1// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2/*
3 * Copyright 2015-2021 Amazon.com, Inc. or its affiliates. All rights reserved.
4 */
5
6#include "ena_xdp.h"
7
8static int validate_xdp_req_id(struct ena_ring *tx_ring, u16 req_id)
9{
10	struct ena_tx_buffer *tx_info;
11
12	tx_info = &tx_ring->tx_buffer_info[req_id];
13	if (likely(tx_info->xdpf))
14		return 0;
15
16	return handle_invalid_req_id(tx_ring, req_id, tx_info, true);
17}
18
19static int ena_xdp_tx_map_frame(struct ena_ring *tx_ring,
20				struct ena_tx_buffer *tx_info,
21				struct xdp_frame *xdpf,
22				struct ena_com_tx_ctx *ena_tx_ctx)
23{
24	struct ena_adapter *adapter = tx_ring->adapter;
25	struct ena_com_buf *ena_buf;
26	int push_len = 0;
27	dma_addr_t dma;
28	void *data;
29	u32 size;
30
31	tx_info->xdpf = xdpf;
32	data = tx_info->xdpf->data;
33	size = tx_info->xdpf->len;
34
35	if (tx_ring->tx_mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV) {
36		/* Designate part of the packet for LLQ */
37		push_len = min_t(u32, size, tx_ring->tx_max_header_size);
38
39		ena_tx_ctx->push_header = data;
40
41		size -= push_len;
42		data += push_len;
43	}
44
45	ena_tx_ctx->header_len = push_len;
46
47	if (size > 0) {
48		dma = dma_map_single(tx_ring->dev,
49				     data,
50				     size,
51				     DMA_TO_DEVICE);
52		if (unlikely(dma_mapping_error(tx_ring->dev, dma)))
53			goto error_report_dma_error;
54
55		tx_info->map_linear_data = 0;
56
57		ena_buf = tx_info->bufs;
58		ena_buf->paddr = dma;
59		ena_buf->len = size;
60
61		ena_tx_ctx->ena_bufs = ena_buf;
62		ena_tx_ctx->num_bufs = tx_info->num_of_bufs = 1;
63	}
64
65	return 0;
66
67error_report_dma_error:
68	ena_increase_stat(&tx_ring->tx_stats.dma_mapping_err, 1,
69			  &tx_ring->syncp);
70	netif_warn(adapter, tx_queued, adapter->netdev, "Failed to map xdp buff\n");
71
72	return -EINVAL;
73}
74
75int ena_xdp_xmit_frame(struct ena_ring *tx_ring,
76		       struct ena_adapter *adapter,
77		       struct xdp_frame *xdpf,
78		       int flags)
79{
80	struct ena_com_tx_ctx ena_tx_ctx = {};
81	struct ena_tx_buffer *tx_info;
82	u16 next_to_use, req_id;
83	int rc;
84
85	next_to_use = tx_ring->next_to_use;
86	req_id = tx_ring->free_ids[next_to_use];
87	tx_info = &tx_ring->tx_buffer_info[req_id];
88	tx_info->num_of_bufs = 0;
89
90	rc = ena_xdp_tx_map_frame(tx_ring, tx_info, xdpf, &ena_tx_ctx);
91	if (unlikely(rc))
92		goto err;
93
94	ena_tx_ctx.req_id = req_id;
95
96	rc = ena_xmit_common(adapter,
97			     tx_ring,
98			     tx_info,
99			     &ena_tx_ctx,
100			     next_to_use,
101			     xdpf->len);
102	if (rc)
103		goto error_unmap_dma;
104
105	/* trigger the dma engine. ena_ring_tx_doorbell()
106	 * calls a memory barrier inside it.
