	dma_unmap_len_set(tx_buffer, len, 0);
547 	/* tx_buffer must be completely set up in the transmit path */
548 }
549 
550 /**
551  * i40e_clean_tx_ring - Free any empty Tx buffers
552  * @tx_ring: ring to be cleaned
553  **/
554 void i40e_clean_tx_ring(struct i40e_ring *tx_ring)
555 {
556 	unsigned long bi_size;
557 	u16 i;
558 
559 	/* ring already cleared, nothing to do */
560 	if (!tx_ring->tx_bi)
561 		return;
562 
563 	/* Free all the Tx ring sk_buffs */
564 	for (i = 0; i < tx_ring->count; i++)
565 		i40e_unmap_and_free_tx_resource(tx_ring, &tx_ring->tx_bi[i]);
566 
567 	bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
568 	memset(tx_ring->tx_bi, 0, bi_size);
569 
570 	/* Zero out the descriptor ring */
571 	memset(tx_ring->desc, 0, tx_ring->size);
572 
573 	tx_ring->next_to_use = 0;
574 	tx_ring->next_to_clean = 0;
575 
576 	if (!tx_ring->netdev)
577 		return;
578 
579 	/* cleanup Tx queue statistics */
580 	netdev_tx_reset_queue(netdev_get_tx_queue(tx_ring->netdev,
581 						  tx_ring->queue_index));
582 }
583 
584 /**
585  * i40e_free_tx_resources - Free Tx resources per queue
586  * @tx_ring: Tx descriptor ring for a specific queue
587  *
588  * Free all transmit software resources
589  **/
590 void i40e_free_tx_resources(struct i40e_ring *tx_ring)
591 {
592 	i40e_clean_tx_ring(tx_ring);
593 	kfree(tx_ring->tx_bi);
594 	tx_ring->tx_bi = NULL;
595 
596 	if (tx_ring->desc) {
597 		dma_free_coherent(tx_ring->dev, tx_ring->size,
598 				  tx_ring->desc, tx_ring->dma);
599 		tx_ring->desc = NULL;
600 	}
601 }
602 
603 /**
604  * i40e_get_head - Retrieve head from head writeback
605  * @tx_ring:  tx ring to fetch head of
606  *
607  * Returns value of Tx ring head based on value stored
608  * in head write-back location
609  **/
610 static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
611 {
612 	void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
613 
614 	return le32_to_cpu(*(volatile __le32 *)head);
615 }
616 
617 /**
618  * i40e_get_tx_pending - how many tx descriptors not processed
619  * @tx_ring: the ring of descriptors
620  *
621  * Since there is no access to the ring head register
622  * in XL710, we need to use our local copies
623  **/
624 static u32 i40e_get_tx_pending(struct i40e_ring *ring)
625 {
626 	u32 head, tail;
627 
628 	head = i40e_get_head(ring);
629 	tail = readl(ring->tail);
630 
631 	if (head != tail)
632 		return (head < tail) ?
633 			tail - head : (tail + ring->count - head);
634 
635 	return 0;
636 }
637 
638 /**
639  * i40e_check_tx_hang - Is there a hang in the Tx queue
640  * @tx_ring: the ring of descriptors
641  **/
642 static bool i40e_check_tx_hang(struct i40e_ring *tx_ring)
643 {
644 	u32 tx_done = tx_ring->stats.packets;
645 	u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
646 	u32 tx_pending = i40e_get_tx_pending(tx_ring);
647 	struct i40e_pf *pf = tx_ring->vsi->back;
648 	bool ret = false;
649 
650 	clear_check_for_tx_hang(tx_ring);
651 
652 	/* Check for a hung queue, but be thorough. This verifies
653 	 * that a transmit has been completed since the previous
654 	 * check AND there is at least one packet pending. The
655 	 * ARMED bit is set to indicate a potential hang. The
656 	 * bit is cleared if a pause frame is received to remove
657 	 * false hang detection due to PFC or 802.3x frames. By
658 	 * requiring this to fail twice we avoid races with
659 	 * PFC clearing the ARMED bit and conditions where we
660 	 * run the check_tx_hang logic with a transmit completion
661 	 * pending but without time to complete it yet.
662 	 */
663 	if ((tx_done_old == tx_done) && tx_pending) {
664 		/* make sure it is true for two checks in a row */
665 		ret = test_and_set_bit(__I40E_HANG_CHECK_ARMED,
666 				       &tx_ring->state);
667 	} else if (tx_done_old == tx_done &&
668 		   (tx_pending < I40E_MIN_DESC_PENDING) && (tx_pending > 0)) {
669 		if (I40E_DEBUG_FLOW & pf->hw.debug_mask)
670 			dev_info(tx_ring->dev, "HW needs some more descs to do a cacheline flush. tx_pending %d, queue %d",
671 				 tx_pending, tx_ring->queue_index);
672 		pf->tx_sluggish_count++;
673 	} else {
674 		/* update completed stats and disarm the hang check */
675 		tx_ring->tx_stats.tx_done_old = tx_done;
676 		clear_bit(__I40E_HANG_CHECK_ARMED, &tx_ring->state);
677 	}
678 
679 	return ret;
680 }
681 
682 #define WB_STRIDE 0x3
683 
684 /**
685  * i40e_clean_tx_irq - Reclaim resources after transmit completes
686  * @tx_ring:  tx ring to clean
687  * @budget:   how many cleans we're allowed
688  *
689  * Returns true if there's any budget left (e.g. the clean is finished)
690  **/
691 static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
692 {
693 	u16 i = tx_ring->next_to_clean;
694 	struct i40e_tx_buffer *tx_buf;
695 	struct i40e_tx_desc *tx_head;
696 	struct i40e_tx_desc *tx_desc;
697 	unsigned int total_packets = 0;
698 	unsigned int total_bytes = 0;
699 
700 	tx_buf = &tx_ring->tx_bi[i];
701 	tx_desc = I40E_TX_DESC(tx_ring, i);
702 	i -= tx_ring->count;
703 
704 	tx_head = I40E_TX_DESC(tx_ring, i40e_get_head(tx_ring));
705 
706 	do {
707 		struct i40e_tx_desc *eop_desc = tx_buf->next_to_watch;
708 
709 		/* if next_to_watch is not set then there is no work pending */
710 		if (!eop_desc)
711 			break;
712 
713 		/* prevent any other reads prior to eop_desc */
714 		read_barrier_depends();
715 
716 		/* we have caught up to head, no work left to do */
717 		if (tx_head == tx_desc)
718 			break;
719 
720 		/* clear next_to_watch to prevent false hangs */
721 		tx_buf->next_to_watch = NULL;
722 
723 		/* update the statistics for this packet */
724 		total_bytes += tx_buf->bytecount;
725 		total_packets += tx_buf->gso_segs;
726 
727 		/* free the skb */
728 		dev_consume_skb_any(tx_buf->skb);
729 
730 		/* unmap skb header data */
731 		dma_unmap_single(tx_ring->dev,
732 				 dma_unmap_addr(tx_buf, dma),
733 				 dma_unmap_len(tx_buf, len),
734 				 DMA_TO_DEVICE);
735 
736 		/* clear tx_buffer data */
737 		tx_buf->skb = NULL;
738 		dma_unmap_len_set(tx_buf, len, 0);
739 
740 		/* unmap remaining buffers */
741 		while (tx_desc != eop_desc) {
742 
743 			tx_buf++;
744 			tx_desc++;
745 			i++;
746 			if (unlikely(!i)) {
747 				i -= tx_ring->count;
748 				tx_buf = tx_ring->tx_bi;
749 				tx_desc = I40E_TX_DESC(tx_ring, 0);
750 			}
751 
752 			/* unmap any remaining paged data */
753 			if (dma_unmap_len(tx_buf, len)) {
754 				dma_unmap_page(tx_ring->dev,
755 					       dma_unmap_addr(tx_buf, dma),
756 					       dma_unmap_len(tx_buf, len),
757 					       DMA_TO_DEVICE);
758 				dma_unmap_len_set(tx_buf, len, 0);
759 			}
760 		}
761 
762 		/* move us one more past the eop_desc for start of next pkt */
763 		tx_buf++;
764 		tx_desc++;
765 		i++;
766 		if (unlikely(!i)) {
767 			i -= tx_ring->count;
768 			tx_buf = tx_ring->tx_bi;
769 			tx_desc = I40E_TX_DESC(tx_ring, 0);
770 		}
771 
772 		prefetch(tx_desc);
773 
774 		/* update budget accounting */
775 		budget--;
776 	} while (likely(budget));
777 
778 	i += tx_ring->count;
779 	tx_ring->next_to_clean = i;
780 	u64_stats_update_begin(&tx_ring->syncp);
781 	tx_ring->stats.bytes += total_bytes;
782 	tx_ring->stats.packets += total_packets;
783 	u64_stats_update_end(&tx_ring->syncp);
784 	tx_ring->q_vector->tx.total_bytes += total_bytes;
785 	tx_ring->q_vector->tx.total_packets += total_packets;
786 
787 	/* check to see if there are any non-cache aligned descriptors
788 	 * waiting to be written back, and kick the hardware to force
789 	 * them to be written back in case of napi polling
790 	 */
791 	if (budget &&
792 	    !((i & WB_STRIDE) == WB_STRIDE) &&
793 	    !test_bit(__I40E_DOWN, &tx_ring->vsi->state) &&
794 	    (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
795 		tx_ring->arm_wb = true;
796 	else
797 		tx_ring->arm_wb = false;
798 
799 	if (check_for_tx_hang(tx_ring) && i40e_check_tx_hang(tx_ring)) {
800 		/* schedule immediate reset if we believe we hung */
801 		dev_info(tx_ring->dev, "Detected Tx Unit Hang\n"
802 			 "  VSI                  <%d>\n"
803 			 "  Tx Queue             <%d>\n"
804 			 "  next_to_use          <%x>\n"
805 			 "  next_to_clean        <%x>\n",
806 			 tx_ring->vsi->seid,
807 			 tx_ring->queue_index,
808 			 tx_ring->next_to_use, i);
809 
810 		netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
811 
812 		dev_info(tx_ring->dev,
813 			 "tx hang detected on queue %d, reset requested\n",
814 			 tx_ring->queue_index);
815 
816 		/* do not fire the reset immediately, wait for the stack to
817 		 * decide we are truly stuck, also prevents every queue from
818 		 * simultaneously requesting a reset
819 		 */
820 
821 		/* the adapter is about to reset, no point in enabling polling */
822 		budget = 1;
823 	}
824 
825 	netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
826 						      tx_ring->queue_index),
827 				  total_packets, total_bytes);
828 
829 #define TX_WAKE_THRESHOLD (DESC_NEEDED * 2)
830 	if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
831 		     (I40E_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) {
832 		/* Make sure that anybody stopping the queue after this
833 		 * sees the new next_to_clean.
834 		 */
835 		smp_mb();
836 		if (__netif_subqueue_stopped(tx_ring->netdev,
837 					     tx_ring->queue_index) &&
838 		   !test_bit(__I40E_DOWN, &tx_ring->vsi->state)) {
839 			netif_wake_subqueue(tx_ring->netdev,
840 					    tx_ring->queue_index);
841 			++tx_ring->tx_stats.restart_queue;
842 		}
843 	}
844 
845 	return !!budget;
846 }
847 
848 /**
849  * i40e_force_wb - Arm hardware to do a wb on noncache aligned descriptors
850  * @vsi: the VSI we care about
851  * @q_vector: the vector  on which to force writeback
852  *
853  **/
854 static void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
855 {
856 	u32 val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
857 		  I40E_PFINT_DYN_CTLN_ITR_INDX_MASK | /* set noitr */
858 		  I40E_PFINT_DYN_CTLN_SWINT_TRIG_MASK |
859 		  I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_MASK;
860 		  /* allow 00 to be written to the index */
861 
862 	wr32(&vsi->back->hw,
863 	     I40E_PFINT_DYN_CTLN(q_vector->v_idx + vsi->base_vector - 1),
864 	     val);
865 }
866 
867 /**
868  * i40e_set_new_dynamic_itr - Find new ITR level
869  * @rc: structure containing ring performance data
870  *
871  * Stores a new ITR value based on packets and byte counts during
872  * the last interrupt.  The advantage of per interrupt computation
873  * is faster updates and more accurate ITR for the current traffic
874  * pattern.  Constants in this function were computed based on
875  * theoretical maximum wire speed and thresholds were set based on
876  * testing data as well as attempting to minimize response time
877  * while increasing bulk throughput.
