1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2018 Intel Corporation. */
3 
4 #include <linux/bpf_trace.h>
5 #include <linux/stringify.h>
6 #include <net/xdp_sock_drv.h>
7 #include <net/xdp.h>
8 
9 #include "i40e.h"
10 #include "i40e_txrx_common.h"
11 #include "i40e_xsk.h"
12 
i40e_clear_rx_bi_zc(struct i40e_ring * rx_ring)13 void i40e_clear_rx_bi_zc(struct i40e_ring *rx_ring)
14 {
15 	memset(rx_ring->rx_bi_zc, 0,
16 	       sizeof(*rx_ring->rx_bi_zc) * rx_ring->count);
17 }
18 
i40e_rx_bi(struct i40e_ring * rx_ring,u32 idx)19 static struct xdp_buff **i40e_rx_bi(struct i40e_ring *rx_ring, u32 idx)
20 {
21 	return &rx_ring->rx_bi_zc[idx];
22 }
23 
24 /**
25  * i40e_realloc_rx_xdp_bi - reallocate SW ring for either XSK or normal buffer
26  * @rx_ring: Current rx ring
27  * @pool_present: is pool for XSK present
28  *
29  * Try allocating memory and return ENOMEM, if failed to allocate.
30  * If allocation was successful, substitute buffer with allocated one.
31  * Returns 0 on success, negative on failure
32  */
i40e_realloc_rx_xdp_bi(struct i40e_ring * rx_ring,bool pool_present)33 static int i40e_realloc_rx_xdp_bi(struct i40e_ring *rx_ring, bool pool_present)
34 {
35 	size_t elem_size = pool_present ? sizeof(*rx_ring->rx_bi_zc) :
36 					  sizeof(*rx_ring->rx_bi);
37 	void *sw_ring = kcalloc(rx_ring->count, elem_size, GFP_KERNEL);
38 
39 	if (!sw_ring)
40 		return -ENOMEM;
41 
42 	if (pool_present) {
43 		kfree(rx_ring->rx_bi);
44 		rx_ring->rx_bi = NULL;
45 		rx_ring->rx_bi_zc = sw_ring;
46 	} else {
47 		kfree(rx_ring->rx_bi_zc);
48 		rx_ring->rx_bi_zc = NULL;
49 		rx_ring->rx_bi = sw_ring;
50 	}
51 	return 0;
52 }
53 
54 /**
55  * i40e_realloc_rx_bi_zc - reallocate rx SW rings
56  * @vsi: Current VSI
57  * @zc: is zero copy set
58  *
59  * Reallocate buffer for rx_rings that might be used by XSK.
60  * XDP requires more memory, than rx_buf provides.
61  * Returns 0 on success, negative on failure
62  */
i40e_realloc_rx_bi_zc(struct i40e_vsi * vsi,bool zc)63 int i40e_realloc_rx_bi_zc(struct i40e_vsi *vsi, bool zc)
64 {
65 	struct i40e_ring *rx_ring;
66 	unsigned long q;
67 
68 	for_each_set_bit(q, vsi->af_xdp_zc_qps, vsi->alloc_queue_pairs) {
69 		rx_ring = vsi->rx_rings[q];
70 		if (i40e_realloc_rx_xdp_bi(rx_ring, zc))
71 			return -ENOMEM;
72 	}
73 	return 0;
74 }
75 
76 /**
77  * i40e_xsk_pool_enable - Enable/associate an AF_XDP buffer pool to a
78  * certain ring/qid
79  * @vsi: Current VSI
80  * @pool: buffer pool
81  * @qid: Rx ring to associate buffer pool with
82  *
83  * Returns 0 on success, <0 on failure
84  **/
