1// SPDX-License-Identifier: GPL-2.0
2/* Copyright(c) 2018 Intel Corporation. */
3
4#include <linux/bpf_trace.h>
5#include <net/xdp_sock_drv.h>
6#include <net/xdp.h>
7
8#include "ixgbe.h"
9#include "ixgbe_txrx_common.h"
10
11struct xsk_buff_pool *ixgbe_xsk_pool(struct ixgbe_adapter *adapter,
12				     struct ixgbe_ring *ring)
13{
14	bool xdp_on = READ_ONCE(adapter->xdp_prog);
15	int qid = ring->ring_idx;
16
17	if (!xdp_on || !test_bit(qid, adapter->af_xdp_zc_qps))
18		return NULL;
19
20	return xsk_get_pool_from_qid(adapter->netdev, qid);
21}
22
23static int ixgbe_xsk_pool_enable(struct ixgbe_adapter *adapter,
24				 struct xsk_buff_pool *pool,
25				 u16 qid)
26{
27	struct net_device *netdev = adapter->netdev;
28	bool if_running;
29	int err;
30
31	if (qid >= adapter->num_rx_queues)
32		return -EINVAL;
33
34	if (qid >= netdev->real_num_rx_queues ||
35	    qid >= netdev->real_num_tx_queues)
36		return -EINVAL;
37
38	err = xsk_pool_dma_map(pool, &adapter->pdev->dev, IXGBE_RX_DMA_ATTR);
39	if (err)
40		return err;
41
42	if_running = netif_running(adapter->netdev) &&
43		     ixgbe_enabled_xdp_adapter(adapter);
44
45	if (if_running)
46		ixgbe_txrx_ring_disable(adapter, qid);
47
48	set_bit(qid, adapter->af_xdp_zc_qps);
49
50	if (if_running) {
51		ixgbe_txrx_ring_enable(adapter, qid);
52
53		/* Kick start the NAPI context so that receiving will start */
54		err = ixgbe_xsk_wakeup(adapter->netdev, qid, XDP_WAKEUP_RX);
55		if (err) {
56			clear_bit(qid, adapter->af_xdp_zc_qps);
57			xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
58			return err;
59		}
60	}
61
62	return 0;
63}
64
65static int ixgbe_xsk_pool_disable(struct ixgbe_adapter *adapter, u16 qid)
66{
67	struct xsk_buff_pool *pool;
68	bool if_running;
69
70	pool = xsk_get_pool_from_qid(adapter->netdev, qid);
71	if (!pool)
72		return -EINVAL;
73
74	if_running = netif_running(adapter->netdev) &&
75		     ixgbe_enabled_xdp_adapter(adapter);
76
77	if (if_running)
78		ixgbe_txrx_ring_disable(adapter, qid);
79
80	clear_bit(qid, adapter->af_xdp_zc_qps);
81	xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
82
83	if (if_running)
84		ixgbe_txrx_ring_enable(adapter, qid);
85
86	return 0;
87}
88
89int ixgbe_xsk_pool_setup(struct ixgbe_adapter *adapter,
90			 struct xsk_buff_pool *pool,
91			 u16 qid)
92{
93	return pool ? ixgbe_xsk_pool_enable(adapter, pool, qid) :
94		ixgbe_xsk_pool_disable(adapter, qid);
95}
96
97static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
98			    struct ixgbe_ring *rx_ring,
99			    struct xdp_buff *xdp)
100{
101	int err, result = IXGBE_XDP_PASS;
102	struct bpf_prog *xdp_prog;
103	struct xdp_frame *xdpf;
104	u32 act;
105
106	rcu_read_lock();
107	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
108	act = bpf_prog_run_xdp(xdp_prog, xdp);
109
110	if (likely(act == XDP_REDIRECT)) {
111		err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
112		if (err)
113			goto out_failure;
114		rcu_read_unlock();
115		return IXGBE_XDP_REDIR;
116	}
117
118	switch (act) {
119	case XDP_PASS:
120		break;
121	case XDP_TX:
122		xdpf = xdp_convert_buff_to_frame(xdp);
123		if (unlikely(!xdpf))
124			goto out_failure;
125		result = ixgbe_xmit_xdp_ring(adapter, xdpf);
126		if (result == IXGBE_XDP_CONSUMED)
127			goto out_failure;
128		break;
129	default:
130		bpf_warn_invalid_xdp_action(act);
131		fallthrough;
132	case XDP_ABORTED:
133out_failure:
134		trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
135		fallthrough; /* handle aborts by dropping packet */
136	case XDP_DROP:
137		result = IXGBE_XDP_CONSUMED;
138		break;
139	}
140	rcu_read_unlock();
141	return result;
142}
143
144bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
145{
146	union ixgbe_adv_rx_desc *rx_desc;
147	struct ixgbe_rx_buffer *bi;
148	u16 i = rx_ring->next_to_use;
149	dma_addr_t dma;
150	bool ok = true;
151
152	/* nothing to do */
153	if (!count)
154		return true;
155
156	rx_desc = IXGBE_RX_DESC(rx_ring, i);
157	bi = &rx_ring->rx_buffer_info[i];
158	i -= rx_ring->count;
159
160	do {
161		bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
162		if (!bi->xdp) {
163			ok = false;
164			break;
165		}
166
167		dma = xsk_buff_xdp_get_dma(bi->xdp);
168
169		/* Refresh the desc even if buffer_addrs didn't change
170		 * because each write-back erases this info.