878  **/
879 static void i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
880 {
881 	enum i40e_latency_range new_latency_range = rc->latency_range;
882 	u32 new_itr = rc->itr;
883 	int bytes_per_int;
884 
885 	if (rc->total_packets == 0 || !rc->itr)
886 		return;
887 
888 	/* simple throttlerate management
889 	 *   0-10MB/s   lowest (100000 ints/s)
890 	 *  10-20MB/s   low    (20000 ints/s)
891 	 *  20-1249MB/s bulk   (8000 ints/s)
892 	 */
893 	bytes_per_int = rc->total_bytes / rc->itr;
894 	switch (new_latency_range) {
895 	case I40E_LOWEST_LATENCY:
896 		if (bytes_per_int > 10)
897 			new_latency_range = I40E_LOW_LATENCY;
898 		break;
899 	case I40E_LOW_LATENCY:
900 		if (bytes_per_int > 20)
901 			new_latency_range = I40E_BULK_LATENCY;
902 		else if (bytes_per_int <= 10)
903 			new_latency_range = I40E_LOWEST_LATENCY;
904 		break;
905 	case I40E_BULK_LATENCY:
906 		if (bytes_per_int <= 20)
907 			new_latency_range = I40E_LOW_LATENCY;
908 		break;
909 	default:
910 		if (bytes_per_int <= 20)
911 			new_latency_range = I40E_LOW_LATENCY;
912 		break;
913 	}
914 	rc->latency_range = new_latency_range;
915 
916 	switch (new_latency_range) {
917 	case I40E_LOWEST_LATENCY:
918 		new_itr = I40E_ITR_100K;
919 		break;
920 	case I40E_LOW_LATENCY:
921 		new_itr = I40E_ITR_20K;
922 		break;
923 	case I40E_BULK_LATENCY:
924 		new_itr = I40E_ITR_8K;
925 		break;
926 	default:
927 		break;
928 	}
929 
930 	if (new_itr != rc->itr)
931 		rc->itr = new_itr;
932 
933 	rc->total_bytes = 0;
934 	rc->total_packets = 0;
935 }
936 
937 /**
938  * i40e_clean_programming_status - clean the programming status descriptor
939  * @rx_ring: the rx ring that has this descriptor
940  * @rx_desc: the rx descriptor written back by HW
941  *
942  * Flow director should handle FD_FILTER_STATUS to check its filter programming
943  * status being successful or not and take actions accordingly. FCoE should
944  * handle its context/filter programming/invalidation status and take actions.
945  *
946  **/
947 static void i40e_clean_programming_status(struct i40e_ring *rx_ring,
948 					  union i40e_rx_desc *rx_desc)
949 {
950 	u64 qw;
951 	u8 id;
952 
953 	qw = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
954 	id = (qw & I40E_RX_PROG_STATUS_DESC_QW1_PROGID_MASK) >>
955 		  I40E_RX_PROG_STATUS_DESC_QW1_PROGID_SHIFT;
956 
957 	if (id == I40E_RX_PROG_STATUS_DESC_FD_FILTER_STATUS)
958 		i40e_fd_handle_status(rx_ring, rx_desc, id);
959 #ifdef I40E_FCOE
960 	else if ((id == I40E_RX_PROG_STATUS_DESC_FCOE_CTXT_PROG_STATUS) ||
961 		 (id == I40E_RX_PROG_STATUS_DESC_FCOE_CTXT_INVL_STATUS))
962 		i40e_fcoe_handle_status(rx_ring, rx_desc, id);
963 #endif
964 }
965 
966 /**
967  * i40e_setup_tx_descriptors - Allocate the Tx descriptors
968  * @tx_ring: the tx ring to set up
969  *
970  * Return 0 on success, negative on error
971  **/
972 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring)
973 {
974 	struct device *dev = tx_ring->dev;
975 	int bi_size;
976 
977 	if (!dev)
978 		return -ENOMEM;
979 
980 	bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
981 	tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL);
982 	if (!tx_ring->tx_bi)
983 		goto err;
984 
985 	/* round up to nearest 4K */
986 	tx_ring->size = tx_ring->count * sizeof(struct i40e_tx_desc);
987 	/* add u32 for head writeback, align after this takes care of
988 	 * guaranteeing this is at least one cache line in size
989 	 */
990 	tx_ring->size += sizeof(u32);
991 	tx_ring->size = ALIGN(tx_ring->size, 4096);
992 	tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
993 					   &tx_ring->dma, GFP_KERNEL);
994 	if (!tx_ring->desc) {
995 		dev_info(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n",
996 			 tx_ring->size);
997 		goto err;
998 	}
999 
1000 	tx_ring->next_to_use = 0;
1001 	tx_ring->next_to_clean = 0;
1002 	return 0;
1003 
1004 err:
1005 	kfree(tx_ring->tx_bi);
1006 	tx_ring->tx_bi = NULL;
1007 	return -ENOMEM;
1008 }
1009 
1010 /**
1011  * i40e_clean_rx_ring - Free Rx buffers
1012  * @rx_ring: ring to be cleaned
1013  **/
1014 void i40e_clean_rx_ring(struct i40e_ring *rx_ring)
1015 {
1016 	struct device *dev = rx_ring->dev;
1017 	struct i40e_rx_buffer *rx_bi;
1018 	unsigned long bi_size;
1019 	u16 i;
1020 
1021 	/* ring already cleared, nothing to do */
1022 	if (!rx_ring->rx_bi)
1023 		return;
1024 
1025 	if (ring_is_ps_enabled(rx_ring)) {
1026 		int bufsz = ALIGN(rx_ring->rx_hdr_len, 256) * rx_ring->count;
1027 
1028 		rx_bi = &rx_ring->rx_bi[0];
1029 		if (rx_bi->hdr_buf) {
1030 			dma_free_coherent(dev,
1031 					  bufsz,
1032 					  rx_bi->hdr_buf,
1033 					  rx_bi->dma);
1034 			for (i = 0; i < rx_ring->count; i++) {
1035 				rx_bi = &rx_ring->rx_bi[i];
1036 				rx_bi->dma = 0;
1037 				rx_bi->hdr_buf = NULL;
1038 			}
1039 		}
1040 	}
1041 	/* Free all the Rx ring sk_buffs */
1042 	for (i = 0; i < rx_ring->count; i++) {
1043 		rx_bi = &rx_ring->rx_bi[i];
1044 		if (rx_bi->dma) {
1045 			dma_unmap_single(dev,
1046 					 rx_bi->dma,
1047 					 rx_ring->rx_buf_len,
1048 					 DMA_FROM_DEVICE);
1049 			rx_bi->dma = 0;
1050 		}
1051 		if (rx_bi->skb) {
1052 			dev_kfree_skb(rx_bi->skb);
1053 			rx_bi->skb = NULL;
1054 		}
1055 		if (rx_bi->page) {
1056 			if (rx_bi->page_dma) {
1057 				dma_unmap_page(dev,
1058 					       rx_bi->page_dma,
1059 					       PAGE_SIZE / 2,
1060 					       DMA_FROM_DEVICE);
1061 				rx_bi->page_dma = 0;
1062 			}
1063 			__free_page(rx_bi->page);
1064 			rx_bi->page = NULL;
1065 			rx_bi->page_offset = 0;
1066 		}
1067 	}
1068 
1069 	bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
1070 	memset(rx_ring->rx_bi, 0, bi_size);
1071 
1072 	/* Zero out the descriptor ring */
1073 	memset(rx_ring->desc, 0, rx_ring->size);
1074 
1075 	rx_ring->next_to_clean = 0;
1076 	rx_ring->next_to_use = 0;
1077 }
1078 
1079 /**
1080  * i40e_free_rx_resources - Free Rx resources
1081  * @rx_ring: ring to clean the resources from
1082  *
1083  * Free all receive software resources
1084  **/
1085 void i40e_free_rx_resources(struct i40e_ring *rx_ring)
1086 {
1087 	i40e_clean_rx_ring(rx_ring);
1088 	kfree(rx_ring->rx_bi);
1089 	rx_ring->rx_bi = NULL;
1090 
1091 	if (rx_ring->desc) {
1092 		dma_free_coherent(rx_ring->dev, rx_ring->size,
1093 				  rx_ring->desc, rx_ring->dma);
1094 		rx_ring->desc = NULL;
1095 	}
1096 }
1097 
1098 /**
1099  * i40e_alloc_rx_headers - allocate rx header buffers
1100  * @rx_ring: ring to alloc buffers
1101  *
1102  * Allocate rx header buffers for the entire ring. As these are static,
1103  * this is only called when setting up a new ring.
1104  **/
1105 void i40e_alloc_rx_headers(struct i40e_ring *rx_ring)
1106 {
1107 	struct device *dev = rx_ring->dev;
1108 	struct i40e_rx_buffer *rx_bi;
1109 	dma_addr_t dma;
1110 	void *buffer;
1111 	int buf_size;
1112 	int i;
1113 
1114 	if (rx_ring->rx_bi[0].hdr_buf)
1115 		return;
1116 	/* Make sure the buffers don't cross cache line boundaries. */
1117 	buf_size = ALIGN(rx_ring->rx_hdr_len, 256);
1118 	buffer = dma_alloc_coherent(dev, buf_size * rx_ring->count,
1119 				    &dma, GFP_KERNEL);
1120 	if (!buffer)
1121 		return;
1122 	for (i = 0; i < rx_ring->count; i++) {
1123 		rx_bi = &rx_ring->rx_bi[i];
1124 		rx_bi->dma = dma + (i * buf_size);
1125 		rx_bi->hdr_buf = buffer + (i * buf_size);
1126 	}
1127 }
1128 
1129 /**
1130  * i40e_setup_rx_descriptors - Allocate Rx descriptors
1131  * @rx_ring: Rx descriptor ring (for a specific queue) to setup
1132  *
1133  * Returns 0 on success, negative on failure
1134  **/
1135 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring)
1136 {
1137 	struct device *dev = rx_ring->dev;
1138 	int bi_size;
1139 
1140 	bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
1141 	rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL);
1142 	if (!rx_ring->rx_bi)
1143 		goto err;
1144 
1145 	u64_stats_init(&rx_ring->syncp);
1146 
1147 	/* Round up to nearest 4K */
1148 	rx_ring->size = ring_is_16byte_desc_enabled(rx_ring)
1149 		? rx_ring->count * sizeof(union i40e_16byte_rx_desc)
1150 		: rx_ring->count * sizeof(union i40e_32byte_rx_desc);
1151 	rx_ring->size = ALIGN(rx_ring->size, 4096);
1152 	rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
1153 					   &rx_ring->dma, GFP_KERNEL);
1154 
1155 	if (!rx_ring->desc) {
1156 		dev_info(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n",
1157 			 rx_ring->size);
1158 		goto err;
1159 	}
1160 
1161 	rx_ring->next_to_clean = 0;
1162 	rx_ring->next_to_use = 0;
1163 
1164 	return 0;
1165 err:
1166 	kfree(rx_ring->rx_bi);
1167 	rx_ring->rx_bi = NULL;
1168 	return -ENOMEM;
1169 }
1170 
1171 /**
1172  * i40e_release_rx_desc - Store the new tail and head values
1173  * @rx_ring: ring to bump
1174  * @val: new head index
1175  **/
1176 static inline void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val)
1177 {
1178 	rx_ring->next_to_use = val;
1179 	/* Force memory writes to complete before letting h/w
1180 	 * know there are new descriptors to fetch.  (Only
1181 	 * applicable for weak-ordered memory model archs,
1182 	 * such as IA-64).
