1 /*
2  * Copyright (C) 2015 Cavium, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License
6  * as published by the Free Software Foundation.
7  */
8 
9 #include <linux/pci.h>
10 #include <linux/netdevice.h>
11 #include <linux/ip.h>
12 #include <linux/etherdevice.h>
13 #include <net/ip.h>
14 #include <net/tso.h>
15 
16 #include "nic_reg.h"
17 #include "nic.h"
18 #include "q_struct.h"
19 #include "nicvf_queues.h"
20 
21 static void nicvf_get_page(struct nicvf *nic)
22 {
23 	if (!nic->rb_pageref || !nic->rb_page)
24 		return;
25 
26 	page_ref_add(nic->rb_page, nic->rb_pageref);
27 	nic->rb_pageref = 0;
28 }
29 
30 /* Poll a register for a specific value */
31 static int nicvf_poll_reg(struct nicvf *nic, int qidx,
32 			  u64 reg, int bit_pos, int bits, int val)
33 {
34 	u64 bit_mask;
35 	u64 reg_val;
36 	int timeout = 10;
37 
38 	bit_mask = (1ULL << bits) - 1;
39 	bit_mask = (bit_mask << bit_pos);
40 
41 	while (timeout) {
42 		reg_val = nicvf_queue_reg_read(nic, reg, qidx);
43 		if (((reg_val & bit_mask) >> bit_pos) == val)
44 			return 0;
45 		usleep_range(1000, 2000);
46 		timeout--;
47 	}
48 	netdev_err(nic->netdev, "Poll on reg 0x%llx failed\n", reg);
49 	return 1;
50 }
51 
52 /* Allocate memory for a queue's descriptors */
53 static int nicvf_alloc_q_desc_mem(struct nicvf *nic, struct q_desc_mem *dmem,
54 				  int q_len, int desc_size, int align_bytes)
55 {
56 	dmem->q_len = q_len;
57 	dmem->size = (desc_size * q_len) + align_bytes;
58 	/* Save address, need it while freeing */
59 	dmem->unalign_base = dma_zalloc_coherent(&nic->pdev->dev, dmem->size,
60 						&dmem->dma, GFP_KERNEL);
61 	if (!dmem->unalign_base)
62 		return -ENOMEM;
63 
64 	/* Align memory address for 'align_bytes' */
65 	dmem->phys_base = NICVF_ALIGNED_ADDR((u64)dmem->dma, align_bytes);
66 	dmem->base = dmem->unalign_base + (dmem->phys_base - dmem->dma);
67 	return 0;
68 }
69 
70 /* Free queue's descriptor memory */
71 static void nicvf_free_q_desc_mem(struct nicvf *nic, struct q_desc_mem *dmem)
72 {
73 	if (!dmem)
74 		return;
75 
76 	dma_free_coherent(&nic->pdev->dev, dmem->size,
77 			  dmem->unalign_base, dmem->dma);
78 	dmem->unalign_base = NULL;
79 	dmem->base = NULL;
80 }
81 
82 /* Allocate buffer for packet reception
83  * HW returns memory address where packet is DMA'ed but not a pointer
84  * into RBDR ring, so save buffer address at the start of fragment and
85  * align the start address to a cache aligned address
86  */
87 static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, gfp_t gfp,
88 					 u32 buf_len, u64 **rbuf)
89 {
90 	int order = (PAGE_SIZE <= 4096) ?  PAGE_ALLOC_COSTLY_ORDER : 0;
91 
92 	/* Check if request can be accomodated in previous allocated page */
93 	if (nic->rb_page &&
94 	    ((nic->rb_page_offset + buf_len) < (PAGE_SIZE << order))) {
95 		nic->rb_pageref++;
96 		goto ret;
97 	}
98 
99 	nicvf_get_page(nic);
100 	nic->rb_page = NULL;
101 
102 	/* Allocate a new page */
103 	if (!nic->rb_page) {
104 		nic->rb_page = alloc_pages(gfp | __GFP_COMP | __GFP_NOWARN,
105 					   order);
106 		if (!nic->rb_page) {
107 			this_cpu_inc(nic->pnicvf->drv_stats->
108 				     rcv_buffer_alloc_failures);
109 			return -ENOMEM;
110 		}
111 		nic->rb_page_offset = 0;
112 	}
113 
114 ret:
115 	*rbuf = (u64 *)((u64)page_address(nic->rb_page) + nic->rb_page_offset);
116 	nic->rb_page_offset += buf_len;
117 
118 	return 0;
119 }
120 
121 /* Build skb around receive buffer */
122 static struct sk_buff *nicvf_rb_ptr_to_skb(struct nicvf *nic,
123 					   u64 rb_ptr, int len)
124 {
125 	void *data;
126 	struct sk_buff *skb;
127 
128 	data = phys_to_virt(rb_ptr);
129 
130 	/* Now build an skb to give to stack */
131 	skb = build_skb(data, RCV_FRAG_LEN);
132 	if (!skb) {
133 		put_page(virt_to_page(data));
134 		return NULL;
135 	}
136 
137 	prefetch(skb->data);
138 	return skb;
139 }
140 
141 /* Allocate RBDR ring and populate receive buffers */
142 static int  nicvf_init_rbdr(struct nicvf *nic, struct rbdr *rbdr,
143 			    int ring_len, int buf_size)
144 {
145 	int idx;
146 	u64 *rbuf;
147 	struct rbdr_entry_t *desc;
148 	int err;
149 
150 	err = nicvf_alloc_q_desc_mem(nic, &rbdr->dmem, ring_len,
151 				     sizeof(struct rbdr_entry_t),
152 				     NICVF_RCV_BUF_ALIGN_BYTES);
153 	if (err)
154 		return err;
155 
156 	rbdr->desc = rbdr->dmem.base;
157 	/* Buffer size has to be in multiples of 128 bytes */
158 	rbdr->dma_size = buf_size;
159 	rbdr->enable = true;
160 	rbdr->thresh = RBDR_THRESH;
161 
162 	nic->rb_page = NULL;
163 	for (idx = 0; idx < ring_len; idx++) {
164 		err = nicvf_alloc_rcv_buffer(nic, GFP_KERNEL, RCV_FRAG_LEN,
165 					     &rbuf);
166 		if (err)
167 			return err;
168 
169 		desc = GET_RBDR_DESC(rbdr, idx);
170 		desc->buf_addr = virt_to_phys(rbuf) >> NICVF_RCV_BUF_ALIGN;
171 	}
172 
173 	nicvf_get_page(nic);
174 
175 	return 0;
176 }
177 
178 /* Free RBDR ring and its receive buffers */
179 static void nicvf_free_rbdr(struct nicvf *nic, struct rbdr *rbdr)
180 {
181 	int head, tail;
182 	u64 buf_addr;
183 	struct rbdr_entry_t *desc;
184 
185 	if (!rbdr)
186 		return;
187 
188 	rbdr->enable = false;
189 	if (!rbdr->dmem.base)
190 		return;
191 
192 	head = rbdr->head;
193 	tail = rbdr->tail;
194 
195 	/* Free SKBs */
196 	while (head != tail) {
197 		desc = GET_RBDR_DESC(rbdr, head);
198 		buf_addr = desc->buf_addr << NICVF_RCV_BUF_ALIGN;
199 		put_page(virt_to_page(phys_to_virt(buf_addr)));
200 		head++;
201 		head &= (rbdr->dmem.q_len - 1);
202 	}
203 	/* Free SKB of tail desc */
204 	desc = GET_RBDR_DESC(rbdr, tail);
205 	buf_addr = desc->buf_addr << NICVF_RCV_BUF_ALIGN;
206 	put_page(virt_to_page(phys_to_virt(buf_addr)));
207 
208 	/* Free RBDR ring */
209 	nicvf_free_q_desc_mem(nic, &rbdr->dmem);
210 }
211 
212 /* Refill receive buffer descriptors with new buffers.