107	 */
108	if (flags & XDP_XMIT_FLUSH)
109		ena_ring_tx_doorbell(tx_ring);
110
111	return rc;
112
113error_unmap_dma:
114	ena_unmap_tx_buff(tx_ring, tx_info);
115err:
116	tx_info->xdpf = NULL;
117
118	return rc;
119}
120
121int ena_xdp_xmit(struct net_device *dev, int n,
122		 struct xdp_frame **frames, u32 flags)
123{
124	struct ena_adapter *adapter = netdev_priv(dev);
125	struct ena_ring *tx_ring;
126	int qid, i, nxmit = 0;
127
128	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
129		return -EINVAL;
130
131	if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
132		return -ENETDOWN;
133
134	/* We assume that all rings have the same XDP program */
135	if (!READ_ONCE(adapter->rx_ring->xdp_bpf_prog))
136		return -ENXIO;
137
138	qid = smp_processor_id() % adapter->xdp_num_queues;
139	qid += adapter->xdp_first_ring;
140	tx_ring = &adapter->tx_ring[qid];
141
142	/* Other CPU ids might try to send thorugh this queue */
143	spin_lock(&tx_ring->xdp_tx_lock);
144
145	for (i = 0; i < n; i++) {
146		if (ena_xdp_xmit_frame(tx_ring, adapter, frames[i], 0))
147			break;
148		nxmit++;
149	}
150
151	/* Ring doorbell to make device aware of the packets */
152	if (flags & XDP_XMIT_FLUSH)
153		ena_ring_tx_doorbell(tx_ring);
154
155	spin_unlock(&tx_ring->xdp_tx_lock);
156
157	/* Return number of packets sent */
158	return nxmit;
159}
160
161static void ena_init_all_xdp_queues(struct ena_adapter *adapter)
162{
163	adapter->xdp_first_ring = adapter->num_io_queues;
164	adapter->xdp_num_queues = adapter->num_io_queues;
165
166	ena_init_io_rings(adapter,
167			  adapter->xdp_first_ring,
168			  adapter->xdp_num_queues);
169}
170
171int ena_setup_and_create_all_xdp_queues(struct ena_adapter *adapter)
172{
173	u32 xdp_first_ring = adapter->xdp_first_ring;
174	u32 xdp_num_queues = adapter->xdp_num_queues;
175	int rc = 0;
176
177	rc = ena_setup_tx_resources_in_range(adapter, xdp_first_ring, xdp_num_queues);
178	if (rc)
179		goto setup_err;
180
181	rc = ena_create_io_tx_queues_in_range(adapter, xdp_first_ring, xdp_num_queues);
182	if (rc)
183		goto create_err;
184
185	return 0;
186
187create_err:
188	ena_free_all_io_tx_resources_in_range(adapter, xdp_first_ring, xdp_num_queues);
189setup_err:
190	return rc;
191}
192
193/* Provides a way for both kernel and bpf-prog to know
194 * more about the RX-queue a given XDP frame arrived on.
195 */
196int ena_xdp_register_rxq_info(struct ena_ring *rx_ring)
197{
198	int rc;
199
200	rc = xdp_rxq_info_reg(&rx_ring->xdp_rxq, rx_ring->netdev, rx_ring->qid, 0);
201
202	netif_dbg(rx_ring->adapter, ifup, rx_ring->netdev, "Registering RX info for queue %d",
203		  rx_ring->qid);
204	if (rc) {
205		netif_err(rx_ring->adapter, ifup, rx_ring->netdev,
206			  "Failed to register xdp rx queue info. RX queue num %d rc: %d\n",
207			  rx_ring->qid, rc);
208		goto err;
209	}
210
211	rc = xdp_rxq_info_reg_mem_model(&rx_ring->xdp_rxq, MEM_TYPE_PAGE_SHARED, NULL);
212
213	if (rc) {
214		netif_err(rx_ring->adapter, ifup, rx_ring->netdev,
215			  "Failed to register xdp rx queue info memory model. RX queue num %d rc: %d\n",
216			  rx_ring->qid, rc);
217		xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
218	}
219
220err:
221	return rc;
222}
223
224void ena_xdp_unregister_rxq_info(struct ena_ring *rx_ring)
225{
226	netif_dbg(rx_ring->adapter, ifdown, rx_ring->netdev,
227		  "Unregistering RX info for queue %d",
228		  rx_ring->qid);
229	xdp_rxq_info_unreg_mem_model(&rx_ring->xdp_rxq);
230	xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
231}
232
233void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter,
234					  struct bpf_prog *prog,
235					  int first, int count)
236{
237	struct bpf_prog *old_bpf_prog;
238	struct ena_ring *rx_ring;
239	int i = 0;
