xref: /linux/drivers/net/ethernet/huawei/hinic/hinic_rx.c (revision 4201c9260a8d3c4ef238e51692a7e9b4e1e29efe)
1 /*
2  * Huawei HiNIC PCI Express Linux driver
3  * Copyright(c) 2017 Huawei Technologies Co., Ltd
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <linux/pci.h>
20 #include <linux/device.h>
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23 #include <linux/u64_stats_sync.h>
24 #include <linux/slab.h>
25 #include <linux/interrupt.h>
26 #include <linux/skbuff.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/prefetch.h>
29 #include <linux/cpumask.h>
30 #include <asm/barrier.h>
31 
32 #include "hinic_common.h"
33 #include "hinic_hw_if.h"
34 #include "hinic_hw_wqe.h"
35 #include "hinic_hw_wq.h"
36 #include "hinic_hw_qp.h"
37 #include "hinic_hw_dev.h"
38 #include "hinic_rx.h"
39 #include "hinic_dev.h"
40 
41 #define RX_IRQ_NO_PENDING               0
42 #define RX_IRQ_NO_COALESC               0
43 #define RX_IRQ_NO_LLI_TIMER             0
44 #define RX_IRQ_NO_CREDIT                0
45 #define RX_IRQ_NO_RESEND_TIMER          0
46 #define HINIC_RX_BUFFER_WRITE           16
47 
48 #define HINIC_RX_IPV6_PKT		7
49 #define LRO_PKT_HDR_LEN_IPV4		66
50 #define LRO_PKT_HDR_LEN_IPV6		86
51 #define LRO_REPLENISH_THLD		256
52 
53 #define LRO_PKT_HDR_LEN(cqe)		\
54 	(HINIC_GET_RX_PKT_TYPE(be32_to_cpu((cqe)->offload_type)) == \
55 	 HINIC_RX_IPV6_PKT ? LRO_PKT_HDR_LEN_IPV6 : LRO_PKT_HDR_LEN_IPV4)
56 
57 /**
58  * hinic_rxq_clean_stats - Clean the statistics of specific queue
59  * @rxq: Logical Rx Queue
60  **/
61 void hinic_rxq_clean_stats(struct hinic_rxq *rxq)
62 {
63 	struct hinic_rxq_stats *rxq_stats = &rxq->rxq_stats;
64 
65 	u64_stats_update_begin(&rxq_stats->syncp);
66 	rxq_stats->pkts  = 0;
67 	rxq_stats->bytes = 0;
68 	u64_stats_update_end(&rxq_stats->syncp);
69 }
70 
71 /**
72  * hinic_rxq_get_stats - get statistics of Rx Queue
73  * @rxq: Logical Rx Queue
74  * @stats: return updated stats here
75  **/
76 void hinic_rxq_get_stats(struct hinic_rxq *rxq, struct hinic_rxq_stats *stats)
77 {
78 	struct hinic_rxq_stats *rxq_stats = &rxq->rxq_stats;
79 	unsigned int start;
80 
81 	u64_stats_update_begin(&stats->syncp);
82 	do {
83 		start = u64_stats_fetch_begin(&rxq_stats->syncp);
84 		stats->pkts = rxq_stats->pkts;
85 		stats->bytes = rxq_stats->bytes;
86 	} while (u64_stats_fetch_retry(&rxq_stats->syncp, start));
87 	u64_stats_update_end(&stats->syncp);
88 }
89 
90 /**
91  * rxq_stats_init - Initialize the statistics of specific queue
92  * @rxq: Logical Rx Queue
93  **/
94 static void rxq_stats_init(struct hinic_rxq *rxq)
95 {
96 	struct hinic_rxq_stats *rxq_stats = &rxq->rxq_stats;
97 
98 	u64_stats_init(&rxq_stats->syncp);
99 	hinic_rxq_clean_stats(rxq);
100 }
101 
102 static void rx_csum(struct hinic_rxq *rxq, u32 status,
103 		    struct sk_buff *skb)
104 {
105 	struct net_device *netdev = rxq->netdev;
106 	u32 csum_err;
107 
108 	csum_err = HINIC_RQ_CQE_STATUS_GET(status, CSUM_ERR);
