i40e, xsk: uninitialized variable in i40e_clean_rx_irq_zc()
[linux-2.6-microblaze.git] / drivers / net / ethernet / intel / i40e / i40e_xsk.c
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 "i40e.h"
9 #include "i40e_txrx_common.h"
10 #include "i40e_xsk.h"
11
12 int i40e_alloc_rx_bi_zc(struct i40e_ring *rx_ring)
13 {
14         unsigned long sz = sizeof(*rx_ring->rx_bi_zc) * rx_ring->count;
15
16         rx_ring->rx_bi_zc = kzalloc(sz, GFP_KERNEL);
17         return rx_ring->rx_bi_zc ? 0 : -ENOMEM;
18 }
19
20 void i40e_clear_rx_bi_zc(struct i40e_ring *rx_ring)
21 {
22         memset(rx_ring->rx_bi_zc, 0,
23                sizeof(*rx_ring->rx_bi_zc) * rx_ring->count);
24 }
25
26 static struct xdp_buff **i40e_rx_bi(struct i40e_ring *rx_ring, u32 idx)
27 {
28         return &rx_ring->rx_bi_zc[idx];
29 }
30
31 /**
32  * i40e_xsk_pool_enable - Enable/associate an AF_XDP buffer pool to a
33  * certain ring/qid
34  * @vsi: Current VSI
35  * @pool: buffer pool
36  * @qid: Rx ring to associate buffer pool with
37  *
38  * Returns 0 on success, <0 on failure
39  **/
40 static int i40e_xsk_pool_enable(struct i40e_vsi *vsi,
41                                 struct xsk_buff_pool *pool,
42                                 u16 qid)
43 {
44         struct net_device *netdev = vsi->netdev;
45         bool if_running;
46         int err;
47
48         if (vsi->type != I40E_VSI_MAIN)
49                 return -EINVAL;
50
51         if (qid >= vsi->num_queue_pairs)
52                 return -EINVAL;
53
54         if (qid >= netdev->real_num_rx_queues ||
55             qid >= netdev->real_num_tx_queues)
56                 return -EINVAL;
57
58         err = xsk_pool_dma_map(pool, &vsi->back->pdev->dev, I40E_RX_DMA_ATTR);
59         if (err)
60                 return err;
61
62         set_bit(qid, vsi->af_xdp_zc_qps);
63
64         if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
65
66         if (if_running) {
67                 err = i40e_queue_pair_disable(vsi, qid);
68                 if (err)
69                         return err;
70
71                 err = i40e_queue_pair_enable(vsi, qid);
72                 if (err)
73                         return err;
74
75                 /* Kick start the NAPI context so that receiving will start */
76                 err = i40e_xsk_wakeup(vsi->netdev, qid, XDP_WAKEUP_RX);
77                 if (err)
78                         return err;
79         }
80
81         return 0;
82 }
83
84 /**
85  * i40e_xsk_pool_disable - Disassociate an AF_XDP buffer pool from a
86  * certain ring/qid
87  * @vsi: Current VSI
88  * @qid: Rx ring to associate buffer pool with
89  *
90  * Returns 0 on success, <0 on failure
91  **/
92 static int i40e_xsk_pool_disable(struct i40e_vsi *vsi, u16 qid)
93 {
94         struct net_device *netdev = vsi->netdev;
95         struct xsk_buff_pool *pool;
96         bool if_running;
97         int err;
98
99         pool = xsk_get_pool_from_qid(netdev, qid);
100         if (!pool)
101                 return -EINVAL;
102
103         if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
104
105         if (if_running) {
106                 err = i40e_queue_pair_disable(vsi, qid);
107                 if (err)
108                         return err;
109         }
110
111         clear_bit(qid, vsi->af_xdp_zc_qps);
112         xsk_pool_dma_unmap(pool, I40E_RX_DMA_ATTR);
113
114         if (if_running) {
115                 err = i40e_queue_pair_enable(vsi, qid);
116                 if (err)
117                         return err;
118         }
119
120         return 0;
121 }
122
123 /**
124  * i40e_xsk_pool_setup - Enable/disassociate an AF_XDP buffer pool to/from
125  * a ring/qid
126  * @vsi: Current VSI
127  * @pool: Buffer pool to enable/associate to a ring, or NULL to disable
128  * @qid: Rx ring to (dis)associate buffer pool (from)to
129  *
130  * This function enables or disables a buffer pool to a certain ring.