1183 	 */
1184 	wmb();
1185 	writel(val, rx_ring->tail);
1186 }
1187 
1188 /**
1189  * i40e_alloc_rx_buffers_ps - Replace used receive buffers; packet split
1190  * @rx_ring: ring to place buffers on
1191  * @cleaned_count: number of buffers to replace
1192  **/
1193 void i40e_alloc_rx_buffers_ps(struct i40e_ring *rx_ring, u16 cleaned_count)
1194 {
1195 	u16 i = rx_ring->next_to_use;
1196 	union i40e_rx_desc *rx_desc;
1197 	struct i40e_rx_buffer *bi;
1198 
1199 	/* do nothing if no valid netdev defined */
1200 	if (!rx_ring->netdev || !cleaned_count)
1201 		return;
1202 
1203 	while (cleaned_count--) {
1204 		rx_desc = I40E_RX_DESC(rx_ring, i);
1205 		bi = &rx_ring->rx_bi[i];
1206 
1207 		if (bi->skb) /* desc is in use */
1208 			goto no_buffers;
1209 		if (!bi->page) {
1210 			bi->page = alloc_page(GFP_ATOMIC);
1211 			if (!bi->page) {
1212 				rx_ring->rx_stats.alloc_page_failed++;
1213 				goto no_buffers;
1214 			}
1215 		}
1216 
1217 		if (!bi->page_dma) {
1218 			/* use a half page if we're re-using */
1219 			bi->page_offset ^= PAGE_SIZE / 2;
1220 			bi->page_dma = dma_map_page(rx_ring->dev,
1221 						    bi->page,
1222 						    bi->page_offset,
1223 						    PAGE_SIZE / 2,
1224 						    DMA_FROM_DEVICE);
1225 			if (dma_mapping_error(rx_ring->dev,
1226 					      bi->page_dma)) {
1227 				rx_ring->rx_stats.alloc_page_failed++;
1228 				bi->page_dma = 0;
1229 				goto no_buffers;
1230 			}
1231 		}
1232 
1233 		dma_sync_single_range_for_device(rx_ring->dev,
1234 						 bi->dma,
1235 						 0,
1236 						 rx_ring->rx_hdr_len,
1237 						 DMA_FROM_DEVICE);
1238 		/* Refresh the desc even if buffer_addrs didn't change
1239 		 * because each write-back erases this info.
1240 		 */
1241 		rx_desc->read.pkt_addr = cpu_to_le64(bi->page_dma);
1242 		rx_desc->read.hdr_addr = cpu_to_le64(bi->dma);
1243 		i++;
1244 		if (i == rx_ring->count)
1245 			i = 0;
1246 	}
1247 
1248 no_buffers:
1249 	if (rx_ring->next_to_use != i)
1250 		i40e_release_rx_desc(rx_ring, i);
1251 }
1252 
1253 /**
1254  * i40e_alloc_rx_buffers_1buf - Replace used receive buffers; single buffer
1255  * @rx_ring: ring to place buffers on
1256  * @cleaned_count: number of buffers to replace
1257  **/
1258 void i40e_alloc_rx_buffers_1buf(struct i40e_ring *rx_ring, u16 cleaned_count)
1259 {
1260 	u16 i = rx_ring->next_to_use;
1261 	union i40e_rx_desc *rx_desc;
1262 	struct i40e_rx_buffer *bi;
1263 	struct sk_buff *skb;
1264 
1265 	/* do nothing if no valid netdev defined */
1266 	if (!rx_ring->netdev || !cleaned_count)
1267 		return;
1268 
1269 	while (cleaned_count--) {
1270 		rx_desc = I40E_RX_DESC(rx_ring, i);
1271 		bi = &rx_ring->rx_bi[i];
1272 		skb = bi->skb;
1273 
1274 		if (!skb) {
1275 			skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
1276 							rx_ring->rx_buf_len);
1277 			if (!skb) {
1278 				rx_ring->rx_stats.alloc_buff_failed++;
1279 				goto no_buffers;
1280 			}
1281 			/* initialize queue mapping */
1282 			skb_record_rx_queue(skb, rx_ring->queue_index);
1283 			bi->skb = skb;
1284 		}
1285 
1286 		if (!bi->dma) {
1287 			bi->dma = dma_map_single(rx_ring->dev,
1288 						 skb->data,
1289 						 rx_ring->rx_buf_len,
1290 						 DMA_FROM_DEVICE);
1291 			if (dma_mapping_error(rx_ring->dev, bi->dma)) {
1292 				rx_ring->rx_stats.alloc_buff_failed++;
1293 				bi->dma = 0;
1294 				goto no_buffers;
1295 			}
1296 		}
1297 
1298 		rx_desc->read.pkt_addr = cpu_to_le64(bi->dma);
1299 		rx_desc->read.hdr_addr = 0;
1300 		i++;
1301 		if (i == rx_ring->count)
1302 			i = 0;
1303 	}
1304 
1305 no_buffers:
1306 	if (rx_ring->next_to_use != i)
1307 		i40e_release_rx_desc(rx_ring, i);
1308 }
1309 
1310 /**
1311  * i40e_receive_skb - Send a completed packet up the stack
1312  * @rx_ring:  rx ring in play
1313  * @skb: packet to send up
1314  * @vlan_tag: vlan tag for packet
1315  **/
1316 static void i40e_receive_skb(struct i40e_ring *rx_ring,
1317 			     struct sk_buff *skb, u16 vlan_tag)
1318 {
1319 	struct i40e_q_vector *q_vector = rx_ring->q_vector;
1320 	struct i40e_vsi *vsi = rx_ring->vsi;
1321 	u64 flags = vsi->back->flags;
1322 
1323 	if (vlan_tag & VLAN_VID_MASK)
1324 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
1325 
1326 	if (flags & I40E_FLAG_IN_NETPOLL)
1327 		netif_rx(skb);
1328 	else
1329 		napi_gro_receive(&q_vector->napi, skb);
1330 }
1331 
1332 /**
1333  * i40e_rx_checksum - Indicate in skb if hw indicated a good cksum
1334  * @vsi: the VSI we care about
1335  * @skb: skb currently being received and modified
1336  * @rx_status: status value of last descriptor in packet
1337  * @rx_error: error value of last descriptor in packet
1338  * @rx_ptype: ptype value of last descriptor in packet
1339  **/
1340 static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
1341 				    struct sk_buff *skb,
1342 				    u32 rx_status,
1343 				    u32 rx_error,
1344 				    u16 rx_ptype)
1345 {
1346 	struct i40e_rx_ptype_decoded decoded = decode_rx_desc_ptype(rx_ptype);
1347 	bool ipv4 = false, ipv6 = false;
1348 	bool ipv4_tunnel, ipv6_tunnel;
1349 	__wsum rx_udp_csum;
1350 	struct iphdr *iph;
1351 	__sum16 csum;
1352 
1353 	ipv4_tunnel = (rx_ptype >= I40E_RX_PTYPE_GRENAT4_MAC_PAY3) &&
1354 		     (rx_ptype <= I40E_RX_PTYPE_GRENAT4_MACVLAN_IPV6_ICMP_PAY4);
1355 	ipv6_tunnel = (rx_ptype >= I40E_RX_PTYPE_GRENAT6_MAC_PAY3) &&
1356 		     (rx_ptype <= I40E_RX_PTYPE_GRENAT6_MACVLAN_IPV6_ICMP_PAY4);
1357 
1358 	skb->ip_summed = CHECKSUM_NONE;
1359 
1360 	/* Rx csum enabled and ip headers found? */
1361 	if (!(vsi->netdev->features & NETIF_F_RXCSUM))
1362 		return;
1363 
1364 	/* did the hardware decode the packet and checksum? */
1365 	if (!(rx_status & BIT(I40E_RX_DESC_STATUS_L3L4P_SHIFT)))
1366 		return;
1367 
1368 	/* both known and outer_ip must be set for the below code to work */
1369 	if (!(decoded.known && decoded.outer_ip))
1370 		return;
1371 
1372 	if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
1373 	    decoded.outer_ip_ver == I40E_RX_PTYPE_OUTER_IPV4)
1374 		ipv4 = true;
1375 	else if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
1376 		 decoded.outer_ip_ver == I40E_RX_PTYPE_OUTER_IPV6)
1377 		ipv6 = true;
1378 
1379 	if (ipv4 &&
1380 	    (rx_error & (BIT(I40E_RX_DESC_ERROR_IPE_SHIFT) |
1381 			 BIT(I40E_RX_DESC_ERROR_EIPE_SHIFT))))
1382 		goto checksum_fail;
1383 
1384 	/* likely incorrect csum if alternate IP extension headers found */
1385 	if (ipv6 &&
1386 	    rx_status & BIT(I40E_RX_DESC_STATUS_IPV6EXADD_SHIFT))
1387 		/* don't increment checksum err here, non-fatal err */
1388 		return;
1389 
1390 	/* there was some L4 error, count error and punt packet to the stack */
1391 	if (rx_error & BIT(I40E_RX_DESC_ERROR_L4E_SHIFT))
1392 		goto checksum_fail;
1393 
1394 	/* handle packets that were not able to be checksummed due
1395 	 * to arrival speed, in this case the stack can compute
1396 	 * the csum.
1397 	 */
1398 	if (rx_error & BIT(I40E_RX_DESC_ERROR_PPRS_SHIFT))
1399 		return;
1400 
1401 	/* If VXLAN traffic has an outer UDPv4 checksum we need to check
1402 	 * it in the driver, hardware does not do it for us.
