xref: /linux/drivers/net/ethernet/huawei/hinic/hinic_rx.c (revision cad4977344b35ea116ec5fefe91a76b1dfa113f5)
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 
47 /**
48  * hinic_rxq_clean_stats - Clean the statistics of specific queue
49  * @rxq: Logical Rx Queue
50  **/
51 void hinic_rxq_clean_stats(struct hinic_rxq *rxq)
52 {
53 	struct hinic_rxq_stats *rxq_stats = &rxq->rxq_stats;
54 
55 	u64_stats_update_begin(&rxq_stats->syncp);
56 	rxq_stats->pkts  = 0;
57 	rxq_stats->bytes = 0;
58 	u64_stats_update_end(&rxq_stats->syncp);
59 }
60 
61 /**
62  * hinic_rxq_get_stats - get statistics of Rx Queue
63  * @rxq: Logical Rx Queue
64  * @stats: return updated stats here
65  **/
66 void hinic_rxq_get_stats(struct hinic_rxq *rxq, struct hinic_rxq_stats *stats)
67 {
68 	struct hinic_rxq_stats *rxq_stats = &rxq->rxq_stats;
69 	unsigned int start;
70 
71 	u64_stats_update_begin(&stats->syncp);
72 	do {
73 		start = u64_stats_fetch_begin(&rxq_stats->syncp);
74 		stats->pkts = rxq_stats->pkts;
75 		stats->bytes = rxq_stats->bytes;
76 	} while (u64_stats_fetch_retry(&rxq_stats->syncp, start));
77 	u64_stats_update_end(&stats->syncp);
78 }
79 
80 /**
81  * rxq_stats_init - Initialize the statistics of specific queue
82  * @rxq: Logical Rx Queue
83  **/
84 static void rxq_stats_init(struct hinic_rxq *rxq)
85 {
86 	struct hinic_rxq_stats *rxq_stats = &rxq->rxq_stats;
87 
88 	u64_stats_init(&rxq_stats->syncp);
89 	hinic_rxq_clean_stats(rxq);
90 }
91 
92 static void rx_csum(struct hinic_rxq *rxq, u16 cons_idx,
93 		    struct sk_buff *skb)
94 {
95 	struct net_device *netdev = rxq->netdev;
96 	struct hinic_rq_cqe *cqe;
97 	struct hinic_rq *rq;
98 	u32 csum_err;
99 	u32 status;
100 
101 	rq = rxq->rq;
102 	cqe = rq->cqe[cons_idx];
103 	status = be32_to_cpu(cqe->status);
104 	csum_err = HINIC_RQ_CQE_STATUS_GET(status, CSUM_ERR);
105 
106 	if (!(netdev->features & NETIF_F_RXCSUM))
107 		return;
108 
109 	if (!csum_err)
110 		skb->ip_summed = CHECKSUM_UNNECESSARY;
111 	else
112 		skb->ip_summed = CHECKSUM_NONE;
113 }
114 /**
115  * rx_alloc_skb - allocate skb and map it to dma address
116  * @rxq: rx queue
117  * @dma_addr: returned dma address for the skb
118  *
119  * Return skb
120  **/
121 static struct sk_buff *rx_alloc_skb(struct hinic_rxq *rxq,
122 				    dma_addr_t *dma_addr)
123 {
124 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
125 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
126 	struct hinic_hwif *hwif = hwdev->hwif;
127 	struct pci_dev *pdev = hwif->pdev;
128 	struct sk_buff *skb;
129 	dma_addr_t addr;
130 	int err;
131 
132 	skb = netdev_alloc_skb_ip_align(rxq->netdev, rxq->rq->buf_sz);
133 	if (!skb) {
134 		netdev_err(rxq->netdev, "Failed to allocate Rx SKB\n");
135 		return NULL;
136 	}
137 
138 	addr = dma_map_single(&pdev->dev, skb->data, rxq->rq->buf_sz,
139 			      DMA_FROM_DEVICE);
140 	err = dma_mapping_error(&pdev->dev, addr);
141 	if (err) {
142 		dev_err(&pdev->dev, "Failed to map Rx DMA, err = %d\n", err);
143 		goto err_rx_map;
144 	}
145 
146 	*dma_addr = addr;
147 	return skb;
148 
149 err_rx_map:
150 	dev_kfree_skb_any(skb);
151 	return NULL;
152 }
153 
154 /**
155  * rx_unmap_skb - unmap the dma address of the skb
156  * @rxq: rx queue
157  * @dma_addr: dma address of the skb
158  **/