i40e_xsk_pool_enable(struct i40e_vsi * vsi,struct xsk_buff_pool * pool,u16 qid)85 static int i40e_xsk_pool_enable(struct i40e_vsi *vsi,
86 				struct xsk_buff_pool *pool,
87 				u16 qid)
88 {
89 	struct net_device *netdev = vsi->netdev;
90 	bool if_running;
91 	int err;
92 
93 	if (vsi->type != I40E_VSI_MAIN)
94 		return -EINVAL;
95 
96 	if (qid >= vsi->num_queue_pairs)
97 		return -EINVAL;
98 
99 	if (qid >= netdev->real_num_rx_queues ||
100 	    qid >= netdev->real_num_tx_queues)
101 		return -EINVAL;
102 
103 	err = xsk_pool_dma_map(pool, &vsi->back->pdev->dev, I40E_RX_DMA_ATTR);
104 	if (err)
105 		return err;
106 
107 	set_bit(qid, vsi->af_xdp_zc_qps);
108 
109 	if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
110 
111 	if (if_running) {
112 		err = i40e_queue_pair_disable(vsi, qid);
113 		if (err)
114 			return err;
115 
116 		err = i40e_realloc_rx_xdp_bi(vsi->rx_rings[qid], true);
117 		if (err)
118 			return err;
119 
120 		err = i40e_queue_pair_enable(vsi, qid);
121 		if (err)
122 			return err;
123 
124 		/* Kick start the NAPI context so that receiving will start */
125 		err = i40e_xsk_wakeup(vsi->netdev, qid, XDP_WAKEUP_RX);
126 		if (err)
127 			return err;
128 	}
129 
130 	return 0;
131 }
132 
133 /**
134  * i40e_xsk_pool_disable - Disassociate an AF_XDP buffer pool from a
135  * certain ring/qid
136  * @vsi: Current VSI
137  * @qid: Rx ring to associate buffer pool with
138  *
139  * Returns 0 on success, <0 on failure
140  **/
i40e_xsk_pool_disable(struct i40e_vsi * vsi,u16 qid)141 static int i40e_xsk_pool_disable(struct i40e_vsi *vsi, u16 qid)
142 {
143 	struct net_device *netdev = vsi->netdev;
144 	struct xsk_buff_pool *pool;
145 	bool if_running;
146 	int err;
147 
148 	pool = xsk_get_pool_from_qid(netdev, qid);
149 	if (!pool)
150 		return -EINVAL;
151 
152 	if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
153 
154 	if (if_running) {
155 		err = i40e_queue_pair_disable(vsi, qid);
156 		if (err)
157 			return err;
158 	}
159 
160 	clear_bit(qid, vsi->af_xdp_zc_qps);
161 	xsk_pool_dma_unmap(pool, I40E_RX_DMA_ATTR);
162 
163 	if (if_running) {
164 		err = i40e_realloc_rx_xdp_bi(vsi->rx_rings[qid], false);
165 		if (err)
166 			return err;
167 		err = i40e_queue_pair_enable(vsi, qid);
168 		if (err)
169 			return err;
170 	}
171 
172 	return 0;
173 }
174 
175 /**
176  * i40e_xsk_pool_setup - Enable/disassociate an AF_XDP buffer pool to/from
177  * a ring/qid
178  * @vsi: Current VSI
179  * @pool: Buffer pool to enable/associate to a ring, or NULL to disable
180  * @qid: Rx ring to (dis)associate buffer pool (from)to
181  *
182  * This function enables or disables a buffer pool to a certain ring.
