1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /*
3  * Copyright(c) 2020 Intel Corporation.
4  *
5  */
6 
7 /*
8  * This file contains HFI1 support for IPOIB SDMA functionality
9  */
10 
11 #include <linux/log2.h>
12 #include <linux/circ_buf.h>
13 
14 #include "sdma.h"
15 #include "verbs.h"
16 #include "trace_ibhdrs.h"
17 #include "ipoib.h"
18 #include "trace_tx.h"
19 
20 /* Add a convenience helper */
21 #define CIRC_ADD(val, add, size) (((val) + (add)) & ((size) - 1))
22 #define CIRC_NEXT(val, size) CIRC_ADD(val, 1, size)
23 #define CIRC_PREV(val, size) CIRC_ADD(val, -1, size)
24 
25 struct ipoib_txparms {
26 	struct hfi1_devdata        *dd;
27 	struct rdma_ah_attr        *ah_attr;
28 	struct hfi1_ibport         *ibp;
29 	struct hfi1_ipoib_txq      *txq;
30 	union hfi1_ipoib_flow       flow;
31 	u32                         dqpn;
32 	u8                          hdr_dwords;
33 	u8                          entropy;
34 };
35 
36 static struct ipoib_txreq *
hfi1_txreq_from_idx(struct hfi1_ipoib_circ_buf * r,u32 idx)37 hfi1_txreq_from_idx(struct hfi1_ipoib_circ_buf *r, u32 idx)
38 {
39 	return (struct ipoib_txreq *)(r->items + (idx << r->shift));
40 }
41 
hfi1_ipoib_txreqs(const u64 sent,const u64 completed)42 static u32 hfi1_ipoib_txreqs(const u64 sent, const u64 completed)
43 {
44 	return sent - completed;
45 }
46 
hfi1_ipoib_used(struct hfi1_ipoib_txq * txq)47 static u64 hfi1_ipoib_used(struct hfi1_ipoib_txq *txq)
48 {
49 	return hfi1_ipoib_txreqs(txq->tx_ring.sent_txreqs,
50 				 txq->tx_ring.complete_txreqs);
51 }
52 
hfi1_ipoib_stop_txq(struct hfi1_ipoib_txq * txq)53 static void hfi1_ipoib_stop_txq(struct hfi1_ipoib_txq *txq)
54 {
55 	trace_hfi1_txq_stop(txq);
56 	if (atomic_inc_return(&txq->tx_ring.stops) == 1)
57 		netif_stop_subqueue(txq->priv->netdev, txq->q_idx);
58 }
59 
hfi1_ipoib_wake_txq(struct hfi1_ipoib_txq * txq)60 static void hfi1_ipoib_wake_txq(struct hfi1_ipoib_txq *txq)
61 {
62 	trace_hfi1_txq_wake(txq);
63 	if (atomic_dec_and_test(&txq->tx_ring.stops))
64 		netif_wake_subqueue(txq->priv->netdev, txq->q_idx);
65 }
66 
hfi1_ipoib_ring_hwat(struct hfi1_ipoib_txq * txq)67 static uint hfi1_ipoib_ring_hwat(struct hfi1_ipoib_txq *txq)
68 {
69 	return min_t(uint, txq->priv->netdev->tx_queue_len,
70 		     txq->tx_ring.max_items - 1);
71 }
72 
hfi1_ipoib_ring_lwat(struct hfi1_ipoib_txq * txq)73 static uint hfi1_ipoib_ring_lwat(struct hfi1_ipoib_txq *txq)
74 {
75 	return min_t(uint, txq->priv->netdev->tx_queue_len,
76 		     txq->tx_ring.max_items) >> 1;
77 }
78 
hfi1_ipoib_check_queue_depth(struct hfi1_ipoib_txq * txq)79 static void hfi1_ipoib_check_queue_depth(struct hfi1_ipoib_txq *txq)
80 {
81 	++txq->tx_ring.sent_txreqs;
82 	if (hfi1_ipoib_used(txq) >= hfi1_ipoib_ring_hwat(txq) &&
83 	    !atomic_xchg(&txq->tx_ring.ring_full, 1)) {
84 		trace_hfi1_txq_full(txq);
85 		hfi1_ipoib_stop_txq(txq);
86 	}
87 }
88 
hfi1_ipoib_check_queue_stopped(struct hfi1_ipoib_txq * txq)89 static void hfi1_ipoib_check_queue_stopped(struct hfi1_ipoib_txq *txq)
90 {
91 	struct net_device *dev = txq->priv->netdev;
92 
93 	/* If shutting down just return as queue state is irrelevant */
94 	if (unlikely(dev->reg_state != NETREG_REGISTERED))
95 		return;
96 
97 	/*
98 	 * When the queue has been drained to less than half full it will be
99 	 * restarted.
100 	 * The size of the txreq ring is fixed at initialization.
101 	 * The tx queue len can be adjusted upward while the interface is
102 	 * running.
103 	 * The tx queue len can be large enough to overflow the txreq_ring.