131  *
132  * Returns 0 on success, <0 on failure
133  **/
134 int i40e_xsk_pool_setup(struct i40e_vsi *vsi, struct xsk_buff_pool *pool,
135                         u16 qid)
136 {
137         return pool ? i40e_xsk_pool_enable(vsi, pool, qid) :
138                 i40e_xsk_pool_disable(vsi, qid);
139 }
140
141 /**
142  * i40e_run_xdp_zc - Executes an XDP program on an xdp_buff
143  * @rx_ring: Rx ring
144  * @xdp: xdp_buff used as input to the XDP program
145  *
146  * Returns any of I40E_XDP_{PASS, CONSUMED, TX, REDIR}
147  **/
148 static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
149 {
150         int err, result = I40E_XDP_PASS;
151         struct i40e_ring *xdp_ring;
152         struct bpf_prog *xdp_prog;
153         u32 act;
154
155         rcu_read_lock();
156         /* NB! xdp_prog will always be !NULL, due to the fact that
157          * this path is enabled by setting an XDP program.
158          */
159         xdp_prog = READ_ONCE(rx_ring->xdp_prog);
160         act = bpf_prog_run_xdp(xdp_prog, xdp);
161
162         switch (act) {
163         case XDP_PASS:
164                 break;
165         case XDP_TX:
166                 xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
167                 result = i40e_xmit_xdp_tx_ring(xdp, xdp_ring);
168                 break;
169         case XDP_REDIRECT:
170                 err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
171                 result = !err ? I40E_XDP_REDIR : I40E_XDP_CONSUMED;
172                 break;
173         default:
174                 bpf_warn_invalid_xdp_action(act);
175                 fallthrough;
176         case XDP_ABORTED:
177                 trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
178                 fallthrough; /* handle aborts by dropping packet */
179         case XDP_DROP:
180                 result = I40E_XDP_CONSUMED;
181                 break;
182         }
183         rcu_read_unlock();
184         return result;
185 }
186
187 bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
188 {
189         u16 ntu = rx_ring->next_to_use;
190         union i40e_rx_desc *rx_desc;
191         struct xdp_buff **bi, *xdp;
192         dma_addr_t dma;
193         bool ok = true;
194
195         rx_desc = I40E_RX_DESC(rx_ring, ntu);
196         bi = i40e_rx_bi(rx_ring, ntu);
197         do {
198                 xdp = xsk_buff_alloc(rx_ring->xsk_pool);
199                 if (!xdp) {
200                         ok = false;
201                         goto no_buffers;
202                 }
203                 *bi = xdp;
204                 dma = xsk_buff_xdp_get_dma(xdp);
205                 rx_desc->read.pkt_addr = cpu_to_le64(dma);
206                 rx_desc->read.hdr_addr = 0;
207
208                 rx_desc++;
209                 bi++;
210                 ntu++;
211
212                 if (unlikely(ntu == rx_ring->count)) {
213                         rx_desc = I40E_RX_DESC(rx_ring, 0);
214                         bi = i40e_rx_bi(rx_ring, 0);
215                         ntu = 0;
216                 }
217
218                 count--;
219         } while (count);
220
221 no_buffers:
222         if (rx_ring->next_to_use != ntu)
223                 i40e_release_rx_desc(rx_ring, ntu);
224
225         return ok;
226 }
227
228 /**
229  * i40e_construct_skb_zc - Create skbuff from zero-copy Rx buffer
230  * @rx_ring: Rx ring
231  * @xdp: xdp_buff
232  *
233  * This functions allocates a new skb from a zero-copy Rx buffer.
234  *
235  * Returns the skb, or NULL on failure.