183  *
184  * Returns 0 on success, <0 on failure
185  **/
i40e_xsk_pool_setup(struct i40e_vsi * vsi,struct xsk_buff_pool * pool,u16 qid)186 int i40e_xsk_pool_setup(struct i40e_vsi *vsi, struct xsk_buff_pool *pool,
187 			u16 qid)
188 {
189 	return pool ? i40e_xsk_pool_enable(vsi, pool, qid) :
190 		i40e_xsk_pool_disable(vsi, qid);
191 }
192 
193 /**
194  * i40e_run_xdp_zc - Executes an XDP program on an xdp_buff
195  * @rx_ring: Rx ring
196  * @xdp: xdp_buff used as input to the XDP program
197  * @xdp_prog: XDP program to run
198  *
199  * Returns any of I40E_XDP_{PASS, CONSUMED, TX, REDIR}
200  **/
i40e_run_xdp_zc(struct i40e_ring * rx_ring,struct xdp_buff * xdp,struct bpf_prog * xdp_prog)201 static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp,
202 			   struct bpf_prog *xdp_prog)
203 {
204 	int err, result = I40E_XDP_PASS;
205 	struct i40e_ring *xdp_ring;
206 	u32 act;
207 
208 	act = bpf_prog_run_xdp(xdp_prog, xdp);
209 
210 	if (likely(act == XDP_REDIRECT)) {
211 		err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
212 		if (!err)
213 			return I40E_XDP_REDIR;
214 		if (xsk_uses_need_wakeup(rx_ring->xsk_pool) && err == -ENOBUFS)
215 			result = I40E_XDP_EXIT;
216 		else
217 			result = I40E_XDP_CONSUMED;
218 		goto out_failure;
219 	}
220 
221 	switch (act) {
222 	case XDP_PASS:
223 		break;
224 	case XDP_TX:
225 		xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
226 		result = i40e_xmit_xdp_tx_ring(xdp, xdp_ring);
227 		if (result == I40E_XDP_CONSUMED)
228 			goto out_failure;
229 		break;
230 	case XDP_DROP:
231 		result = I40E_XDP_CONSUMED;
232 		break;
233 	default:
234 		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
235 		fallthrough;
236 	case XDP_ABORTED:
237 		result = I40E_XDP_CONSUMED;
238 out_failure:
239 		trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
240 	}
241 	return result;
242 }
243 
i40e_alloc_rx_buffers_zc(struct i40e_ring * rx_ring,u16 count)244 bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
245 {
246 	u16 ntu = rx_ring->next_to_use;
247 	union i40e_rx_desc *rx_desc;
248 	struct xdp_buff **xdp;
249 	u32 nb_buffs, i;
250 	dma_addr_t dma;
251 
252 	rx_desc = I40E_RX_DESC(rx_ring, ntu);
253 	xdp = i40e_rx_bi(rx_ring, ntu);
254 
255 	nb_buffs = min_t(u16, count, rx_ring->count - ntu);
256 	nb_buffs = xsk_buff_alloc_batch(rx_ring->xsk_pool, xdp, nb_buffs);
257 	if (!nb_buffs)
258 		return false;
259 
260 	i = nb_buffs;
261 	while (i--) {
262 		dma = xsk_buff_xdp_get_dma(*xdp);
263 		rx_desc->read.pkt_addr = cpu_to_le64(dma);
264 		rx_desc->read.hdr_addr = 0;
265 
266 		rx_desc++;
267 		xdp++;
268 	}
269 
270 	ntu += nb_buffs;
271 	if (ntu == rx_ring->count) {
272 		rx_desc = I40E_RX_DESC(rx_ring, 0);
273 		ntu = 0;
274 	}
275 
276 	/* clear the status bits for the next_to_use descriptor */
277 	rx_desc->wb.qword1.status_error_len = 0;
278 	i40e_release_rx_desc(rx_ring, ntu);
279 
280 	return count == nb_buffs;
281 }
282 
283 /**
284  * i40e_construct_skb_zc - Create skbuff from zero-copy Rx buffer
285  * @rx_ring: Rx ring
286  * @xdp: xdp_buff
287  *
288  * This functions allocates a new skb from a zero-copy Rx buffer.
289  *
290  * Returns the skb, or NULL on failure.
