1 /* Broadcom NetXtreme-C/E network driver.
2 *
3 * Copyright (c) 2016-2017 Broadcom Limited
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation.
8 */
9 #include <linux/kernel.h>
10 #include <linux/errno.h>
11 #include <linux/pci.h>
12 #include <linux/netdevice.h>
13 #include <linux/etherdevice.h>
14 #include <linux/if_vlan.h>
15 #include <linux/bpf.h>
16 #include <linux/bpf_trace.h>
17 #include <linux/filter.h>
18 #include <net/page_pool/helpers.h>
19 #include "bnxt_hsi.h"
20 #include "bnxt.h"
21 #include "bnxt_xdp.h"
22
23 DEFINE_STATIC_KEY_FALSE(bnxt_xdp_locking_key);
24
bnxt_xmit_bd(struct bnxt * bp,struct bnxt_tx_ring_info * txr,dma_addr_t mapping,u32 len,struct xdp_buff * xdp)25 struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp,
26 struct bnxt_tx_ring_info *txr,
27 dma_addr_t mapping, u32 len,
28 struct xdp_buff *xdp)
29 {
30 struct skb_shared_info *sinfo;
31 struct bnxt_sw_tx_bd *tx_buf;
32 struct tx_bd *txbd;
33 int num_frags = 0;
34 u32 flags;
35 u16 prod;
36 int i;
37
38 if (xdp && xdp_buff_has_frags(xdp)) {
39 sinfo = xdp_get_shared_info_from_buff(xdp);
40 num_frags = sinfo->nr_frags;
41 }
42
43 /* fill up the first buffer */
44 prod = txr->tx_prod;
45 tx_buf = &txr->tx_buf_ring[prod];
46 tx_buf->nr_frags = num_frags;
47 if (xdp)
48 tx_buf->page = virt_to_head_page(xdp->data);
49
50 txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
51 flags = (len << TX_BD_LEN_SHIFT) |
52 ((num_frags + 1) << TX_BD_FLAGS_BD_CNT_SHIFT) |
53 bnxt_lhint_arr[len >> 9];
54 txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
55 txbd->tx_bd_opaque = prod;
56 txbd->tx_bd_haddr = cpu_to_le64(mapping);
57
58 /* now let us fill up the frags into the next buffers */
59 for (i = 0; i < num_frags ; i++) {
60 skb_frag_t *frag = &sinfo->frags[i];
61 struct bnxt_sw_tx_bd *frag_tx_buf;
62 struct pci_dev *pdev = bp->pdev;
63 dma_addr_t frag_mapping;
64 int frag_len;
65
66 prod = NEXT_TX(prod);
67 WRITE_ONCE(txr->tx_prod, prod);
68
69 /* first fill up the first buffer */
70 frag_tx_buf = &txr->tx_buf_ring[prod];
71 frag_tx_buf->page = skb_frag_page(frag);
72
73 txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
74
75 frag_len = skb_frag_size(frag);
76 frag_mapping = skb_frag_dma_map(&pdev->dev, frag, 0,
77 frag_len, DMA_TO_DEVICE);
78
79 if (unlikely(dma_mapping_error(&pdev->dev, frag_mapping)))
80 return NULL;
81
82 dma_unmap_addr_set(frag_tx_buf, mapping, frag_mapping);
83
84 flags = frag_len << TX_BD_LEN_SHIFT;
85 txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
86 txbd->tx_bd_haddr = cpu_to_le64(frag_mapping);
87
88 len = frag_len;
89 }
90
91 flags &= ~TX_BD_LEN;
92 txbd->tx_bd_len_flags_type = cpu_to_le32(((len) << TX_BD_LEN_SHIFT) | flags |
93 TX_BD_FLAGS_PACKET_END);
94 /* Sync TX BD */
95 wmb();
96 prod = NEXT_TX(prod);
97 WRITE_ONCE(txr->tx_prod, prod);
98
99 return tx_buf;
100 }
101
__bnxt_xmit_xdp(struct bnxt * bp,struct bnxt_tx_ring_info * txr,dma_addr_t mapping,u32 len,u16 rx_prod,struct xdp_buff * xdp)102 static void __bnxt_xmit_xdp(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
103 dma_addr_t mapping, u32 len, u16 rx_prod,