159 static void rx_unmap_skb(struct hinic_rxq *rxq, dma_addr_t dma_addr)
160 {
161 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
162 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
163 	struct hinic_hwif *hwif = hwdev->hwif;
164 	struct pci_dev *pdev = hwif->pdev;
165 
166 	dma_unmap_single(&pdev->dev, dma_addr, rxq->rq->buf_sz,
167 			 DMA_FROM_DEVICE);
168 }
169 
170 /**
171  * rx_free_skb - unmap and free skb
172  * @rxq: rx queue
173  * @skb: skb to free
174  * @dma_addr: dma address of the skb
175  **/
176 static void rx_free_skb(struct hinic_rxq *rxq, struct sk_buff *skb,
177 			dma_addr_t dma_addr)
178 {
179 	rx_unmap_skb(rxq, dma_addr);
180 	dev_kfree_skb_any(skb);
181 }
182 
183 /**
184  * rx_alloc_pkts - allocate pkts in rx queue
185  * @rxq: rx queue
186  *
187  * Return number of skbs allocated
188  **/
189 static int rx_alloc_pkts(struct hinic_rxq *rxq)
190 {
191 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
192 	struct hinic_rq_wqe *rq_wqe;
193 	unsigned int free_wqebbs;
194 	struct hinic_sge sge;
195 	dma_addr_t dma_addr;
196 	struct sk_buff *skb;
197 	u16 prod_idx;
198 	int i;
199 
200 	free_wqebbs = hinic_get_rq_free_wqebbs(rxq->rq);
201 
202 	/* Limit the allocation chunks */
203 	if (free_wqebbs > nic_dev->rx_weight)
204 		free_wqebbs = nic_dev->rx_weight;
205 
206 	for (i = 0; i < free_wqebbs; i++) {
207 		skb = rx_alloc_skb(rxq, &dma_addr);
208 		if (!skb) {
209 			netdev_err(rxq->netdev, "Failed to alloc Rx skb\n");
210 			goto skb_out;
211 		}
212 
213 		hinic_set_sge(&sge, dma_addr, skb->len);
214 
215 		rq_wqe = hinic_rq_get_wqe(rxq->rq, HINIC_RQ_WQE_SIZE,
216 					  &prod_idx);
217 		if (!rq_wqe) {
218 			rx_free_skb(rxq, skb, dma_addr);
219 			goto skb_out;
220 		}
221 
222 		hinic_rq_prepare_wqe(rxq->rq, prod_idx, rq_wqe, &sge);
223 
224 		hinic_rq_write_wqe(rxq->rq, prod_idx, rq_wqe, skb);
225 	}
226 
227 skb_out:
228 	if (i) {
229 		wmb();  /* write all the wqes before update PI */
230 
231 		hinic_rq_update(rxq->rq, prod_idx);
232 		tasklet_schedule(&rxq->rx_task);
233 	}
234 
235 	return i;
236 }
237 
238 /**
239  * free_all_rx_skbs - free all skbs in rx queue
240  * @rxq: rx queue
241  **/
242 static void free_all_rx_skbs(struct hinic_rxq *rxq)
243 {
244 	struct hinic_rq *rq = rxq->rq;
245 	struct hinic_hw_wqe *hw_wqe;
246 	struct hinic_sge sge;
247 	u16 ci;
248 
249 	while ((hw_wqe = hinic_read_wqe(rq->wq, HINIC_RQ_WQE_SIZE, &ci))) {
250 		if (IS_ERR(hw_wqe))
251 			break;
252 
253 		hinic_rq_get_sge(rq, &hw_wqe->rq_wqe, ci, &sge);
254 
255 		hinic_put_wqe(rq->wq, HINIC_RQ_WQE_SIZE);
256 
257 		rx_free_skb(rxq, rq->saved_skb[ci], hinic_sge_to_dma(&sge));
258 	}
259 }
260 
261 /**
262  * rx_alloc_task - tasklet for queue allocation
263  * @data: rx queue
264  **/
265 static void rx_alloc_task(unsigned long data)
266 {
267 	struct hinic_rxq *rxq = (struct hinic_rxq *)data;
268 
269 	(void)rx_alloc_pkts(rxq);
270 }
271 
272 /**
273  * rx_recv_jumbo_pkt - Rx handler for jumbo pkt
274  * @rxq: rx queue
275  * @head_skb: the first skb in the list
276  * @left_pkt_len: left size of the pkt exclude head skb
277  * @ci: consumer index
278  *
279  * Return number of wqes that used for the left of the pkt
280  **/
281 static int rx_recv_jumbo_pkt(struct hinic_rxq *rxq, struct sk_buff *head_skb,