104 	 * Use the minimum of the current tx_queue_len or the rings max txreqs
105 	 * to protect against ring overflow.
106 	 */
107 	if (hfi1_ipoib_used(txq) < hfi1_ipoib_ring_lwat(txq) &&
108 	    atomic_xchg(&txq->tx_ring.ring_full, 0)) {
109 		trace_hfi1_txq_xmit_unstopped(txq);
110 		hfi1_ipoib_wake_txq(txq);
111 	}
112 }
113 
hfi1_ipoib_free_tx(struct ipoib_txreq * tx,int budget)114 static void hfi1_ipoib_free_tx(struct ipoib_txreq *tx, int budget)
115 {
116 	struct hfi1_ipoib_dev_priv *priv = tx->txq->priv;
117 
118 	if (likely(!tx->sdma_status)) {
119 		dev_sw_netstats_tx_add(priv->netdev, 1, tx->skb->len);
120 	} else {
121 		++priv->netdev->stats.tx_errors;
122 		dd_dev_warn(priv->dd,
123 			    "%s: Status = 0x%x pbc 0x%llx txq = %d sde = %d\n",
124 			    __func__, tx->sdma_status,
125 			    le64_to_cpu(tx->sdma_hdr->pbc), tx->txq->q_idx,
126 			    tx->txq->sde->this_idx);
127 	}
128 
129 	napi_consume_skb(tx->skb, budget);
130 	tx->skb = NULL;
131 	sdma_txclean(priv->dd, &tx->txreq);
132 }
133 
hfi1_ipoib_drain_tx_ring(struct hfi1_ipoib_txq * txq)134 static void hfi1_ipoib_drain_tx_ring(struct hfi1_ipoib_txq *txq)
135 {
136 	struct hfi1_ipoib_circ_buf *tx_ring = &txq->tx_ring;
137 	int i;
138 	struct ipoib_txreq *tx;
139 
140 	for (i = 0; i < tx_ring->max_items; i++) {
141 		tx = hfi1_txreq_from_idx(tx_ring, i);
142 		tx->complete = 0;
143 		dev_kfree_skb_any(tx->skb);
144 		tx->skb = NULL;
145 		sdma_txclean(txq->priv->dd, &tx->txreq);
146 	}
147 	tx_ring->head = 0;
148 	tx_ring->tail = 0;
149 	tx_ring->complete_txreqs = 0;
150 	tx_ring->sent_txreqs = 0;
151 	tx_ring->avail = hfi1_ipoib_ring_hwat(txq);
152 }
153 
hfi1_ipoib_poll_tx_ring(struct napi_struct * napi,int budget)154 static int hfi1_ipoib_poll_tx_ring(struct napi_struct *napi, int budget)
155 {
156 	struct hfi1_ipoib_txq *txq =
157 		container_of(napi, struct hfi1_ipoib_txq, napi);
158 	struct hfi1_ipoib_circ_buf *tx_ring = &txq->tx_ring;
159 	u32 head = tx_ring->head;
160 	u32 max_tx = tx_ring->max_items;
161 	int work_done;
162 	struct ipoib_txreq *tx =  hfi1_txreq_from_idx(tx_ring, head);
163 
164 	trace_hfi1_txq_poll(txq);
165 	for (work_done = 0; work_done < budget; work_done++) {
166 		/* See hfi1_ipoib_sdma_complete() */
167 		if (!smp_load_acquire(&tx->complete))
168 			break;
169 		tx->complete = 0;
170 		trace_hfi1_tx_produce(tx, head);
171 		hfi1_ipoib_free_tx(tx, budget);
172 		head = CIRC_NEXT(head, max_tx);
173 		tx =  hfi1_txreq_from_idx(tx_ring, head);
174 	}
175 	tx_ring->complete_txreqs += work_done;
176 
177 	/* Finished freeing tx items so store the head value. */
178 	smp_store_release(&tx_ring->head, head);
179 
180 	hfi1_ipoib_check_queue_stopped(txq);
181 
182 	if (work_done < budget)
183 		napi_complete_done(napi, work_done);
184 
185 	return work_done;
186 }
187 
hfi1_ipoib_sdma_complete(struct sdma_txreq * txreq,int status)188 static void hfi1_ipoib_sdma_complete(struct sdma_txreq *txreq, int status)
189 {
190 	struct ipoib_txreq *tx = container_of(txreq, struct ipoib_txreq, txreq);
191 
192 	trace_hfi1_txq_complete(tx->txq);
193 	tx->sdma_status = status;
194 	/* see hfi1_ipoib_poll_tx_ring */
195 	smp_store_release(&tx->complete, 1);
196 	napi_schedule_irqoff(&tx->txq->napi);
197 }
198 
hfi1_ipoib_build_ulp_payload(struct ipoib_txreq * tx,struct ipoib_txparms * txp)199 static int hfi1_ipoib_build_ulp_payload(struct ipoib_txreq *tx,
200 					struct ipoib_txparms *txp)
201 {
202 	struct hfi1_devdata *dd = txp->dd;
203 	struct sdma_txreq *txreq = &tx->txreq;
