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/netdevice.h>
18 #include <linux/u64_stats_sync.h>
19 #include <linux/errno.h>
20 #include <linux/types.h>
21 #include <linux/pci.h>
22 #include <linux/device.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/slab.h>
25 #include <linux/interrupt.h>
26 #include <linux/skbuff.h>
27 #include <linux/smp.h>
28 #include <asm/byteorder.h>
29 
30 #include "hinic_common.h"
31 #include "hinic_hw_if.h"
32 #include "hinic_hw_wqe.h"
33 #include "hinic_hw_wq.h"
34 #include "hinic_hw_qp.h"
35 #include "hinic_hw_dev.h"
36 #include "hinic_dev.h"
37 #include "hinic_tx.h"
38 
39 #define TX_IRQ_NO_PENDING               0
40 #define TX_IRQ_NO_COALESC               0
41 #define TX_IRQ_NO_LLI_TIMER             0
42 #define TX_IRQ_NO_CREDIT                0
43 #define TX_IRQ_NO_RESEND_TIMER          0
44 
45 #define CI_UPDATE_NO_PENDING            0
46 #define CI_UPDATE_NO_COALESC            0
47 
48 #define HW_CONS_IDX(sq)         be16_to_cpu(*(u16 *)((sq)->hw_ci_addr))
49 
50 #define MIN_SKB_LEN             64
51 
52 /**
53  * hinic_txq_clean_stats - Clean the statistics of specific queue
54  * @txq: Logical Tx Queue
55  **/
56 void hinic_txq_clean_stats(struct hinic_txq *txq)
57 {
58 	struct hinic_txq_stats *txq_stats = &txq->txq_stats;
59 
60 	u64_stats_update_begin(&txq_stats->syncp);
61 	txq_stats->pkts    = 0;
62 	txq_stats->bytes   = 0;
63 	txq_stats->tx_busy = 0;
64 	txq_stats->tx_wake = 0;
65 	txq_stats->tx_dropped = 0;
66 	u64_stats_update_end(&txq_stats->syncp);
67 }
68 
69 /**
70  * hinic_txq_get_stats - get statistics of Tx Queue
71  * @txq: Logical Tx Queue
72  * @stats: return updated stats here
73  **/
74 void hinic_txq_get_stats(struct hinic_txq *txq, struct hinic_txq_stats *stats)
75 {
76 	struct hinic_txq_stats *txq_stats = &txq->txq_stats;
77 	unsigned int start;
78 
79 	u64_stats_update_begin(&stats->syncp);
80 	do {
81 		start = u64_stats_fetch_begin(&txq_stats->syncp);
82 		stats->pkts    = txq_stats->pkts;
83 		stats->bytes   = txq_stats->bytes;
84 		stats->tx_busy = txq_stats->tx_busy;
85 		stats->tx_wake = txq_stats->tx_wake;
86 		stats->tx_dropped = txq_stats->tx_dropped;
87 	} while (u64_stats_fetch_retry(&txq_stats->syncp, start));
88 	u64_stats_update_end(&stats->syncp);
89 }
90 
91 /**
92  * txq_stats_init - Initialize the statistics of specific queue
93  * @txq: Logical Tx Queue
94  **/
95 static void txq_stats_init(struct hinic_txq *txq)
96 {
97 	struct hinic_txq_stats *txq_stats = &txq->txq_stats;
98 
99 	u64_stats_init(&txq_stats->syncp);
100 	hinic_txq_clean_stats(txq);
101 }
102 
103 /**
104  * tx_map_skb - dma mapping for skb and return sges
105  * @nic_dev: nic device
106  * @skb: the skb
107  * @sges: returned sges
108  *
109  * Return 0 - Success, negative - Failure
110  **/