291  **/
i40e_construct_skb_zc(struct i40e_ring * rx_ring,struct xdp_buff * xdp)292 static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
293 					     struct xdp_buff *xdp)
294 {
295 	unsigned int totalsize = xdp->data_end - xdp->data_meta;
296 	unsigned int metasize = xdp->data - xdp->data_meta;
297 	struct sk_buff *skb;
298 
299 	net_prefetch(xdp->data_meta);
300 
301 	/* allocate a skb to store the frags */
302 	skb = __napi_alloc_skb(&rx_ring->q_vector->napi, totalsize,
303 			       GFP_ATOMIC | __GFP_NOWARN);
304 	if (unlikely(!skb))
305 		goto out;
306 
307 	memcpy(__skb_put(skb, totalsize), xdp->data_meta,
308 	       ALIGN(totalsize, sizeof(long)));
309 
310 	if (metasize) {
311 		skb_metadata_set(skb, metasize);
312 		__skb_pull(skb, metasize);
313 	}
314 
315 out:
316 	xsk_buff_free(xdp);
317 	return skb;
318 }
319 
i40e_handle_xdp_result_zc(struct i40e_ring * rx_ring,struct xdp_buff * xdp_buff,union i40e_rx_desc * rx_desc,unsigned int * rx_packets,unsigned int * rx_bytes,unsigned int size,unsigned int xdp_res,bool * failure)320 static void i40e_handle_xdp_result_zc(struct i40e_ring *rx_ring,
321 				      struct xdp_buff *xdp_buff,
322 				      union i40e_rx_desc *rx_desc,
323 				      unsigned int *rx_packets,
324 				      unsigned int *rx_bytes,
325 				      unsigned int size,
326 				      unsigned int xdp_res,
327 				      bool *failure)
328 {
329 	struct sk_buff *skb;
330 
331 	*rx_packets = 1;
332 	*rx_bytes = size;
333 
334 	if (likely(xdp_res == I40E_XDP_REDIR) || xdp_res == I40E_XDP_TX)
335 		return;
336 
337 	if (xdp_res == I40E_XDP_EXIT) {
338 		*failure = true;
339 		return;
340 	}
341 
342 	if (xdp_res == I40E_XDP_CONSUMED) {
343 		xsk_buff_free(xdp_buff);
344 		return;
345 	}
346 	if (xdp_res == I40E_XDP_PASS) {
347 		/* NB! We are not checking for errors using
348 		 * i40e_test_staterr with
349 		 * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that
350 		 * SBP is *not* set in PRT_SBPVSI (default not set).
351 		 */
352 		skb = i40e_construct_skb_zc(rx_ring, xdp_buff);
353 		if (!skb) {
354 			rx_ring->rx_stats.alloc_buff_failed++;
355 			*rx_packets = 0;
356 			*rx_bytes = 0;
357 			return;
358 		}
359 
360 		if (eth_skb_pad(skb)) {
361 			*rx_packets = 0;
362 			*rx_bytes = 0;
363 			return;
364 		}
365 
366 		*rx_bytes = skb->len;
367 		i40e_process_skb_fields(rx_ring, rx_desc, skb);
368 		napi_gro_receive(&rx_ring->q_vector->napi, skb);
369 		return;
370 	}
371 
372 	/* Should never get here, as all valid cases have been handled already.
373 	 */
374 	WARN_ON_ONCE(1);
375 }
376 
377 /**
378  * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
379  * @rx_ring: Rx ring
380  * @budget: NAPI budget
381  *
382  * Returns amount of work completed
383  **/
i40e_clean_rx_irq_zc(struct i40e_ring * rx_ring,int budget)384 int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
385 {
386 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
387 	u16 next_to_clean = rx_ring->next_to_clean;
388 	u16 count_mask = rx_ring->count - 1;
389 	unsigned int xdp_res, xdp_xmit = 0;
390 	struct bpf_prog *xdp_prog;
391 	bool failure = false;
392 	u16 cleaned_count;
393 
394 	/* NB! xdp_prog will always be !NULL, due to the fact that
395 	 * this path is enabled by setting an XDP program.