213  */
214 static void nicvf_refill_rbdr(struct nicvf *nic, gfp_t gfp)
215 {
216 	struct queue_set *qs = nic->qs;
217 	int rbdr_idx = qs->rbdr_cnt;
218 	int tail, qcount;
219 	int refill_rb_cnt;
220 	struct rbdr *rbdr;
221 	struct rbdr_entry_t *desc;
222 	u64 *rbuf;
223 	int new_rb = 0;
224 
225 refill:
226 	if (!rbdr_idx)
227 		return;
228 	rbdr_idx--;
229 	rbdr = &qs->rbdr[rbdr_idx];
230 	/* Check if it's enabled */
231 	if (!rbdr->enable)
232 		goto next_rbdr;
233 
234 	/* Get no of desc's to be refilled */
235 	qcount = nicvf_queue_reg_read(nic, NIC_QSET_RBDR_0_1_STATUS0, rbdr_idx);
236 	qcount &= 0x7FFFF;
237 	/* Doorbell can be ringed with a max of ring size minus 1 */
238 	if (qcount >= (qs->rbdr_len - 1))
239 		goto next_rbdr;
240 	else
241 		refill_rb_cnt = qs->rbdr_len - qcount - 1;
242 
243 	/* Start filling descs from tail */
244 	tail = nicvf_queue_reg_read(nic, NIC_QSET_RBDR_0_1_TAIL, rbdr_idx) >> 3;
245 	while (refill_rb_cnt) {
246 		tail++;
247 		tail &= (rbdr->dmem.q_len - 1);
248 
249 		if (nicvf_alloc_rcv_buffer(nic, gfp, RCV_FRAG_LEN, &rbuf))
250 			break;
251 
252 		desc = GET_RBDR_DESC(rbdr, tail);
253 		desc->buf_addr = virt_to_phys(rbuf) >> NICVF_RCV_BUF_ALIGN;
254 		refill_rb_cnt--;
255 		new_rb++;
256 	}
257 
258 	nicvf_get_page(nic);
259 
260 	/* make sure all memory stores are done before ringing doorbell */
261 	smp_wmb();
262 
263 	/* Check if buffer allocation failed */
264 	if (refill_rb_cnt)
265 		nic->rb_alloc_fail = true;
266 	else
267 		nic->rb_alloc_fail = false;
268 
269 	/* Notify HW */
270 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_DOOR,
271 			      rbdr_idx, new_rb);
272 next_rbdr:
273 	/* Re-enable RBDR interrupts only if buffer allocation is success */
274 	if (!nic->rb_alloc_fail && rbdr->enable &&
275 	    netif_running(nic->pnicvf->netdev))
276 		nicvf_enable_intr(nic, NICVF_INTR_RBDR, rbdr_idx);
277 
278 	if (rbdr_idx)
279 		goto refill;
280 }
281 
282 /* Alloc rcv buffers in non-atomic mode for better success */
283 void nicvf_rbdr_work(struct work_struct *work)
284 {
285 	struct nicvf *nic = container_of(work, struct nicvf, rbdr_work.work);
286 
287 	nicvf_refill_rbdr(nic, GFP_KERNEL);
288 	if (nic->rb_alloc_fail)
289 		schedule_delayed_work(&nic->rbdr_work, msecs_to_jiffies(10));
290 	else
291 		nic->rb_work_scheduled = false;
292 }
293 
294 /* In Softirq context, alloc rcv buffers in atomic mode */
295 void nicvf_rbdr_task(unsigned long data)
296 {
297 	struct nicvf *nic = (struct nicvf *)data;
298 
299 	nicvf_refill_rbdr(nic, GFP_ATOMIC);
300 	if (nic->rb_alloc_fail) {
301 		nic->rb_work_scheduled = true;
302 		schedule_delayed_work(&nic->rbdr_work, msecs_to_jiffies(10));
303 	}
304 }
305 
306 /* Initialize completion queue */
307 static int nicvf_init_cmp_queue(struct nicvf *nic,
308 				struct cmp_queue *cq, int q_len)
309 {
310 	int err;
311 
312 	err = nicvf_alloc_q_desc_mem(nic, &cq->dmem, q_len, CMP_QUEUE_DESC_SIZE,
313 				     NICVF_CQ_BASE_ALIGN_BYTES);
314 	if (err)
315 		return err;
316 
317 	cq->desc = cq->dmem.base;
318 	cq->thresh = pass1_silicon(nic->pdev) ? 0 : CMP_QUEUE_CQE_THRESH;
319 	nic->cq_coalesce_usecs = (CMP_QUEUE_TIMER_THRESH * 0.05) - 1;
320 
321 	return 0;
322 }
323 
324 static void nicvf_free_cmp_queue(struct nicvf *nic, struct cmp_queue *cq)
325 {
326 	if (!cq)
327 		return;
328 	if (!cq->dmem.base)
329 		return;
330 
331 	nicvf_free_q_desc_mem(nic, &cq->dmem);
332 }
333 
334 /* Initialize transmit queue */
335 static int nicvf_init_snd_queue(struct nicvf *nic,
336 				struct snd_queue *sq, int q_len)
337 {
338 	int err;
339 
340 	err = nicvf_alloc_q_desc_mem(nic, &sq->dmem, q_len, SND_QUEUE_DESC_SIZE,
341 				     NICVF_SQ_BASE_ALIGN_BYTES);
342 	if (err)
343 		return err;
344 
345 	sq->desc = sq->dmem.base;
346 	sq->skbuff = kcalloc(q_len, sizeof(u64), GFP_KERNEL);
347 	if (!sq->skbuff)
348 		return -ENOMEM;
349 	sq->head = 0;
350 	sq->tail = 0;
351 	atomic_set(&sq->free_cnt, q_len - 1);
352 	sq->thresh = SND_QUEUE_THRESH;
353 
354 	/* Preallocate memory for TSO segment's header */
355 	sq->tso_hdrs = dma_alloc_coherent(&nic->pdev->dev,
356 					  q_len * TSO_HEADER_SIZE,
357 					  &sq->tso_hdrs_phys, GFP_KERNEL);
358 	if (!sq->tso_hdrs)
359 		return -ENOMEM;
360 
361 	return 0;
362 }
363 
364 static void nicvf_free_snd_queue(struct nicvf *nic, struct snd_queue *sq)
365 {
366 	struct sk_buff *skb;
367 
368 	if (!sq)
369 		return;
370 	if (!sq->dmem.base)
371 		return;
372 
373 	if (sq->tso_hdrs)
374 		dma_free_coherent(&nic->pdev->dev,
375 				  sq->dmem.q_len * TSO_HEADER_SIZE,
376 				  sq->tso_hdrs, sq->tso_hdrs_phys);
377 
378 	/* Free pending skbs in the queue */
379 	smp_rmb();
380 	while (sq->head != sq->tail) {
381 		skb = (struct sk_buff *)sq->skbuff[sq->head];
382 		if (skb)
383 			dev_kfree_skb_any(skb);
384 		sq->head++;
385 		sq->head &= (sq->dmem.q_len - 1);
386 	}
387 	kfree(sq->skbuff);
388 	nicvf_free_q_desc_mem(nic, &sq->dmem);
389 }
390 
391 static void nicvf_reclaim_snd_queue(struct nicvf *nic,
392 				    struct queue_set *qs, int qidx)
393 {
394 	/* Disable send queue */
395 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_CFG, qidx, 0);
396 	/* Check if SQ is stopped */
397 	if (nicvf_poll_reg(nic, qidx, NIC_QSET_SQ_0_7_STATUS, 21, 1, 0x01))
398 		return;
399 	/* Reset send queue */
400 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_CFG, qidx, NICVF_SQ_RESET);
401 }
402 
403 static void nicvf_reclaim_rcv_queue(struct nicvf *nic,
404 				    struct queue_set *qs, int qidx)
405 {
406 	union nic_mbx mbx = {};
407 
408 	/* Make sure all packets in the pipeline are written back into mem */
409 	mbx.msg.msg = NIC_MBOX_MSG_RQ_SW_SYNC;
410 	nicvf_send_msg_to_pf(nic, &mbx);
411 }
412 
413 static void nicvf_reclaim_cmp_queue(struct nicvf *nic,
414 				    struct queue_set *qs, int qidx)
415 {
416 	/* Disable timer threshold (doesn't get reset upon CQ reset */
417 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_CFG2, qidx, 0);
418 	/* Disable completion queue */
419 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_CFG, qidx, 0);
420 	/* Reset completion queue */
421 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_CFG, qidx, NICVF_CQ_RESET);
422 }
423 
424 static void nicvf_reclaim_rbdr(struct nicvf *nic,
425 			       struct rbdr *rbdr, int qidx)
426 {
427 	u64 tmp, fifo_state;
428 	int timeout = 10;
429 
430 	/* Save head and tail pointers for feeing up buffers */
431 	rbdr->head = nicvf_queue_reg_read(nic,
432 					  NIC_QSET_RBDR_0_1_HEAD,
433 					  qidx) >> 3;
434 	rbdr->tail = nicvf_queue_reg_read(nic,
435 					  NIC_QSET_RBDR_0_1_TAIL,
436 					  qidx) >> 3;
437 
438 	/* If RBDR FIFO is in 'FAIL' state then do a reset first
439 	 * before relaiming.