236  **/
237 static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
238                                              struct xdp_buff *xdp)
239 {
240         unsigned int metasize = xdp->data - xdp->data_meta;
241         unsigned int datasize = xdp->data_end - xdp->data;
242         struct sk_buff *skb;
243
244         /* allocate a skb to store the frags */
245         skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
246                                xdp->data_end - xdp->data_hard_start,
247                                GFP_ATOMIC | __GFP_NOWARN);
248         if (unlikely(!skb))
249                 return NULL;
250
251         skb_reserve(skb, xdp->data - xdp->data_hard_start);
252         memcpy(__skb_put(skb, datasize), xdp->data, datasize);
253         if (metasize)
254                 skb_metadata_set(skb, metasize);
255
256         xsk_buff_free(xdp);
257         return skb;
258 }
259
260 /**
261  * i40e_inc_ntc: Advance the next_to_clean index
262  * @rx_ring: Rx ring
263  **/
264 static void i40e_inc_ntc(struct i40e_ring *rx_ring)
265 {
266         u32 ntc = rx_ring->next_to_clean + 1;
267
268         ntc = (ntc < rx_ring->count) ? ntc : 0;
269         rx_ring->next_to_clean = ntc;
270 }
271
272 /**
273  * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
274  * @rx_ring: Rx ring
275  * @budget: NAPI budget
276  *
277  * Returns amount of work completed
278  **/
279 int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
280 {
281         unsigned int total_rx_bytes = 0, total_rx_packets = 0;
282         u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
283         unsigned int xdp_res, xdp_xmit = 0;
284         bool failure = false;
285         struct sk_buff *skb;
286
287         while (likely(total_rx_packets < (unsigned int)budget)) {
288                 union i40e_rx_desc *rx_desc;
289                 struct xdp_buff **bi;
290                 unsigned int size;
291                 u64 qword;
292
293                 rx_desc = I40E_RX_DESC(rx_ring, rx_ring->next_to_clean);
294                 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
295
296                 /* This memory barrier is needed to keep us from reading
297                  * any other fields out of the rx_desc until we have
298                  * verified the descriptor has been written back.
299                  */
300                 dma_rmb();
301
302                 if (i40e_rx_is_programming_status(qword)) {
303                         i40e_clean_programming_status(rx_ring,
304                                                       rx_desc->raw.qword[0],
305                                                       qword);
306                         bi = i40e_rx_bi(rx_ring, rx_ring->next_to_clean);
307                         xsk_buff_free(*bi);
308                         *bi = NULL;
309                         cleaned_count++;
310                         i40e_inc_ntc(rx_ring);
311                         continue;
312                 }
313
314                 bi = i40e_rx_bi(rx_ring, rx_ring->next_to_clean);
315                 size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
316                        I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
317                 if (!size)
318                         break;
319
320                 bi = i40e_rx_bi(rx_ring, rx_ring->next_to_clean);
321                 (*bi)->data_end = (*bi)->data + size;
322                 xsk_buff_dma_sync_for_cpu(*bi, rx_ring->xsk_pool);
323
324                 xdp_res = i40e_run_xdp_zc(rx_ring, *bi);
325                 if (xdp_res) {
326                         if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR))
327                                 xdp_xmit |= xdp_res;
328                         else
329                                 xsk_buff_free(*bi);
330
331                         *bi = NULL;
332                         total_rx_bytes += size;
333                         total_rx_packets++;
334
335                         cleaned_count++;
336                         i40e_inc_ntc(rx_ring);
337                         continue;
338                 }
339
340                 /* XDP_PASS path */
341
342                 /* NB! We are not checking for errors using
343                  * i40e_test_staterr with
344                  * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that
345                  * SBP is *not* set in PRT_SBPVSI (default not set).
346                  */
347                 skb = i40e_construct_skb_zc(rx_ring, *bi);
348                 *bi = NULL;
349                 if (!skb) {
350                         rx_ring->rx_stats.alloc_buff_failed++;
351                         break;
352                 }
353
354                 cleaned_count++;
355                 i40e_inc_ntc(rx_ring);
356
357                 if (eth_skb_pad(skb))
358                         continue;
359
360                 total_rx_bytes += skb->len;
361                 total_rx_packets++;
362
363                 i40e_process_skb_fields(rx_ring, rx_desc, skb);
364                 napi_gro_receive(&rx_ring->q_vector->napi, skb);
365         }
366
367         if (cleaned_count >= I40E_RX_BUFFER_WRITE)
368                 failure = !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count);
369
370         i40e_finalize_xdp_rx(rx_ring, xdp_xmit);
371         i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets);
372
373         if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
374                 if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
375                         xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
376                 else
377                         xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
378
379                 return (int)total_rx_packets;
380         }
381         return failure ? budget : (int)total_rx_packets;
382 }
383
384 /**
385  * i40e_xmit_zc - Performs zero-copy Tx AF_XDP
386  * @xdp_ring: XDP Tx ring
387  * @budget: NAPI budget
388  *
389  * Returns true if the work is finished.