396 	 */
397 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
398 
399 	while (likely(total_rx_packets < (unsigned int)budget)) {
400 		union i40e_rx_desc *rx_desc;
401 		unsigned int rx_packets;
402 		unsigned int rx_bytes;
403 		struct xdp_buff *bi;
404 		unsigned int size;
405 		u64 qword;
406 
407 		rx_desc = I40E_RX_DESC(rx_ring, next_to_clean);
408 		qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
409 
410 		/* This memory barrier is needed to keep us from reading
411 		 * any other fields out of the rx_desc until we have
412 		 * verified the descriptor has been written back.
413 		 */
414 		dma_rmb();
415 
416 		if (i40e_rx_is_programming_status(qword)) {
417 			i40e_clean_programming_status(rx_ring,
418 						      rx_desc->raw.qword[0],
419 						      qword);
420 			bi = *i40e_rx_bi(rx_ring, next_to_clean);
421 			xsk_buff_free(bi);
422 			next_to_clean = (next_to_clean + 1) & count_mask;
423 			continue;
424 		}
425 
426 		size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
427 		       I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
428 		if (!size)
429 			break;
430 
431 		bi = *i40e_rx_bi(rx_ring, next_to_clean);
432 		xsk_buff_set_size(bi, size);
433 		xsk_buff_dma_sync_for_cpu(bi, rx_ring->xsk_pool);
434 
435 		xdp_res = i40e_run_xdp_zc(rx_ring, bi, xdp_prog);
436 		i40e_handle_xdp_result_zc(rx_ring, bi, rx_desc, &rx_packets,
437 					  &rx_bytes, size, xdp_res, &failure);
438 		if (failure)
439 			break;
440 		total_rx_packets += rx_packets;
441 		total_rx_bytes += rx_bytes;
442 		xdp_xmit |= xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR);
443 		next_to_clean = (next_to_clean + 1) & count_mask;
444 	}
445 
446 	rx_ring->next_to_clean = next_to_clean;
447 	cleaned_count = (next_to_clean - rx_ring->next_to_use - 1) & count_mask;
448 
449 	if (cleaned_count >= I40E_RX_BUFFER_WRITE)
450 		failure |= !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count);
451 
452 	i40e_finalize_xdp_rx(rx_ring, xdp_xmit);
453 	i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets);
454 
455 	if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
456 		if (failure || next_to_clean == rx_ring->next_to_use)
457 			xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
458 		else
459 			xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
460 
461 		return (int)total_rx_packets;
462 	}
463 	return failure ? budget : (int)total_rx_packets;
464 }
465 
i40e_xmit_pkt(struct i40e_ring * xdp_ring,struct xdp_desc * desc,unsigned int * total_bytes)466 static void i40e_xmit_pkt(struct i40e_ring *xdp_ring, struct xdp_desc *desc,