282 			     unsigned int left_pkt_len, u16 ci)
283 {
284 	struct sk_buff *skb, *curr_skb = head_skb;
285 	struct hinic_rq_wqe *rq_wqe;
286 	unsigned int curr_len;
287 	struct hinic_sge sge;
288 	int num_wqes = 0;
289 
290 	while (left_pkt_len > 0) {
291 		rq_wqe = hinic_rq_read_next_wqe(rxq->rq, HINIC_RQ_WQE_SIZE,
292 						&skb, &ci);
293 
294 		num_wqes++;
295 
296 		hinic_rq_get_sge(rxq->rq, rq_wqe, ci, &sge);
297 
298 		rx_unmap_skb(rxq, hinic_sge_to_dma(&sge));
299 
300 		prefetch(skb->data);
301 
302 		curr_len = (left_pkt_len > HINIC_RX_BUF_SZ) ? HINIC_RX_BUF_SZ :
303 			    left_pkt_len;
304 
305 		left_pkt_len -= curr_len;
306 
307 		__skb_put(skb, curr_len);
308 
309 		if (curr_skb == head_skb)
310 			skb_shinfo(head_skb)->frag_list = skb;
311 		else
312 			curr_skb->next = skb;
313 
314 		head_skb->len += skb->len;
315 		head_skb->data_len += skb->len;
316 		head_skb->truesize += skb->truesize;
317 
318 		curr_skb = skb;
319 	}
320 
321 	return num_wqes;
322 }
323 
324 /**
325  * rxq_recv - Rx handler
326  * @rxq: rx queue
327  * @budget: maximum pkts to process
328  *
329  * Return number of pkts received
330  **/
331 static int rxq_recv(struct hinic_rxq *rxq, int budget)
332 {
333 	struct hinic_qp *qp = container_of(rxq->rq, struct hinic_qp, rq);
334 	u64 pkt_len = 0, rx_bytes = 0;
335 	struct hinic_rq_wqe *rq_wqe;
336 	int num_wqes, pkts = 0;
337 	struct hinic_sge sge;
338 	struct sk_buff *skb;
339 	u16 ci;
340 
341 	while (pkts < budget) {
342 		num_wqes = 0;
343 
344 		rq_wqe = hinic_rq_read_wqe(rxq->rq, HINIC_RQ_WQE_SIZE, &skb,
345 					   &ci);
346 		if (!rq_wqe)
347 			break;
348 
349 		hinic_rq_get_sge(rxq->rq, rq_wqe, ci, &sge);
350 
351 		rx_unmap_skb(rxq, hinic_sge_to_dma(&sge));
352 
353 		rx_csum(rxq, ci, skb);
354 
355 		prefetch(skb->data);
356 
357 		pkt_len = sge.len;
358 
359 		if (pkt_len <= HINIC_RX_BUF_SZ) {
360 			__skb_put(skb, pkt_len);
361 		} else {
362 			__skb_put(skb, HINIC_RX_BUF_SZ);
363 			num_wqes = rx_recv_jumbo_pkt(rxq, skb, pkt_len -
364 						     HINIC_RX_BUF_SZ, ci);
365 		}
366 
367 		hinic_rq_put_wqe(rxq->rq, ci,
368 				 (num_wqes + 1) * HINIC_RQ_WQE_SIZE);
369 
370 		skb_record_rx_queue(skb, qp->q_id);
371 		skb->protocol = eth_type_trans(skb, rxq->netdev);
372 
373 		napi_gro_receive(&rxq->napi, skb);
374 
375 		pkts++;
376 		rx_bytes += pkt_len;
377 	}
378 
379 	if (pkts)
380 		tasklet_schedule(&rxq->rx_task); /* rx_alloc_pkts */
381 
382 	u64_stats_update_begin(&rxq->rxq_stats.syncp);
383 	rxq->rxq_stats.pkts += pkts;
384 	rxq->rxq_stats.bytes += rx_bytes;
385 	u64_stats_update_end(&rxq->rxq_stats.syncp);
386 
387 	return pkts;
388 }
389 
390 static int rx_poll(struct napi_struct *napi, int budget)
391 {
392 	struct hinic_rxq *rxq = container_of(napi, struct hinic_rxq, napi);
393 	struct hinic_rq *rq = rxq->rq;
394 	int pkts;
395 
396 	pkts = rxq_recv(rxq, budget);
397 	if (pkts >= budget)
398 		return budget;
399 
400 	napi_complete(napi);
401 	enable_irq(rq->irq);
402 	return pkts;
403 }
404 
405 static void rx_add_napi(struct hinic_rxq *rxq)
406 {
407 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
408 
409 	netif_napi_add(rxq->netdev, &rxq->napi, rx_poll, nic_dev->rx_weight);
410 	napi_enable(&rxq->napi);
411 }
412 