204 	struct sk_buff *skb = tx->skb;
205 	int ret = 0;
206 	int i;
207 
208 	if (skb_headlen(skb)) {
209 		ret = sdma_txadd_kvaddr(dd, txreq, skb->data, skb_headlen(skb));
210 		if (unlikely(ret))
211 			return ret;
212 	}
213 
214 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
215 		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
216 
217 		ret = sdma_txadd_page(dd,
218 				      txreq,
219 				      skb_frag_page(frag),
220 				      frag->bv_offset,
221 				      skb_frag_size(frag),
222 				      NULL, NULL, NULL);
223 		if (unlikely(ret))
224 			break;
225 	}
226 
227 	return ret;
228 }
229 
hfi1_ipoib_build_tx_desc(struct ipoib_txreq * tx,struct ipoib_txparms * txp)230 static int hfi1_ipoib_build_tx_desc(struct ipoib_txreq *tx,
231 				    struct ipoib_txparms *txp)
232 {
233 	struct hfi1_devdata *dd = txp->dd;
234 	struct sdma_txreq *txreq = &tx->txreq;
235 	struct hfi1_sdma_header *sdma_hdr = tx->sdma_hdr;
236 	u16 pkt_bytes =
237 		sizeof(sdma_hdr->pbc) + (txp->hdr_dwords << 2) + tx->skb->len;
238 	int ret;
239 
240 	ret = sdma_txinit(txreq, 0, pkt_bytes, hfi1_ipoib_sdma_complete);
241 	if (unlikely(ret))
242 		return ret;
243 
244 	/* add pbc + headers */
245 	ret = sdma_txadd_kvaddr(dd,
246 				txreq,
247 				sdma_hdr,
248 				sizeof(sdma_hdr->pbc) + (txp->hdr_dwords << 2));
249 	if (unlikely(ret))
250 		return ret;
251 
252 	/* add the ulp payload */
253 	return hfi1_ipoib_build_ulp_payload(tx, txp);
254 }
255 
hfi1_ipoib_build_ib_tx_headers(struct ipoib_txreq * tx,struct ipoib_txparms * txp)256 static void hfi1_ipoib_build_ib_tx_headers(struct ipoib_txreq *tx,
257 					   struct ipoib_txparms *txp)
258 {
259 	struct hfi1_ipoib_dev_priv *priv = tx->txq->priv;
260 	struct hfi1_sdma_header *sdma_hdr = tx->sdma_hdr;
261 	struct sk_buff *skb = tx->skb;
262 	struct hfi1_pportdata *ppd = ppd_from_ibp(txp->ibp);
263 	struct rdma_ah_attr *ah_attr = txp->ah_attr;
264 	struct ib_other_headers *ohdr;
265 	struct ib_grh *grh;
266 	u16 dwords;
267 	u16 slid;
268 	u16 dlid;
269 	u16 lrh0;
270 	u32 bth0;
271 	u32 sqpn = (u32)(priv->netdev->dev_addr[1] << 16 |
272 			 priv->netdev->dev_addr[2] << 8 |
273 			 priv->netdev->dev_addr[3]);
274 	u16 payload_dwords;
275 	u8 pad_cnt;
276 
277 	pad_cnt = -skb->len & 3;
278 
279 	/* Includes ICRC */
280 	payload_dwords = ((skb->len + pad_cnt) >> 2) + SIZE_OF_CRC;
281 
282 	/* header size in dwords LRH+BTH+DETH = (8+12+8)/4. */
283 	txp->hdr_dwords = 7;
284 
285 	if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
286 		grh = &sdma_hdr->hdr.ibh.u.l.grh;
287 		txp->hdr_dwords +=
288 			hfi1_make_grh(txp->ibp,
289 				      grh,
290 				      rdma_ah_read_grh(ah_attr),
291 				      txp->hdr_dwords - LRH_9B_DWORDS,
292 				      payload_dwords);
293 		lrh0 = HFI1_LRH_GRH;
294 		ohdr = &sdma_hdr->hdr.ibh.u.l.oth;
295 	} else {
296 		lrh0 = HFI1_LRH_BTH;
297 		ohdr = &sdma_hdr->hdr.ibh.u.oth;
298 	}
299 
300 	lrh0 |= (rdma_ah_get_sl(ah_attr) & 0xf) << 4;
301 	lrh0 |= (txp->flow.sc5 & 0xf) << 12;
302 
303 	dlid = opa_get_lid(rdma_ah_get_dlid(ah_attr), 9B);
304 	if (dlid == be16_to_cpu(IB_LID_PERMISSIVE)) {
305 		slid = be16_to_cpu(IB_LID_PERMISSIVE);
306 	} else {
307 		u16 lid = (u16)ppd->lid;
308 
309 		if (lid) {
310 			lid |= rdma_ah_get_path_bits(ah_attr) &
311 				((1 << ppd->lmc) - 1);
312 			slid = lid;
313 		} else {
314 			slid = be16_to_cpu(IB_LID_PERMISSIVE);
315 		}
316 	}
317 
318 	/* Includes ICRC */
319 	dwords = txp->hdr_dwords + payload_dwords;
320 
321 	/* Build the lrh */