440 	 */
441 	fifo_state = nicvf_queue_reg_read(nic, NIC_QSET_RBDR_0_1_STATUS0, qidx);
442 	if (((fifo_state >> 62) & 0x03) == 0x3)
443 		nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_CFG,
444 				      qidx, NICVF_RBDR_RESET);
445 
446 	/* Disable RBDR */
447 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_CFG, qidx, 0);
448 	if (nicvf_poll_reg(nic, qidx, NIC_QSET_RBDR_0_1_STATUS0, 62, 2, 0x00))
449 		return;
450 	while (1) {
451 		tmp = nicvf_queue_reg_read(nic,
452 					   NIC_QSET_RBDR_0_1_PREFETCH_STATUS,
453 					   qidx);
454 		if ((tmp & 0xFFFFFFFF) == ((tmp >> 32) & 0xFFFFFFFF))
455 			break;
456 		usleep_range(1000, 2000);
457 		timeout--;
458 		if (!timeout) {
459 			netdev_err(nic->netdev,
460 				   "Failed polling on prefetch status\n");
461 			return;
462 		}
463 	}
464 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_CFG,
465 			      qidx, NICVF_RBDR_RESET);
466 
467 	if (nicvf_poll_reg(nic, qidx, NIC_QSET_RBDR_0_1_STATUS0, 62, 2, 0x02))
468 		return;
469 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_CFG, qidx, 0x00);
470 	if (nicvf_poll_reg(nic, qidx, NIC_QSET_RBDR_0_1_STATUS0, 62, 2, 0x00))
471 		return;
472 }
473 
474 void nicvf_config_vlan_stripping(struct nicvf *nic, netdev_features_t features)
475 {
476 	u64 rq_cfg;
477 	int sqs;
478 
479 	rq_cfg = nicvf_queue_reg_read(nic, NIC_QSET_RQ_GEN_CFG, 0);
480 
481 	/* Enable first VLAN stripping */
482 	if (features & NETIF_F_HW_VLAN_CTAG_RX)
483 		rq_cfg |= (1ULL << 25);
484 	else
485 		rq_cfg &= ~(1ULL << 25);
486 	nicvf_queue_reg_write(nic, NIC_QSET_RQ_GEN_CFG, 0, rq_cfg);
487 
488 	/* Configure Secondary Qsets, if any */
489 	for (sqs = 0; sqs < nic->sqs_count; sqs++)
490 		if (nic->snicvf[sqs])
491 			nicvf_queue_reg_write(nic->snicvf[sqs],
492 					      NIC_QSET_RQ_GEN_CFG, 0, rq_cfg);
493 }
494 
495 static void nicvf_reset_rcv_queue_stats(struct nicvf *nic)
496 {
497 	union nic_mbx mbx = {};
498 
499 	/* Reset all RQ/SQ and VF stats */
500 	mbx.reset_stat.msg = NIC_MBOX_MSG_RESET_STAT_COUNTER;
501 	mbx.reset_stat.rx_stat_mask = 0x3FFF;
502 	mbx.reset_stat.tx_stat_mask = 0x1F;
503 	mbx.reset_stat.rq_stat_mask = 0xFFFF;
504 	mbx.reset_stat.sq_stat_mask = 0xFFFF;
505 	nicvf_send_msg_to_pf(nic, &mbx);
506 }
507 
508 /* Configures receive queue */
509 static void nicvf_rcv_queue_config(struct nicvf *nic, struct queue_set *qs,
510 				   int qidx, bool enable)
511 {
512 	union nic_mbx mbx = {};
513 	struct rcv_queue *rq;
514 	struct rq_cfg rq_cfg;
515 
516 	rq = &qs->rq[qidx];
517 	rq->enable = enable;
518 
519 	/* Disable receive queue */
520 	nicvf_queue_reg_write(nic, NIC_QSET_RQ_0_7_CFG, qidx, 0);
521 
522 	if (!rq->enable) {
523 		nicvf_reclaim_rcv_queue(nic, qs, qidx);
524 		return;
525 	}
526 
527 	rq->cq_qs = qs->vnic_id;
528 	rq->cq_idx = qidx;
529 	rq->start_rbdr_qs = qs->vnic_id;
530 	rq->start_qs_rbdr_idx = qs->rbdr_cnt - 1;
531 	rq->cont_rbdr_qs = qs->vnic_id;
532 	rq->cont_qs_rbdr_idx = qs->rbdr_cnt - 1;
533 	/* all writes of RBDR data to be loaded into L2 Cache as well*/
534 	rq->caching = 1;
535 
536 	/* Send a mailbox msg to PF to config RQ */
537 	mbx.rq.msg = NIC_MBOX_MSG_RQ_CFG;
538 	mbx.rq.qs_num = qs->vnic_id;
539 	mbx.rq.rq_num = qidx;
540 	mbx.rq.cfg = (rq->caching << 26) | (rq->cq_qs << 19) |
541 			  (rq->cq_idx << 16) | (rq->cont_rbdr_qs << 9) |
542 			  (rq->cont_qs_rbdr_idx << 8) |
543 			  (rq->start_rbdr_qs << 1) | (rq->start_qs_rbdr_idx);
544 	nicvf_send_msg_to_pf(nic, &mbx);
545 
546 	mbx.rq.msg = NIC_MBOX_MSG_RQ_BP_CFG;
547 	mbx.rq.cfg = BIT_ULL(63) | BIT_ULL(62) |
548 		     (RQ_PASS_RBDR_LVL << 16) | (RQ_PASS_CQ_LVL << 8) |
549 		     (qs->vnic_id << 0);
550 	nicvf_send_msg_to_pf(nic, &mbx);
551 
552 	/* RQ drop config
553 	 * Enable CQ drop to reserve sufficient CQEs for all tx packets
554 	 */
555 	mbx.rq.msg = NIC_MBOX_MSG_RQ_DROP_CFG;
556 	mbx.rq.cfg = BIT_ULL(63) | BIT_ULL(62) |
557 		     (RQ_PASS_RBDR_LVL << 40) | (RQ_DROP_RBDR_LVL << 32) |
558 		     (RQ_PASS_CQ_LVL << 16) | (RQ_DROP_CQ_LVL << 8);
559 	nicvf_send_msg_to_pf(nic, &mbx);
560 
561 	if (!nic->sqs_mode && (qidx == 0)) {
562 		/* Enable checking L3/L4 length and TCP/UDP checksums */
563 		nicvf_queue_reg_write(nic, NIC_QSET_RQ_GEN_CFG, 0,
564 				      (BIT(24) | BIT(23) | BIT(21)));
565 		nicvf_config_vlan_stripping(nic, nic->netdev->features);
566 	}
567 
568 	/* Enable Receive queue */
569 	memset(&rq_cfg, 0, sizeof(struct rq_cfg));
570 	rq_cfg.ena = 1;
571 	rq_cfg.tcp_ena = 0;
572 	nicvf_queue_reg_write(nic, NIC_QSET_RQ_0_7_CFG, qidx, *(u64 *)&rq_cfg);
573 }
574 
575 /* Configures completion queue */
576 void nicvf_cmp_queue_config(struct nicvf *nic, struct queue_set *qs,
577 			    int qidx, bool enable)
578 {
579 	struct cmp_queue *cq;
580 	struct cq_cfg cq_cfg;
581 
582 	cq = &qs->cq[qidx];
583 	cq->enable = enable;
584 
585 	if (!cq->enable) {
586 		nicvf_reclaim_cmp_queue(nic, qs, qidx);
587 		return;
588 	}
589 
590 	/* Reset completion queue */
591 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_CFG, qidx, NICVF_CQ_RESET);
592 
593 	if (!cq->enable)
594 		return;
595 
596 	spin_lock_init(&cq->lock);
597 	/* Set completion queue base address */
598 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_BASE,
599 			      qidx, (u64)(cq->dmem.phys_base));
600 
601 	/* Enable Completion queue */
602 	memset(&cq_cfg, 0, sizeof(struct cq_cfg));
603 	cq_cfg.ena = 1;
604 	cq_cfg.reset = 0;
605 	cq_cfg.caching = 0;
606 	cq_cfg.qsize = ilog2(qs->cq_len >> 10);
607 	cq_cfg.avg_con = 0;
608 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_CFG, qidx, *(u64 *)&cq_cfg);
609 
610 	/* Set threshold value for interrupt generation */
611 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_THRESH, qidx, cq->thresh);
612 	nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_CFG2,
613 			      qidx, CMP_QUEUE_TIMER_THRESH);
614 }
615 
616 /* Configures transmit queue */
617 static void nicvf_snd_queue_config(struct nicvf *nic, struct queue_set *qs,
618 				   int qidx, bool enable)
619 {
620 	union nic_mbx mbx = {};
621 	struct snd_queue *sq;
622 	struct sq_cfg sq_cfg;
623 
624 	sq = &qs->sq[qidx];
625 	sq->enable = enable;
626 
627 	if (!sq->enable) {
628 		nicvf_reclaim_snd_queue(nic, qs, qidx);
629 		return;
630 	}
631 
632 	/* Reset send queue */
633 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_CFG, qidx, NICVF_SQ_RESET);
634 
635 	sq->cq_qs = qs->vnic_id;
636 	sq->cq_idx = qidx;
637 
638 	/* Send a mailbox msg to PF to config SQ */
639 	mbx.sq.msg = NIC_MBOX_MSG_SQ_CFG;
640 	mbx.sq.qs_num = qs->vnic_id;
641 	mbx.sq.sq_num = qidx;
642 	mbx.sq.sqs_mode = nic->sqs_mode;
643 	mbx.sq.cfg = (sq->cq_qs << 3) | sq->cq_idx;
644 	nicvf_send_msg_to_pf(nic, &mbx);
645 
646 	/* Set queue base address */
647 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_BASE,
648 			      qidx, (u64)(sq->dmem.phys_base));
649 
650 	/* Enable send queue  & set queue size */
651 	memset(&sq_cfg, 0, sizeof(struct sq_cfg));
652 	sq_cfg.ena = 1;
653 	sq_cfg.reset = 0;
654 	sq_cfg.ldwb = 0;
655 	sq_cfg.qsize = ilog2(qs->sq_len >> 10);
656 	sq_cfg.tstmp_bgx_intf = 0;
657 	/* CQ's level at which HW will stop processing SQEs to avoid
658 	 * transmitting a pkt with no space in CQ to post CQE_TX.