111 static int tx_map_skb(struct hinic_dev *nic_dev, struct sk_buff *skb,
112 		      struct hinic_sge *sges)
113 {
114 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
115 	struct hinic_hwif *hwif = hwdev->hwif;
116 	struct pci_dev *pdev = hwif->pdev;
117 	struct skb_frag_struct *frag;
118 	dma_addr_t dma_addr;
119 	int i, j;
120 
121 	dma_addr = dma_map_single(&pdev->dev, skb->data, skb_headlen(skb),
122 				  DMA_TO_DEVICE);
123 	if (dma_mapping_error(&pdev->dev, dma_addr)) {
124 		dev_err(&pdev->dev, "Failed to map Tx skb data\n");
125 		return -EFAULT;
126 	}
127 
128 	hinic_set_sge(&sges[0], dma_addr, skb_headlen(skb));
129 
130 	for (i = 0 ; i < skb_shinfo(skb)->nr_frags; i++) {
131 		frag = &skb_shinfo(skb)->frags[i];
132 
133 		dma_addr = skb_frag_dma_map(&pdev->dev, frag, 0,
134 					    skb_frag_size(frag),
135 					    DMA_TO_DEVICE);
136 		if (dma_mapping_error(&pdev->dev, dma_addr)) {
137 			dev_err(&pdev->dev, "Failed to map Tx skb frag\n");
138 			goto err_tx_map;
139 		}
140 
141 		hinic_set_sge(&sges[i + 1], dma_addr, skb_frag_size(frag));
142 	}
143 
144 	return 0;
145 
146 err_tx_map:
147 	for (j = 0; j < i; j++)
148 		dma_unmap_page(&pdev->dev, hinic_sge_to_dma(&sges[j + 1]),
149 			       sges[j + 1].len, DMA_TO_DEVICE);
150 
151 	dma_unmap_single(&pdev->dev, hinic_sge_to_dma(&sges[0]), sges[0].len,
152 			 DMA_TO_DEVICE);
153 	return -EFAULT;
154 }
155 
156 /**
157  * tx_unmap_skb - unmap the dma address of the skb
158  * @nic_dev: nic device
159  * @skb: the skb
160  * @sges: the sges that are connected to the skb
161  **/
162 static void tx_unmap_skb(struct hinic_dev *nic_dev, struct sk_buff *skb,
163 			 struct hinic_sge *sges)
164 {
165 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
166 	struct hinic_hwif *hwif = hwdev->hwif;
167 	struct pci_dev *pdev = hwif->pdev;
168 	int i;
169 
170 	for (i = 0; i < skb_shinfo(skb)->nr_frags ; i++)
171 		dma_unmap_page(&pdev->dev, hinic_sge_to_dma(&sges[i + 1]),
172 			       sges[i + 1].len, DMA_TO_DEVICE);
173 
174 	dma_unmap_single(&pdev->dev, hinic_sge_to_dma(&sges[0]), sges[0].len,
175 			 DMA_TO_DEVICE);
176 }
177 
178 netdev_tx_t hinic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
179 {
180 	struct hinic_dev *nic_dev = netdev_priv(netdev);
181 	struct netdev_queue *netdev_txq;
182 	int nr_sges, err = NETDEV_TX_OK;
183 	struct hinic_sq_wqe *sq_wqe;
184 	unsigned int wqe_size;
185 	struct hinic_txq *txq;
186 	struct hinic_qp *qp;
187 	u16 prod_idx;
188 
189 	txq = &nic_dev->txqs[skb->queue_mapping];
190 	qp = container_of(txq->sq, struct hinic_qp, sq);
191 
192 	if (skb->len < MIN_SKB_LEN) {
193 		if (skb_pad(skb, MIN_SKB_LEN - skb->len)) {
194 			netdev_err(netdev, "Failed to pad skb\n");
195 			goto update_error_stats;
196 		}
197 
198 		skb->len = MIN_SKB_LEN;
199 	}
200 
201 	nr_sges = skb_shinfo(skb)->nr_frags + 1;