109 
110 	if (!(netdev->features & NETIF_F_RXCSUM))
111 		return;
112 
113 	if (!csum_err)
114 		skb->ip_summed = CHECKSUM_UNNECESSARY;
115 	else
116 		skb->ip_summed = CHECKSUM_NONE;
117 }
118 /**
119  * rx_alloc_skb - allocate skb and map it to dma address
120  * @rxq: rx queue
121  * @dma_addr: returned dma address for the skb
122  *
123  * Return skb
124  **/
125 static struct sk_buff *rx_alloc_skb(struct hinic_rxq *rxq,
126 				    dma_addr_t *dma_addr)
127 {
128 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
129 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
130 	struct hinic_hwif *hwif = hwdev->hwif;
131 	struct pci_dev *pdev = hwif->pdev;
132 	struct sk_buff *skb;
133 	dma_addr_t addr;
134 	int err;
135 
136 	skb = netdev_alloc_skb_ip_align(rxq->netdev, rxq->rq->buf_sz);
137 	if (!skb) {
138 		netdev_err(rxq->netdev, "Failed to allocate Rx SKB\n");
139 		return NULL;
140 	}
141 
142 	addr = dma_map_single(&pdev->dev, skb->data, rxq->rq->buf_sz,
143 			      DMA_FROM_DEVICE);
144 	err = dma_mapping_error(&pdev->dev, addr);
145 	if (err) {
146 		dev_err(&pdev->dev, "Failed to map Rx DMA, err = %d\n", err);
147 		goto err_rx_map;
148 	}
149 
150 	*dma_addr = addr;
151 	return skb;
152 
153 err_rx_map:
154 	dev_kfree_skb_any(skb);
155 	return NULL;
156 }
157 
158 /**
159  * rx_unmap_skb - unmap the dma address of the skb
160  * @rxq: rx queue
161  * @dma_addr: dma address of the skb
162  **/
163 static void rx_unmap_skb(struct hinic_rxq *rxq, dma_addr_t dma_addr)
164 {
165 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
166 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
167 	struct hinic_hwif *hwif = hwdev->hwif;
168 	struct pci_dev *pdev = hwif->pdev;
169 
170 	dma_unmap_single(&pdev->dev, dma_addr, rxq->rq->buf_sz,
171 			 DMA_FROM_DEVICE);
172 }
173 
174 /**
175  * rx_free_skb - unmap and free skb
176  * @rxq: rx queue
177  * @skb: skb to free
178  * @dma_addr: dma address of the skb
179  **/
180 static void rx_free_skb(struct hinic_rxq *rxq, struct sk_buff *skb,
181 			dma_addr_t dma_addr)
182 {
183 	rx_unmap_skb(rxq, dma_addr);
184 	dev_kfree_skb_any(skb);
185 }
186 
187 /**
188  * rx_alloc_pkts - allocate pkts in rx queue
189  * @rxq: rx queue
190  *
191  * Return number of skbs allocated
192  **/
193 static int rx_alloc_pkts(struct hinic_rxq *rxq)
194 {
195 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
196 	struct hinic_rq_wqe *rq_wqe;
197 	unsigned int free_wqebbs;
198 	struct hinic_sge sge;
199 	dma_addr_t dma_addr;
200 	struct sk_buff *skb;
201 	u16 prod_idx;
202 	int i;
203 
204 	free_wqebbs = hinic_get_rq_free_wqebbs(rxq->rq);
205 
206 	/* Limit the allocation chunks */
207 	if (free_wqebbs > nic_dev->rx_weight)
208 		free_wqebbs = nic_dev->rx_weight;
209 
210 	for (i = 0; i < free_wqebbs; i++) {
211 		skb = rx_alloc_skb(rxq, &dma_addr);
212 		if (!skb) {
213 			netdev_err(rxq->netdev, "Failed to alloc Rx skb\n");