322 	sdma_hdr->hdr.hdr_type = HFI1_PKT_TYPE_9B;
323 	hfi1_make_ib_hdr(&sdma_hdr->hdr.ibh, lrh0, dwords, dlid, slid);
324 
325 	/* Build the bth */
326 	bth0 = (IB_OPCODE_UD_SEND_ONLY << 24) | (pad_cnt << 20) | priv->pkey;
327 
328 	ohdr->bth[0] = cpu_to_be32(bth0);
329 	ohdr->bth[1] = cpu_to_be32(txp->dqpn);
330 	ohdr->bth[2] = cpu_to_be32(mask_psn((u32)txp->txq->tx_ring.sent_txreqs));
331 
332 	/* Build the deth */
333 	ohdr->u.ud.deth[0] = cpu_to_be32(priv->qkey);
334 	ohdr->u.ud.deth[1] = cpu_to_be32((txp->entropy <<
335 					  HFI1_IPOIB_ENTROPY_SHIFT) | sqpn);
336 
337 	/* Construct the pbc. */
338 	sdma_hdr->pbc =
339 		cpu_to_le64(create_pbc(ppd,
340 				       ib_is_sc5(txp->flow.sc5) <<
341 							      PBC_DC_INFO_SHIFT,
342 				       0,
343 				       sc_to_vlt(priv->dd, txp->flow.sc5),
344 				       dwords - SIZE_OF_CRC +
345 						(sizeof(sdma_hdr->pbc) >> 2)));
346 }
347 
hfi1_ipoib_send_dma_common(struct net_device * dev,struct sk_buff * skb,struct ipoib_txparms * txp)348 static struct ipoib_txreq *hfi1_ipoib_send_dma_common(struct net_device *dev,
349 						      struct sk_buff *skb,
350 						      struct ipoib_txparms *txp)
351 {
352 	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
353 	struct hfi1_ipoib_txq *txq = txp->txq;
354 	struct ipoib_txreq *tx;
355 	struct hfi1_ipoib_circ_buf *tx_ring = &txq->tx_ring;
356 	u32 tail = tx_ring->tail;
357 	int ret;
358 
359 	if (unlikely(!tx_ring->avail)) {
360 		u32 head;
361 
362 		if (hfi1_ipoib_used(txq) >= hfi1_ipoib_ring_hwat(txq))
363 			/* This shouldn't happen with a stopped queue */
364 			return ERR_PTR(-ENOMEM);
365 		/* See hfi1_ipoib_poll_tx_ring() */
366 		head = smp_load_acquire(&tx_ring->head);
367 		tx_ring->avail =
368 			min_t(u32, hfi1_ipoib_ring_hwat(txq),
369 			      CIRC_CNT(head, tail, tx_ring->max_items));
370 	} else {
371 		tx_ring->avail--;
372 	}
373 	tx = hfi1_txreq_from_idx(tx_ring, tail);
374 	trace_hfi1_txq_alloc_tx(txq);
375 
376 	/* so that we can test if the sdma descriptors are there */
377 	tx->txreq.num_desc = 0;
378 	tx->txq = txq;
379 	tx->skb = skb;
380 	INIT_LIST_HEAD(&tx->txreq.list);
381 
382 	hfi1_ipoib_build_ib_tx_headers(tx, txp);
383 
384 	ret = hfi1_ipoib_build_tx_desc(tx, txp);
385 	if (likely(!ret)) {
386 		if (txq->flow.as_int != txp->flow.as_int) {
387 			txq->flow.tx_queue = txp->flow.tx_queue;
388 			txq->flow.sc5 = txp->flow.sc5;
389 			txq->sde =
390 				sdma_select_engine_sc(priv->dd,
391 						      txp->flow.tx_queue,
392 						      txp->flow.sc5);
393 			trace_hfi1_flow_switch(txq);
394 		}
395 
396 		return tx;
397 	}
398 
399 	sdma_txclean(priv->dd, &tx->txreq);
400 
401 	return ERR_PTR(ret);
402 }
403 
hfi1_ipoib_submit_tx_list(struct net_device * dev,struct hfi1_ipoib_txq * txq)404 static int hfi1_ipoib_submit_tx_list(struct net_device *dev,
405 				     struct hfi1_ipoib_txq *txq)
406 {
407 	int ret;
408 	u16 count_out;
409 
410 	ret = sdma_send_txlist(txq->sde,
411 			       iowait_get_ib_work(&txq->wait),
412 			       &txq->tx_list,
413 			       &count_out);
414 	if (likely(!ret) || ret == -EBUSY || ret == -ECOMM)
415 		return ret;
416 
417 	dd_dev_warn(txq->priv->dd, "cannot send skb tx list, err %d.\n", ret);
418 
419 	return ret;
420 }
421 
hfi1_ipoib_flush_tx_list(struct net_device * dev,struct hfi1_ipoib_txq * txq)422 static int hfi1_ipoib_flush_tx_list(struct net_device *dev,
423 				    struct hfi1_ipoib_txq *txq)
424 {
425 	int ret = 0;
426 
427 	if (!list_empty(&txq->tx_list)) {
428 		/* Flush the current list */