659 	 */
660 	sq_cfg.cq_limit = (CMP_QUEUE_PIPELINE_RSVD * 256) / qs->cq_len;
661 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_CFG, qidx, *(u64 *)&sq_cfg);
662 
663 	/* Set threshold value for interrupt generation */
664 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_THRESH, qidx, sq->thresh);
665 
666 	/* Set queue:cpu affinity for better load distribution */
667 	if (cpu_online(qidx)) {
668 		cpumask_set_cpu(qidx, &sq->affinity_mask);
669 		netif_set_xps_queue(nic->netdev,
670 				    &sq->affinity_mask, qidx);
671 	}
672 }
673 
674 /* Configures receive buffer descriptor ring */
675 static void nicvf_rbdr_config(struct nicvf *nic, struct queue_set *qs,
676 			      int qidx, bool enable)
677 {
678 	struct rbdr *rbdr;
679 	struct rbdr_cfg rbdr_cfg;
680 
681 	rbdr = &qs->rbdr[qidx];
682 	nicvf_reclaim_rbdr(nic, rbdr, qidx);
683 	if (!enable)
684 		return;
685 
686 	/* Set descriptor base address */
687 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_BASE,
688 			      qidx, (u64)(rbdr->dmem.phys_base));
689 
690 	/* Enable RBDR  & set queue size */
691 	/* Buffer size should be in multiples of 128 bytes */
692 	memset(&rbdr_cfg, 0, sizeof(struct rbdr_cfg));
693 	rbdr_cfg.ena = 1;
694 	rbdr_cfg.reset = 0;
695 	rbdr_cfg.ldwb = 0;
696 	rbdr_cfg.qsize = RBDR_SIZE;
697 	rbdr_cfg.avg_con = 0;
698 	rbdr_cfg.lines = rbdr->dma_size / 128;
699 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_CFG,
700 			      qidx, *(u64 *)&rbdr_cfg);
701 
702 	/* Notify HW */
703 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_DOOR,
704 			      qidx, qs->rbdr_len - 1);
705 
706 	/* Set threshold value for interrupt generation */
707 	nicvf_queue_reg_write(nic, NIC_QSET_RBDR_0_1_THRESH,
708 			      qidx, rbdr->thresh - 1);
709 }
710 
711 /* Requests PF to assign and enable Qset */
712 void nicvf_qset_config(struct nicvf *nic, bool enable)
713 {
714 	union nic_mbx mbx = {};
715 	struct queue_set *qs = nic->qs;
716 	struct qs_cfg *qs_cfg;
717 
718 	if (!qs) {
719 		netdev_warn(nic->netdev,
720 			    "Qset is still not allocated, don't init queues\n");
721 		return;
722 	}
723 
724 	qs->enable = enable;
725 	qs->vnic_id = nic->vf_id;
726 
727 	/* Send a mailbox msg to PF to config Qset */
728 	mbx.qs.msg = NIC_MBOX_MSG_QS_CFG;
729 	mbx.qs.num = qs->vnic_id;
730 	mbx.qs.sqs_count = nic->sqs_count;
731 
732 	mbx.qs.cfg = 0;
733 	qs_cfg = (struct qs_cfg *)&mbx.qs.cfg;
734 	if (qs->enable) {
735 		qs_cfg->ena = 1;
736 #ifdef __BIG_ENDIAN
737 		qs_cfg->be = 1;
738 #endif
739 		qs_cfg->vnic = qs->vnic_id;
740 	}
741 	nicvf_send_msg_to_pf(nic, &mbx);
742 }
743 
744 static void nicvf_free_resources(struct nicvf *nic)
745 {
746 	int qidx;
747 	struct queue_set *qs = nic->qs;
748 
749 	/* Free receive buffer descriptor ring */
750 	for (qidx = 0; qidx < qs->rbdr_cnt; qidx++)
751 		nicvf_free_rbdr(nic, &qs->rbdr[qidx]);
752 
753 	/* Free completion queue */
754 	for (qidx = 0; qidx < qs->cq_cnt; qidx++)
755 		nicvf_free_cmp_queue(nic, &qs->cq[qidx]);
756 
757 	/* Free send queue */
758 	for (qidx = 0; qidx < qs->sq_cnt; qidx++)
759 		nicvf_free_snd_queue(nic, &qs->sq[qidx]);
760 }
761 
762 static int nicvf_alloc_resources(struct nicvf *nic)
763 {
764 	int qidx;
765 	struct queue_set *qs = nic->qs;
766 
767 	/* Alloc receive buffer descriptor ring */
768 	for (qidx = 0; qidx < qs->rbdr_cnt; qidx++) {
769 		if (nicvf_init_rbdr(nic, &qs->rbdr[qidx], qs->rbdr_len,
770 				    DMA_BUFFER_LEN))
771 			goto alloc_fail;
772 	}
773 
774 	/* Alloc send queue */
775 	for (qidx = 0; qidx < qs->sq_cnt; qidx++) {
776 		if (nicvf_init_snd_queue(nic, &qs->sq[qidx], qs->sq_len))
777 			goto alloc_fail;
778 	}
779 
780 	/* Alloc completion queue */
781 	for (qidx = 0; qidx < qs->cq_cnt; qidx++) {
782 		if (nicvf_init_cmp_queue(nic, &qs->cq[qidx], qs->cq_len))
783 			goto alloc_fail;
784 	}
785 
786 	return 0;
787 alloc_fail:
788 	nicvf_free_resources(nic);
789 	return -ENOMEM;
790 }
791 
792 int nicvf_set_qset_resources(struct nicvf *nic)
793 {
794 	struct queue_set *qs;
795 
796 	qs = devm_kzalloc(&nic->pdev->dev, sizeof(*qs), GFP_KERNEL);
797 	if (!qs)
798 		return -ENOMEM;
799 	nic->qs = qs;
800 
801 	/* Set count of each queue */
802 	qs->rbdr_cnt = DEFAULT_RBDR_CNT;
803 	qs->rq_cnt = min_t(u8, MAX_RCV_QUEUES_PER_QS, num_online_cpus());
804 	qs->sq_cnt = min_t(u8, MAX_SND_QUEUES_PER_QS, num_online_cpus());
805 	qs->cq_cnt = max_t(u8, qs->rq_cnt, qs->sq_cnt);
806 
807 	/* Set queue lengths */
808 	qs->rbdr_len = RCV_BUF_COUNT;
809 	qs->sq_len = SND_QUEUE_LEN;
810 	qs->cq_len = CMP_QUEUE_LEN;
811 
812 	nic->rx_queues = qs->rq_cnt;
813 	nic->tx_queues = qs->sq_cnt;
814 
815 	return 0;
816 }
817 
818 int nicvf_config_data_transfer(struct nicvf *nic, bool enable)
819 {
820 	bool disable = false;
821 	struct queue_set *qs = nic->qs;
822 	struct queue_set *pqs = nic->pnicvf->qs;
823 	int qidx;
824 
825 	if (!qs)
826 		return 0;
827 
828 	/* Take primary VF's queue lengths.
829 	 * This is needed to take queue lengths set from ethtool
830 	 * into consideration.