214 			goto skb_out;
215 		}
216 
217 		hinic_set_sge(&sge, dma_addr, skb->len);
218 
219 		rq_wqe = hinic_rq_get_wqe(rxq->rq, HINIC_RQ_WQE_SIZE,
220 					  &prod_idx);
221 		if (!rq_wqe) {
222 			rx_free_skb(rxq, skb, dma_addr);
223 			goto skb_out;
224 		}
225 
226 		hinic_rq_prepare_wqe(rxq->rq, prod_idx, rq_wqe, &sge);
227 
228 		hinic_rq_write_wqe(rxq->rq, prod_idx, rq_wqe, skb);
229 	}
230 
231 skb_out:
232 	if (i) {
233 		wmb();  /* write all the wqes before update PI */
234 
235 		hinic_rq_update(rxq->rq, prod_idx);
236 	}
237 
238 	return i;
239 }
240 
241 /**
242  * free_all_rx_skbs - free all skbs in rx queue
243  * @rxq: rx queue
244  **/
245 static void free_all_rx_skbs(struct hinic_rxq *rxq)
246 {
247 	struct hinic_rq *rq = rxq->rq;
248 	struct hinic_hw_wqe *hw_wqe;
249 	struct hinic_sge sge;
250 	u16 ci;
251 
252 	while ((hw_wqe = hinic_read_wqe(rq->wq, HINIC_RQ_WQE_SIZE, &ci))) {
253 		if (IS_ERR(hw_wqe))
254 			break;
255 
256 		hinic_rq_get_sge(rq, &hw_wqe->rq_wqe, ci, &sge);
257 
258 		hinic_put_wqe(rq->wq, HINIC_RQ_WQE_SIZE);
259 
260 		rx_free_skb(rxq, rq->saved_skb[ci], hinic_sge_to_dma(&sge));
261 	}
262 }
263 
264 /**
265  * rx_recv_jumbo_pkt - Rx handler for jumbo pkt
266  * @rxq: rx queue
267  * @head_skb: the first skb in the list
268  * @left_pkt_len: left size of the pkt exclude head skb
269  * @ci: consumer index
270  *
271  * Return number of wqes that used for the left of the pkt
272  **/
273 static int rx_recv_jumbo_pkt(struct hinic_rxq *rxq, struct sk_buff *head_skb,
274 			     unsigned int left_pkt_len, u16 ci)
275 {
276 	struct sk_buff *skb, *curr_skb = head_skb;
277 	struct hinic_rq_wqe *rq_wqe;
278 	unsigned int curr_len;
279 	struct hinic_sge sge;
280 	int num_wqes = 0;
281 
282 	while (left_pkt_len > 0) {
283 		rq_wqe = hinic_rq_read_next_wqe(rxq->rq, HINIC_RQ_WQE_SIZE,
284 						&skb, &ci);
285 
286 		num_wqes++;
287 
288 		hinic_rq_get_sge(rxq->rq, rq_wqe, ci, &sge);
289 
290 		rx_unmap_skb(rxq, hinic_sge_to_dma(&sge));
291 
292 		prefetch(skb->data);
293 
294 		curr_len = (left_pkt_len > HINIC_RX_BUF_SZ) ? HINIC_RX_BUF_SZ :
295 			    left_pkt_len;
296 
297 		left_pkt_len -= curr_len;
298 
299 		__skb_put(skb, curr_len);
300 
301 		if (curr_skb == head_skb)
302 			skb_shinfo(head_skb)->frag_list = skb;
303 		else
304 			curr_skb->next = skb;
305 
306 		head_skb->len += skb->len;
307 		head_skb->data_len += skb->len;
308 		head_skb->truesize += skb->truesize;
309 
310 		curr_skb = skb;
311 	}
312 
313 	return num_wqes;
314 }
315 
316 /**
317  * rxq_recv - Rx handler
318  * @rxq: rx queue
319  * @budget: maximum pkts to process
320  *
321  * Return number of pkts received
322  **/
323 static int rxq_recv(struct hinic_rxq *rxq, int budget)
324 {
325 	struct hinic_qp *qp = container_of(rxq->rq, struct hinic_qp, rq);
326 	u64 pkt_len = 0, rx_bytes = 0;
327 	struct hinic_rq *rq = rxq->rq;
328 	struct hinic_rq_wqe *rq_wqe;