240
241	for (i = first; i < count; i++) {
242		rx_ring = &adapter->rx_ring[i];
243		old_bpf_prog = xchg(&rx_ring->xdp_bpf_prog, prog);
244
245		if (!old_bpf_prog && prog) {
246			rx_ring->rx_headroom = XDP_PACKET_HEADROOM;
247		} else if (old_bpf_prog && !prog) {
248			rx_ring->rx_headroom = NET_SKB_PAD;
249		}
250	}
251}
252
253static void ena_xdp_exchange_program(struct ena_adapter *adapter,
254				     struct bpf_prog *prog)
255{
256	struct bpf_prog *old_bpf_prog = xchg(&adapter->xdp_bpf_prog, prog);
257
258	ena_xdp_exchange_program_rx_in_range(adapter,
259					     prog,
260					     0,
261					     adapter->num_io_queues);
262
263	if (old_bpf_prog)
264		bpf_prog_put(old_bpf_prog);
265}
266
267static int ena_destroy_and_free_all_xdp_queues(struct ena_adapter *adapter)
268{
269	bool was_up;
270	int rc;
271
272	was_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
273
274	if (was_up)
275		ena_down(adapter);
276
277	adapter->xdp_first_ring = 0;
278	adapter->xdp_num_queues = 0;
279	ena_xdp_exchange_program(adapter, NULL);
280	if (was_up) {
281		rc = ena_up(adapter);
282		if (rc)
283			return rc;
284	}
285	return 0;
286}
287
288static int ena_xdp_set(struct net_device *netdev, struct netdev_bpf *bpf)
289{
290	struct ena_adapter *adapter = netdev_priv(netdev);
291	struct bpf_prog *prog = bpf->prog;
292	struct bpf_prog *old_bpf_prog;
293	int rc, prev_mtu;
294	bool is_up;
295
296	is_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
297	rc = ena_xdp_allowed(adapter);
298	if (rc == ENA_XDP_ALLOWED) {
299		old_bpf_prog = adapter->xdp_bpf_prog;
300		if (prog) {
301			if (!is_up) {
302				ena_init_all_xdp_queues(adapter);
303			} else if (!old_bpf_prog) {
304				ena_down(adapter);
305				ena_init_all_xdp_queues(adapter);
306			}
307			ena_xdp_exchange_program(adapter, prog);
308
309			netif_dbg(adapter, drv, adapter->netdev, "Set a new XDP program\n");
310
311			if (is_up && !old_bpf_prog) {
312				rc = ena_up(adapter);
313				if (rc)
314					return rc;
315			}
316			xdp_features_set_redirect_target(netdev, false);
317		} else if (old_bpf_prog) {
318			xdp_features_clear_redirect_target(netdev);
319			netif_dbg(adapter, drv, adapter->netdev, "Removing XDP program\n");
320
321			rc = ena_destroy_and_free_all_xdp_queues(adapter);
322			if (rc)
323				return rc;
324		}
325
326		prev_mtu = netdev->max_mtu;
327		netdev->max_mtu = prog ? ENA_XDP_MAX_MTU : adapter->max_mtu;
328
329		if (!old_bpf_prog)
330			netif_info(adapter, drv, adapter->netdev,
331				   "XDP program is set, changing the max_mtu from %d to %d",
332				   prev_mtu, netdev->max_mtu);
333
334	} else if (rc == ENA_XDP_CURRENT_MTU_TOO_LARGE) {
335		netif_err(adapter, drv, adapter->netdev,
336			  "Failed to set xdp program, the current MTU (%d) is larger than the maximum allowed MTU (%lu) while xdp is on",
337			  netdev->mtu, ENA_XDP_MAX_MTU);
338		NL_SET_ERR_MSG_MOD(bpf->extack,
339				   "Failed to set xdp program, the current MTU is larger than the maximum allowed MTU. Check the dmesg for more info");
340		return -EINVAL;
341	} else if (rc == ENA_XDP_NO_ENOUGH_QUEUES) {
342		netif_err(adapter, drv, adapter->netdev,
343			  "Failed to set xdp program, the Rx/Tx channel count should be at most half of the maximum allowed channel count. The current queue count (%d), the maximal queue count (%d)\n",
344			  adapter->num_io_queues, adapter->max_num_io_queues);
345		NL_SET_ERR_MSG_MOD(bpf->extack,
346				   "Failed to set xdp program, there is no enough space for allocating XDP queues, Check the dmesg for more info");
347		return -EINVAL;
348	}
349
350	return 0;
351}
352
353/* This is the main xdp callback, it's used by the kernel to set/unset the xdp
354 * program as well as to query the current xdp program id.