1403 	 * Since L3L4P bit was set we assume a valid IHL value (>=5)
1404 	 * so the total length of IPv4 header is IHL*4 bytes
1405 	 * The UDP_0 bit *may* bet set if the *inner* header is UDP
1406 	 */
1407 	if (ipv4_tunnel) {
1408 		skb->transport_header = skb->mac_header +
1409 					sizeof(struct ethhdr) +
1410 					(ip_hdr(skb)->ihl * 4);
1411 
1412 		/* Add 4 bytes for VLAN tagged packets */
1413 		skb->transport_header += (skb->protocol == htons(ETH_P_8021Q) ||
1414 					  skb->protocol == htons(ETH_P_8021AD))
1415 					  ? VLAN_HLEN : 0;
1416 
1417 		if ((ip_hdr(skb)->protocol == IPPROTO_UDP) &&
1418 		    (udp_hdr(skb)->check != 0)) {
1419 			rx_udp_csum = udp_csum(skb);
1420 			iph = ip_hdr(skb);
1421 			csum = csum_tcpudp_magic(
1422 					iph->saddr, iph->daddr,
1423 					(skb->len - skb_transport_offset(skb)),
1424 					IPPROTO_UDP, rx_udp_csum);
1425 
1426 			if (udp_hdr(skb)->check != csum)
1427 				goto checksum_fail;
1428 
1429 		} /* else its GRE and so no outer UDP header */
1430 	}
1431 
1432 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1433 	skb->csum_level = ipv4_tunnel || ipv6_tunnel;
1434 
1435 	return;
1436 
1437 checksum_fail:
1438 	vsi->back->hw_csum_rx_error++;
1439 }
1440 
1441 /**
1442  * i40e_rx_hash - returns the hash value from the Rx descriptor
1443  * @ring: descriptor ring
1444  * @rx_desc: specific descriptor
1445  **/
1446 static inline u32 i40e_rx_hash(struct i40e_ring *ring,
1447 			       union i40e_rx_desc *rx_desc)
1448 {
1449 	const __le64 rss_mask =
1450 		cpu_to_le64((u64)I40E_RX_DESC_FLTSTAT_RSS_HASH <<
1451 			    I40E_RX_DESC_STATUS_FLTSTAT_SHIFT);
1452 
1453 	if ((ring->netdev->features & NETIF_F_RXHASH) &&
1454 	    (rx_desc->wb.qword1.status_error_len & rss_mask) == rss_mask)
1455 		return le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss);
1456 	else
1457 		return 0;
1458 }
1459 
1460 /**
1461  * i40e_ptype_to_hash - get a hash type
1462  * @ptype: the ptype value from the descriptor
1463  *
1464  * Returns a hash type to be used by skb_set_hash
1465  **/
1466 static inline enum pkt_hash_types i40e_ptype_to_hash(u8 ptype)
1467 {
1468 	struct i40e_rx_ptype_decoded decoded = decode_rx_desc_ptype(ptype);
1469 
1470 	if (!decoded.known)
1471 		return PKT_HASH_TYPE_NONE;
1472 
1473 	if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
1474 	    decoded.payload_layer == I40E_RX_PTYPE_PAYLOAD_LAYER_PAY4)
1475 		return PKT_HASH_TYPE_L4;
1476 	else if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
1477 		 decoded.payload_layer == I40E_RX_PTYPE_PAYLOAD_LAYER_PAY3)
1478 		return PKT_HASH_TYPE_L3;
1479 	else
1480 		return PKT_HASH_TYPE_L2;
1481 }
1482 
1483 /**
1484  * i40e_clean_rx_irq_ps - Reclaim resources after receive; packet split
1485  * @rx_ring:  rx ring to clean
1486  * @budget:   how many cleans we're allowed
1487  *
1488  * Returns true if there's any budget left (e.g. the clean is finished)
1489  **/
1490 static int i40e_clean_rx_irq_ps(struct i40e_ring *rx_ring, int budget)
1491 {
1492 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
1493 	u16 rx_packet_len, rx_header_len, rx_sph, rx_hbo;
1494 	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
1495 	const int current_node = numa_node_id();
1496 	struct i40e_vsi *vsi = rx_ring->vsi;
1497 	u16 i = rx_ring->next_to_clean;
1498 	union i40e_rx_desc *rx_desc;
1499 	u32 rx_error, rx_status;
1500 	u8 rx_ptype;
1501 	u64 qword;
1502 
1503 	if (budget <= 0)
1504 		return 0;
1505 
1506 	do {
1507 		struct i40e_rx_buffer *rx_bi;
1508 		struct sk_buff *skb;
1509 		u16 vlan_tag;
1510 		/* return some buffers to hardware, one at a time is too slow */
1511 		if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
1512 			i40e_alloc_rx_buffers_ps(rx_ring, cleaned_count);
1513 			cleaned_count = 0;
1514 		}
1515 
1516 		i = rx_ring->next_to_clean;
1517 		rx_desc = I40E_RX_DESC(rx_ring, i);
1518 		qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
1519 		rx_status = (qword & I40E_RXD_QW1_STATUS_MASK) >>
1520 			I40E_RXD_QW1_STATUS_SHIFT;
1521 
1522 		if (!(rx_status & BIT(I40E_RX_DESC_STATUS_DD_SHIFT)))
1523 			break;
1524 
1525 		/* This memory barrier is needed to keep us from reading
1526 		 * any other fields out of the rx_desc until we know the
1527 		 * DD bit is set.
1528 		 */
1529 		dma_rmb();
1530 		if (i40e_rx_is_programming_status(qword)) {
1531 			i40e_clean_programming_status(rx_ring, rx_desc);
1532 			I40E_RX_INCREMENT(rx_ring, i);
1533 			continue;
1534 		}
1535 		rx_bi = &rx_ring->rx_bi[i];
1536 		skb = rx_bi->skb;
1537 		if (likely(!skb)) {
1538 			skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
1539 							rx_ring->rx_hdr_len);
1540 			if (!skb) {
1541 				rx_ring->rx_stats.alloc_buff_failed++;
1542 				break;
1543 			}
1544 
1545 			/* initialize queue mapping */
1546 			skb_record_rx_queue(skb, rx_ring->queue_index);
1547 			/* we are reusing so sync this buffer for CPU use */
1548 			dma_sync_single_range_for_cpu(rx_ring->dev,
1549 						      rx_bi->dma,
1550 						      0,
1551 						      rx_ring->rx_hdr_len,
1552 						      DMA_FROM_DEVICE);
1553 		}
1554 		rx_packet_len = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
1555 				I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
1556 		rx_header_len = (qword & I40E_RXD_QW1_LENGTH_HBUF_MASK) >>
1557 				I40E_RXD_QW1_LENGTH_HBUF_SHIFT;
1558 		rx_sph = (qword & I40E_RXD_QW1_LENGTH_SPH_MASK) >>
1559 			 I40E_RXD_QW1_LENGTH_SPH_SHIFT;
1560 
1561 		rx_error = (qword & I40E_RXD_QW1_ERROR_MASK) >>
1562 			   I40E_RXD_QW1_ERROR_SHIFT;
1563 		rx_hbo = rx_error & BIT(I40E_RX_DESC_ERROR_HBO_SHIFT);
1564 		rx_error &= ~BIT(I40E_RX_DESC_ERROR_HBO_SHIFT);
1565 
1566 		rx_ptype = (qword & I40E_RXD_QW1_PTYPE_MASK) >>
1567 			   I40E_RXD_QW1_PTYPE_SHIFT;
1568 		prefetch(rx_bi->page);
1569 		rx_bi->skb = NULL;
1570 		cleaned_count++;
1571 		if (rx_hbo || rx_sph) {
1572 			int len;
1573 			if (rx_hbo)
1574 				len = I40E_RX_HDR_SIZE;
1575 			else
1576 				len = rx_header_len;
1577 			memcpy(__skb_put(skb, len), rx_bi->hdr_buf, len);
1578 		} else if (skb->len == 0) {
1579 			int len;
1580 
1581 			len = (rx_packet_len > skb_headlen(skb) ?
1582 				skb_headlen(skb) : rx_packet_len);
1583 			memcpy(__skb_put(skb, len),
1584 			       rx_bi->page + rx_bi->page_offset,
1585 			       len);
1586 			rx_bi->page_offset += len;
1587 			rx_packet_len -= len;
1588 		}
1589 
1590 		/* Get the rest of the data if this was a header split */
1591 		if (rx_packet_len) {
1592 			skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
1593 					   rx_bi->page,
1594 					   rx_bi->page_offset,
1595 					   rx_packet_len);
1596 
1597 			skb->len += rx_packet_len;
1598 			skb->data_len += rx_packet_len;
1599 			skb->truesize += rx_packet_len;
1600 
1601 			if ((page_count(rx_bi->page) == 1) &&
1602 			    (page_to_nid(rx_bi->page) == current_node))
1603 				get_page(rx_bi->page);
1604 			else
1605 				rx_bi->page = NULL;
1606 
1607 			dma_unmap_page(rx_ring->dev,
1608 				       rx_bi->page_dma,
1609 				       PAGE_SIZE / 2,
1610 				       DMA_FROM_DEVICE);
1611 			rx_bi->page_dma = 0;
1612 		}
1613 		I40E_RX_INCREMENT(rx_ring, i);
1614 
1615 		if (unlikely(
1616 		    !(rx_status & BIT(I40E_RX_DESC_STATUS_EOF_SHIFT)))) {
1617 			struct i40e_rx_buffer *next_buffer;
1618 
1619 			next_buffer = &rx_ring->rx_bi[i];
1620 			next_buffer->skb = skb;
1621 			rx_ring->rx_stats.non_eop_descs++;
1622 			continue;
1623 		}
1624 
1625 		/* ERR_MASK will only have valid bits if EOP set */
1626 		if (unlikely(rx_error & BIT(I40E_RX_DESC_ERROR_RXE_SHIFT))) {
1627 			dev_kfree_skb_any(skb);
1628 			continue;
1629 		}
1630 
1631 		skb_set_hash(skb, i40e_rx_hash(rx_ring, rx_desc),
1632 			     i40e_ptype_to_hash(rx_ptype));
1633 		if (unlikely(rx_status & I40E_RXD_QW1_STATUS_TSYNVALID_MASK)) {
1634 			i40e_ptp_rx_hwtstamp(vsi->back, skb, (rx_status &
1635 					   I40E_RXD_QW1_STATUS_TSYNINDX_MASK) >>
1636 					   I40E_RXD_QW1_STATUS_TSYNINDX_SHIFT);
1637 			rx_ring->last_rx_timestamp = jiffies;
1638 		}
1639 
1640 		/* probably a little skewed due to removing CRC */
1641 		total_rx_bytes += skb->len;
1642 		total_rx_packets++;
1643 
1644 		skb->protocol = eth_type_trans(skb, rx_ring->netdev);
1645 
1646 		i40e_rx_checksum(vsi, skb, rx_status, rx_error, rx_ptype);
1647 
1648 		vlan_tag = rx_status & BIT(I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)
1649 			 ? le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1)
1650 			 : 0;
1651 #ifdef I40E_FCOE
1652 		if (!i40e_fcoe_handle_offload(rx_ring, rx_desc, skb)) {
1653 			dev_kfree_skb_any(skb);
1654 			continue;
1655 		}
1656 #endif
1657 		skb_mark_napi_id(skb, &rx_ring->q_vector->napi);
1658 		i40e_receive_skb(rx_ring, skb, vlan_tag);
1659 
1660 		rx_desc->wb.qword1.status_error_len = 0;
1661 
1662 	} while (likely(total_rx_packets < budget));
1663 
1664 	u64_stats_update_begin(&rx_ring->syncp);
1665 	rx_ring->stats.packets += total_rx_packets;
1666 	rx_ring->stats.bytes += total_rx_bytes;
1667 	u64_stats_update_end(&rx_ring->syncp);
1668 	rx_ring->q_vector->rx.total_packets += total_rx_packets;
1669 	rx_ring->q_vector->rx.total_bytes += total_rx_bytes;
1670 
1671 	return total_rx_packets;
1672 }
1673 
1674 /**
1675  * i40e_clean_rx_irq_1buf - Reclaim resources after receive; single buffer
1676  * @rx_ring:  rx ring to clean
1677  * @budget:   how many cleans we're allowed
1678  *
1679  * Returns number of packets cleaned
1680  **/
1681 static int i40e_clean_rx_irq_1buf(struct i40e_ring *rx_ring, int budget)
1682 {
1683 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
1684 	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
1685 	struct i40e_vsi *vsi = rx_ring->vsi;
1686 	union i40e_rx_desc *rx_desc;
1687 	u32 rx_error, rx_status;
1688 	u16 rx_packet_len;
1689 	u8 rx_ptype;
1690 	u64 qword;
1691 	u16 i;
1692 
1693 	do {
1694 		struct i40e_rx_buffer *rx_bi;
1695 		struct sk_buff *skb;
1696 		u16 vlan_tag;
1697 		/* return some buffers to hardware, one at a time is too slow */
1698 		if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
1699 			i40e_alloc_rx_buffers_1buf(rx_ring, cleaned_count);
1700 			cleaned_count = 0;
1701 		}
1702 
1703 		i = rx_ring->next_to_clean;
1704 		rx_desc = I40E_RX_DESC(rx_ring, i);
1705 		qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
1706 		rx_status = (qword & I40E_RXD_QW1_STATUS_MASK) >>
1707 			I40E_RXD_QW1_STATUS_SHIFT;
1708 
1709 		if (!(rx_status & BIT(I40E_RX_DESC_STATUS_DD_SHIFT)))
1710 			break;
1711 
1712 		/* This memory barrier is needed to keep us from reading
1713 		 * any other fields out of the rx_desc until we know the
1714 		 * DD bit is set.