104 struct xdp_buff *xdp)
105 {
106 struct bnxt_sw_tx_bd *tx_buf;
107
108 tx_buf = bnxt_xmit_bd(bp, txr, mapping, len, xdp);
109 tx_buf->rx_prod = rx_prod;
110 tx_buf->action = XDP_TX;
111
112 }
113
__bnxt_xmit_xdp_redirect(struct bnxt * bp,struct bnxt_tx_ring_info * txr,dma_addr_t mapping,u32 len,struct xdp_frame * xdpf)114 static void __bnxt_xmit_xdp_redirect(struct bnxt *bp,
115 struct bnxt_tx_ring_info *txr,
116 dma_addr_t mapping, u32 len,
117 struct xdp_frame *xdpf)
118 {
119 struct bnxt_sw_tx_bd *tx_buf;
120
121 tx_buf = bnxt_xmit_bd(bp, txr, mapping, len, NULL);
122 tx_buf->action = XDP_REDIRECT;
123 tx_buf->xdpf = xdpf;
124 dma_unmap_addr_set(tx_buf, mapping, mapping);
125 dma_unmap_len_set(tx_buf, len, 0);
126 }
127
bnxt_tx_int_xdp(struct bnxt * bp,struct bnxt_napi * bnapi,int budget)128 void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int budget)
129 {
130 struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
131 struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
132 bool rx_doorbell_needed = false;
133 int nr_pkts = bnapi->tx_pkts;
134 struct bnxt_sw_tx_bd *tx_buf;
135 u16 tx_cons = txr->tx_cons;
136 u16 last_tx_cons = tx_cons;
137 int i, j, frags;
138
139 if (!budget)
140 return;
141
142 for (i = 0; i < nr_pkts; i++) {
143 tx_buf = &txr->tx_buf_ring[tx_cons];
144
145 if (tx_buf->action == XDP_REDIRECT) {
146 struct pci_dev *pdev = bp->pdev;
147
148 dma_unmap_single(&pdev->dev,
149 dma_unmap_addr(tx_buf, mapping),
150 dma_unmap_len(tx_buf, len),
151 DMA_TO_DEVICE);
152 xdp_return_frame(tx_buf->xdpf);
153 tx_buf->action = 0;
154 tx_buf->xdpf = NULL;
155 } else if (tx_buf->action == XDP_TX) {
156 tx_buf->action = 0;
157 rx_doorbell_needed = true;
158 last_tx_cons = tx_cons;
159
160 frags = tx_buf->nr_frags;
161 for (j = 0; j < frags; j++) {
162 tx_cons = NEXT_TX(tx_cons);
163 tx_buf = &txr->tx_buf_ring[tx_cons];
164 page_pool_recycle_direct(rxr->page_pool, tx_buf->page);
165 }
166 } else {
167 bnxt_sched_reset_txr(bp, txr, i);
168 return;
169 }
170 tx_cons = NEXT_TX(tx_cons);
171 }
172
173 bnapi->tx_pkts = 0;
174 WRITE_ONCE(txr->tx_cons, tx_cons);
175 if (rx_doorbell_needed) {
176 tx_buf = &txr->tx_buf_ring[last_tx_cons];
177 bnxt_db_write(bp, &rxr->rx_db, tx_buf->rx_prod);
178
179 }
180 }
181
bnxt_xdp_attached(struct bnxt * bp,struct bnxt_rx_ring_info * rxr)182 bool bnxt_xdp_attached(struct bnxt *bp, struct bnxt_rx_ring_info *rxr)
183 {
184 struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
185
186 return !!xdp_prog;
187 }
188
bnxt_xdp_buff_init(struct bnxt * bp,struct bnxt_rx_ring_info * rxr,u16 cons,u8 * data_ptr,unsigned int len,struct xdp_buff * xdp)189 void bnxt_xdp_buff_init(struct bnxt *bp, struct bnxt_rx_ring_info *rxr,
190 u16 cons, u8 *data_ptr, unsigned int len,
191 struct xdp_buff *xdp)
192 {
193 u32 buflen = BNXT_RX_PAGE_SIZE;
194 struct bnxt_sw_rx_bd *rx_buf;
195 struct pci_dev *pdev;
196 dma_addr_t mapping;
197 u32 offset;
198
199 pdev = bp->pdev;
200 rx_buf = &rxr->rx_buf_ring[cons];
201 offset = bp->rx_offset;
202
203 mapping = rx_buf->mapping - bp->rx_dma_offset;