429 		ret = hfi1_ipoib_submit_tx_list(dev, txq);
430 
431 		if (unlikely(ret))
432 			if (ret != -EBUSY)
433 				++dev->stats.tx_carrier_errors;
434 	}
435 
436 	return ret;
437 }
438 
hfi1_ipoib_submit_tx(struct hfi1_ipoib_txq * txq,struct ipoib_txreq * tx)439 static int hfi1_ipoib_submit_tx(struct hfi1_ipoib_txq *txq,
440 				struct ipoib_txreq *tx)
441 {
442 	int ret;
443 
444 	ret = sdma_send_txreq(txq->sde,
445 			      iowait_get_ib_work(&txq->wait),
446 			      &tx->txreq,
447 			      txq->pkts_sent);
448 	if (likely(!ret)) {
449 		txq->pkts_sent = true;
450 		iowait_starve_clear(txq->pkts_sent, &txq->wait);
451 	}
452 
453 	return ret;
454 }
455 
hfi1_ipoib_send_dma_single(struct net_device * dev,struct sk_buff * skb,struct ipoib_txparms * txp)456 static int hfi1_ipoib_send_dma_single(struct net_device *dev,
457 				      struct sk_buff *skb,
458 				      struct ipoib_txparms *txp)
459 {
460 	struct hfi1_ipoib_txq *txq = txp->txq;
461 	struct hfi1_ipoib_circ_buf *tx_ring;
462 	struct ipoib_txreq *tx;
463 	int ret;
464 
465 	tx = hfi1_ipoib_send_dma_common(dev, skb, txp);
466 	if (IS_ERR(tx)) {
467 		int ret = PTR_ERR(tx);
468 
469 		dev_kfree_skb_any(skb);
470 
471 		if (ret == -ENOMEM)
472 			++dev->stats.tx_errors;
473 		else
474 			++dev->stats.tx_carrier_errors;
475 
476 		return NETDEV_TX_OK;
477 	}
478 
479 	tx_ring = &txq->tx_ring;
480 	trace_hfi1_tx_consume(tx, tx_ring->tail);
481 	/* consume tx */
482 	smp_store_release(&tx_ring->tail, CIRC_NEXT(tx_ring->tail, tx_ring->max_items));
483 	ret = hfi1_ipoib_submit_tx(txq, tx);
484 	if (likely(!ret)) {
485 tx_ok:
486 		trace_sdma_output_ibhdr(txq->priv->dd,
487 					&tx->sdma_hdr->hdr,
488 					ib_is_sc5(txp->flow.sc5));
489 		hfi1_ipoib_check_queue_depth(txq);
490 		return NETDEV_TX_OK;
491 	}
492 
493 	txq->pkts_sent = false;
494 
495 	if (ret == -EBUSY || ret == -ECOMM)
496 		goto tx_ok;
497 
498 	/* mark complete and kick napi tx */
499 	smp_store_release(&tx->complete, 1);
500 	napi_schedule(&tx->txq->napi);
501 
502 	++dev->stats.tx_carrier_errors;
503 
504 	return NETDEV_TX_OK;
505 }
506 
hfi1_ipoib_send_dma_list(struct net_device * dev,struct sk_buff * skb,struct ipoib_txparms * txp)507 static int hfi1_ipoib_send_dma_list(struct net_device *dev,
508 				    struct sk_buff *skb,
509 				    struct ipoib_txparms *txp)
510 {
511 	struct hfi1_ipoib_txq *txq = txp->txq;
512 	struct hfi1_ipoib_circ_buf *tx_ring;
513 	struct ipoib_txreq *tx;
514 
515 	/* Has the flow change ? */
516 	if (txq->flow.as_int != txp->flow.as_int) {
517 		int ret;
518 
519 		trace_hfi1_flow_flush(txq);
520 		ret = hfi1_ipoib_flush_tx_list(dev, txq);
521 		if (unlikely(ret)) {
522 			if (ret == -EBUSY)
523 				++dev->stats.tx_dropped;
524 			dev_kfree_skb_any(skb);
525 			return NETDEV_TX_OK;
526 		}
527 	}
528 	tx = hfi1_ipoib_send_dma_common(dev, skb, txp);
529 	if (IS_ERR(tx)) {
530 		int ret = PTR_ERR(tx);
531 
532 		dev_kfree_skb_any(skb);
533 
534 		if (ret == -ENOMEM)
535 			++dev->stats.tx_errors;
536 		else
537 			++dev->stats.tx_carrier_errors;
538 
539 		return NETDEV_TX_OK;
540 	}
541 
542 	tx_ring = &txq->tx_ring;
543 	trace_hfi1_tx_consume(tx, tx_ring->tail);
544 	/* consume tx */
545 	smp_store_release(&tx_ring->tail, CIRC_NEXT(tx_ring->tail, tx_ring->max_items));
546 	list_add_tail(&tx->txreq.list, &txq->tx_list);
547 
548 	hfi1_ipoib_check_queue_depth(txq);
549 
550 	trace_sdma_output_ibhdr(txq->priv->dd,
551 				&tx->sdma_hdr->hdr,
552 				ib_is_sc5(txp->flow.sc5));
553 
554 	if (!netdev_xmit_more())