831 	 */
832 	if (nic->sqs_mode && pqs) {
833 		qs->cq_len = pqs->cq_len;
834 		qs->sq_len = pqs->sq_len;
835 	}
836 
837 	if (enable) {
838 		if (nicvf_alloc_resources(nic))
839 			return -ENOMEM;
840 
841 		for (qidx = 0; qidx < qs->sq_cnt; qidx++)
842 			nicvf_snd_queue_config(nic, qs, qidx, enable);
843 		for (qidx = 0; qidx < qs->cq_cnt; qidx++)
844 			nicvf_cmp_queue_config(nic, qs, qidx, enable);
845 		for (qidx = 0; qidx < qs->rbdr_cnt; qidx++)
846 			nicvf_rbdr_config(nic, qs, qidx, enable);
847 		for (qidx = 0; qidx < qs->rq_cnt; qidx++)
848 			nicvf_rcv_queue_config(nic, qs, qidx, enable);
849 	} else {
850 		for (qidx = 0; qidx < qs->rq_cnt; qidx++)
851 			nicvf_rcv_queue_config(nic, qs, qidx, disable);
852 		for (qidx = 0; qidx < qs->rbdr_cnt; qidx++)
853 			nicvf_rbdr_config(nic, qs, qidx, disable);
854 		for (qidx = 0; qidx < qs->sq_cnt; qidx++)
855 			nicvf_snd_queue_config(nic, qs, qidx, disable);
856 		for (qidx = 0; qidx < qs->cq_cnt; qidx++)
857 			nicvf_cmp_queue_config(nic, qs, qidx, disable);
858 
859 		nicvf_free_resources(nic);
860 	}
861 
862 	/* Reset RXQ's stats.
863 	 * SQ's stats will get reset automatically once SQ is reset.
864 	 */
865 	nicvf_reset_rcv_queue_stats(nic);
866 
867 	return 0;
868 }
869 
870 /* Get a free desc from SQ
871  * returns descriptor ponter & descriptor number
872  */
873 static inline int nicvf_get_sq_desc(struct snd_queue *sq, int desc_cnt)
874 {
875 	int qentry;
876 
877 	qentry = sq->tail;
878 	atomic_sub(desc_cnt, &sq->free_cnt);
879 	sq->tail += desc_cnt;
880 	sq->tail &= (sq->dmem.q_len - 1);
881 
882 	return qentry;
883 }
884 
885 /* Free descriptor back to SQ for future use */
886 void nicvf_put_sq_desc(struct snd_queue *sq, int desc_cnt)
887 {
888 	atomic_add(desc_cnt, &sq->free_cnt);
889 	sq->head += desc_cnt;
890 	sq->head &= (sq->dmem.q_len - 1);
891 }
892 
893 static inline int nicvf_get_nxt_sqentry(struct snd_queue *sq, int qentry)
894 {
895 	qentry++;
896 	qentry &= (sq->dmem.q_len - 1);
897 	return qentry;
898 }
899 
900 void nicvf_sq_enable(struct nicvf *nic, struct snd_queue *sq, int qidx)
901 {
902 	u64 sq_cfg;
903 
904 	sq_cfg = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_CFG, qidx);
905 	sq_cfg |= NICVF_SQ_EN;
906 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_CFG, qidx, sq_cfg);
907 	/* Ring doorbell so that H/W restarts processing SQEs */
908 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_DOOR, qidx, 0);
909 }
910 
911 void nicvf_sq_disable(struct nicvf *nic, int qidx)
912 {
913 	u64 sq_cfg;
914 
915 	sq_cfg = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_CFG, qidx);
916 	sq_cfg &= ~NICVF_SQ_EN;
917 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_CFG, qidx, sq_cfg);
918 }
919 
920 void nicvf_sq_free_used_descs(struct net_device *netdev, struct snd_queue *sq,
921 			      int qidx)
922 {
923 	u64 head, tail;
924 	struct sk_buff *skb;
925 	struct nicvf *nic = netdev_priv(netdev);
926 	struct sq_hdr_subdesc *hdr;
927 
928 	head = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_HEAD, qidx) >> 4;
929 	tail = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_TAIL, qidx) >> 4;
930 	while (sq->head != head) {
931 		hdr = (struct sq_hdr_subdesc *)GET_SQ_DESC(sq, sq->head);
932 		if (hdr->subdesc_type != SQ_DESC_TYPE_HEADER) {
933 			nicvf_put_sq_desc(sq, 1);
934 			continue;
935 		}
936 		skb = (struct sk_buff *)sq->skbuff[sq->head];
937 		if (skb)
938 			dev_kfree_skb_any(skb);
939 		atomic64_add(1, (atomic64_t *)&netdev->stats.tx_packets);
940 		atomic64_add(hdr->tot_len,
941 			     (atomic64_t *)&netdev->stats.tx_bytes);
942 		nicvf_put_sq_desc(sq, hdr->subdesc_cnt + 1);
943 	}
944 }
945 
946 /* Calculate no of SQ subdescriptors needed to transmit all
947  * segments of this TSO packet.
948  * Taken from 'Tilera network driver' with a minor modification.
949  */
950 static int nicvf_tso_count_subdescs(struct sk_buff *skb)
951 {
952 	struct skb_shared_info *sh = skb_shinfo(skb);
953 	unsigned int sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
954 	unsigned int data_len = skb->len - sh_len;
955 	unsigned int p_len = sh->gso_size;
956 	long f_id = -1;    /* id of the current fragment */
957 	long f_size = skb_headlen(skb) - sh_len;  /* current fragment size */
958 	long f_used = 0;  /* bytes used from the current fragment */
959 	long n;            /* size of the current piece of payload */
960 	int num_edescs = 0;
961 	int segment;
962 
963 	for (segment = 0; segment < sh->gso_segs; segment++) {
964 		unsigned int p_used = 0;
965 
966 		/* One edesc for header and for each piece of the payload. */
967 		for (num_edescs++; p_used < p_len; num_edescs++) {
968 			/* Advance as needed. */
969 			while (f_used >= f_size) {
970 				f_id++;
971 				f_size = skb_frag_size(&sh->frags[f_id]);
972 				f_used = 0;
973 			}
974 
975 			/* Use bytes from the current fragment. */
976 			n = p_len - p_used;
977 			if (n > f_size - f_used)
978 				n = f_size - f_used;
979 			f_used += n;
980 			p_used += n;
981 		}
982 
983 		/* The last segment may be less than gso_size. */
984 		data_len -= p_len;
985 		if (data_len < p_len)
986 			p_len = data_len;
987 	}
988 
989 	/* '+ gso_segs' for SQ_HDR_SUDESCs for each segment */
990 	return num_edescs + sh->gso_segs;
991 }
992 
993 #define POST_CQE_DESC_COUNT 2
994 
995 /* Get the number of SQ descriptors needed to xmit this skb */
996 static int nicvf_sq_subdesc_required(struct nicvf *nic, struct sk_buff *skb)
997 {
998 	int subdesc_cnt = MIN_SQ_DESC_PER_PKT_XMIT;
999 
1000 	if (skb_shinfo(skb)->gso_size && !nic->hw_tso) {
1001 		subdesc_cnt = nicvf_tso_count_subdescs(skb);
1002 		return subdesc_cnt;
1003 	}
1004 
1005 	/* Dummy descriptors to get TSO pkt completion notification */
1006 	if (nic->t88 && nic->hw_tso && skb_shinfo(skb)->gso_size)
1007 		subdesc_cnt += POST_CQE_DESC_COUNT;
1008 
1009 	if (skb_shinfo(skb)->nr_frags)
1010 		subdesc_cnt += skb_shinfo(skb)->nr_frags;
1011 
1012 	return subdesc_cnt;
1013 }
1014 
1015 /* Add SQ HEADER subdescriptor.
1016  * First subdescriptor for every send descriptor.
1017  */
1018 static inline void
1019 nicvf_sq_add_hdr_subdesc(struct nicvf *nic, struct snd_queue *sq, int qentry,
1020 			 int subdesc_cnt, struct sk_buff *skb, int len)
1021 {
1022 	int proto;
1023 	struct sq_hdr_subdesc *hdr;
1024 
1025 	hdr = (struct sq_hdr_subdesc *)GET_SQ_DESC(sq, qentry);
1026 	memset(hdr, 0, SND_QUEUE_DESC_SIZE);
1027 	hdr->subdesc_type = SQ_DESC_TYPE_HEADER;
1028 
1029 	if (nic->t88 && nic->hw_tso && skb_shinfo(skb)->gso_size) {
1030 		/* post_cqe = 0, to avoid HW posting a CQE for every TSO
1031 		 * segment transmitted on 88xx.
