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.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 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 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 nr_pkts)128 void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
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 struct bnxt_sw_tx_bd *tx_buf;
134 u16 tx_cons = txr->tx_cons;
135 u16 last_tx_cons = tx_cons;
136 int i, j, frags;
137
138 for (i = 0; i < nr_pkts; i++) {
139 tx_buf = &txr->tx_buf_ring[tx_cons];
140
141 if (tx_buf->action == XDP_REDIRECT) {
142 struct pci_dev *pdev = bp->pdev;
143
144 dma_unmap_single(&pdev->dev,
145 dma_unmap_addr(tx_buf, mapping),
146 dma_unmap_len(tx_buf, len),
147 DMA_TO_DEVICE);
148 xdp_return_frame(tx_buf->xdpf);
149 tx_buf->action = 0;
150 tx_buf->xdpf = NULL;
151 } else if (tx_buf->action == XDP_TX) {
152 rx_doorbell_needed = true;
153 last_tx_cons = tx_cons;
154
155 frags = tx_buf->nr_frags;
156 for (j = 0; j < frags; j++) {
157 tx_cons = NEXT_TX(tx_cons);
158 tx_buf = &txr->tx_buf_ring[tx_cons];
159 page_pool_recycle_direct(rxr->page_pool, tx_buf->page);
160 }
161 }
162 tx_cons = NEXT_TX(tx_cons);
163 }
164 txr->tx_cons = tx_cons;
165 if (rx_doorbell_needed) {
166 tx_buf = &txr->tx_buf_ring[last_tx_cons];
167 bnxt_db_write(bp, &rxr->rx_db, tx_buf->rx_prod);
168
169 }
170 }
171
bnxt_xdp_attached(struct bnxt * bp,struct bnxt_rx_ring_info * rxr)172 bool bnxt_xdp_attached(struct bnxt *bp, struct bnxt_rx_ring_info *rxr)
173 {
174 struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
175
176 return !!xdp_prog;
177 }
178
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)179 void bnxt_xdp_buff_init(struct bnxt *bp, struct bnxt_rx_ring_info *rxr,
180 u16 cons, u8 *data_ptr, unsigned int len,
181 struct xdp_buff *xdp)
182 {
183 struct bnxt_sw_rx_bd *rx_buf;
184 u32 buflen = PAGE_SIZE;
185 struct pci_dev *pdev;
186 dma_addr_t mapping;
187 u32 offset;
188
189 pdev = bp->pdev;
190 rx_buf = &rxr->rx_buf_ring[cons];
191 offset = bp->rx_offset;
192
193 mapping = rx_buf->mapping - bp->rx_dma_offset;
194 dma_sync_single_for_cpu(&pdev->dev, mapping + offset, len, bp->rx_dir);
195
196 xdp_init_buff(xdp, buflen, &rxr->xdp_rxq);
197 xdp_prepare_buff(xdp, data_ptr - offset, offset, len, false);
198 }
199
bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info * rxr,struct xdp_buff * xdp)200 void bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info *rxr,
201 struct xdp_buff *xdp)
202 {
203 struct skb_shared_info *shinfo;
204 int i;
205
206 if (!xdp || !xdp_buff_has_frags(xdp))
207 return;
208 shinfo = xdp_get_shared_info_from_buff(xdp);
209 for (i = 0; i < shinfo->nr_frags; i++) {
210 struct page *page = skb_frag_page(&shinfo->frags[i]);
211
212 page_pool_recycle_direct(rxr->page_pool, page);
213 }
214 shinfo->nr_frags = 0;
215 }
216
217 /* returns the following:
218 * true - packet consumed by XDP and new buffer is allocated.
219 * false - packet should be passed to the stack.
220 */
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)221 bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
222 struct xdp_buff xdp, struct page *page, u8 **data_ptr,
223 unsigned int *len, u8 *event)
224 {
225 struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
226 struct bnxt_tx_ring_info *txr;
227 struct bnxt_sw_rx_bd *rx_buf;
228 struct pci_dev *pdev;
229 dma_addr_t mapping;
230 u32 tx_needed = 1;
231 void *orig_data;
232 u32 tx_avail;
233 u32 offset;
234 u32 act;
235
236 if (!xdp_prog)
237 return false;
238
239 pdev = bp->pdev;
240 offset = bp->rx_offset;
241
242 txr = rxr->bnapi->tx_ring;
243 /* BNXT_RX_PAGE_MODE(bp) when XDP enabled */
244 orig_data = xdp.data;
245
246 act = bpf_prog_run_xdp(xdp_prog, &xdp);
247
248 tx_avail = bnxt_tx_avail(bp, txr);
249 /* If the tx ring is not full, we must not update the rx producer yet
250 * because we may still be transmitting on some BDs.