390  **/
391 static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
392 {
393         unsigned int sent_frames = 0, total_bytes = 0;
394         struct i40e_tx_desc *tx_desc = NULL;
395         struct i40e_tx_buffer *tx_bi;
396         struct xdp_desc desc;
397         dma_addr_t dma;
398
399         while (budget-- > 0) {
400                 if (!xsk_tx_peek_desc(xdp_ring->xsk_pool, &desc))
401                         break;
402
403                 dma = xsk_buff_raw_get_dma(xdp_ring->xsk_pool, desc.addr);
404                 xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma,
405                                                  desc.len);
406
407                 tx_bi = &xdp_ring->tx_bi[xdp_ring->next_to_use];
408                 tx_bi->bytecount = desc.len;
409
410                 tx_desc = I40E_TX_DESC(xdp_ring, xdp_ring->next_to_use);
411                 tx_desc->buffer_addr = cpu_to_le64(dma);
412                 tx_desc->cmd_type_offset_bsz =
413                         build_ctob(I40E_TX_DESC_CMD_ICRC
414                                    | I40E_TX_DESC_CMD_EOP,
415                                    0, desc.len, 0);
416
417                 sent_frames++;
418                 total_bytes += tx_bi->bytecount;
419
420                 xdp_ring->next_to_use++;
421                 if (xdp_ring->next_to_use == xdp_ring->count)
422                         xdp_ring->next_to_use = 0;
423         }
424
425         if (tx_desc) {
426                 /* Request an interrupt for the last frame and bump tail ptr. */
427                 tx_desc->cmd_type_offset_bsz |= (I40E_TX_DESC_CMD_RS <<
428                                                  I40E_TXD_QW1_CMD_SHIFT);
429                 i40e_xdp_ring_update_tail(xdp_ring);
430
431                 xsk_tx_release(xdp_ring->xsk_pool);
432                 i40e_update_tx_stats(xdp_ring, sent_frames, total_bytes);
433         }
434
435         return !!budget;
436 }
437
438 /**
439  * i40e_clean_xdp_tx_buffer - Frees and unmaps an XDP Tx entry
440  * @tx_ring: XDP Tx ring
441  * @tx_bi: Tx buffer info to clean
442  **/
443 static void i40e_clean_xdp_tx_buffer(struct i40e_ring *tx_ring,
444                                      struct i40e_tx_buffer *tx_bi)
445 {
446         xdp_return_frame(tx_bi->xdpf);
447         tx_ring->xdp_tx_active--;
448         dma_unmap_single(tx_ring->dev,
449                          dma_unmap_addr(tx_bi, dma),
450                          dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
451         dma_unmap_len_set(tx_bi, len, 0);
452 }
453
454 /**
455  * i40e_clean_xdp_tx_irq - Completes AF_XDP entries, and cleans XDP entries
456  * @vsi: Current VSI
457  * @tx_ring: XDP Tx ring
458  *
459  * Returns true if cleanup/tranmission is done.