202 	if (nr_sges > txq->max_sges) {
203 		netdev_err(netdev, "Too many Tx sges\n");
204 		goto skb_error;
205 	}
206 
207 	err = tx_map_skb(nic_dev, skb, txq->sges);
208 	if (err)
209 		goto skb_error;
210 
211 	wqe_size = HINIC_SQ_WQE_SIZE(nr_sges);
212 
213 	sq_wqe = hinic_sq_get_wqe(txq->sq, wqe_size, &prod_idx);
214 	if (!sq_wqe) {
215 		tx_unmap_skb(nic_dev, skb, txq->sges);
216 
217 		netif_stop_subqueue(netdev, qp->q_id);
218 
219 		u64_stats_update_begin(&txq->txq_stats.syncp);
220 		txq->txq_stats.tx_busy++;
221 		u64_stats_update_end(&txq->txq_stats.syncp);
222 		err = NETDEV_TX_BUSY;
223 		goto flush_skbs;
224 	}
225 
226 	hinic_sq_prepare_wqe(txq->sq, prod_idx, sq_wqe, txq->sges, nr_sges);
227 
228 	hinic_sq_write_wqe(txq->sq, prod_idx, sq_wqe, skb, wqe_size);
229 
230 flush_skbs:
231 	netdev_txq = netdev_get_tx_queue(netdev, skb->queue_mapping);
232 	if ((!skb->xmit_more) || (netif_xmit_stopped(netdev_txq)))
233 		hinic_sq_write_db(txq->sq, prod_idx, wqe_size, 0);
234 
235 	return err;
236 
237 skb_error:
238 	dev_kfree_skb_any(skb);
239 
240 update_error_stats:
241 	u64_stats_update_begin(&txq->txq_stats.syncp);
242 	txq->txq_stats.tx_dropped++;
243 	u64_stats_update_end(&txq->txq_stats.syncp);
244 	return err;
245 }
246 
247 /**
248  * tx_free_skb - unmap and free skb
249  * @nic_dev: nic device
250  * @skb: the skb
251  * @sges: the sges that are connected to the skb
252  **/
253 static void tx_free_skb(struct hinic_dev *nic_dev, struct sk_buff *skb,
254 			struct hinic_sge *sges)
255 {
256 	tx_unmap_skb(nic_dev, skb, sges);
257 
258 	dev_kfree_skb_any(skb);
259 }
260 
261 /**
262  * free_all_rx_skbs - free all skbs in tx queue
263  * @txq: tx queue
264  **/
265 static void free_all_tx_skbs(struct hinic_txq *txq)
266 {
267 	struct hinic_dev *nic_dev = netdev_priv(txq->netdev);
268 	struct hinic_sq *sq = txq->sq;
269 	struct hinic_sq_wqe *sq_wqe;
270 	unsigned int wqe_size;
271 	struct sk_buff *skb;
272 	int nr_sges;
273 	u16 ci;
274 
275 	while ((sq_wqe = hinic_sq_read_wqe(sq, &skb, &wqe_size, &ci))) {
276 		nr_sges = skb_shinfo(skb)->nr_frags + 1;
277 
278 		hinic_sq_get_sges(sq_wqe, txq->free_sges, nr_sges);
279 
280 		hinic_sq_put_wqe(sq, wqe_size);
281 
282 		tx_free_skb(nic_dev, skb, txq->free_sges);
283 	}
284 }
285 
286 /**
287  * free_tx_poll - free finished tx skbs in tx queue that connected to napi
288  * @napi: napi
289  * @budget: number of tx
290  *
291  * Return 0 - Success, negative - Failure
292  **/
293 static int free_tx_poll(struct napi_struct *napi, int budget)
294 {
295 	struct hinic_txq *txq = container_of(napi, struct hinic_txq, napi);
296 	struct hinic_qp *qp = container_of(txq->sq, struct hinic_qp, sq);
297 	struct hinic_dev *nic_dev = netdev_priv(txq->netdev);
298 	struct netdev_queue *netdev_txq;