171		 */
172		rx_desc->read.pkt_addr = cpu_to_le64(dma);
173
174		rx_desc++;
175		bi++;
176		i++;
177		if (unlikely(!i)) {
178			rx_desc = IXGBE_RX_DESC(rx_ring, 0);
179			bi = rx_ring->rx_buffer_info;
180			i -= rx_ring->count;
181		}
182
183		/* clear the length for the next_to_use descriptor */
184		rx_desc->wb.upper.length = 0;
185
186		count--;
187	} while (count);
188
189	i += rx_ring->count;
190
191	if (rx_ring->next_to_use != i) {
192		rx_ring->next_to_use = i;
193
194		/* Force memory writes to complete before letting h/w
195		 * know there are new descriptors to fetch.  (Only
196		 * applicable for weak-ordered memory model archs,
197		 * such as IA-64).
198		 */
199		wmb();
200		writel(i, rx_ring->tail);
201	}
202
203	return ok;
204}
205
206static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
207					      struct ixgbe_rx_buffer *bi)
208{
209	unsigned int metasize = bi->xdp->data - bi->xdp->data_meta;
210	unsigned int datasize = bi->xdp->data_end - bi->xdp->data;
211	struct sk_buff *skb;
212
213	/* allocate a skb to store the frags */
214	skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
215			       bi->xdp->data_end - bi->xdp->data_hard_start,
216			       GFP_ATOMIC | __GFP_NOWARN);
217	if (unlikely(!skb))
218		return NULL;
219
220	skb_reserve(skb, bi->xdp->data - bi->xdp->data_hard_start);
221	memcpy(__skb_put(skb, datasize), bi->xdp->data, datasize);
222	if (metasize)
223		skb_metadata_set(skb, metasize);
224
225	xsk_buff_free(bi->xdp);
226	bi->xdp = NULL;
227	return skb;
228}
229
230static void ixgbe_inc_ntc(struct ixgbe_ring *rx_ring)
231{
232	u32 ntc = rx_ring->next_to_clean + 1;
233
234	ntc = (ntc < rx_ring->count) ? ntc : 0;
235	rx_ring->next_to_clean = ntc;
236	prefetch(IXGBE_RX_DESC(rx_ring, ntc));
237}
238
239int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
240			  struct ixgbe_ring *rx_ring,
241			  const int budget)
242{
243	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
244	struct ixgbe_adapter *adapter = q_vector->adapter;
245	u16 cleaned_count = ixgbe_desc_unused(rx_ring);
246	unsigned int xdp_res, xdp_xmit = 0;
247	bool failure = false;
248	struct sk_buff *skb;
249
250	while (likely(total_rx_packets < budget)) {
251		union ixgbe_adv_rx_desc *rx_desc;
252		struct ixgbe_rx_buffer *bi;
253		unsigned int size;
254
255		/* return some buffers to hardware, one at a time is too slow */
256		if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
257			failure = failure ||
258				  !ixgbe_alloc_rx_buffers_zc(rx_ring,
259							     cleaned_count);
260			cleaned_count = 0;
261		}
262
263		rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
264		size = le16_to_cpu(rx_desc->wb.upper.length);
265		if (!size)
266			break;
267
268		/* This memory barrier is needed to keep us from reading
269		 * any other fields out of the rx_desc until we know the
270		 * descriptor has been written back
271		 */
272		dma_rmb();
273
274		bi = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
275
276		if (unlikely(!ixgbe_test_staterr(rx_desc,
277						 IXGBE_RXD_STAT_EOP))) {
278			struct ixgbe_rx_buffer *next_bi;
279
280			xsk_buff_free(bi->xdp);
281			bi->xdp = NULL;
282			ixgbe_inc_ntc(rx_ring);
283			next_bi =
284			       &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
285			next_bi->discard = true;
286			continue;
287		}
288
289		if (unlikely(bi->discard)) {
290			xsk_buff_free(bi->xdp);
291			bi->xdp = NULL;
292			bi->discard = false;
293			ixgbe_inc_ntc(rx_ring);
294			continue;
295		}
296