1715 		 */
1716 		dma_rmb();
1717 
1718 		if (i40e_rx_is_programming_status(qword)) {
1719 			i40e_clean_programming_status(rx_ring, rx_desc);
1720 			I40E_RX_INCREMENT(rx_ring, i);
1721 			continue;
1722 		}
1723 		rx_bi = &rx_ring->rx_bi[i];
1724 		skb = rx_bi->skb;
1725 		prefetch(skb->data);
1726 
1727 		rx_packet_len = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
1728 				I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
1729 
1730 		rx_error = (qword & I40E_RXD_QW1_ERROR_MASK) >>
1731 			   I40E_RXD_QW1_ERROR_SHIFT;
1732 		rx_error &= ~BIT(I40E_RX_DESC_ERROR_HBO_SHIFT);
1733 
1734 		rx_ptype = (qword & I40E_RXD_QW1_PTYPE_MASK) >>
1735 			   I40E_RXD_QW1_PTYPE_SHIFT;
1736 		rx_bi->skb = NULL;
1737 		cleaned_count++;
1738 
1739 		/* Get the header and possibly the whole packet
1740 		 * If this is an skb from previous receive dma will be 0
1741 		 */
1742 		skb_put(skb, rx_packet_len);
1743 		dma_unmap_single(rx_ring->dev, rx_bi->dma, rx_ring->rx_buf_len,
1744 				 DMA_FROM_DEVICE);
1745 		rx_bi->dma = 0;
1746 
1747 		I40E_RX_INCREMENT(rx_ring, i);
1748 
1749 		if (unlikely(
1750 		    !(rx_status & BIT(I40E_RX_DESC_STATUS_EOF_SHIFT)))) {
1751 			rx_ring->rx_stats.non_eop_descs++;
1752 			continue;
1753 		}
1754 
1755 		/* ERR_MASK will only have valid bits if EOP set */
1756 		if (unlikely(rx_error & BIT(I40E_RX_DESC_ERROR_RXE_SHIFT))) {
1757 			dev_kfree_skb_any(skb);
1758 			/* TODO: shouldn't we increment a counter indicating the
1759 			 * drop?
1760 			 */
1761 			continue;
1762 		}
1763 
1764 		skb_set_hash(skb, i40e_rx_hash(rx_ring, rx_desc),
1765 			     i40e_ptype_to_hash(rx_ptype));
1766 		if (unlikely(rx_status & I40E_RXD_QW1_STATUS_TSYNVALID_MASK)) {
1767 			i40e_ptp_rx_hwtstamp(vsi->back, skb, (rx_status &
1768 					   I40E_RXD_QW1_STATUS_TSYNINDX_MASK) >>
1769 					   I40E_RXD_QW1_STATUS_TSYNINDX_SHIFT);
1770 			rx_ring->last_rx_timestamp = jiffies;
1771 		}
1772 
1773 		/* probably a little skewed due to removing CRC */
1774 		total_rx_bytes += skb->len;
1775 		total_rx_packets++;
1776 
1777 		skb->protocol = eth_type_trans(skb, rx_ring->netdev);
1778 
1779 		i40e_rx_checksum(vsi, skb, rx_status, rx_error, rx_ptype);
1780 
1781 		vlan_tag = rx_status & BIT(I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)
1782 			 ? le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1)
1783 			 : 0;
1784 #ifdef I40E_FCOE
1785 		if (!i40e_fcoe_handle_offload(rx_ring, rx_desc, skb)) {
1786 			dev_kfree_skb_any(skb);
1787 			continue;
1788 		}
1789 #endif
1790 		i40e_receive_skb(rx_ring, skb, vlan_tag);
1791 
1792 		rx_desc->wb.qword1.status_error_len = 0;
1793 	} while (likely(total_rx_packets < budget));
1794 
1795 	u64_stats_update_begin(&rx_ring->syncp);
1796 	rx_ring->stats.packets += total_rx_packets;
1797 	rx_ring->stats.bytes += total_rx_bytes;
1798 	u64_stats_update_end(&rx_ring->syncp);
1799 	rx_ring->q_vector->rx.total_packets += total_rx_packets;
1800 	rx_ring->q_vector->rx.total_bytes += total_rx_bytes;
1801 
1802 	return total_rx_packets;
1803 }
1804 
1805 /**
1806  * i40e_update_enable_itr - Update itr and re-enable MSIX interrupt
1807  * @vsi: the VSI we care about
1808  * @q_vector: q_vector for which itr is being updated and interrupt enabled
1809  *
1810  **/
1811 static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
1812 					  struct i40e_q_vector *q_vector)
1813 {
1814 	struct i40e_hw *hw = &vsi->back->hw;
1815 	u16 old_itr;
1816 	int vector;
1817 	u32 val;
1818 
1819 	vector = (q_vector->v_idx + vsi->base_vector);
1820 	if (ITR_IS_DYNAMIC(vsi->rx_itr_setting)) {
1821 		old_itr = q_vector->rx.itr;
1822 		i40e_set_new_dynamic_itr(&q_vector->rx);
1823 		if (old_itr != q_vector->rx.itr) {
1824 			val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
1825 			I40E_PFINT_DYN_CTLN_CLEARPBA_MASK |
1826 			(I40E_RX_ITR <<
1827 				I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT) |
1828 			(q_vector->rx.itr <<
1829 				I40E_PFINT_DYN_CTLN_INTERVAL_SHIFT);
1830 		} else {
1831 			val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
1832 			I40E_PFINT_DYN_CTLN_CLEARPBA_MASK |
1833 			(I40E_ITR_NONE <<
1834 				I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT);
1835 		}
1836 		if (!test_bit(__I40E_DOWN, &vsi->state))
1837 			wr32(hw, I40E_PFINT_DYN_CTLN(vector - 1), val);
1838 	} else {
1839 		i40e_irq_dynamic_enable(vsi,
1840 					q_vector->v_idx + vsi->base_vector);
1841 	}
1842 	if (ITR_IS_DYNAMIC(vsi->tx_itr_setting)) {
1843 		old_itr = q_vector->tx.itr;
1844 		i40e_set_new_dynamic_itr(&q_vector->tx);
1845 		if (old_itr != q_vector->tx.itr) {
1846 			val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
1847 				I40E_PFINT_DYN_CTLN_CLEARPBA_MASK |
1848 				(I40E_TX_ITR <<
1849 				   I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT) |
1850 				(q_vector->tx.itr <<
1851 				   I40E_PFINT_DYN_CTLN_INTERVAL_SHIFT);
1852 		} else {
1853 			val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
1854 				I40E_PFINT_DYN_CTLN_CLEARPBA_MASK |
1855 				(I40E_ITR_NONE <<
1856 				   I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT);
1857 		}
1858 		if (!test_bit(__I40E_DOWN, &vsi->state))
1859 			wr32(hw, I40E_PFINT_DYN_CTLN(q_vector->v_idx +
1860 			      vsi->base_vector - 1), val);
1861 	} else {
1862 		i40e_irq_dynamic_enable(vsi,
1863 					q_vector->v_idx + vsi->base_vector);
1864 	}
1865 }
1866 
1867 /**
1868  * i40e_napi_poll - NAPI polling Rx/Tx cleanup routine
1869  * @napi: napi struct with our devices info in it
1870  * @budget: amount of work driver is allowed to do this pass, in packets
1871  *
1872  * This function will clean all queues associated with a q_vector.
1873  *
1874  * Returns the amount of work done
1875  **/
1876 int i40e_napi_poll(struct napi_struct *napi, int budget)
1877 {
1878 	struct i40e_q_vector *q_vector =
1879 			       container_of(napi, struct i40e_q_vector, napi);
1880 	struct i40e_vsi *vsi = q_vector->vsi;
1881 	struct i40e_ring *ring;
1882 	bool clean_complete = true;
1883 	bool arm_wb = false;
1884 	int budget_per_ring;
1885 	int cleaned;
1886 
1887 	if (test_bit(__I40E_DOWN, &vsi->state)) {
1888 		napi_complete(napi);
1889 		return 0;
1890 	}
1891 
1892 	/* Since the actual Tx work is minimal, we can give the Tx a larger
1893 	 * budget and be more aggressive about cleaning up the Tx descriptors.
1894 	 */
1895 	i40e_for_each_ring(ring, q_vector->tx) {
1896 		clean_complete &= i40e_clean_tx_irq(ring, vsi->work_limit);
1897 		arm_wb |= ring->arm_wb;
1898 	}
1899 
1900 	/* We attempt to distribute budget to each Rx queue fairly, but don't
1901 	 * allow the budget to go below 1 because that would exit polling early.
1902 	 */
1903 	budget_per_ring = max(budget/q_vector->num_ringpairs, 1);
1904 
1905 	i40e_for_each_ring(ring, q_vector->rx) {
1906 		if (ring_is_ps_enabled(ring))
1907 			cleaned = i40e_clean_rx_irq_ps(ring, budget_per_ring);
1908 		else
1909 			cleaned = i40e_clean_rx_irq_1buf(ring, budget_per_ring);
1910 		/* if we didn't clean as many as budgeted, we must be done */
1911 		clean_complete &= (budget_per_ring != cleaned);
1912 	}
1913 
1914 	/* If work not completed, return budget and polling will return */
1915 	if (!clean_complete) {
1916 		if (arm_wb)
1917 			i40e_force_wb(vsi, q_vector);
1918 		return budget;
1919 	}
1920 
1921 	/* Work is done so exit the polling mode and re-enable the interrupt */
1922 	napi_complete(napi);
1923 	if (vsi->back->flags & I40E_FLAG_MSIX_ENABLED) {
1924 		i40e_update_enable_itr(vsi, q_vector);
1925 	} else { /* Legacy mode */
1926 		struct i40e_hw *hw = &vsi->back->hw;
1927 		/* We re-enable the queue 0 cause, but
1928 		 * don't worry about dynamic_enable
1929 		 * because we left it on for the other
1930 		 * possible interrupts during napi
1931 		 */
1932 		u32 qval = rd32(hw, I40E_QINT_RQCTL(0)) |
1933 			   I40E_QINT_RQCTL_CAUSE_ENA_MASK;
1934 
1935 		wr32(hw, I40E_QINT_RQCTL(0), qval);
1936 		qval = rd32(hw, I40E_QINT_TQCTL(0)) |
1937 		       I40E_QINT_TQCTL_CAUSE_ENA_MASK;
1938 		wr32(hw, I40E_QINT_TQCTL(0), qval);
1939 		i40e_irq_dynamic_enable_icr0(vsi->back);
1940 	}
1941 	return 0;
1942 }
1943 
1944 /**
1945  * i40e_atr - Add a Flow Director ATR filter
1946  * @tx_ring:  ring to add programming descriptor to
1947  * @skb:      send buffer
1948  * @tx_flags: send tx flags
1949  * @protocol: wire protocol
1950  **/
1951 static void i40e_atr(struct i40e_ring *tx_ring, struct sk_buff *skb,
1952 		     u32 tx_flags, __be16 protocol)
1953 {
1954 	struct i40e_filter_program_desc *fdir_desc;
1955 	struct i40e_pf *pf = tx_ring->vsi->back;
1956 	union {
1957 		unsigned char *network;
1958 		struct iphdr *ipv4;
1959 		struct ipv6hdr *ipv6;
1960 	} hdr;
1961 	struct tcphdr *th;
1962 	unsigned int hlen;
1963 	u32 flex_ptype, dtype_cmd;
1964 	u16 i;
1965 
1966 	/* make sure ATR is enabled */
1967 	if (!(pf->flags & I40E_FLAG_FD_ATR_ENABLED))
1968 		return;
1969 
1970 	if ((pf->auto_disable_flags & I40E_FLAG_FD_ATR_ENABLED))
1971 		return;
1972 
1973 	/* if sampling is disabled do nothing */
1974 	if (!tx_ring->atr_sample_rate)
1975 		return;
1976 
1977 	if (!(tx_flags & (I40E_TX_FLAGS_IPV4 | I40E_TX_FLAGS_IPV6)))
1978 		return;
1979 
1980 	if (!(tx_flags & I40E_TX_FLAGS_VXLAN_TUNNEL)) {
1981 		/* snag network header to get L4 type and address */
1982 		hdr.network = skb_network_header(skb);
1983 
1984 		/* Currently only IPv4/IPv6 with TCP is supported
1985 		 * access ihl as u8 to avoid unaligned access on ia64
1986 		 */
1987 		if (tx_flags & I40E_TX_FLAGS_IPV4)
1988 			hlen = (hdr.network[0] & 0x0F) << 2;
1989 		else if (protocol == htons(ETH_P_IPV6))
1990 			hlen = sizeof(struct ipv6hdr);
1991 		else
1992 			return;
1993 	} else {
1994 		hdr.network = skb_inner_network_header(skb);
1995 		hlen = skb_inner_network_header_len(skb);
1996 	}
1997 
1998 	/* Currently only IPv4/IPv6 with TCP is supported
1999 	 * Note: tx_flags gets modified to reflect inner protocols in
2000 	 * tx_enable_csum function if encap is enabled.