467 			  unsigned int *total_bytes)
468 {
469 	struct i40e_tx_desc *tx_desc;
470 	dma_addr_t dma;
471 
472 	dma = xsk_buff_raw_get_dma(xdp_ring->xsk_pool, desc->addr);
473 	xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma, desc->len);
474 
475 	tx_desc = I40E_TX_DESC(xdp_ring, xdp_ring->next_to_use++);
476 	tx_desc->buffer_addr = cpu_to_le64(dma);
477 	tx_desc->cmd_type_offset_bsz = build_ctob(I40E_TX_DESC_CMD_ICRC | I40E_TX_DESC_CMD_EOP,
478 						  0, desc->len, 0);
479 
480 	*total_bytes += desc->len;
481 }
482 
i40e_xmit_pkt_batch(struct i40e_ring * xdp_ring,struct xdp_desc * desc,unsigned int * total_bytes)483 static void i40e_xmit_pkt_batch(struct i40e_ring *xdp_ring, struct xdp_desc *desc,
484 				unsigned int *total_bytes)
485 {
486 	u16 ntu = xdp_ring->next_to_use;
487 	struct i40e_tx_desc *tx_desc;
488 	dma_addr_t dma;
489 	u32 i;
490 
491 	loop_unrolled_for(i = 0; i < PKTS_PER_BATCH; i++) {
492 		dma = xsk_buff_raw_get_dma(xdp_ring->xsk_pool, desc[i].addr);
493 		xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma, desc[i].len);
494 
495 		tx_desc = I40E_TX_DESC(xdp_ring, ntu++);
496 		tx_desc->buffer_addr = cpu_to_le64(dma);
497 		tx_desc->cmd_type_offset_bsz = build_ctob(I40E_TX_DESC_CMD_ICRC |
498 							  I40E_TX_DESC_CMD_EOP,
499 							  0, desc[i].len, 0);
500 
501 		*total_bytes += desc[i].len;
502 	}
503 
504 	xdp_ring->next_to_use = ntu;
505 }
506 
i40e_fill_tx_hw_ring(struct i40e_ring * xdp_ring,struct xdp_desc * descs,u32 nb_pkts,unsigned int * total_bytes)507 static void i40e_fill_tx_hw_ring(struct i40e_ring *xdp_ring, struct xdp_desc *descs, u32 nb_pkts,
508 				 unsigned int *total_bytes)
509 {
510 	u32 batched, leftover, i;
511 
512 	batched = nb_pkts & ~(PKTS_PER_BATCH - 1);
513 	leftover = nb_pkts & (PKTS_PER_BATCH - 1);
514 	for (i = 0; i < batched; i += PKTS_PER_BATCH)
515 		i40e_xmit_pkt_batch(xdp_ring, &descs[i], total_bytes);
516 	for (i = batched; i < batched + leftover; i++)
517 		i40e_xmit_pkt(xdp_ring, &descs[i], total_bytes);
518 }
519 
i40e_set_rs_bit(struct i40e_ring * xdp_ring)520 static void i40e_set_rs_bit(struct i40e_ring *xdp_ring)
521 {
522 	u16 ntu = xdp_ring->next_to_use ? xdp_ring->next_to_use - 1 : xdp_ring->count - 1;
523 	struct i40e_tx_desc *tx_desc;
524 
525 	tx_desc = I40E_TX_DESC(xdp_ring, ntu);
526 	tx_desc->cmd_type_offset_bsz |= cpu_to_le64(I40E_TX_DESC_CMD_RS << I40E_TXD_QW1_CMD_SHIFT);
527 }
528 
529 /**
530  * i40e_xmit_zc - Performs zero-copy Tx AF_XDP
531  * @xdp_ring: XDP Tx ring
532  * @budget: NAPI budget
533  *
534  * Returns true if the work is finished.