297		bi->xdp->data_end = bi->xdp->data + size;
298		xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);
299		xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);
300
301		if (xdp_res) {
302			if (xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))
303				xdp_xmit |= xdp_res;
304			else
305				xsk_buff_free(bi->xdp);
306
307			bi->xdp = NULL;
308			total_rx_packets++;
309			total_rx_bytes += size;
310
311			cleaned_count++;
312			ixgbe_inc_ntc(rx_ring);
313			continue;
314		}
315
316		/* XDP_PASS path */
317		skb = ixgbe_construct_skb_zc(rx_ring, bi);
318		if (!skb) {
319			rx_ring->rx_stats.alloc_rx_buff_failed++;
320			break;
321		}
322
323		cleaned_count++;
324		ixgbe_inc_ntc(rx_ring);
325
326		if (eth_skb_pad(skb))
327			continue;
328
329		total_rx_bytes += skb->len;
330		total_rx_packets++;
331
332		ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
333		ixgbe_rx_skb(q_vector, skb);
334	}
335
336	if (xdp_xmit & IXGBE_XDP_REDIR)
337		xdp_do_flush_map();
338
339	if (xdp_xmit & IXGBE_XDP_TX) {
340		struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()];
341
342		/* Force memory writes to complete before letting h/w
343		 * know there are new descriptors to fetch.
344		 */
345		wmb();
346		writel(ring->next_to_use, ring->tail);
347	}
348
349	u64_stats_update_begin(&rx_ring->syncp);
350	rx_ring->stats.packets += total_rx_packets;
351	rx_ring->stats.bytes += total_rx_bytes;
352	u64_stats_update_end(&rx_ring->syncp);
353	q_vector->rx.total_packets += total_rx_packets;
354	q_vector->rx.total_bytes += total_rx_bytes;
355
356	if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
357		if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
358			xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
359		else
360			xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
361
362		return (int)total_rx_packets;
363	}
364	return failure ? budget : (int)total_rx_packets;
365}
366
367void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
368{
369	struct ixgbe_rx_buffer *bi;
370	u16 i;
371
372	for (i = 0; i < rx_ring->count; i++) {
373		bi = &rx_ring->rx_buffer_info[i];
374
375		if (!bi->xdp)
376			continue;
377
378		xsk_buff_free(bi->xdp);
379		bi->xdp = NULL;
380	}
381}
382
383static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
384{
385	struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
386	union ixgbe_adv_tx_desc *tx_desc = NULL;
387	struct ixgbe_tx_buffer *tx_bi;
388	bool work_done = true;
389	struct xdp_desc desc;
390	dma_addr_t dma;
391	u32 cmd_type;
392
393	while (budget-- > 0) {
394		if (unlikely(!ixgbe_desc_unused(xdp_ring))) {
395			work_done = false;
396			break;
397		}
398
399		if (!netif_carrier_ok(xdp_ring->netdev))
400			break;
401
402		if (!xsk_tx_peek_desc(pool, &desc))
403			break;
404
405		dma = xsk_buff_raw_get_dma(pool, desc.addr);
406		xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);
407
408		tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
409		tx_bi->bytecount = desc.len;
410		tx_bi->xdpf = NULL;
411		tx_bi->gso_segs = 1;
412
413		tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
414		tx_desc->read.buffer_addr = cpu_to_le64(dma);
415
416		/* put descriptor type bits */
417		cmd_type = IXGBE_ADVTXD_DTYP_DATA |
418			   IXGBE_ADVTXD_DCMD_DEXT |
419			   IXGBE_ADVTXD_DCMD_IFCS;
420		cmd_type |= desc.len | IXGBE_TXD_CMD;
421		tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
422		tx_desc->read.olinfo_status =
423			cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);
424