251 */
252 if (tx_avail != bp->tx_ring_size)
253 *event &= ~BNXT_RX_EVENT;
254
255 *len = xdp.data_end - xdp.data;
256 if (orig_data != xdp.data) {
257 offset = xdp.data - xdp.data_hard_start;
258 *data_ptr = xdp.data_hard_start + offset;
259 }
260
261 switch (act) {
262 case XDP_PASS:
263 return false;
264
265 case XDP_TX:
266 rx_buf = &rxr->rx_buf_ring[cons];
267 mapping = rx_buf->mapping - bp->rx_dma_offset;
268 *event = 0;
269
270 if (unlikely(xdp_buff_has_frags(&xdp))) {
271 struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(&xdp);
272
273 tx_needed += sinfo->nr_frags;
274 *event = BNXT_AGG_EVENT;
275 }
276
277 if (tx_avail < tx_needed) {
278 trace_xdp_exception(bp->dev, xdp_prog, act);
279 bnxt_xdp_buff_frags_free(rxr, &xdp);
280 bnxt_reuse_rx_data(rxr, cons, page);
281 return true;
282 }
283
284 dma_sync_single_for_device(&pdev->dev, mapping + offset, *len,
285 bp->rx_dir);
286
287 *event |= BNXT_TX_EVENT;
288 __bnxt_xmit_xdp(bp, txr, mapping + offset, *len,
289 NEXT_RX(rxr->rx_prod), &xdp);
290 bnxt_reuse_rx_data(rxr, cons, page);
291 return true;
292 case XDP_REDIRECT:
293 /* if we are calling this here then we know that the
294 * redirect is coming from a frame received by the
295 * bnxt_en driver.
296 */
297 rx_buf = &rxr->rx_buf_ring[cons];
298 mapping = rx_buf->mapping - bp->rx_dma_offset;
299 dma_unmap_page_attrs(&pdev->dev, mapping,
300 PAGE_SIZE, bp->rx_dir,
301 DMA_ATTR_WEAK_ORDERING);
302
303 /* if we are unable to allocate a new buffer, abort and reuse */
304 if (bnxt_alloc_rx_data(bp, rxr, rxr->rx_prod, GFP_ATOMIC)) {
305 trace_xdp_exception(bp->dev, xdp_prog, act);
306 bnxt_xdp_buff_frags_free(rxr, &xdp);
307 bnxt_reuse_rx_data(rxr, cons, page);
308 return true;
309 }
310
311 if (xdp_do_redirect(bp->dev, &xdp, xdp_prog)) {
312 trace_xdp_exception(bp->dev, xdp_prog, act);
313 page_pool_recycle_direct(rxr->page_pool, page);
314 return true;
315 }
316
317 *event |= BNXT_REDIRECT_EVENT;
318 break;
319 default:
320 bpf_warn_invalid_xdp_action(bp->dev, xdp_prog, act);
321 fallthrough;
322 case XDP_ABORTED:
323 trace_xdp_exception(bp->dev, xdp_prog, act);
324 fallthrough;
325 case XDP_DROP:
326 bnxt_xdp_buff_frags_free(rxr, &xdp);
327 bnxt_reuse_rx_data(rxr, cons, page);
328 break;
329 }
330 return true;
331 }
332
bnxt_xdp_xmit(struct net_device * dev,int num_frames,struct xdp_frame ** frames,u32 flags)333 int bnxt_xdp_xmit(struct net_device *dev, int num_frames,
334 struct xdp_frame **frames, u32 flags)
335 {
336 struct bnxt *bp = netdev_priv(dev);
337 struct bpf_prog *xdp_prog = READ_ONCE(bp->xdp_prog);
338 struct pci_dev *pdev = bp->pdev;
339 struct bnxt_tx_ring_info *txr;
340 dma_addr_t mapping;
341 int nxmit = 0;
342 int ring;
343 int i;
344
345 if (!test_bit(BNXT_STATE_OPEN, &bp->state) ||
346 !bp->tx_nr_rings_xdp ||
347 !xdp_prog)
348 return -EINVAL;
349
350 ring = smp_processor_id() % bp->tx_nr_rings_xdp;
351 txr = &bp->tx_ring[ring];
352
353 if (READ_ONCE(txr->dev_state) == BNXT_DEV_STATE_CLOSING)
354 return -EINVAL;
355
356 if (static_branch_unlikely(&bnxt_xdp_locking_key))
357 spin_lock(&txr->xdp_tx_lock);
358
359 for (i = 0; i < num_frames; i++) {
360 struct xdp_frame *xdp = frames[i];
361
362 if (!bnxt_tx_avail(bp, txr))
363 break;
364