2001 	 */
2002 	if ((tx_flags & I40E_TX_FLAGS_IPV4) &&
2003 	    (hdr.ipv4->protocol != IPPROTO_TCP))
2004 		return;
2005 	else if ((tx_flags & I40E_TX_FLAGS_IPV6) &&
2006 		 (hdr.ipv6->nexthdr != IPPROTO_TCP))
2007 		return;
2008 
2009 	th = (struct tcphdr *)(hdr.network + hlen);
2010 
2011 	/* Due to lack of space, no more new filters can be programmed */
2012 	if (th->syn && (pf->auto_disable_flags & I40E_FLAG_FD_ATR_ENABLED))
2013 		return;
2014 
2015 	tx_ring->atr_count++;
2016 
2017 	/* sample on all syn/fin/rst packets or once every atr sample rate */
2018 	if (!th->fin &&
2019 	    !th->syn &&
2020 	    !th->rst &&
2021 	    (tx_ring->atr_count < tx_ring->atr_sample_rate))
2022 		return;
2023 
2024 	tx_ring->atr_count = 0;
2025 
2026 	/* grab the next descriptor */
2027 	i = tx_ring->next_to_use;
2028 	fdir_desc = I40E_TX_FDIRDESC(tx_ring, i);
2029 
2030 	i++;
2031 	tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
2032 
2033 	flex_ptype = (tx_ring->queue_index << I40E_TXD_FLTR_QW0_QINDEX_SHIFT) &
2034 		      I40E_TXD_FLTR_QW0_QINDEX_MASK;
2035 	flex_ptype |= (protocol == htons(ETH_P_IP)) ?
2036 		      (I40E_FILTER_PCTYPE_NONF_IPV4_TCP <<
2037 		       I40E_TXD_FLTR_QW0_PCTYPE_SHIFT) :
2038 		      (I40E_FILTER_PCTYPE_NONF_IPV6_TCP <<
2039 		       I40E_TXD_FLTR_QW0_PCTYPE_SHIFT);
2040 
2041 	flex_ptype |= tx_ring->vsi->id << I40E_TXD_FLTR_QW0_DEST_VSI_SHIFT;
2042 
2043 	dtype_cmd = I40E_TX_DESC_DTYPE_FILTER_PROG;
2044 
2045 	dtype_cmd |= (th->fin || th->rst) ?
2046 		     (I40E_FILTER_PROGRAM_DESC_PCMD_REMOVE <<
2047 		      I40E_TXD_FLTR_QW1_PCMD_SHIFT) :
2048 		     (I40E_FILTER_PROGRAM_DESC_PCMD_ADD_UPDATE <<
2049 		      I40E_TXD_FLTR_QW1_PCMD_SHIFT);
2050 
2051 	dtype_cmd |= I40E_FILTER_PROGRAM_DESC_DEST_DIRECT_PACKET_QINDEX <<
2052 		     I40E_TXD_FLTR_QW1_DEST_SHIFT;
2053 
2054 	dtype_cmd |= I40E_FILTER_PROGRAM_DESC_FD_STATUS_FD_ID <<
2055 		     I40E_TXD_FLTR_QW1_FD_STATUS_SHIFT;
2056 
2057 	dtype_cmd |= I40E_TXD_FLTR_QW1_CNT_ENA_MASK;
2058 	if (!(tx_flags & I40E_TX_FLAGS_VXLAN_TUNNEL))
2059 		dtype_cmd |=
2060 			((u32)I40E_FD_ATR_STAT_IDX(pf->hw.pf_id) <<
2061 			I40E_TXD_FLTR_QW1_CNTINDEX_SHIFT) &
2062 			I40E_TXD_FLTR_QW1_CNTINDEX_MASK;
2063 	else
2064 		dtype_cmd |=
2065 			((u32)I40E_FD_ATR_TUNNEL_STAT_IDX(pf->hw.pf_id) <<
2066 			I40E_TXD_FLTR_QW1_CNTINDEX_SHIFT) &
2067 			I40E_TXD_FLTR_QW1_CNTINDEX_MASK;
2068 
2069 	fdir_desc->qindex_flex_ptype_vsi = cpu_to_le32(flex_ptype);
2070 	fdir_desc->rsvd = cpu_to_le32(0);
2071 	fdir_desc->dtype_cmd_cntindex = cpu_to_le32(dtype_cmd);
2072 	fdir_desc->fd_id = cpu_to_le32(0);
2073 }
2074 
2075 /**
2076  * i40e_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW
2077  * @skb:     send buffer
2078  * @tx_ring: ring to send buffer on
2079  * @flags:   the tx flags to be set
2080  *
2081  * Checks the skb and set up correspondingly several generic transmit flags
2082  * related to VLAN tagging for the HW, such as VLAN, DCB, etc.
2083  *
2084  * Returns error code indicate the frame should be dropped upon error and the
2085  * otherwise  returns 0 to indicate the flags has been set properly.
2086  **/
2087 #ifdef I40E_FCOE
2088 inline int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
2089 				      struct i40e_ring *tx_ring,
2090 				      u32 *flags)
2091 #else
2092 static inline int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
2093 					     struct i40e_ring *tx_ring,
2094 					     u32 *flags)
2095 #endif
2096 {
2097 	__be16 protocol = skb->protocol;
2098 	u32  tx_flags = 0;
2099 
2100 	if (protocol == htons(ETH_P_8021Q) &&
2101 	    !(tx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_TX)) {
2102 		/* When HW VLAN acceleration is turned off by the user the
2103 		 * stack sets the protocol to 8021q so that the driver
2104 		 * can take any steps required to support the SW only
2105 		 * VLAN handling.  In our case the driver doesn't need
2106 		 * to take any further steps so just set the protocol
2107 		 * to the encapsulated ethertype.
2108 		 */
2109 		skb->protocol = vlan_get_protocol(skb);
2110 		goto out;
2111 	}
2112 
2113 	/* if we have a HW VLAN tag being added, default to the HW one */
2114 	if (skb_vlan_tag_present(skb)) {
2115 		tx_flags |= skb_vlan_tag_get(skb) << I40E_TX_FLAGS_VLAN_SHIFT;
2116 		tx_flags |= I40E_TX_FLAGS_HW_VLAN;
2117 	/* else if it is a SW VLAN, check the next protocol and store the tag */
2118 	} else if (protocol == htons(ETH_P_8021Q)) {
2119 		struct vlan_hdr *vhdr, _vhdr;
2120 		vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(_vhdr), &_vhdr);
2121 		if (!vhdr)
2122 			return -EINVAL;
2123 
2124 		protocol = vhdr->h_vlan_encapsulated_proto;
2125 		tx_flags |= ntohs(vhdr->h_vlan_TCI) << I40E_TX_FLAGS_VLAN_SHIFT;
2126 		tx_flags |= I40E_TX_FLAGS_SW_VLAN;
2127 	}
2128 
2129 	if (!(tx_ring->vsi->back->flags & I40E_FLAG_DCB_ENABLED))
2130 		goto out;
2131 
2132 	/* Insert 802.1p priority into VLAN header */
2133 	if ((tx_flags & (I40E_TX_FLAGS_HW_VLAN | I40E_TX_FLAGS_SW_VLAN)) ||
2134 	    (skb->priority != TC_PRIO_CONTROL)) {
2135 		tx_flags &= ~I40E_TX_FLAGS_VLAN_PRIO_MASK;
2136 		tx_flags |= (skb->priority & 0x7) <<
2137 				I40E_TX_FLAGS_VLAN_PRIO_SHIFT;
2138 		if (tx_flags & I40E_TX_FLAGS_SW_VLAN) {
2139 			struct vlan_ethhdr *vhdr;
2140 			int rc;
2141 
2142 			rc = skb_cow_head(skb, 0);
2143 			if (rc < 0)
2144 				return rc;
2145 			vhdr = (struct vlan_ethhdr *)skb->data;
2146 			vhdr->h_vlan_TCI = htons(tx_flags >>
2147 						 I40E_TX_FLAGS_VLAN_SHIFT);
2148 		} else {
2149 			tx_flags |= I40E_TX_FLAGS_HW_VLAN;
2150 		}
2151 	}
2152 
2153 out:
2154 	*flags = tx_flags;
2155 	return 0;
2156 }
2157 
2158 /**
2159  * i40e_tso - set up the tso context descriptor
2160  * @tx_ring:  ptr to the ring to send
2161  * @skb:      ptr to the skb we're sending
2162  * @hdr_len:  ptr to the size of the packet header
2163  * @cd_tunneling: ptr to context descriptor bits
2164  *
2165  * Returns 0 if no TSO can happen, 1 if tso is going, or error
2166  **/
2167 static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb,
2168 		    u8 *hdr_len, u64 *cd_type_cmd_tso_mss,
2169 		    u32 *cd_tunneling)
2170 {
2171 	u32 cd_cmd, cd_tso_len, cd_mss;
2172 	struct ipv6hdr *ipv6h;
2173 	struct tcphdr *tcph;
2174 	struct iphdr *iph;
2175 	u32 l4len;
2176 	int err;
2177 
2178 	if (!skb_is_gso(skb))
2179 		return 0;
2180 
2181 	err = skb_cow_head(skb, 0);
2182 	if (err < 0)
2183 		return err;
2184 
2185 	iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
2186 	ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
2187 
2188 	if (iph->version == 4) {
2189 		tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
2190 		iph->tot_len = 0;
2191 		iph->check = 0;
2192 		tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
2193 						 0, IPPROTO_TCP, 0);
2194 	} else if (ipv6h->version == 6) {
2195 		tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
2196 		ipv6h->payload_len = 0;
2197 		tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
2198 					       0, IPPROTO_TCP, 0);
2199 	}
2200 
2201 	l4len = skb->encapsulation ? inner_tcp_hdrlen(skb) : tcp_hdrlen(skb);
2202 	*hdr_len = (skb->encapsulation
2203 		    ? (skb_inner_transport_header(skb) - skb->data)
2204 		    : skb_transport_offset(skb)) + l4len;
2205 
2206 	/* find the field values */
2207 	cd_cmd = I40E_TX_CTX_DESC_TSO;
2208 	cd_tso_len = skb->len - *hdr_len;
2209 	cd_mss = skb_shinfo(skb)->gso_size;
2210 	*cd_type_cmd_tso_mss |= ((u64)cd_cmd << I40E_TXD_CTX_QW1_CMD_SHIFT) |
2211 				((u64)cd_tso_len <<
2212 				 I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
2213 				((u64)cd_mss << I40E_TXD_CTX_QW1_MSS_SHIFT);
2214 	return 1;
2215 }
2216 
2217 /**
2218  * i40e_tsyn - set up the tsyn context descriptor
2219  * @tx_ring:  ptr to the ring to send
2220  * @skb:      ptr to the skb we're sending
2221  * @tx_flags: the collected send information
2222  *
2223  * Returns 0 if no Tx timestamp can happen and 1 if the timestamp will happen
2224  **/
2225 static int i40e_tsyn(struct i40e_ring *tx_ring, struct sk_buff *skb,
2226 		     u32 tx_flags, u64 *cd_type_cmd_tso_mss)
2227 {
2228 	struct i40e_pf *pf;