413 static void rx_del_napi(struct hinic_rxq *rxq)
414 {
415 	napi_disable(&rxq->napi);
416 	netif_napi_del(&rxq->napi);
417 }
418 
419 static irqreturn_t rx_irq(int irq, void *data)
420 {
421 	struct hinic_rxq *rxq = (struct hinic_rxq *)data;
422 	struct hinic_rq *rq = rxq->rq;
423 	struct hinic_dev *nic_dev;
424 
425 	/* Disable the interrupt until napi will be completed */
426 	disable_irq_nosync(rq->irq);
427 
428 	nic_dev = netdev_priv(rxq->netdev);
429 	hinic_hwdev_msix_cnt_set(nic_dev->hwdev, rq->msix_entry);
430 
431 	napi_schedule(&rxq->napi);
432 	return IRQ_HANDLED;
433 }
434 
435 static int rx_request_irq(struct hinic_rxq *rxq)
436 {
437 	struct hinic_dev *nic_dev = netdev_priv(rxq->netdev);
438 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
439 	struct hinic_rq *rq = rxq->rq;
440 	struct hinic_qp *qp;
441 	struct cpumask mask;
442 	int err;
443 
444 	rx_add_napi(rxq);
445 
446 	hinic_hwdev_msix_set(hwdev, rq->msix_entry,
447 			     RX_IRQ_NO_PENDING, RX_IRQ_NO_COALESC,
448 			     RX_IRQ_NO_LLI_TIMER, RX_IRQ_NO_CREDIT,
449 			     RX_IRQ_NO_RESEND_TIMER);
450 
451 	err = request_irq(rq->irq, rx_irq, 0, rxq->irq_name, rxq);
452 	if (err) {
453 		rx_del_napi(rxq);
454 		return err;
455 	}
456 
457 	qp = container_of(rq, struct hinic_qp, rq);
458 	cpumask_set_cpu(qp->q_id % num_online_cpus(), &mask);
459 	return irq_set_affinity_hint(rq->irq, &mask);
460 }
461 
462 static void rx_free_irq(struct hinic_rxq *rxq)
463 {
464 	struct hinic_rq *rq = rxq->rq;
465 
466 	irq_set_affinity_hint(rq->irq, NULL);
467 	free_irq(rq->irq, rxq);
468 	rx_del_napi(rxq);
469 }
470 
471 /**
472  * hinic_init_rxq - Initialize the Rx Queue
473  * @rxq: Logical Rx Queue
474  * @rq: Hardware Rx Queue to connect the Logical queue with
475  * @netdev: network device to connect the Logical queue with
476  *
477  * Return 0 - Success, negative - Failure
478  **/
479 int hinic_init_rxq(struct hinic_rxq *rxq, struct hinic_rq *rq,
480 		   struct net_device *netdev)
481 {
482 	struct hinic_qp *qp = container_of(rq, struct hinic_qp, rq);
483 	int err, pkts, irqname_len;
484 
485 	rxq->netdev = netdev;
486 	rxq->rq = rq;
487 
488 	rxq_stats_init(rxq);
489 
490 	irqname_len = snprintf(NULL, 0, "hinic_rxq%d", qp->q_id) + 1;
491 	rxq->irq_name = devm_kzalloc(&netdev->dev, irqname_len, GFP_KERNEL);
492 	if (!rxq->irq_name)
493 		return -ENOMEM;
494 
495 	sprintf(rxq->irq_name, "hinic_rxq%d", qp->q_id);
496 
497 	tasklet_init(&rxq->rx_task, rx_alloc_task, (unsigned long)rxq);
498 
499 	pkts = rx_alloc_pkts(rxq);
500 	if (!pkts) {
501 		err = -ENOMEM;
502 		goto err_rx_pkts;
503 	}
504 
505 	err = rx_request_irq(rxq);
506 	if (err) {
507 		netdev_err(netdev, "Failed to request Rx irq\n");
508 		goto err_req_rx_irq;
509 	}
510 
511 	return 0;
512 
513 err_req_rx_irq:
514 err_rx_pkts:
515 	tasklet_kill(&rxq->rx_task);
516 	free_all_rx_skbs(rxq);
517 	devm_kfree(&netdev->dev, rxq->irq_name);
518 	return err;
519 }
520 
521 /**
522  * hinic_clean_rxq - Clean the Rx Queue
523  * @rxq: Logical Rx Queue
524  **/
525 void hinic_clean_rxq(struct hinic_rxq *rxq)
526 {
527 	struct net_device *netdev = rxq->netdev;
528 
529 	rx_free_irq(rxq);
530 
531 	tasklet_kill(&rxq->rx_task);
532 	free_all_rx_skbs(rxq);
533 	devm_kfree(&netdev->dev, rxq->irq_name);
534 }
535