329 	unsigned int free_wqebbs;
330 	struct hinic_rq_cqe *cqe;
331 	int num_wqes, pkts = 0;
332 	struct hinic_sge sge;
333 	unsigned int status;
334 	struct sk_buff *skb;
335 	u16 ci, num_lro;
336 	u16 num_wqe = 0;
337 
338 	while (pkts < budget) {
339 		num_wqes = 0;
340 
341 		rq_wqe = hinic_rq_read_wqe(rxq->rq, HINIC_RQ_WQE_SIZE, &skb,
342 					   &ci);
343 		if (!rq_wqe)
344 			break;
345 
346 		cqe = rq->cqe[ci];
347 		status =  be32_to_cpu(cqe->status);
348 		hinic_rq_get_sge(rxq->rq, rq_wqe, ci, &sge);
349 
350 		rx_unmap_skb(rxq, hinic_sge_to_dma(&sge));
351 
352 		rx_csum(rxq, status, skb);
353 
354 		prefetch(skb->data);
355 
356 		pkt_len = sge.len;
357 
358 		if (pkt_len <= HINIC_RX_BUF_SZ) {
359 			__skb_put(skb, pkt_len);
360 		} else {
361 			__skb_put(skb, HINIC_RX_BUF_SZ);
362 			num_wqes = rx_recv_jumbo_pkt(rxq, skb, pkt_len -
363 						     HINIC_RX_BUF_SZ, ci);
364 		}
365 
366 		hinic_rq_put_wqe(rq, ci,
367 				 (num_wqes + 1) * HINIC_RQ_WQE_SIZE);
368 
369 		skb_record_rx_queue(skb, qp->q_id);
370 		skb->protocol = eth_type_trans(skb, rxq->netdev);
371 
372 		napi_gro_receive(&rxq->napi, skb);
373 
374 		pkts++;
375 		rx_bytes += pkt_len;
376 
377 		num_lro = HINIC_GET_RX_NUM_LRO(status);
378 		if (num_lro) {
379 			rx_bytes += ((num_lro - 1) *
380 				     LRO_PKT_HDR_LEN(cqe));
381 
382 			num_wqe +=
383 			(u16)(pkt_len >> rxq->rx_buff_shift) +
384 			((pkt_len & (rxq->buf_len - 1)) ? 1 : 0);
385 		}
386 
387 		cqe->status = 0;
388 
389 		if (num_wqe >= LRO_REPLENISH_THLD)
390 			break;
391 	}
392 
393 	free_wqebbs = hinic_get_rq_free_wqebbs(rxq->rq);
394 	if (free_wqebbs > HINIC_RX_BUFFER_WRITE)
395 		rx_alloc_pkts(rxq);
396 
397 	u64_stats_update_begin(&rxq->rxq_stats.syncp);
398 	rxq->rxq_stats.pkts += pkts;
399 	rxq->rxq_stats.bytes += rx_bytes;
400 	u64_stats_update_end(&rxq->rxq_stats.syncp);
401 
402 	return pkts;
403 }
404 
405 static int rx_poll(struct napi_struct *napi, int budget)
406 {
407 	struct hinic_rxq *rxq = container_of(napi, struct hinic_rxq, napi);
408 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
409 	struct hinic_rq *rq = rxq->rq;
410 	int pkts;
411 
412 	pkts = rxq_recv(rxq, budget);
413 	if (pkts >= budget)
414 		return budget;
415 
416 	napi_complete(napi);
417 	hinic_hwdev_set_msix_state(nic_dev->hwdev,
418 				   rq->msix_entry,
419 				   HINIC_MSIX_ENABLE);
420 
421 	return pkts;
422 }
423 
424 static void rx_add_napi(struct hinic_rxq *rxq)
425 {
426 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
427 
428 	netif_napi_add(rxq->netdev, &rxq->napi, rx_poll, nic_dev->rx_weight);
429 	napi_enable(&rxq->napi);
430 }
431 
432 static void rx_del_napi(struct hinic_rxq *rxq)
433 {
434 	napi_disable(&rxq->napi);
435 	netif_napi_del(&rxq->napi);
436 }
437 
438 static irqreturn_t rx_irq(int irq, void *data)
439 {
440 	struct hinic_rxq *rxq = (struct hinic_rxq *)data;
441 	struct hinic_rq *rq = rxq->rq;
442 	struct hinic_dev *nic_dev;