1032 		 */
1033 		hdr->subdesc_cnt = subdesc_cnt - POST_CQE_DESC_COUNT;
1034 	} else {
1035 		sq->skbuff[qentry] = (u64)skb;
1036 		/* Enable notification via CQE after processing SQE */
1037 		hdr->post_cqe = 1;
1038 		/* No of subdescriptors following this */
1039 		hdr->subdesc_cnt = subdesc_cnt;
1040 	}
1041 	hdr->tot_len = len;
1042 
1043 	/* Offload checksum calculation to HW */
1044 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
1045 		hdr->csum_l3 = 1; /* Enable IP csum calculation */
1046 		hdr->l3_offset = skb_network_offset(skb);
1047 		hdr->l4_offset = skb_transport_offset(skb);
1048 
1049 		proto = ip_hdr(skb)->protocol;
1050 		switch (proto) {
1051 		case IPPROTO_TCP:
1052 			hdr->csum_l4 = SEND_L4_CSUM_TCP;
1053 			break;
1054 		case IPPROTO_UDP:
1055 			hdr->csum_l4 = SEND_L4_CSUM_UDP;
1056 			break;
1057 		case IPPROTO_SCTP:
1058 			hdr->csum_l4 = SEND_L4_CSUM_SCTP;
1059 			break;
1060 		}
1061 	}
1062 
1063 	if (nic->hw_tso && skb_shinfo(skb)->gso_size) {
1064 		hdr->tso = 1;
1065 		hdr->tso_start = skb_transport_offset(skb) + tcp_hdrlen(skb);
1066 		hdr->tso_max_paysize = skb_shinfo(skb)->gso_size;
1067 		/* For non-tunneled pkts, point this to L2 ethertype */
1068 		hdr->inner_l3_offset = skb_network_offset(skb) - 2;
1069 		this_cpu_inc(nic->pnicvf->drv_stats->tx_tso);
1070 	}
1071 }
1072 
1073 /* SQ GATHER subdescriptor
1074  * Must follow HDR descriptor
1075  */
1076 static inline void nicvf_sq_add_gather_subdesc(struct snd_queue *sq, int qentry,
1077 					       int size, u64 data)
1078 {
1079 	struct sq_gather_subdesc *gather;
1080 
1081 	qentry &= (sq->dmem.q_len - 1);
1082 	gather = (struct sq_gather_subdesc *)GET_SQ_DESC(sq, qentry);
1083 
1084 	memset(gather, 0, SND_QUEUE_DESC_SIZE);
1085 	gather->subdesc_type = SQ_DESC_TYPE_GATHER;
1086 	gather->ld_type = NIC_SEND_LD_TYPE_E_LDD;
1087 	gather->size = size;
1088 	gather->addr = data;
1089 }
1090 
1091 /* Add HDR + IMMEDIATE subdescriptors right after descriptors of a TSO
1092  * packet so that a CQE is posted as a notifation for transmission of
1093  * TSO packet.
1094  */
1095 static inline void nicvf_sq_add_cqe_subdesc(struct snd_queue *sq, int qentry,
1096 					    int tso_sqe, struct sk_buff *skb)
1097 {
1098 	struct sq_imm_subdesc *imm;
1099 	struct sq_hdr_subdesc *hdr;
1100 
1101 	sq->skbuff[qentry] = (u64)skb;
1102 
1103 	hdr = (struct sq_hdr_subdesc *)GET_SQ_DESC(sq, qentry);
1104 	memset(hdr, 0, SND_QUEUE_DESC_SIZE);
1105 	hdr->subdesc_type = SQ_DESC_TYPE_HEADER;
1106 	/* Enable notification via CQE after processing SQE */
1107 	hdr->post_cqe = 1;
1108 	/* There is no packet to transmit here */
1109 	hdr->dont_send = 1;
1110 	hdr->subdesc_cnt = POST_CQE_DESC_COUNT - 1;
1111 	hdr->tot_len = 1;
1112 	/* Actual TSO header SQE index, needed for cleanup */
1113 	hdr->rsvd2 = tso_sqe;
1114 
1115 	qentry = nicvf_get_nxt_sqentry(sq, qentry);
1116 	imm = (struct sq_imm_subdesc *)GET_SQ_DESC(sq, qentry);
1117 	memset(imm, 0, SND_QUEUE_DESC_SIZE);
1118 	imm->subdesc_type = SQ_DESC_TYPE_IMMEDIATE;
1119 	imm->len = 1;
1120 }
1121 
1122 static inline void nicvf_sq_doorbell(struct nicvf *nic, struct sk_buff *skb,
1123 				     int sq_num, int desc_cnt)
1124 {
1125 	struct netdev_queue *txq;
1126 
1127 	txq = netdev_get_tx_queue(nic->pnicvf->netdev,
1128 				  skb_get_queue_mapping(skb));
1129 
1130 	netdev_tx_sent_queue(txq, skb->len);
1131 
1132 	/* make sure all memory stores are done before ringing doorbell */
1133 	smp_wmb();
1134 
1135 	/* Inform HW to xmit all TSO segments */
1136 	nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_DOOR,
1137 			      sq_num, desc_cnt);
1138 }
1139 
1140 /* Segment a TSO packet into 'gso_size' segments and append
1141  * them to SQ for transfer
1142  */
1143 static int nicvf_sq_append_tso(struct nicvf *nic, struct snd_queue *sq,
1144 			       int sq_num, int qentry, struct sk_buff *skb)
1145 {
1146 	struct tso_t tso;
1147 	int seg_subdescs = 0, desc_cnt = 0;
1148 	int seg_len, total_len, data_left;
1149 	int hdr_qentry = qentry;
1150 	int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
1151 
1152 	tso_start(skb, &tso);
1153 	total_len = skb->len - hdr_len;
1154 	while (total_len > 0) {
1155 		char *hdr;
1156 
1157 		/* Save Qentry for adding HDR_SUBDESC at the end */
1158 		hdr_qentry = qentry;
1159 
1160 		data_left = min_t(int, skb_shinfo(skb)->gso_size, total_len);
1161 		total_len -= data_left;
1162 
1163 		/* Add segment's header */
1164 		qentry = nicvf_get_nxt_sqentry(sq, qentry);
1165 		hdr = sq->tso_hdrs + qentry * TSO_HEADER_SIZE;
1166 		tso_build_hdr(skb, hdr, &tso, data_left, total_len == 0);
1167 		nicvf_sq_add_gather_subdesc(sq, qentry, hdr_len,
1168 					    sq->tso_hdrs_phys +
1169 					    qentry * TSO_HEADER_SIZE);
1170 		/* HDR_SUDESC + GATHER */
1171 		seg_subdescs = 2;
1172 		seg_len = hdr_len;
1173 
1174 		/* Add segment's payload fragments */
1175 		while (data_left > 0) {
1176 			int size;
1177 
1178 			size = min_t(int, tso.size, data_left);
1179 
1180 			qentry = nicvf_get_nxt_sqentry(sq, qentry);
1181 			nicvf_sq_add_gather_subdesc(sq, qentry, size,
1182 						    virt_to_phys(tso.data));
1183 			seg_subdescs++;
1184 			seg_len += size;
1185 
1186 			data_left -= size;
1187 			tso_build_data(skb, &tso, size);
1188 		}
1189 		nicvf_sq_add_hdr_subdesc(nic, sq, hdr_qentry,
1190 					 seg_subdescs - 1, skb, seg_len);
1191 		sq->skbuff[hdr_qentry] = (u64)NULL;
1192 		qentry = nicvf_get_nxt_sqentry(sq, qentry);
1193 
1194 		desc_cnt += seg_subdescs;
1195 	}
1196 	/* Save SKB in the last segment for freeing */
1197 	sq->skbuff[hdr_qentry] = (u64)skb;
1198 
1199 	nicvf_sq_doorbell(nic, skb, sq_num, desc_cnt);
1200 
1201 	this_cpu_inc(nic->pnicvf->drv_stats->tx_tso);
1202 	return 1;
1203 }
1204 
1205 /* Append an skb to a SQ for packet transfer. */
1206 int nicvf_sq_append_skb(struct nicvf *nic, struct snd_queue *sq,