555 		(void)hfi1_ipoib_flush_tx_list(dev, txq);
556 
557 	return NETDEV_TX_OK;
558 }
559 
hfi1_ipoib_calc_entropy(struct sk_buff * skb)560 static u8 hfi1_ipoib_calc_entropy(struct sk_buff *skb)
561 {
562 	if (skb_transport_header_was_set(skb)) {
563 		u8 *hdr = (u8 *)skb_transport_header(skb);
564 
565 		return (hdr[0] ^ hdr[1] ^ hdr[2] ^ hdr[3]);
566 	}
567 
568 	return (u8)skb_get_queue_mapping(skb);
569 }
570 
hfi1_ipoib_send(struct net_device * dev,struct sk_buff * skb,struct ib_ah * address,u32 dqpn)571 int hfi1_ipoib_send(struct net_device *dev,
572 		    struct sk_buff *skb,
573 		    struct ib_ah *address,
574 		    u32 dqpn)
575 {
576 	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
577 	struct ipoib_txparms txp;
578 	struct rdma_netdev *rn = netdev_priv(dev);
579 
580 	if (unlikely(skb->len > rn->mtu + HFI1_IPOIB_ENCAP_LEN)) {
581 		dd_dev_warn(priv->dd, "packet len %d (> %d) too long to send, dropping\n",
582 			    skb->len,
583 			    rn->mtu + HFI1_IPOIB_ENCAP_LEN);
584 		++dev->stats.tx_dropped;
585 		++dev->stats.tx_errors;
586 		dev_kfree_skb_any(skb);
587 		return NETDEV_TX_OK;
588 	}
589 
590 	txp.dd = priv->dd;
591 	txp.ah_attr = &ibah_to_rvtah(address)->attr;
592 	txp.ibp = to_iport(priv->device, priv->port_num);
593 	txp.txq = &priv->txqs[skb_get_queue_mapping(skb)];
594 	txp.dqpn = dqpn;
595 	txp.flow.sc5 = txp.ibp->sl_to_sc[rdma_ah_get_sl(txp.ah_attr)];
596 	txp.flow.tx_queue = (u8)skb_get_queue_mapping(skb);
597 	txp.entropy = hfi1_ipoib_calc_entropy(skb);
598 
599 	if (netdev_xmit_more() || !list_empty(&txp.txq->tx_list))
600 		return hfi1_ipoib_send_dma_list(dev, skb, &txp);
601 
602 	return hfi1_ipoib_send_dma_single(dev, skb,  &txp);
603 }
604 
605 /*
606  * hfi1_ipoib_sdma_sleep - ipoib sdma sleep function
607  *
608  * This function gets called from sdma_send_txreq() when there are not enough
609  * sdma descriptors available to send the packet. It adds Tx queue's wait
610  * structure to sdma engine's dmawait list to be woken up when descriptors
611  * become available.
612  */
hfi1_ipoib_sdma_sleep(struct sdma_engine * sde,struct iowait_work * wait,struct sdma_txreq * txreq,uint seq,bool pkts_sent)613 static int hfi1_ipoib_sdma_sleep(struct sdma_engine *sde,
614 				 struct iowait_work *wait,
615 				 struct sdma_txreq *txreq,
616 				 uint seq,
617 				 bool pkts_sent)
618 {
619 	struct hfi1_ipoib_txq *txq =
620 		container_of(wait->iow, struct hfi1_ipoib_txq, wait);
621 
622 	write_seqlock(&sde->waitlock);
623 
624 	if (likely(txq->priv->netdev->reg_state == NETREG_REGISTERED)) {
625 		if (sdma_progress(sde, seq, txreq)) {
626 			write_sequnlock(&sde->waitlock);
627 			return -EAGAIN;
628 		}
629 
630 		if (list_empty(&txreq->list))
631 			/* came from non-list submit */
632 			list_add_tail(&txreq->list, &txq->tx_list);
633 		if (list_empty(&txq->wait.list)) {
634 			struct hfi1_ibport *ibp = &sde->ppd->ibport_data;
635 
636 			if (!atomic_xchg(&txq->tx_ring.no_desc, 1)) {
637 				trace_hfi1_txq_queued(txq);
638 				hfi1_ipoib_stop_txq(txq);
639 			}
640 			ibp->rvp.n_dmawait++;
641 			iowait_queue(pkts_sent, wait->iow, &sde->dmawait);
642 		}
643 
644 		write_sequnlock(&sde->waitlock);
645 		return -EBUSY;
646 	}
647 
648 	write_sequnlock(&sde->waitlock);
649 	return -EINVAL;
650 }
651 
652 /*
653  * hfi1_ipoib_sdma_wakeup - ipoib sdma wakeup function
654  *
655  * This function gets called when SDMA descriptors becomes available and Tx
656  * queue's wait structure was previously added to sdma engine's dmawait list.