2229 
2230 	if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)))
2231 		return 0;
2232 
2233 	/* Tx timestamps cannot be sampled when doing TSO */
2234 	if (tx_flags & I40E_TX_FLAGS_TSO)
2235 		return 0;
2236 
2237 	/* only timestamp the outbound packet if the user has requested it and
2238 	 * we are not already transmitting a packet to be timestamped
2239 	 */
2240 	pf = i40e_netdev_to_pf(tx_ring->netdev);
2241 	if (!(pf->flags & I40E_FLAG_PTP))
2242 		return 0;
2243 
2244 	if (pf->ptp_tx &&
2245 	    !test_and_set_bit_lock(__I40E_PTP_TX_IN_PROGRESS, &pf->state)) {
2246 		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
2247 		pf->ptp_tx_skb = skb_get(skb);
2248 	} else {
2249 		return 0;
2250 	}
2251 
2252 	*cd_type_cmd_tso_mss |= (u64)I40E_TX_CTX_DESC_TSYN <<
2253 				I40E_TXD_CTX_QW1_CMD_SHIFT;
2254 
2255 	return 1;
2256 }
2257 
2258 /**
2259  * i40e_tx_enable_csum - Enable Tx checksum offloads
2260  * @skb: send buffer
2261  * @tx_flags: pointer to Tx flags currently set
2262  * @td_cmd: Tx descriptor command bits to set
2263  * @td_offset: Tx descriptor header offsets to set
2264  * @cd_tunneling: ptr to context desc bits
2265  **/
2266 static void i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
2267 				u32 *td_cmd, u32 *td_offset,
2268 				struct i40e_ring *tx_ring,
2269 				u32 *cd_tunneling)
2270 {
2271 	struct ipv6hdr *this_ipv6_hdr;
2272 	unsigned int this_tcp_hdrlen;
2273 	struct iphdr *this_ip_hdr;
2274 	u32 network_hdr_len;
2275 	u8 l4_hdr = 0;
2276 	u32 l4_tunnel = 0;
2277 
2278 	if (skb->encapsulation) {
2279 		switch (ip_hdr(skb)->protocol) {
2280 		case IPPROTO_UDP:
2281 			l4_tunnel = I40E_TXD_CTX_UDP_TUNNELING;
2282 			*tx_flags |= I40E_TX_FLAGS_VXLAN_TUNNEL;
2283 			break;
2284 		default:
2285 			return;
2286 		}
2287 		network_hdr_len = skb_inner_network_header_len(skb);
2288 		this_ip_hdr = inner_ip_hdr(skb);
2289 		this_ipv6_hdr = inner_ipv6_hdr(skb);
2290 		this_tcp_hdrlen = inner_tcp_hdrlen(skb);
2291 
2292 		if (*tx_flags & I40E_TX_FLAGS_IPV4) {
2293 			if (*tx_flags & I40E_TX_FLAGS_TSO) {
2294 				*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV4;
2295 				ip_hdr(skb)->check = 0;
2296 			} else {
2297 				*cd_tunneling |=
2298 					 I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
2299 			}
2300 		} else if (*tx_flags & I40E_TX_FLAGS_IPV6) {
2301 			*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV6;
2302 			if (*tx_flags & I40E_TX_FLAGS_TSO)
2303 				ip_hdr(skb)->check = 0;
2304 		}
2305 
2306 		/* Now set the ctx descriptor fields */
2307 		*cd_tunneling |= (skb_network_header_len(skb) >> 2) <<
2308 				   I40E_TXD_CTX_QW0_EXT_IPLEN_SHIFT      |
2309 				   l4_tunnel                             |
2310 				   ((skb_inner_network_offset(skb) -
2311 					skb_transport_offset(skb)) >> 1) <<
2312 				   I40E_TXD_CTX_QW0_NATLEN_SHIFT;
2313 		if (this_ip_hdr->version == 6) {
2314 			*tx_flags &= ~I40E_TX_FLAGS_IPV4;
2315 			*tx_flags |= I40E_TX_FLAGS_IPV6;
2316 		}
2317 	} else {
2318 		network_hdr_len = skb_network_header_len(skb);
2319 		this_ip_hdr = ip_hdr(skb);
2320 		this_ipv6_hdr = ipv6_hdr(skb);
2321 		this_tcp_hdrlen = tcp_hdrlen(skb);
2322 	}
2323 
2324 	/* Enable IP checksum offloads */
2325 	if (*tx_flags & I40E_TX_FLAGS_IPV4) {
2326 		l4_hdr = this_ip_hdr->protocol;
2327 		/* the stack computes the IP header already, the only time we
2328 		 * need the hardware to recompute it is in the case of TSO.
2329 		 */
2330 		if (*tx_flags & I40E_TX_FLAGS_TSO) {
2331 			*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4_CSUM;
2332 			this_ip_hdr->check = 0;
2333 		} else {
2334 			*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4;
2335 		}
2336 		/* Now set the td_offset for IP header length */
2337 		*td_offset = (network_hdr_len >> 2) <<
2338 			      I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
2339 	} else if (*tx_flags & I40E_TX_FLAGS_IPV6) {
2340 		l4_hdr = this_ipv6_hdr->nexthdr;
2341 		*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV6;
2342 		/* Now set the td_offset for IP header length */
2343 		*td_offset = (network_hdr_len >> 2) <<
2344 			      I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
2345 	}
2346 	/* words in MACLEN + dwords in IPLEN + dwords in L4Len */
2347 	*td_offset |= (skb_network_offset(skb) >> 1) <<
2348 		       I40E_TX_DESC_LENGTH_MACLEN_SHIFT;
2349 
2350 	/* Enable L4 checksum offloads */
2351 	switch (l4_hdr) {
2352 	case IPPROTO_TCP:
2353 		/* enable checksum offloads */
2354 		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_TCP;
2355 		*td_offset |= (this_tcp_hdrlen >> 2) <<
2356 			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
2357 		break;
2358 	case IPPROTO_SCTP:
2359 		/* enable SCTP checksum offload */
2360 		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_SCTP;
2361 		*td_offset |= (sizeof(struct sctphdr) >> 2) <<
2362 			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
2363 		break;
2364 	case IPPROTO_UDP:
2365 		/* enable UDP checksum offload */
2366 		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_UDP;
2367 		*td_offset |= (sizeof(struct udphdr) >> 2) <<
2368 			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
2369 		break;
2370 	default:
2371 		break;
2372 	}
2373 }
2374 
2375 /**
2376  * i40e_create_tx_ctx Build the Tx context descriptor
2377  * @tx_ring:  ring to create the descriptor on
2378  * @cd_type_cmd_tso_mss: Quad Word 1
2379  * @cd_tunneling: Quad Word 0 - bits 0-31
2380  * @cd_l2tag2: Quad Word 0 - bits 32-63
2381  **/
2382 static void i40e_create_tx_ctx(struct i40e_ring *tx_ring,
2383 			       const u64 cd_type_cmd_tso_mss,
2384 			       const u32 cd_tunneling, const u32 cd_l2tag2)
2385 {
2386 	struct i40e_tx_context_desc *context_desc;
2387 	int i = tx_ring->next_to_use;
2388 
2389 	if ((cd_type_cmd_tso_mss == I40E_TX_DESC_DTYPE_CONTEXT) &&
2390 	    !cd_tunneling && !cd_l2tag2)
2391 		return;
2392 
2393 	/* grab the next descriptor */
2394 	context_desc = I40E_TX_CTXTDESC(tx_ring, i);
2395 
2396 	i++;
2397 	tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
2398 
2399 	/* cpu_to_le32 and assign to struct fields */
2400 	context_desc->tunneling_params = cpu_to_le32(cd_tunneling);
2401 	context_desc->l2tag2 = cpu_to_le16(cd_l2tag2);
2402 	context_desc->rsvd = cpu_to_le16(0);
2403 	context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss);
2404 }
2405 
2406 /**
2407  * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions
2408  * @tx_ring: the ring to be checked
2409  * @size:    the size buffer we want to assure is available
2410  *
2411  * Returns -EBUSY if a stop is needed, else 0
2412  **/
2413 static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
2414 {
2415 	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
2416 	/* Memory barrier before checking head and tail */
2417 	smp_mb();
2418 
2419 	/* Check again in a case another CPU has just made room available. */
2420 	if (likely(I40E_DESC_UNUSED(tx_ring) < size))
2421 		return -EBUSY;
2422 
2423 	/* A reprieve! - use start_queue because it doesn't call schedule */
2424 	netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
2425 	++tx_ring->tx_stats.restart_queue;
2426 	return 0;
2427 }
2428 
2429 /**
2430  * i40e_maybe_stop_tx - 1st level check for tx stop conditions
2431  * @tx_ring: the ring to be checked
2432  * @size:    the size buffer we want to assure is available
2433  *
2434  * Returns 0 if stop is not needed
2435  **/
2436 #ifdef I40E_FCOE
2437 inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
2438 #else
2439 static inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
2440 #endif
2441 {
2442 	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
2443 		return 0;
2444 	return __i40e_maybe_stop_tx(tx_ring, size);
2445 }
2446 
2447 /**
2448  * i40e_chk_linearize - Check if there are more than 8 fragments per packet
2449  * @skb:      send buffer
2450  * @tx_flags: collected send information
2451  *
2452  * Note: Our HW can't scatter-gather more than 8 fragments to build
2453  * a packet on the wire and so we need to figure out the cases where we
2454  * need to linearize the skb.