299 	struct hinic_sq *sq = txq->sq;
300 	struct hinic_wq *wq = sq->wq;
301 	struct hinic_sq_wqe *sq_wqe;
302 	unsigned int wqe_size;
303 	int nr_sges, pkts = 0;
304 	struct sk_buff *skb;
305 	u64 tx_bytes = 0;
306 	u16 hw_ci, sw_ci;
307 
308 	do {
309 		hw_ci = HW_CONS_IDX(sq) & wq->mask;
310 
311 		sq_wqe = hinic_sq_read_wqe(sq, &skb, &wqe_size, &sw_ci);
312 		if ((!sq_wqe) ||
313 		    (((hw_ci - sw_ci) & wq->mask) * wq->wqebb_size < wqe_size))
314 			break;
315 
316 		tx_bytes += skb->len;
317 		pkts++;
318 
319 		nr_sges = skb_shinfo(skb)->nr_frags + 1;
320 
321 		hinic_sq_get_sges(sq_wqe, txq->free_sges, nr_sges);
322 
323 		hinic_sq_put_wqe(sq, wqe_size);
324 
325 		tx_free_skb(nic_dev, skb, txq->free_sges);
326 	} while (pkts < budget);
327 
328 	if (__netif_subqueue_stopped(nic_dev->netdev, qp->q_id) &&
329 	    hinic_get_sq_free_wqebbs(sq) >= HINIC_MIN_TX_NUM_WQEBBS(sq)) {
330 		netdev_txq = netdev_get_tx_queue(txq->netdev, qp->q_id);
331 
332 		__netif_tx_lock(netdev_txq, smp_processor_id());
333 
334 		netif_wake_subqueue(nic_dev->netdev, qp->q_id);
335 
336 		__netif_tx_unlock(netdev_txq);
337 
338 		u64_stats_update_begin(&txq->txq_stats.syncp);
339 		txq->txq_stats.tx_wake++;
340 		u64_stats_update_end(&txq->txq_stats.syncp);
341 	}
342 
343 	u64_stats_update_begin(&txq->txq_stats.syncp);
344 	txq->txq_stats.bytes += tx_bytes;
345 	txq->txq_stats.pkts += pkts;
346 	u64_stats_update_end(&txq->txq_stats.syncp);
347 
348 	if (pkts < budget) {
349 		napi_complete(napi);
350 		enable_irq(sq->irq);
351 		return pkts;
352 	}
353 
354 	return budget;
355 }
356 
357 static void tx_napi_add(struct hinic_txq *txq, int weight)
358 {
359 	netif_napi_add(txq->netdev, &txq->napi, free_tx_poll, weight);
360 	napi_enable(&txq->napi);
361 }
362 
363 static void tx_napi_del(struct hinic_txq *txq)
364 {
365 	napi_disable(&txq->napi);
366 	netif_napi_del(&txq->napi);
367 }
368 
369 static irqreturn_t tx_irq(int irq, void *data)
370 {
371 	struct hinic_txq *txq = data;
372 	struct hinic_dev *nic_dev;
373 
374 	nic_dev = netdev_priv(txq->netdev);
375 
376 	/* Disable the interrupt until napi will be completed */
377 	disable_irq_nosync(txq->sq->irq);
378 
379 	hinic_hwdev_msix_cnt_set(nic_dev->hwdev, txq->sq->msix_entry);
380 
381 	napi_schedule(&txq->napi);
382 	return IRQ_HANDLED;
383 }
384 
385 static int tx_request_irq(struct hinic_txq *txq)
386 {
387 	struct hinic_dev *nic_dev = netdev_priv(txq->netdev);
388 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
389 	struct hinic_hwif *hwif = hwdev->hwif;
390 	struct pci_dev *pdev = hwif->pdev;
391 	struct hinic_sq *sq = txq->sq;
392 	int err;
393 
394 	tx_napi_add(txq, nic_dev->tx_weight);
395 
396 	hinic_hwdev_msix_set(nic_dev->hwdev, sq->msix_entry,
397 			     TX_IRQ_NO_PENDING, TX_IRQ_NO_COALESC,
398 			     TX_IRQ_NO_LLI_TIMER, TX_IRQ_NO_CREDIT,