355 */
356int ena_xdp(struct net_device *netdev, struct netdev_bpf *bpf)
357{
358	switch (bpf->command) {
359	case XDP_SETUP_PROG:
360		return ena_xdp_set(netdev, bpf);
361	default:
362		return -EINVAL;
363	}
364	return 0;
365}
366
367static int ena_clean_xdp_irq(struct ena_ring *tx_ring, u32 budget)
368{
369	u32 total_done = 0;
370	u16 next_to_clean;
371	int tx_pkts = 0;
372	u16 req_id;
373	int rc;
374
375	if (unlikely(!tx_ring))
376		return 0;
377	next_to_clean = tx_ring->next_to_clean;
378
379	while (tx_pkts < budget) {
380		struct ena_tx_buffer *tx_info;
381		struct xdp_frame *xdpf;
382
383		rc = ena_com_tx_comp_req_id_get(tx_ring->ena_com_io_cq,
384						&req_id);
385		if (rc) {
386			if (unlikely(rc == -EINVAL))
387				handle_invalid_req_id(tx_ring, req_id, NULL, true);
388			break;
389		}
390
391		/* validate that the request id points to a valid xdp_frame */
392		rc = validate_xdp_req_id(tx_ring, req_id);
393		if (rc)
394			break;
395
396		tx_info = &tx_ring->tx_buffer_info[req_id];
397
398		tx_info->last_jiffies = 0;
399
400		xdpf = tx_info->xdpf;
401		tx_info->xdpf = NULL;
402		ena_unmap_tx_buff(tx_ring, tx_info);
403		xdp_return_frame(xdpf);
404
405		tx_pkts++;
406		total_done += tx_info->tx_descs;
407		tx_ring->free_ids[next_to_clean] = req_id;
408		next_to_clean = ENA_TX_RING_IDX_NEXT(next_to_clean,
409						     tx_ring->ring_size);
410
411		netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
412			  "tx_poll: q %d pkt #%d req_id %d\n", tx_ring->qid, tx_pkts, req_id);
413	}
414
415	tx_ring->next_to_clean = next_to_clean;
416	ena_com_comp_ack(tx_ring->ena_com_io_sq, total_done);
417
418	netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
419		  "tx_poll: q %d done. total pkts: %d\n",
420		  tx_ring->qid, tx_pkts);
421
422	return tx_pkts;
423}
424
425/* This is the XDP napi callback. XDP queues use a separate napi callback
426 * than Rx/Tx queues.
427 */
428int ena_xdp_io_poll(struct napi_struct *napi, int budget)
429{
430	struct ena_napi *ena_napi = container_of(napi, struct ena_napi, napi);
431	struct ena_ring *tx_ring;
432	u32 work_done;
433	int ret;
434
435	tx_ring = ena_napi->tx_ring;
436
437	if (!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags) ||
438	    test_bit(ENA_FLAG_TRIGGER_RESET, &tx_ring->adapter->flags)) {
439		napi_complete_done(napi, 0);
440		return 0;
441	}
442
443	work_done = ena_clean_xdp_irq(tx_ring, budget);
444
445	/* If the device is about to reset or down, avoid unmask
446	 * the interrupt and return 0 so NAPI won't reschedule
447	 */
448	if (unlikely(!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags))) {
449		napi_complete_done(napi, 0);
450		ret = 0;
451	} else if (budget > work_done) {
452		ena_increase_stat(&tx_ring->tx_stats.napi_comp, 1,
453				  &tx_ring->syncp);
454		if (napi_complete_done(napi, work_done))
455			ena_unmask_interrupt(tx_ring, NULL);
456
457		ena_update_ring_numa_node(tx_ring, NULL);
458		ret = work_done;
459	} else {
460		ret = budget;
461	}
462
463	u64_stats_update_begin(&tx_ring->syncp);
464	tx_ring->tx_stats.tx_poll++;
465	u64_stats_update_end(&tx_ring->syncp);
466	tx_ring->tx_stats.last_napi_jiffies = jiffies;
467
468	return ret;
469}
470