204 dma_sync_single_for_cpu(&pdev->dev, mapping + offset, len, bp->rx_dir);
205
206 xdp_init_buff(xdp, buflen, &rxr->xdp_rxq);
207 xdp_prepare_buff(xdp, data_ptr - offset, offset, len, false);
208 }
209
bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info * rxr,struct xdp_buff * xdp)210 void bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info *rxr,
211 struct xdp_buff *xdp)
212 {
213 struct skb_shared_info *shinfo;
214 int i;
215
216 if (!xdp || !xdp_buff_has_frags(xdp))
217 return;
218 shinfo = xdp_get_shared_info_from_buff(xdp);
219 for (i = 0; i < shinfo->nr_frags; i++) {
220 struct page *page = skb_frag_page(&shinfo->frags[i]);
221
222 page_pool_recycle_direct(rxr->page_pool, page);
223 }
224 shinfo->nr_frags = 0;
225 }
226
227 /* returns the following:
228 * true - packet consumed by XDP and new buffer is allocated.
229 * false - packet should be passed to the stack.
230 */
bnxt_rx_xdp(struct bnxt * bp,struct bnxt_rx_ring_info * rxr,u16 cons,struct xdp_buff xdp,struct page * page,u8 ** data_ptr,unsigned int * len,u8 * event)231 bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
232 struct xdp_buff xdp, struct page *page, u8 **data_ptr,
233 unsigned int *len, u8 *event)
234 {
235 struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
236 struct bnxt_tx_ring_info *txr;
237 struct bnxt_sw_rx_bd *rx_buf;
238 struct pci_dev *pdev;
239 dma_addr_t mapping;
240 u32 tx_needed = 1;
241 void *orig_data;
242 u32 tx_avail;
243 u32 offset;
244 u32 act;
245
246 if (!xdp_prog)
247 return false;
248
249 pdev = bp->pdev;
250 offset = bp->rx_offset;
251
252 txr = rxr->bnapi->tx_ring;
253 /* BNXT_RX_PAGE_MODE(bp) when XDP enabled */
254 orig_data = xdp.data;
255
256 act = bpf_prog_run_xdp(xdp_prog, &xdp);
257
258 tx_avail = bnxt_tx_avail(bp, txr);
259 /* If the tx ring is not full, we must not update the rx producer yet
260 * because we may still be transmitting on some BDs.
261 */
262 if (tx_avail != bp->tx_ring_size)
263 *event &= ~BNXT_RX_EVENT;
264
265 *len = xdp.data_end - xdp.data;
266 if (orig_data != xdp.data) {
267 offset = xdp.data - xdp.data_hard_start;
268 *data_ptr = xdp.data_hard_start + offset;
269 }
270
271 switch (act) {
272 case XDP_PASS:
273 return false;
274
275 case XDP_TX:
276 rx_buf = &rxr->rx_buf_ring[cons];
277 mapping = rx_buf->mapping - bp->rx_dma_offset;
278 *event = 0;
279
280 if (unlikely(xdp_buff_has_frags(&xdp))) {
281 struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(&xdp);
282
283 tx_needed += sinfo->nr_frags;
284 *event = BNXT_AGG_EVENT;
285 }
286
287 if (tx_avail < tx_needed) {
288 trace_xdp_exception(bp->dev, xdp_prog, act);
289 bnxt_xdp_buff_frags_free(rxr, &xdp);
290 bnxt_reuse_rx_data(rxr, cons, page);
291 return true;
292 }
293
294 dma_sync_single_for_device(&pdev->dev, mapping + offset, *len,
295 bp->rx_dir);
296
297 *event |= BNXT_TX_EVENT;
298 __bnxt_xmit_xdp(bp, txr, mapping + offset, *len,
299 NEXT_RX(rxr->rx_prod), &xdp);
300 bnxt_reuse_rx_data(rxr, cons, page);
301 return true;
302 case XDP_REDIRECT:
303 /* if we are calling this here then we know that the
304 * redirect is coming from a frame received by the
305 * bnxt_en driver.