2455  **/
2456 static bool i40e_chk_linearize(struct sk_buff *skb, u32 tx_flags)
2457 {
2458 	struct skb_frag_struct *frag;
2459 	bool linearize = false;
2460 	unsigned int size = 0;
2461 	u16 num_frags;
2462 	u16 gso_segs;
2463 
2464 	num_frags = skb_shinfo(skb)->nr_frags;
2465 	gso_segs = skb_shinfo(skb)->gso_segs;
2466 
2467 	if (tx_flags & (I40E_TX_FLAGS_TSO | I40E_TX_FLAGS_FSO)) {
2468 		u16 j = 0;
2469 
2470 		if (num_frags < (I40E_MAX_BUFFER_TXD))
2471 			goto linearize_chk_done;
2472 		/* try the simple math, if we have too many frags per segment */
2473 		if (DIV_ROUND_UP((num_frags + gso_segs), gso_segs) >
2474 		    I40E_MAX_BUFFER_TXD) {
2475 			linearize = true;
2476 			goto linearize_chk_done;
2477 		}
2478 		frag = &skb_shinfo(skb)->frags[0];
2479 		/* we might still have more fragments per segment */
2480 		do {
2481 			size += skb_frag_size(frag);
2482 			frag++; j++;
2483 			if ((size >= skb_shinfo(skb)->gso_size) &&
2484 			    (j < I40E_MAX_BUFFER_TXD)) {
2485 				size = (size % skb_shinfo(skb)->gso_size);
2486 				j = (size) ? 1 : 0;
2487 			}
2488 			if (j == I40E_MAX_BUFFER_TXD) {
2489 				linearize = true;
2490 				break;
2491 			}
2492 			num_frags--;
2493 		} while (num_frags);
2494 	} else {
2495 		if (num_frags >= I40E_MAX_BUFFER_TXD)
2496 			linearize = true;
2497 	}
2498 
2499 linearize_chk_done:
2500 	return linearize;
2501 }
2502 
2503 /**
2504  * i40e_tx_map - Build the Tx descriptor
2505  * @tx_ring:  ring to send buffer on
2506  * @skb:      send buffer
2507  * @first:    first buffer info buffer to use
2508  * @tx_flags: collected send information
2509  * @hdr_len:  size of the packet header
2510  * @td_cmd:   the command field in the descriptor
2511  * @td_offset: offset for checksum or crc
2512  **/
2513 #ifdef I40E_FCOE
2514 inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
2515 			struct i40e_tx_buffer *first, u32 tx_flags,
2516 			const u8 hdr_len, u32 td_cmd, u32 td_offset)
2517 #else
2518 static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
2519 			       struct i40e_tx_buffer *first, u32 tx_flags,
2520 			       const u8 hdr_len, u32 td_cmd, u32 td_offset)
2521 #endif
2522 {
2523 	unsigned int data_len = skb->data_len;
2524 	unsigned int size = skb_headlen(skb);
2525 	struct skb_frag_struct *frag;
2526 	struct i40e_tx_buffer *tx_bi;
2527 	struct i40e_tx_desc *tx_desc;
2528 	u16 i = tx_ring->next_to_use;
2529 	u32 td_tag = 0;
2530 	dma_addr_t dma;
2531 	u16 gso_segs;
2532 
2533 	if (tx_flags & I40E_TX_FLAGS_HW_VLAN) {
2534 		td_cmd |= I40E_TX_DESC_CMD_IL2TAG1;
2535 		td_tag = (tx_flags & I40E_TX_FLAGS_VLAN_MASK) >>
2536 			 I40E_TX_FLAGS_VLAN_SHIFT;
2537 	}
2538 
2539 	if (tx_flags & (I40E_TX_FLAGS_TSO | I40E_TX_FLAGS_FSO))
2540 		gso_segs = skb_shinfo(skb)->gso_segs;
2541 	else
2542 		gso_segs = 1;
2543 
2544 	/* multiply data chunks by size of headers */
2545 	first->bytecount = skb->len - hdr_len + (gso_segs * hdr_len);
2546 	first->gso_segs = gso_segs;
2547 	first->skb = skb;
2548 	first->tx_flags = tx_flags;
2549 
2550 	dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
2551 
2552 	tx_desc = I40E_TX_DESC(tx_ring, i);
2553 	tx_bi = first;
2554 
2555 	for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
2556 		if (dma_mapping_error(tx_ring->dev, dma))
2557 			goto dma_error;
2558 
2559 		/* record length, and DMA address */
2560 		dma_unmap_len_set(tx_bi, len, size);
2561 		dma_unmap_addr_set(tx_bi, dma, dma);
2562 
2563 		tx_desc->buffer_addr = cpu_to_le64(dma);
2564 
2565 		while (unlikely(size > I40E_MAX_DATA_PER_TXD)) {
2566 			tx_desc->cmd_type_offset_bsz =
2567 				build_ctob(td_cmd, td_offset,
2568 					   I40E_MAX_DATA_PER_TXD, td_tag);
2569 
2570 			tx_desc++;
2571 			i++;
2572 			if (i == tx_ring->count) {
2573 				tx_desc = I40E_TX_DESC(tx_ring, 0);
2574 				i = 0;
2575 			}
2576 
2577 			dma += I40E_MAX_DATA_PER_TXD;
2578 			size -= I40E_MAX_DATA_PER_TXD;
2579 
2580 			tx_desc->buffer_addr = cpu_to_le64(dma);
2581 		}
2582 
2583 		if (likely(!data_len))
2584 			break;
2585 
2586 		tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset,
2587 							  size, td_tag);
2588 
2589 		tx_desc++;
2590 		i++;
2591 		if (i == tx_ring->count) {
2592 			tx_desc = I40E_TX_DESC(tx_ring, 0);
2593 			i = 0;
2594 		}
2595 
2596 		size = skb_frag_size(frag);
2597 		data_len -= size;
2598 
2599 		dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
2600 				       DMA_TO_DEVICE);
2601 
2602 		tx_bi = &tx_ring->tx_bi[i];
2603 	}
2604 
2605 	/* Place RS bit on last descriptor of any packet that spans across the
2606 	 * 4th descriptor (WB_STRIDE aka 0x3) in a 64B cacheline.
2607 	 */
2608 	if (((i & WB_STRIDE) != WB_STRIDE) &&
2609 	    (first <= &tx_ring->tx_bi[i]) &&
2610 	    (first >= &tx_ring->tx_bi[i & ~WB_STRIDE])) {
2611 		tx_desc->cmd_type_offset_bsz =
2612 			build_ctob(td_cmd, td_offset, size, td_tag) |
2613 			cpu_to_le64((u64)I40E_TX_DESC_CMD_EOP <<
2614 					 I40E_TXD_QW1_CMD_SHIFT);
2615 	} else {
2616 		tx_desc->cmd_type_offset_bsz =
2617 			build_ctob(td_cmd, td_offset, size, td_tag) |
2618 			cpu_to_le64((u64)I40E_TXD_CMD <<
2619 					 I40E_TXD_QW1_CMD_SHIFT);
2620 	}
2621 
2622 	netdev_tx_sent_queue(netdev_get_tx_queue(tx_ring->netdev,
2623 						 tx_ring->queue_index),
2624 			     first->bytecount);
2625 
2626 	/* Force memory writes to complete before letting h/w
2627 	 * know there are new descriptors to fetch.  (Only
2628 	 * applicable for weak-ordered memory model archs,
2629 	 * such as IA-64).
2630 	 */
2631 	wmb();
2632 
2633 	/* set next_to_watch value indicating a packet is present */
2634 	first->next_to_watch = tx_desc;
2635 
2636 	i++;
2637 	if (i == tx_ring->count)
2638 		i = 0;
2639 
2640 	tx_ring->next_to_use = i;
2641 
2642 	i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
2643 	/* notify HW of packet */
2644 	if (!skb->xmit_more ||
2645 	    netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev,
2646 						   tx_ring->queue_index)))
2647 		writel(i, tx_ring->tail);
2648 	else
2649 		prefetchw(tx_desc + 1);
2650 
2651 	return;
2652 
2653 dma_error:
2654 	dev_info(tx_ring->dev, "TX DMA map failed\n");
2655 
2656 	/* clear dma mappings for failed tx_bi map */
2657 	for (;;) {
2658 		tx_bi = &tx_ring->tx_bi[i];
2659 		i40e_unmap_and_free_tx_resource(tx_ring, tx_bi);
2660 		if (tx_bi == first)
2661 			break;
2662 		if (i == 0)
2663 			i = tx_ring->count;
2664 		i--;
2665 	}
2666 
2667 	tx_ring->next_to_use = i;
2668 }
2669 
2670 /**
2671  * i40e_xmit_descriptor_count - calculate number of tx descriptors needed
2672  * @skb:     send buffer
2673  * @tx_ring: ring to send buffer on
2674  *
2675  * Returns number of data descriptors needed for this skb. Returns 0 to indicate
2676  * there is not enough descriptors available in this ring since we need at least
2677  * one descriptor.
2678  **/
2679 #ifdef I40E_FCOE
2680 inline int i40e_xmit_descriptor_count(struct sk_buff *skb,
2681 				      struct i40e_ring *tx_ring)
2682 #else
2683 static inline int i40e_xmit_descriptor_count(struct sk_buff *skb,
2684 					     struct i40e_ring *tx_ring)
2685 #endif
2686 {
2687 	unsigned int f;
2688 	int count = 0;
2689 
2690 	/* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD,
2691 	 *       + 1 desc for skb_head_len/I40E_MAX_DATA_PER_TXD,
2692 	 *       + 4 desc gap to avoid the cache line where head is,
2693 	 *       + 1 desc for context descriptor,
2694 	 * otherwise try next time
2695 	 */
2696 	for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
2697 		count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size);
2698 
2699 	count += TXD_USE_COUNT(skb_headlen(skb));
2700 	if (i40e_maybe_stop_tx(tx_ring, count + 4 + 1)) {
2701 		tx_ring->tx_stats.tx_busy++;
2702 		return 0;
2703 	}
2704 	return count;
2705 }
2706 
2707 /**
2708  * i40e_xmit_frame_ring - Sends buffer on Tx ring
2709  * @skb:     send buffer
2710  * @tx_ring: ring to send buffer on
2711  *
2712  * Returns NETDEV_TX_OK if sent, else an error code
2713  **/
2714 static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
2715 					struct i40e_ring *tx_ring)
2716 {
2717 	u64 cd_type_cmd_tso_mss = I40E_TX_DESC_DTYPE_CONTEXT;
2718 	u32 cd_tunneling = 0, cd_l2tag2 = 0;
2719 	struct i40e_tx_buffer *first;
2720 	u32 td_offset = 0;
2721 	u32 tx_flags = 0;
2722 	__be16 protocol;
2723 	u32 td_cmd = 0;
2724 	u8 hdr_len = 0;
2725 	int tsyn;
2726 	int tso;
2727 	if (0 == i40e_xmit_descriptor_count(skb, tx_ring))
2728 		return NETDEV_TX_BUSY;
2729 
2730 	/* prepare the xmit flags */
2731 	if (i40e_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))
2732 		goto out_drop;
2733 
2734 	/* obtain protocol of skb */
2735 	protocol = vlan_get_protocol(skb);
2736 
2737 	/* record the location of the first descriptor for this packet */
2738 	first = &tx_ring->tx_bi[tx_ring->next_to_use];
2739 
2740 	/* setup IPv4/IPv6 offloads */
2741 	if (protocol == htons(ETH_P_IP))
2742 		tx_flags |= I40E_TX_FLAGS_IPV4;
2743 	else if (protocol == htons(ETH_P_IPV6))
2744 		tx_flags |= I40E_TX_FLAGS_IPV6;
2745 
2746 	tso = i40e_tso(tx_ring, skb, &hdr_len,
2747 		       &cd_type_cmd_tso_mss, &cd_tunneling);
2748 
2749 	if (tso < 0)
2750 		goto out_drop;
2751 	else if (tso)
2752 		tx_flags |= I40E_TX_FLAGS_TSO;
2753 
2754 	tsyn = i40e_tsyn(tx_ring, skb, tx_flags, &cd_type_cmd_tso_mss);
2755 
2756 	if (tsyn)
2757 		tx_flags |= I40E_TX_FLAGS_TSYN;
2758 
2759 	if (i40e_chk_linearize(skb, tx_flags))
2760 		if (skb_linearize(skb))
2761 			goto out_drop;
2762 
2763 	skb_tx_timestamp(skb);
2764 
2765 	/* always enable CRC insertion offload */
2766 	td_cmd |= I40E_TX_DESC_CMD_ICRC;
2767 
2768 	/* Always offload the checksum, since it's in the data descriptor */
2769 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
2770 		tx_flags |= I40E_TX_FLAGS_CSUM;
2771 
2772 		i40e_tx_enable_csum(skb, &tx_flags, &td_cmd, &td_offset,
2773 				    tx_ring, &cd_tunneling);
2774 	}
2775 
2776 	i40e_create_tx_ctx(tx_ring, cd_type_cmd_tso_mss,
2777 			   cd_tunneling, cd_l2tag2);
2778 
2779 	/* Add Flow Director ATR if it's enabled.
2780 	 *
2781 	 * NOTE: this must always be directly before the data descriptor.
2782 	 */
2783 	i40e_atr(tx_ring, skb, tx_flags, protocol);
2784 
2785 	i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,
2786 		    td_cmd, td_offset);
2787 
2788 	return NETDEV_TX_OK;
2789 
2790 out_drop:
2791 	dev_kfree_skb_any(skb);
2792 	return NETDEV_TX_OK;
2793 }
2794 
2795 /**
2796  * i40e_lan_xmit_frame - Selects the correct VSI and Tx queue to send buffer
2797  * @skb:    send buffer
2798  * @netdev: network interface device structure
2799  *
2800  * Returns NETDEV_TX_OK if sent, else an error code
2801  **/
2802 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
2803 {
2804 	struct i40e_netdev_priv *np = netdev_priv(netdev);
2805 	struct i40e_vsi *vsi = np->vsi;
2806 	struct i40e_ring *tx_ring = vsi->tx_rings[skb->queue_mapping];
2807 
2808 	/* hardware can't handle really short frames, hardware padding works
2809 	 * beyond this point
2810 	 */
2811 	if (skb_put_padto(skb, I40E_MIN_TX_LEN))
2812 		return NETDEV_TX_OK;
2813 
2814 	return i40e_xmit_frame_ring(skb, tx_ring);
2815 }
2816