365 mapping = dma_map_single(&pdev->dev, xdp->data, xdp->len,
366 DMA_TO_DEVICE);
367
368 if (dma_mapping_error(&pdev->dev, mapping))
369 break;
370
371 __bnxt_xmit_xdp_redirect(bp, txr, mapping, xdp->len, xdp);
372 nxmit++;
373 }
374
375 if (flags & XDP_XMIT_FLUSH) {
376 /* Sync BD data before updating doorbell */
377 wmb();
378 bnxt_db_write(bp, &txr->tx_db, txr->tx_prod);
379 }
380
381 if (static_branch_unlikely(&bnxt_xdp_locking_key))
382 spin_unlock(&txr->xdp_tx_lock);
383
384 return nxmit;
385 }
386
387 /* Under rtnl_lock */
bnxt_xdp_set(struct bnxt * bp,struct bpf_prog * prog)388 static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
389 {
390 struct net_device *dev = bp->dev;
391 int tx_xdp = 0, rc, tc;
392 struct bpf_prog *old;
393
394 if (prog && !prog->aux->xdp_has_frags &&
395 bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) {
396 netdev_warn(dev, "MTU %d larger than %d without XDP frag support.\n",
397 bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU);
398 return -EOPNOTSUPP;
399 }
400 if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) {
401 netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
402 return -EOPNOTSUPP;
403 }
404 if (prog)
405 tx_xdp = bp->rx_nr_rings;
406
407 tc = netdev_get_num_tc(dev);
408 if (!tc)
409 tc = 1;
410 rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings,
411 true, tc, tx_xdp);
412 if (rc) {
413 netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n");
414 return rc;
415 }
416 if (netif_running(dev))
417 bnxt_close_nic(bp, true, false);
418
419 old = xchg(&bp->xdp_prog, prog);
420 if (old)
421 bpf_prog_put(old);
422
423 if (prog) {
424 bnxt_set_rx_skb_mode(bp, true);
425 } else {
426 int rx, tx;
427
428 bnxt_set_rx_skb_mode(bp, false);
429 bnxt_get_max_rings(bp, &rx, &tx, true);
430 if (rx > 1) {
431 bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS;
432 bp->dev->hw_features |= NETIF_F_LRO;
433 }
434 }
435 bp->tx_nr_rings_xdp = tx_xdp;
436 bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;
437 bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings);
438 bnxt_set_tpa_flags(bp);
439 bnxt_set_ring_params(bp);
440
441 if (netif_running(dev))
442 return bnxt_open_nic(bp, true, false);
443
444 return 0;
445 }
446
bnxt_xdp(struct net_device * dev,struct netdev_bpf * xdp)447 int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
448 {
449 struct bnxt *bp = netdev_priv(dev);
450 int rc;
451
452 switch (xdp->command) {
453 case XDP_SETUP_PROG:
454 rc = bnxt_xdp_set(bp, xdp->prog);
455 break;
456 default:
457 rc = -EINVAL;
458 break;
459 }
460 return rc;
461 }
462
463 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)464 bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
465 struct page_pool *pool, struct xdp_buff *xdp,
466 struct rx_cmp_ext *rxcmp1)
467 {
468 struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
469
470 if (!skb)
471 return NULL;
472 skb_checksum_none_assert(skb);
473 if (RX_CMP_L4_CS_OK(rxcmp1)) {
474 if (bp->dev->features & NETIF_F_RXCSUM) {
475 skb->ip_summed = CHECKSUM_UNNECESSARY;
476 skb->csum_level = RX_CMP_ENCAP(rxcmp1);
477 }
478 }
479 xdp_update_skb_shared_info(skb, num_frags,
480 sinfo->xdp_frags_size,
481 PAGE_SIZE * sinfo->nr_frags,
482 xdp_buff_is_frag_pfmemalloc(xdp));
483 return skb;
484 }
485