1207 			struct sk_buff *skb, u8 sq_num)
1208 {
1209 	int i, size;
1210 	int subdesc_cnt, tso_sqe = 0;
1211 	int qentry;
1212 
1213 	subdesc_cnt = nicvf_sq_subdesc_required(nic, skb);
1214 	if (subdesc_cnt > atomic_read(&sq->free_cnt))
1215 		goto append_fail;
1216 
1217 	qentry = nicvf_get_sq_desc(sq, subdesc_cnt);
1218 
1219 	/* Check if its a TSO packet */
1220 	if (skb_shinfo(skb)->gso_size && !nic->hw_tso)
1221 		return nicvf_sq_append_tso(nic, sq, sq_num, qentry, skb);
1222 
1223 	/* Add SQ header subdesc */
1224 	nicvf_sq_add_hdr_subdesc(nic, sq, qentry, subdesc_cnt - 1,
1225 				 skb, skb->len);
1226 	tso_sqe = qentry;
1227 
1228 	/* Add SQ gather subdescs */
1229 	qentry = nicvf_get_nxt_sqentry(sq, qentry);
1230 	size = skb_is_nonlinear(skb) ? skb_headlen(skb) : skb->len;
1231 	nicvf_sq_add_gather_subdesc(sq, qentry, size, virt_to_phys(skb->data));
1232 
1233 	/* Check for scattered buffer */
1234 	if (!skb_is_nonlinear(skb))
1235 		goto doorbell;
1236 
1237 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1238 		const struct skb_frag_struct *frag;
1239 
1240 		frag = &skb_shinfo(skb)->frags[i];
1241 
1242 		qentry = nicvf_get_nxt_sqentry(sq, qentry);
1243 		size = skb_frag_size(frag);
1244 		nicvf_sq_add_gather_subdesc(sq, qentry, size,
1245 					    virt_to_phys(
1246 					    skb_frag_address(frag)));
1247 	}
1248 
1249 doorbell:
1250 	if (nic->t88 && skb_shinfo(skb)->gso_size) {
1251 		qentry = nicvf_get_nxt_sqentry(sq, qentry);
1252 		nicvf_sq_add_cqe_subdesc(sq, qentry, tso_sqe, skb);
1253 	}
1254 
1255 	nicvf_sq_doorbell(nic, skb, sq_num, subdesc_cnt);
1256 
1257 	return 1;
1258 
1259 append_fail:
1260 	/* Use original PCI dev for debug log */
1261 	nic = nic->pnicvf;
1262 	netdev_dbg(nic->netdev, "Not enough SQ descriptors to xmit pkt\n");
1263 	return 0;
1264 }
1265 
1266 static inline unsigned frag_num(unsigned i)
1267 {
1268 #ifdef __BIG_ENDIAN
1269 	return (i & ~3) + 3 - (i & 3);
1270 #else
1271 	return i;
1272 #endif
1273 }
1274 
1275 /* Returns SKB for a received packet */
1276 struct sk_buff *nicvf_get_rcv_skb(struct nicvf *nic, struct cqe_rx_t *cqe_rx)
1277 {
1278 	int frag;
1279 	int payload_len = 0;
1280 	struct sk_buff *skb = NULL;
1281 	struct page *page;
1282 	int offset;
1283 	u16 *rb_lens = NULL;
1284 	u64 *rb_ptrs = NULL;
1285 
1286 	rb_lens = (void *)cqe_rx + (3 * sizeof(u64));
1287 	/* Except 88xx pass1 on all other chips CQE_RX2_S is added to
1288 	 * CQE_RX at word6, hence buffer pointers move by word
1289 	 *
1290 	 * Use existing 'hw_tso' flag which will be set for all chips
1291 	 * except 88xx pass1 instead of a additional cache line
1292 	 * access (or miss) by using pci dev's revision.
1293 	 */
1294 	if (!nic->hw_tso)
1295 		rb_ptrs = (void *)cqe_rx + (6 * sizeof(u64));
1296 	else
1297 		rb_ptrs = (void *)cqe_rx + (7 * sizeof(u64));
1298 
1299 	netdev_dbg(nic->netdev, "%s rb_cnt %d rb0_ptr %llx rb0_sz %d\n",
1300 		   __func__, cqe_rx->rb_cnt, cqe_rx->rb0_ptr, cqe_rx->rb0_sz);
1301 
1302 	for (frag = 0; frag < cqe_rx->rb_cnt; frag++) {
1303 		payload_len = rb_lens[frag_num(frag)];
1304 		if (!frag) {
1305 			/* First fragment */
1306 			skb = nicvf_rb_ptr_to_skb(nic,
1307 						  *rb_ptrs - cqe_rx->align_pad,
1308 						  payload_len);
1309 			if (!skb)
1310 				return NULL;
1311 			skb_reserve(skb, cqe_rx->align_pad);
1312 			skb_put(skb, payload_len);
1313 		} else {
1314 			/* Add fragments */
1315 			page = virt_to_page(phys_to_virt(*rb_ptrs));
1316 			offset = phys_to_virt(*rb_ptrs) - page_address(page);
1317 			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
1318 					offset, payload_len, RCV_FRAG_LEN);
1319 		}
1320 		/* Next buffer pointer */
1321 		rb_ptrs++;
1322 	}
1323 	return skb;
1324 }
1325 
1326 static u64 nicvf_int_type_to_mask(int int_type, int q_idx)
1327 {
1328 	u64 reg_val;
1329 
1330 	switch (int_type) {
1331 	case NICVF_INTR_CQ:
1332 		reg_val = ((1ULL << q_idx) << NICVF_INTR_CQ_SHIFT);
1333 		break;
1334 	case NICVF_INTR_SQ:
1335 		reg_val = ((1ULL << q_idx) << NICVF_INTR_SQ_SHIFT);
1336 		break;
1337 	case NICVF_INTR_RBDR:
1338 		reg_val = ((1ULL << q_idx) << NICVF_INTR_RBDR_SHIFT);
1339 		break;
1340 	case NICVF_INTR_PKT_DROP:
1341 		reg_val = (1ULL << NICVF_INTR_PKT_DROP_SHIFT);
1342 		break;
1343 	case NICVF_INTR_TCP_TIMER:
1344 		reg_val = (1ULL << NICVF_INTR_TCP_TIMER_SHIFT);
1345 		break;
1346 	case NICVF_INTR_MBOX:
1347 		reg_val = (1ULL << NICVF_INTR_MBOX_SHIFT);
1348 		break;
1349 	case NICVF_INTR_QS_ERR:
1350 		reg_val = (1ULL << NICVF_INTR_QS_ERR_SHIFT);
1351 		break;
1352 	default:
1353 		reg_val = 0;
1354 	}
1355 
1356 	return reg_val;
1357 }
1358 
1359 /* Enable interrupt */
1360 void nicvf_enable_intr(struct nicvf *nic, int int_type, int q_idx)
1361 {
1362 	u64 mask = nicvf_int_type_to_mask(int_type, q_idx);
1363 
1364 	if (!mask) {
1365 		netdev_dbg(nic->netdev,
1366 			   "Failed to enable interrupt: unknown type\n");
1367 		return;
1368 	}
1369 	nicvf_reg_write(nic, NIC_VF_ENA_W1S,
1370 			nicvf_reg_read(nic, NIC_VF_ENA_W1S) | mask);
1371 }
1372 
1373 /* Disable interrupt */
1374 void nicvf_disable_intr(struct nicvf *nic, int int_type, int q_idx)
1375 {
1376 	u64 mask = nicvf_int_type_to_mask(int_type, q_idx);
1377 
1378 	if (!mask) {
1379 		netdev_dbg(nic->netdev,
1380 			   "Failed to disable interrupt: unknown type\n");
1381 		return;
1382 	}
1383 
1384 	nicvf_reg_write(nic, NIC_VF_ENA_W1C, mask);
1385 }
1386 
1387 /* Clear interrupt */
1388 void nicvf_clear_intr(struct nicvf *nic, int int_type, int q_idx)
1389 {
1390 	u64 mask = nicvf_int_type_to_mask(int_type, q_idx);
1391 
1392 	if (!mask) {
1393 		netdev_dbg(nic->netdev,
1394 			   "Failed to clear interrupt: unknown type\n");
1395 		return;
1396 	}
1397 
1398 	nicvf_reg_write(nic, NIC_VF_INT, mask);
1399 }
1400 
1401 /* Check if interrupt is enabled */
1402 int nicvf_is_intr_enabled(struct nicvf *nic, int int_type, int q_idx)