399 			     TX_IRQ_NO_RESEND_TIMER);
400 
401 	err = request_irq(sq->irq, tx_irq, 0, txq->irq_name, txq);
402 	if (err) {
403 		dev_err(&pdev->dev, "Failed to request Tx irq\n");
404 		tx_napi_del(txq);
405 		return err;
406 	}
407 
408 	return 0;
409 }
410 
411 static void tx_free_irq(struct hinic_txq *txq)
412 {
413 	struct hinic_sq *sq = txq->sq;
414 
415 	free_irq(sq->irq, txq);
416 	tx_napi_del(txq);
417 }
418 
419 /**
420  * hinic_init_txq - Initialize the Tx Queue
421  * @txq: Logical Tx Queue
422  * @sq: Hardware Tx Queue to connect the Logical queue with
423  * @netdev: network device to connect the Logical queue with
424  *
425  * Return 0 - Success, negative - Failure
426  **/
427 int hinic_init_txq(struct hinic_txq *txq, struct hinic_sq *sq,
428 		   struct net_device *netdev)
429 {
430 	struct hinic_qp *qp = container_of(sq, struct hinic_qp, sq);
431 	struct hinic_dev *nic_dev = netdev_priv(netdev);
432 	struct hinic_hwdev *hwdev = nic_dev->hwdev;
433 	int err, irqname_len;
434 	size_t sges_size;
435 
436 	txq->netdev = netdev;
437 	txq->sq = sq;
438 
439 	txq_stats_init(txq);
440 
441 	txq->max_sges = HINIC_MAX_SQ_BUFDESCS;
442 
443 	sges_size = txq->max_sges * sizeof(*txq->sges);
444 	txq->sges = devm_kzalloc(&netdev->dev, sges_size, GFP_KERNEL);
445 	if (!txq->sges)
446 		return -ENOMEM;
447 
448 	sges_size = txq->max_sges * sizeof(*txq->free_sges);
449 	txq->free_sges = devm_kzalloc(&netdev->dev, sges_size, GFP_KERNEL);
450 	if (!txq->free_sges) {
451 		err = -ENOMEM;
452 		goto err_alloc_free_sges;
453 	}
454 
455 	irqname_len = snprintf(NULL, 0, "hinic_txq%d", qp->q_id) + 1;
456 	txq->irq_name = devm_kzalloc(&netdev->dev, irqname_len, GFP_KERNEL);
457 	if (!txq->irq_name) {
458 		err = -ENOMEM;
459 		goto err_alloc_irqname;
460 	}
461 
462 	sprintf(txq->irq_name, "hinic_txq%d", qp->q_id);
463 
464 	err = hinic_hwdev_hw_ci_addr_set(hwdev, sq, CI_UPDATE_NO_PENDING,
465 					 CI_UPDATE_NO_COALESC);
466 	if (err)
467 		goto err_hw_ci;
468 
469 	err = tx_request_irq(txq);
470 	if (err) {
471 		netdev_err(netdev, "Failed to request Tx irq\n");
472 		goto err_req_tx_irq;
473 	}
474 
475 	return 0;
476 
477 err_req_tx_irq:
478 err_hw_ci:
479 	devm_kfree(&netdev->dev, txq->irq_name);
480 
481 err_alloc_irqname:
482 	devm_kfree(&netdev->dev, txq->free_sges);
483 
484 err_alloc_free_sges:
485 	devm_kfree(&netdev->dev, txq->sges);
486 	return err;
487 }
488 
489 /**
490  * hinic_clean_txq - Clean the Tx Queue
491  * @txq: Logical Tx Queue
492  **/
493 void hinic_clean_txq(struct hinic_txq *txq)
494 {
495 	struct net_device *netdev = txq->netdev;
496 
497 	tx_free_irq(txq);
498 
499 	free_all_tx_skbs(txq);
500 
501 	devm_kfree(&netdev->dev, txq->irq_name);
502 	devm_kfree(&netdev->dev, txq->free_sges);
503 	devm_kfree(&netdev->dev, txq->sges);
504 }
505