425		xdp_ring->next_to_use++;
426		if (xdp_ring->next_to_use == xdp_ring->count)
427			xdp_ring->next_to_use = 0;
428	}
429
430	if (tx_desc) {
431		ixgbe_xdp_ring_update_tail(xdp_ring);
432		xsk_tx_release(pool);
433	}
434
435	return !!budget && work_done;
436}
437
438static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
439				      struct ixgbe_tx_buffer *tx_bi)
440{
441	xdp_return_frame(tx_bi->xdpf);
442	dma_unmap_single(tx_ring->dev,
443			 dma_unmap_addr(tx_bi, dma),
444			 dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
445	dma_unmap_len_set(tx_bi, len, 0);
446}
447
448bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
449			    struct ixgbe_ring *tx_ring, int napi_budget)
450{
451	u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
452	unsigned int total_packets = 0, total_bytes = 0;
453	struct xsk_buff_pool *pool = tx_ring->xsk_pool;
454	union ixgbe_adv_tx_desc *tx_desc;
455	struct ixgbe_tx_buffer *tx_bi;
456	u32 xsk_frames = 0;
457
458	tx_bi = &tx_ring->tx_buffer_info[ntc];
459	tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
460
461	while (ntc != ntu) {
462		if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
463			break;
464
465		total_bytes += tx_bi->bytecount;
466		total_packets += tx_bi->gso_segs;
467
468		if (tx_bi->xdpf)
469			ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
470		else
471			xsk_frames++;
472
473		tx_bi->xdpf = NULL;
474
475		tx_bi++;
476		tx_desc++;
477		ntc++;
478		if (unlikely(ntc == tx_ring->count)) {
479			ntc = 0;
480			tx_bi = tx_ring->tx_buffer_info;
481			tx_desc = IXGBE_TX_DESC(tx_ring, 0);
482		}
483
484		/* issue prefetch for next Tx descriptor */
485		prefetch(tx_desc);
486	}
487
488	tx_ring->next_to_clean = ntc;
489
490	u64_stats_update_begin(&tx_ring->syncp);
491	tx_ring->stats.bytes += total_bytes;
492	tx_ring->stats.packets += total_packets;
493	u64_stats_update_end(&tx_ring->syncp);
494	q_vector->tx.total_bytes += total_bytes;
495	q_vector->tx.total_packets += total_packets;
496
497	if (xsk_frames)
498		xsk_tx_completed(pool, xsk_frames);
499
500	if (xsk_uses_need_wakeup(pool))
501		xsk_set_tx_need_wakeup(pool);
502
503	return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
504}
505
506int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
507{
508	struct ixgbe_adapter *adapter = netdev_priv(dev);
509	struct ixgbe_ring *ring;
510
511	if (test_bit(__IXGBE_DOWN, &adapter->state))
512		return -ENETDOWN;
513
514	if (!READ_ONCE(adapter->xdp_prog))
515		return -ENXIO;
516
517	if (qid >= adapter->num_xdp_queues)
518		return -ENXIO;
519
520	ring = adapter->xdp_ring[qid];
521
522	if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
523		return -ENETDOWN;
524
525	if (!ring->xsk_pool)
526		return -ENXIO;
527
528	if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
529		u64 eics = BIT_ULL(ring->q_vector->v_idx);
530
531		ixgbe_irq_rearm_queues(adapter, eics);
532	}
533
534	return 0;
535}
536
537void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
538{
539	u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
540	struct xsk_buff_pool *pool = tx_ring->xsk_pool;
541	struct ixgbe_tx_buffer *tx_bi;
542	u32 xsk_frames = 0;
543
544	while (ntc != ntu) {
545		tx_bi = &tx_ring->tx_buffer_info[ntc];
546
547		if (tx_bi->xdpf)
548			ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
549		else
550			xsk_frames++;
551
552		tx_bi->xdpf = NULL;
553
554		ntc++;
555		if (ntc == tx_ring->count)
556			ntc = 0;
557	}
558
559	if (xsk_frames)
560		xsk_tx_completed(pool, xsk_frames);
561}
562