1403 {
1404 	u64 mask = nicvf_int_type_to_mask(int_type, q_idx);
1405 	/* If interrupt type is unknown, we treat it disabled. */
1406 	if (!mask) {
1407 		netdev_dbg(nic->netdev,
1408 			   "Failed to check interrupt enable: unknown type\n");
1409 		return 0;
1410 	}
1411 
1412 	return mask & nicvf_reg_read(nic, NIC_VF_ENA_W1S);
1413 }
1414 
1415 void nicvf_update_rq_stats(struct nicvf *nic, int rq_idx)
1416 {
1417 	struct rcv_queue *rq;
1418 
1419 #define GET_RQ_STATS(reg) \
1420 	nicvf_reg_read(nic, NIC_QSET_RQ_0_7_STAT_0_1 |\
1421 			    (rq_idx << NIC_Q_NUM_SHIFT) | (reg << 3))
1422 
1423 	rq = &nic->qs->rq[rq_idx];
1424 	rq->stats.bytes = GET_RQ_STATS(RQ_SQ_STATS_OCTS);
1425 	rq->stats.pkts = GET_RQ_STATS(RQ_SQ_STATS_PKTS);
1426 }
1427 
1428 void nicvf_update_sq_stats(struct nicvf *nic, int sq_idx)
1429 {
1430 	struct snd_queue *sq;
1431 
1432 #define GET_SQ_STATS(reg) \
1433 	nicvf_reg_read(nic, NIC_QSET_SQ_0_7_STAT_0_1 |\
1434 			    (sq_idx << NIC_Q_NUM_SHIFT) | (reg << 3))
1435 
1436 	sq = &nic->qs->sq[sq_idx];
1437 	sq->stats.bytes = GET_SQ_STATS(RQ_SQ_STATS_OCTS);
1438 	sq->stats.pkts = GET_SQ_STATS(RQ_SQ_STATS_PKTS);
1439 }
1440 
1441 /* Check for errors in the receive cmp.queue entry */
1442 int nicvf_check_cqe_rx_errs(struct nicvf *nic, struct cqe_rx_t *cqe_rx)
1443 {
1444 	if (!cqe_rx->err_level && !cqe_rx->err_opcode)
1445 		return 0;
1446 
1447 	if (netif_msg_rx_err(nic))
1448 		netdev_err(nic->netdev,
1449 			   "%s: RX error CQE err_level 0x%x err_opcode 0x%x\n",
1450 			   nic->netdev->name,
1451 			   cqe_rx->err_level, cqe_rx->err_opcode);
1452 
1453 	switch (cqe_rx->err_opcode) {
1454 	case CQ_RX_ERROP_RE_PARTIAL:
1455 		this_cpu_inc(nic->drv_stats->rx_bgx_truncated_pkts);
1456 		break;
1457 	case CQ_RX_ERROP_RE_JABBER:
1458 		this_cpu_inc(nic->drv_stats->rx_jabber_errs);
1459 		break;
1460 	case CQ_RX_ERROP_RE_FCS:
1461 		this_cpu_inc(nic->drv_stats->rx_fcs_errs);
1462 		break;
1463 	case CQ_RX_ERROP_RE_RX_CTL:
1464 		this_cpu_inc(nic->drv_stats->rx_bgx_errs);
1465 		break;
1466 	case CQ_RX_ERROP_PREL2_ERR:
1467 		this_cpu_inc(nic->drv_stats->rx_prel2_errs);
1468 		break;
1469 	case CQ_RX_ERROP_L2_MAL:
1470 		this_cpu_inc(nic->drv_stats->rx_l2_hdr_malformed);
1471 		break;
1472 	case CQ_RX_ERROP_L2_OVERSIZE:
1473 		this_cpu_inc(nic->drv_stats->rx_oversize);
1474 		break;
1475 	case CQ_RX_ERROP_L2_UNDERSIZE:
1476 		this_cpu_inc(nic->drv_stats->rx_undersize);
1477 		break;
1478 	case CQ_RX_ERROP_L2_LENMISM:
1479 		this_cpu_inc(nic->drv_stats->rx_l2_len_mismatch);
1480 		break;
1481 	case CQ_RX_ERROP_L2_PCLP:
1482 		this_cpu_inc(nic->drv_stats->rx_l2_pclp);
1483 		break;
1484 	case CQ_RX_ERROP_IP_NOT:
1485 		this_cpu_inc(nic->drv_stats->rx_ip_ver_errs);
1486 		break;
1487 	case CQ_RX_ERROP_IP_CSUM_ERR:
1488 		this_cpu_inc(nic->drv_stats->rx_ip_csum_errs);
1489 		break;
1490 	case CQ_RX_ERROP_IP_MAL:
1491 		this_cpu_inc(nic->drv_stats->rx_ip_hdr_malformed);
1492 		break;
1493 	case CQ_RX_ERROP_IP_MALD:
1494 		this_cpu_inc(nic->drv_stats->rx_ip_payload_malformed);
1495 		break;
1496 	case CQ_RX_ERROP_IP_HOP:
1497 		this_cpu_inc(nic->drv_stats->rx_ip_ttl_errs);
1498 		break;
1499 	case CQ_RX_ERROP_L3_PCLP:
1500 		this_cpu_inc(nic->drv_stats->rx_l3_pclp);
1501 		break;
1502 	case CQ_RX_ERROP_L4_MAL:
1503 		this_cpu_inc(nic->drv_stats->rx_l4_malformed);
1504 		break;
1505 	case CQ_RX_ERROP_L4_CHK:
1506 		this_cpu_inc(nic->drv_stats->rx_l4_csum_errs);
1507 		break;
1508 	case CQ_RX_ERROP_UDP_LEN:
1509 		this_cpu_inc(nic->drv_stats->rx_udp_len_errs);
1510 		break;
1511 	case CQ_RX_ERROP_L4_PORT:
1512 		this_cpu_inc(nic->drv_stats->rx_l4_port_errs);
1513 		break;
1514 	case CQ_RX_ERROP_TCP_FLAG:
1515 		this_cpu_inc(nic->drv_stats->rx_tcp_flag_errs);
1516 		break;
1517 	case CQ_RX_ERROP_TCP_OFFSET:
1518 		this_cpu_inc(nic->drv_stats->rx_tcp_offset_errs);
1519 		break;
1520 	case CQ_RX_ERROP_L4_PCLP:
1521 		this_cpu_inc(nic->drv_stats->rx_l4_pclp);
1522 		break;
1523 	case CQ_RX_ERROP_RBDR_TRUNC:
1524 		this_cpu_inc(nic->drv_stats->rx_truncated_pkts);
1525 		break;
1526 	}
1527 
1528 	return 1;
1529 }
1530 
1531 /* Check for errors in the send cmp.queue entry */
1532 int nicvf_check_cqe_tx_errs(struct nicvf *nic, struct cqe_send_t *cqe_tx)
1533 {
1534 	switch (cqe_tx->send_status) {
1535 	case CQ_TX_ERROP_GOOD:
1536 		return 0;
1537 	case CQ_TX_ERROP_DESC_FAULT:
1538 		this_cpu_inc(nic->drv_stats->tx_desc_fault);
1539 		break;
1540 	case CQ_TX_ERROP_HDR_CONS_ERR:
1541 		this_cpu_inc(nic->drv_stats->tx_hdr_cons_err);
1542 		break;
1543 	case CQ_TX_ERROP_SUBDC_ERR:
1544 		this_cpu_inc(nic->drv_stats->tx_subdesc_err);
1545 		break;
1546 	case CQ_TX_ERROP_MAX_SIZE_VIOL:
1547 		this_cpu_inc(nic->drv_stats->tx_max_size_exceeded);
1548 		break;
1549 	case CQ_TX_ERROP_IMM_SIZE_OFLOW:
1550 		this_cpu_inc(nic->drv_stats->tx_imm_size_oflow);
1551 		break;
1552 	case CQ_TX_ERROP_DATA_SEQUENCE_ERR:
1553 		this_cpu_inc(nic->drv_stats->tx_data_seq_err);
1554 		break;
1555 	case CQ_TX_ERROP_MEM_SEQUENCE_ERR:
1556 		this_cpu_inc(nic->drv_stats->tx_mem_seq_err);
1557 		break;
1558 	case CQ_TX_ERROP_LOCK_VIOL:
1559 		this_cpu_inc(nic->drv_stats->tx_lock_viol);
1560 		break;
1561 	case CQ_TX_ERROP_DATA_FAULT:
1562 		this_cpu_inc(nic->drv_stats->tx_data_fault);
1563 		break;
1564 	case CQ_TX_ERROP_TSTMP_CONFLICT:
1565 		this_cpu_inc(nic->drv_stats->tx_tstmp_conflict);
1566 		break;
1567 	case CQ_TX_ERROP_TSTMP_TIMEOUT:
1568 		this_cpu_inc(nic->drv_stats->tx_tstmp_timeout);
1569 		break;
1570 	case CQ_TX_ERROP_MEM_FAULT:
1571 		this_cpu_inc(nic->drv_stats->tx_mem_fault);
1572 		break;
1573 	case CQ_TX_ERROP_CK_OVERLAP:
1574 		this_cpu_inc(nic->drv_stats->tx_csum_overlap);
1575 		break;
1576 	case CQ_TX_ERROP_CK_OFLOW:
1577 		this_cpu_inc(nic->drv_stats->tx_csum_overflow);
1578 		break;
1579 	}
1580 
1581 	return 1;
1582 }
1583