657  */
hfi1_ipoib_sdma_wakeup(struct iowait * wait,int reason)658 static void hfi1_ipoib_sdma_wakeup(struct iowait *wait, int reason)
659 {
660 	struct hfi1_ipoib_txq *txq =
661 		container_of(wait, struct hfi1_ipoib_txq, wait);
662 
663 	trace_hfi1_txq_wakeup(txq);
664 	if (likely(txq->priv->netdev->reg_state == NETREG_REGISTERED))
665 		iowait_schedule(wait, system_highpri_wq, WORK_CPU_UNBOUND);
666 }
667 
hfi1_ipoib_flush_txq(struct work_struct * work)668 static void hfi1_ipoib_flush_txq(struct work_struct *work)
669 {
670 	struct iowait_work *ioww =
671 		container_of(work, struct iowait_work, iowork);
672 	struct iowait *wait = iowait_ioww_to_iow(ioww);
673 	struct hfi1_ipoib_txq *txq =
674 		container_of(wait, struct hfi1_ipoib_txq, wait);
675 	struct net_device *dev = txq->priv->netdev;
676 
677 	if (likely(dev->reg_state == NETREG_REGISTERED) &&
678 	    likely(!hfi1_ipoib_flush_tx_list(dev, txq)))
679 		if (atomic_xchg(&txq->tx_ring.no_desc, 0))
680 			hfi1_ipoib_wake_txq(txq);
681 }
682 
hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv * priv)683 int hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv *priv)
684 {
685 	struct net_device *dev = priv->netdev;
686 	u32 tx_ring_size, tx_item_size;
687 	struct hfi1_ipoib_circ_buf *tx_ring;
688 	int i, j;
689 
690 	/*
691 	 * Ring holds 1 less than tx_ring_size
692 	 * Round up to next power of 2 in order to hold at least tx_queue_len
693 	 */
694 	tx_ring_size = roundup_pow_of_two(dev->tx_queue_len + 1);
695 	tx_item_size = roundup_pow_of_two(sizeof(struct ipoib_txreq));
696 
697 	priv->txqs = kcalloc_node(dev->num_tx_queues,
698 				  sizeof(struct hfi1_ipoib_txq),
699 				  GFP_KERNEL,
700 				  priv->dd->node);
701 	if (!priv->txqs)
702 		return -ENOMEM;
703 
704 	for (i = 0; i < dev->num_tx_queues; i++) {
705 		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
706 		struct ipoib_txreq *tx;
707 
708 		tx_ring = &txq->tx_ring;
709 		iowait_init(&txq->wait,
710 			    0,
711 			    hfi1_ipoib_flush_txq,
712 			    NULL,
713 			    hfi1_ipoib_sdma_sleep,
714 			    hfi1_ipoib_sdma_wakeup,
715 			    NULL,
716 			    NULL);
717 		txq->priv = priv;
718 		txq->sde = NULL;
719 		INIT_LIST_HEAD(&txq->tx_list);
720 		atomic_set(&txq->tx_ring.stops, 0);
721 		atomic_set(&txq->tx_ring.ring_full, 0);
722 		atomic_set(&txq->tx_ring.no_desc, 0);
723 		txq->q_idx = i;
724 		txq->flow.tx_queue = 0xff;
725 		txq->flow.sc5 = 0xff;
726 		txq->pkts_sent = false;
727 
728 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
729 					     priv->dd->node);
730 
731 		txq->tx_ring.items =
732 			kvzalloc_node(array_size(tx_ring_size, tx_item_size),
733 				      GFP_KERNEL, priv->dd->node);
734 		if (!txq->tx_ring.items)
735 			goto free_txqs;
736 
737 		txq->tx_ring.max_items = tx_ring_size;
738 		txq->tx_ring.shift = ilog2(tx_item_size);
739 		txq->tx_ring.avail = hfi1_ipoib_ring_hwat(txq);
740 		tx_ring = &txq->tx_ring;
741 		for (j = 0; j < tx_ring_size; j++) {
742 			hfi1_txreq_from_idx(tx_ring, j)->sdma_hdr =
743 				kzalloc_node(sizeof(*tx->sdma_hdr),
744 					     GFP_KERNEL, priv->dd->node);
745 			if (!hfi1_txreq_from_idx(tx_ring, j)->sdma_hdr)
746 				goto free_txqs;
747 		}
748 
749 		netif_napi_add_tx(dev, &txq->napi, hfi1_ipoib_poll_tx_ring);
750 	}
751 
752 	return 0;
753 
754 free_txqs:
755 	for (i--; i >= 0; i--) {
756 		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
757 
758 		netif_napi_del(&txq->napi);
759 		tx_ring = &txq->tx_ring;
760 		for (j = 0; j < tx_ring_size; j++)
761 			kfree(hfi1_txreq_from_idx(tx_ring, j)->sdma_hdr);
762 		kvfree(tx_ring->items);
763 	}
764 
765 	kfree(priv->txqs);