535  **/
i40e_xmit_zc(struct i40e_ring * xdp_ring,unsigned int budget)536 static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
537 {
538 	struct xdp_desc *descs = xdp_ring->xsk_pool->tx_descs;
539 	u32 nb_pkts, nb_processed = 0;
540 	unsigned int total_bytes = 0;
541 
542 	nb_pkts = xsk_tx_peek_release_desc_batch(xdp_ring->xsk_pool, budget);
543 	if (!nb_pkts)
544 		return true;
545 
546 	if (xdp_ring->next_to_use + nb_pkts >= xdp_ring->count) {
547 		nb_processed = xdp_ring->count - xdp_ring->next_to_use;
548 		i40e_fill_tx_hw_ring(xdp_ring, descs, nb_processed, &total_bytes);
549 		xdp_ring->next_to_use = 0;
550 	}
551 
552 	i40e_fill_tx_hw_ring(xdp_ring, &descs[nb_processed], nb_pkts - nb_processed,
553 			     &total_bytes);
554 
555 	/* Request an interrupt for the last frame and bump tail ptr. */
556 	i40e_set_rs_bit(xdp_ring);
557 	i40e_xdp_ring_update_tail(xdp_ring);
558 
559 	i40e_update_tx_stats(xdp_ring, nb_pkts, total_bytes);
560 
561 	return nb_pkts < budget;
562 }
563 
564 /**
565  * i40e_clean_xdp_tx_buffer - Frees and unmaps an XDP Tx entry
566  * @tx_ring: XDP Tx ring
567  * @tx_bi: Tx buffer info to clean
568  **/
i40e_clean_xdp_tx_buffer(struct i40e_ring * tx_ring,struct i40e_tx_buffer * tx_bi)569 static void i40e_clean_xdp_tx_buffer(struct i40e_ring *tx_ring,
570 				     struct i40e_tx_buffer *tx_bi)
571 {
572 	xdp_return_frame(tx_bi->xdpf);
573 	tx_ring->xdp_tx_active--;
574 	dma_unmap_single(tx_ring->dev,
575 			 dma_unmap_addr(tx_bi, dma),
576 			 dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
577 	dma_unmap_len_set(tx_bi, len, 0);
578 }
579 
580 /**
581  * i40e_clean_xdp_tx_irq - Completes AF_XDP entries, and cleans XDP entries
582  * @vsi: Current VSI
583  * @tx_ring: XDP Tx ring
584  *
585  * Returns true if cleanup/tranmission is done.
586  **/
i40e_clean_xdp_tx_irq(struct i40e_vsi * vsi,struct i40e_ring * tx_ring)587 bool i40e_clean_xdp_tx_irq(struct i40e_vsi *vsi, struct i40e_ring *tx_ring)
588 {
589 	struct xsk_buff_pool *bp = tx_ring->xsk_pool;
590 	u32 i, completed_frames, xsk_frames = 0;
591 	u32 head_idx = i40e_get_head(tx_ring);
592 	struct i40e_tx_buffer *tx_bi;
593 	unsigned int ntc;
594 
595 	if (head_idx < tx_ring->next_to_clean)
596 		head_idx += tx_ring->count;
597 	completed_frames = head_idx - tx_ring->next_to_clean;
598 
599 	if (completed_frames == 0)
600 		goto out_xmit;
601 
602 	if (likely(!tx_ring->xdp_tx_active)) {
603 		xsk_frames = completed_frames;
604 		goto skip;
605 	}
606 
607 	ntc = tx_ring->next_to_clean;
608 
609 	for (i = 0; i < completed_frames; i++) {
610 		tx_bi = &tx_ring->tx_bi[ntc];
611 
612 		if (tx_bi->xdpf) {
613 			i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
614 			tx_bi->xdpf = NULL;
615 		} else {
616 			xsk_frames++;
617 		}
618 
619 		if (++ntc >= tx_ring->count)
620 			ntc = 0;
621 	}
622 
623 skip:
624 	tx_ring->next_to_clean += completed_frames;
625 	if (unlikely(tx_ring->next_to_clean >= tx_ring->count))
626 		tx_ring->next_to_clean -= tx_ring->count;
627 
628 	if (xsk_frames)
629 		xsk_tx_completed(bp, xsk_frames);
630 
631 	i40e_arm_wb(tx_ring, vsi, completed_frames);
632 
633 out_xmit:
634 	if (xsk_uses_need_wakeup(tx_ring->xsk_pool))
635 		xsk_set_tx_need_wakeup(tx_ring->xsk_pool);
636 
637 	return i40e_xmit_zc(tx_ring, I40E_DESC_UNUSED(tx_ring));
638 }
639 
640 /**
641  * i40e_xsk_wakeup - Implements the ndo_xsk_wakeup
642  * @dev: the netdevice
643  * @queue_id: queue id to wake up
644  * @flags: ignored in our case since we have Rx and Tx in the same NAPI.
645  *
646  * Returns <0 for errors, 0 otherwise.