306 */
307 rx_buf = &rxr->rx_buf_ring[cons];
308 mapping = rx_buf->mapping - bp->rx_dma_offset;
309 dma_unmap_page_attrs(&pdev->dev, mapping,
310 BNXT_RX_PAGE_SIZE, bp->rx_dir,
311 DMA_ATTR_WEAK_ORDERING);
312
313 /* if we are unable to allocate a new buffer, abort and reuse */
314 if (bnxt_alloc_rx_data(bp, rxr, rxr->rx_prod, GFP_ATOMIC)) {
315 trace_xdp_exception(bp->dev, xdp_prog, act);
316 bnxt_xdp_buff_frags_free(rxr, &xdp);
317 bnxt_reuse_rx_data(rxr, cons, page);
318 return true;
319 }
320
321 if (xdp_do_redirect(bp->dev, &xdp, xdp_prog)) {
322 trace_xdp_exception(bp->dev, xdp_prog, act);
323 page_pool_recycle_direct(rxr->page_pool, page);
324 return true;
325 }
326
327 *event |= BNXT_REDIRECT_EVENT;
328 break;
329 default:
330 bpf_warn_invalid_xdp_action(bp->dev, xdp_prog, act);
331 fallthrough;
332 case XDP_ABORTED:
333 trace_xdp_exception(bp->dev, xdp_prog, act);
334 fallthrough;
335 case XDP_DROP:
336 bnxt_xdp_buff_frags_free(rxr, &xdp);
337 bnxt_reuse_rx_data(rxr, cons, page);
338 break;
339 }
340 return true;
341 }
342
bnxt_xdp_xmit(struct net_device * dev,int num_frames,struct xdp_frame ** frames,u32 flags)343 int bnxt_xdp_xmit(struct net_device *dev, int num_frames,
344 struct xdp_frame **frames, u32 flags)
345 {
346 struct bnxt *bp = netdev_priv(dev);
347 struct bpf_prog *xdp_prog = READ_ONCE(bp->xdp_prog);
348 struct pci_dev *pdev = bp->pdev;
349 struct bnxt_tx_ring_info *txr;
350 dma_addr_t mapping;
351 int nxmit = 0;
352 int ring;
353 int i;
354
355 if (!test_bit(BNXT_STATE_OPEN, &bp->state) ||
356 !bp->tx_nr_rings_xdp ||
357 !xdp_prog)
358 return -EINVAL;
359
360 ring = smp_processor_id() % bp->tx_nr_rings_xdp;
361 txr = &bp->tx_ring[ring];
362
363 if (READ_ONCE(txr->dev_state) == BNXT_DEV_STATE_CLOSING)
364 return -EINVAL;
365
366 if (static_branch_unlikely(&bnxt_xdp_locking_key))
367 spin_lock(&txr->xdp_tx_lock);
368
369 for (i = 0; i < num_frames; i++) {
370 struct xdp_frame *xdp = frames[i];
371
372 if (!bnxt_tx_avail(bp, txr))
373 break;
374
375 mapping = dma_map_single(&pdev->dev, xdp->data, xdp->len,
376 DMA_TO_DEVICE);
377
378 if (dma_mapping_error(&pdev->dev, mapping))
379 break;
380
381 __bnxt_xmit_xdp_redirect(bp, txr, mapping, xdp->len, xdp);
382 nxmit++;
383 }
384
385 if (flags & XDP_XMIT_FLUSH) {
386 /* Sync BD data before updating doorbell */
387 wmb();
388 bnxt_db_write(bp, &txr->tx_db, txr->tx_prod);
389 }
390
391 if (static_branch_unlikely(&bnxt_xdp_locking_key))
392 spin_unlock(&txr->xdp_tx_lock);
393
394 return nxmit;
395 }
396
397 /* Under rtnl_lock */
bnxt_xdp_set(struct bnxt * bp,struct bpf_prog * prog)398 static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
399 {
400 struct net_device *dev = bp->dev;
401 int tx_xdp = 0, rc, tc;
402 struct bpf_prog *old;