443 
444 	/* Disable the interrupt until napi will be completed */
445 	nic_dev = netdev_priv(rxq->netdev);
446 	hinic_hwdev_set_msix_state(nic_dev->hwdev,
447 				   rq->msix_entry,
448 				   HINIC_MSIX_DISABLE);
449 
450 	nic_dev = netdev_priv(rxq->netdev);
451 	hinic_hwdev_msix_cnt_set(nic_dev->hwdev, rq->msix_entry);
452 
453 	napi_schedule(&rxq->napi);
454 	return IRQ_HANDLED;
455 }
456 
457 static int rx_request_irq(struct hinic_rxq *rxq)
458 {
459 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
460 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
461 	struct hinic_rq *rq = rxq->rq;
462 	struct hinic_qp *qp;
463 	struct cpumask mask;
464 	int err;
465 
466 	rx_add_napi(rxq);
467 
468 	hinic_hwdev_msix_set(hwdev, rq->msix_entry,
469 			     RX_IRQ_NO_PENDING, RX_IRQ_NO_COALESC,
470 			     RX_IRQ_NO_LLI_TIMER, RX_IRQ_NO_CREDIT,
471 			     RX_IRQ_NO_RESEND_TIMER);
472 
473 	err = request_irq(rq->irq, rx_irq, 0, rxq->irq_name, rxq);
474 	if (err) {
475 		rx_del_napi(rxq);
476 		return err;
477 	}
478 
479 	qp = container_of(rq, struct hinic_qp, rq);
480 	cpumask_set_cpu(qp->q_id % num_online_cpus(), &mask);
481 	return irq_set_affinity_hint(rq->irq, &mask);
482 }
483 
484 static void rx_free_irq(struct hinic_rxq *rxq)
485 {
486 	struct hinic_rq *rq = rxq->rq;
487 
488 	irq_set_affinity_hint(rq->irq, NULL);
489 	free_irq(rq->irq, rxq);
490 	rx_del_napi(rxq);
491 }
492 
493 /**
494  * hinic_init_rxq - Initialize the Rx Queue
495  * @rxq: Logical Rx Queue
496  * @rq: Hardware Rx Queue to connect the Logical queue with
497  * @netdev: network device to connect the Logical queue with
498  *
499  * Return 0 - Success, negative - Failure
500  **/
501 int hinic_init_rxq(struct hinic_rxq *rxq, struct hinic_rq *rq,
502 		   struct net_device *netdev)
503 {
504 	struct hinic_qp *qp = container_of(rq, struct hinic_qp, rq);
505 	int err, pkts;
506 
507 	rxq->netdev = netdev;
508 	rxq->rq = rq;
509 	rxq->buf_len = HINIC_RX_BUF_SZ;
510 	rxq->rx_buff_shift = ilog2(HINIC_RX_BUF_SZ);
511 
512 	rxq_stats_init(rxq);
513 
514 	rxq->irq_name = devm_kasprintf(&netdev->dev, GFP_KERNEL,
515 				       "hinic_rxq%d", qp->q_id);
516 	if (!rxq->irq_name)
517 		return -ENOMEM;
518 
519 	pkts = rx_alloc_pkts(rxq);
520 	if (!pkts) {
521 		err = -ENOMEM;
522 		goto err_rx_pkts;
523 	}
524 
525 	err = rx_request_irq(rxq);
526 	if (err) {
527 		netdev_err(netdev, "Failed to request Rx irq\n");
528 		goto err_req_rx_irq;
529 	}
530 
531 	return 0;
532 
533 err_req_rx_irq:
534 err_rx_pkts:
535 	free_all_rx_skbs(rxq);
536 	devm_kfree(&netdev->dev, rxq->irq_name);
537 	return err;
538 }
539 
540 /**
541  * hinic_clean_rxq - Clean the Rx Queue
542  * @rxq: Logical Rx Queue
543  **/
544 void hinic_clean_rxq(struct hinic_rxq *rxq)
545 {
546 	struct net_device *netdev = rxq->netdev;
547 
548 	rx_free_irq(rxq);
549 
550 	free_all_rx_skbs(rxq);
551 	devm_kfree(&netdev->dev, rxq->irq_name);
552 }
553