647  **/
i40e_xsk_wakeup(struct net_device * dev,u32 queue_id,u32 flags)648 int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
649 {
650 	struct i40e_netdev_priv *np = netdev_priv(dev);
651 	struct i40e_vsi *vsi = np->vsi;
652 	struct i40e_pf *pf = vsi->back;
653 	struct i40e_ring *ring;
654 
655 	if (test_bit(__I40E_CONFIG_BUSY, pf->state))
656 		return -EAGAIN;
657 
658 	if (test_bit(__I40E_VSI_DOWN, vsi->state))
659 		return -ENETDOWN;
660 
661 	if (!i40e_enabled_xdp_vsi(vsi))
662 		return -EINVAL;
663 
664 	if (queue_id >= vsi->num_queue_pairs)
665 		return -EINVAL;
666 
667 	if (!vsi->xdp_rings[queue_id]->xsk_pool)
668 		return -EINVAL;
669 
670 	ring = vsi->xdp_rings[queue_id];
671 
672 	/* The idea here is that if NAPI is running, mark a miss, so
673 	 * it will run again. If not, trigger an interrupt and
674 	 * schedule the NAPI from interrupt context. If NAPI would be
675 	 * scheduled here, the interrupt affinity would not be
676 	 * honored.
677 	 */
678 	if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi))
679 		i40e_force_wb(vsi, ring->q_vector);
680 
681 	return 0;
682 }
683 
i40e_xsk_clean_rx_ring(struct i40e_ring * rx_ring)684 void i40e_xsk_clean_rx_ring(struct i40e_ring *rx_ring)
685 {
686 	u16 count_mask = rx_ring->count - 1;
687 	u16 ntc = rx_ring->next_to_clean;
688 	u16 ntu = rx_ring->next_to_use;
689 
690 	for ( ; ntc != ntu; ntc = (ntc + 1)  & count_mask) {
691 		struct xdp_buff *rx_bi = *i40e_rx_bi(rx_ring, ntc);
692 
693 		xsk_buff_free(rx_bi);
694 	}
695 }
696 
697 /**
698  * i40e_xsk_clean_tx_ring - Clean the XDP Tx ring on shutdown
699  * @tx_ring: XDP Tx ring
700  **/
i40e_xsk_clean_tx_ring(struct i40e_ring * tx_ring)701 void i40e_xsk_clean_tx_ring(struct i40e_ring *tx_ring)
702 {
703 	u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
704 	struct xsk_buff_pool *bp = tx_ring->xsk_pool;
705 	struct i40e_tx_buffer *tx_bi;
706 	u32 xsk_frames = 0;
707 
708 	while (ntc != ntu) {
709 		tx_bi = &tx_ring->tx_bi[ntc];
710 
711 		if (tx_bi->xdpf)
712 			i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
713 		else
714 			xsk_frames++;
715 
716 		tx_bi->xdpf = NULL;
717 
718 		ntc++;
719 		if (ntc >= tx_ring->count)
720 			ntc = 0;
721 	}
722 
723 	if (xsk_frames)
724 		xsk_tx_completed(bp, xsk_frames);
725 }
726 
727 /**
728  * i40e_xsk_any_rx_ring_enabled - Checks if Rx rings have an AF_XDP
729  * buffer pool attached
730  * @vsi: vsi
731  *
732  * Returns true if any of the Rx rings has an AF_XDP buffer pool attached
733  **/
i40e_xsk_any_rx_ring_enabled(struct i40e_vsi * vsi)734 bool i40e_xsk_any_rx_ring_enabled(struct i40e_vsi *vsi)
735 {
736 	struct net_device *netdev = vsi->netdev;
737 	int i;
738 
739 	for (i = 0; i < vsi->num_queue_pairs; i++) {
740 		if (xsk_get_pool_from_qid(netdev, i))
741 			return true;
742 	}
743 
744 	return false;
745 }
746