403
404 if (prog && !prog->aux->xdp_has_frags &&
405 bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) {
406 netdev_warn(dev, "MTU %d larger than %d without XDP frag support.\n",
407 bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU);
408 return -EOPNOTSUPP;
409 }
410 if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) {
411 netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
412 return -EOPNOTSUPP;
413 }
414 if (prog)
415 tx_xdp = bp->rx_nr_rings;
416
417 tc = netdev_get_num_tc(dev);
418 if (!tc)
419 tc = 1;
420 rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings,
421 true, tc, tx_xdp);
422 if (rc) {
423 netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n");
424 return rc;
425 }
426 if (netif_running(dev))
427 bnxt_close_nic(bp, true, false);
428
429 old = xchg(&bp->xdp_prog, prog);
430 if (old)
431 bpf_prog_put(old);
432
433 if (prog) {
434 bnxt_set_rx_skb_mode(bp, true);
435 xdp_features_set_redirect_target(dev, true);
436 } else {
437 int rx, tx;
438
439 xdp_features_clear_redirect_target(dev);
440 bnxt_set_rx_skb_mode(bp, false);
441 bnxt_get_max_rings(bp, &rx, &tx, true);
442 if (rx > 1) {
443 bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS;
444 bp->dev->hw_features |= NETIF_F_LRO;
445 }
446 }
447 bp->tx_nr_rings_xdp = tx_xdp;
448 bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;
449 bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings);
450 bnxt_set_tpa_flags(bp);
451 bnxt_set_ring_params(bp);
452
453 if (netif_running(dev))
454 return bnxt_open_nic(bp, true, false);
455
456 return 0;
457 }
458
bnxt_xdp(struct net_device * dev,struct netdev_bpf * xdp)459 int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
460 {
461 struct bnxt *bp = netdev_priv(dev);
462 int rc;
463
464 switch (xdp->command) {
465 case XDP_SETUP_PROG:
466 rc = bnxt_xdp_set(bp, xdp->prog);
467 break;
468 default:
469 rc = -EINVAL;
470 break;
471 }
472 return rc;
473 }
474
475 struct sk_buff *
bnxt_xdp_build_skb(struct bnxt * bp,struct sk_buff * skb,u8 num_frags,struct page_pool * pool,struct xdp_buff * xdp,struct rx_cmp_ext * rxcmp1)476 bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
477 struct page_pool *pool, struct xdp_buff *xdp,
478 struct rx_cmp_ext *rxcmp1)
479 {
480 struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
481
482 if (!skb)
483 return NULL;
484 skb_checksum_none_assert(skb);
485 if (RX_CMP_L4_CS_OK(rxcmp1)) {
486 if (bp->dev->features & NETIF_F_RXCSUM) {
487 skb->ip_summed = CHECKSUM_UNNECESSARY;
488 skb->csum_level = RX_CMP_ENCAP(rxcmp1);
489 }
490 }
491 xdp_update_skb_shared_info(skb, num_frags,
492 sinfo->xdp_frags_size,
493 BNXT_RX_PAGE_SIZE * sinfo->nr_frags,
494 xdp_buff_is_frag_pfmemalloc(xdp));
495 return skb;
496 }
497