766 	priv->txqs = NULL;
767 	return -ENOMEM;
768 }
769 
hfi1_ipoib_drain_tx_list(struct hfi1_ipoib_txq * txq)770 static void hfi1_ipoib_drain_tx_list(struct hfi1_ipoib_txq *txq)
771 {
772 	struct sdma_txreq *txreq;
773 	struct sdma_txreq *txreq_tmp;
774 
775 	list_for_each_entry_safe(txreq, txreq_tmp, &txq->tx_list, list) {
776 		struct ipoib_txreq *tx =
777 			container_of(txreq, struct ipoib_txreq, txreq);
778 
779 		list_del(&txreq->list);
780 		sdma_txclean(txq->priv->dd, &tx->txreq);
781 		dev_kfree_skb_any(tx->skb);
782 		tx->skb = NULL;
783 		txq->tx_ring.complete_txreqs++;
784 	}
785 
786 	if (hfi1_ipoib_used(txq))
787 		dd_dev_warn(txq->priv->dd,
788 			    "txq %d not empty found %u requests\n",
789 			    txq->q_idx,
790 			    hfi1_ipoib_txreqs(txq->tx_ring.sent_txreqs,
791 					      txq->tx_ring.complete_txreqs));
792 }
793 
hfi1_ipoib_txreq_deinit(struct hfi1_ipoib_dev_priv * priv)794 void hfi1_ipoib_txreq_deinit(struct hfi1_ipoib_dev_priv *priv)
795 {
796 	int i, j;
797 
798 	for (i = 0; i < priv->netdev->num_tx_queues; i++) {
799 		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
800 		struct hfi1_ipoib_circ_buf *tx_ring = &txq->tx_ring;
801 
802 		iowait_cancel_work(&txq->wait);
803 		iowait_sdma_drain(&txq->wait);
804 		hfi1_ipoib_drain_tx_list(txq);
805 		netif_napi_del(&txq->napi);
806 		hfi1_ipoib_drain_tx_ring(txq);
807 		for (j = 0; j < tx_ring->max_items; j++)
808 			kfree(hfi1_txreq_from_idx(tx_ring, j)->sdma_hdr);
809 		kvfree(tx_ring->items);
810 	}
811 
812 	kfree(priv->txqs);
813 	priv->txqs = NULL;
814 }
815 
hfi1_ipoib_napi_tx_enable(struct net_device * dev)816 void hfi1_ipoib_napi_tx_enable(struct net_device *dev)
817 {
818 	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
819 	int i;
820 
821 	for (i = 0; i < dev->num_tx_queues; i++) {
822 		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
823 
824 		napi_enable(&txq->napi);
825 	}
826 }
827 
hfi1_ipoib_napi_tx_disable(struct net_device * dev)828 void hfi1_ipoib_napi_tx_disable(struct net_device *dev)
829 {
830 	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
831 	int i;
832 
833 	for (i = 0; i < dev->num_tx_queues; i++) {
834 		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
835 
836 		napi_disable(&txq->napi);
837 		hfi1_ipoib_drain_tx_ring(txq);
838 	}
839 }
840 
hfi1_ipoib_tx_timeout(struct net_device * dev,unsigned int q)841 void hfi1_ipoib_tx_timeout(struct net_device *dev, unsigned int q)
842 {
843 	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
844 	struct hfi1_ipoib_txq *txq = &priv->txqs[q];
845 
846 	dd_dev_info(priv->dd, "timeout txq %p q %u stopped %u stops %d no_desc %d ring_full %d\n",
847 		    txq, q,
848 		    __netif_subqueue_stopped(dev, txq->q_idx),
849 		    atomic_read(&txq->tx_ring.stops),
850 		    atomic_read(&txq->tx_ring.no_desc),
851 		    atomic_read(&txq->tx_ring.ring_full));
852 	dd_dev_info(priv->dd, "sde %p engine %u\n",
853 		    txq->sde,
854 		    txq->sde ? txq->sde->this_idx : 0);
855 	dd_dev_info(priv->dd, "flow %x\n", txq->flow.as_int);
856 	dd_dev_info(priv->dd, "sent %llu completed %llu used %llu\n",
857 		    txq->tx_ring.sent_txreqs, txq->tx_ring.complete_txreqs,
858 		    hfi1_ipoib_used(txq));
859 	dd_dev_info(priv->dd, "tx_queue_len %u max_items %u\n",
860 		    dev->tx_queue_len, txq->tx_ring.max_items);
861 	dd_dev_info(priv->dd, "head %u tail %u\n",
862 		    txq->tx_ring.head, txq->tx_ring.tail);
863 	dd_dev_info(priv->dd, "wait queued %u\n",
864 		    !list_empty(&txq->wait.list));
865 	dd_dev_info(priv->dd, "tx_list empty %u\n",
866 		    list_empty(&txq->tx_list));
867 }
868 
869