460  **/
461 bool i40e_clean_xdp_tx_irq(struct i40e_vsi *vsi, struct i40e_ring *tx_ring)
462 {
463         struct xsk_buff_pool *bp = tx_ring->xsk_pool;
464         u32 i, completed_frames, xsk_frames = 0;
465         u32 head_idx = i40e_get_head(tx_ring);
466         struct i40e_tx_buffer *tx_bi;
467         unsigned int ntc;
468
469         if (head_idx < tx_ring->next_to_clean)
470                 head_idx += tx_ring->count;
471         completed_frames = head_idx - tx_ring->next_to_clean;
472
473         if (completed_frames == 0)
474                 goto out_xmit;
475
476         if (likely(!tx_ring->xdp_tx_active)) {
477                 xsk_frames = completed_frames;
478                 goto skip;
479         }
480
481         ntc = tx_ring->next_to_clean;
482
483         for (i = 0; i < completed_frames; i++) {
484                 tx_bi = &tx_ring->tx_bi[ntc];
485
486                 if (tx_bi->xdpf) {
487                         i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
488                         tx_bi->xdpf = NULL;
489                 } else {
490                         xsk_frames++;
491                 }
492
493                 if (++ntc >= tx_ring->count)
494                         ntc = 0;
495         }
496
497 skip:
498         tx_ring->next_to_clean += completed_frames;
499         if (unlikely(tx_ring->next_to_clean >= tx_ring->count))
500                 tx_ring->next_to_clean -= tx_ring->count;
501
502         if (xsk_frames)
503                 xsk_tx_completed(bp, xsk_frames);
504
505         i40e_arm_wb(tx_ring, vsi, completed_frames);
506
507 out_xmit:
508         if (xsk_uses_need_wakeup(tx_ring->xsk_pool))
509                 xsk_set_tx_need_wakeup(tx_ring->xsk_pool);
510
511         return i40e_xmit_zc(tx_ring, I40E_DESC_UNUSED(tx_ring));
512 }
513
514 /**
515  * i40e_xsk_wakeup - Implements the ndo_xsk_wakeup
516  * @dev: the netdevice
517  * @queue_id: queue id to wake up
518  * @flags: ignored in our case since we have Rx and Tx in the same NAPI.
519  *
520  * Returns <0 for errors, 0 otherwise.
521  **/
522 int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
523 {
524         struct i40e_netdev_priv *np = netdev_priv(dev);
525         struct i40e_vsi *vsi = np->vsi;
526         struct i40e_pf *pf = vsi->back;
527         struct i40e_ring *ring;
528
529         if (test_bit(__I40E_CONFIG_BUSY, pf->state))
530                 return -EAGAIN;
531
532         if (test_bit(__I40E_VSI_DOWN, vsi->state))
533                 return -ENETDOWN;
534
535         if (!i40e_enabled_xdp_vsi(vsi))
536                 return -ENXIO;
537
538         if (queue_id >= vsi->num_queue_pairs)
539                 return -ENXIO;
540
541         if (!vsi->xdp_rings[queue_id]->xsk_pool)
542                 return -ENXIO;
543
544         ring = vsi->xdp_rings[queue_id];
545
546         /* The idea here is that if NAPI is running, mark a miss, so
547          * it will run again. If not, trigger an interrupt and
548          * schedule the NAPI from interrupt context. If NAPI would be
549          * scheduled here, the interrupt affinity would not be
550          * honored.
551          */
552         if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi))
553                 i40e_force_wb(vsi, ring->q_vector);
554
555         return 0;
556 }
557
558 void i40e_xsk_clean_rx_ring(struct i40e_ring *rx_ring)
559 {
560         u16 i;
561
562         for (i = 0; i < rx_ring->count; i++) {
563                 struct xdp_buff *rx_bi = *i40e_rx_bi(rx_ring, i);
564
565                 if (!rx_bi)
566                         continue;
567
568                 xsk_buff_free(rx_bi);
569                 rx_bi = NULL;
570         }
571 }
572
573 /**
574  * i40e_xsk_clean_xdp_ring - Clean the XDP Tx ring on shutdown
575  * @tx_ring: XDP Tx ring
576  **/
577 void i40e_xsk_clean_tx_ring(struct i40e_ring *tx_ring)
578 {
579         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
580         struct xsk_buff_pool *bp = tx_ring->xsk_pool;
581         struct i40e_tx_buffer *tx_bi;
582         u32 xsk_frames = 0;
583
584         while (ntc != ntu) {
585                 tx_bi = &tx_ring->tx_bi[ntc];
586
587                 if (tx_bi->xdpf)
588                         i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
589                 else
590                         xsk_frames++;
591
592                 tx_bi->xdpf = NULL;
593
594                 ntc++;
595                 if (ntc >= tx_ring->count)
596                         ntc = 0;
597         }
598
599         if (xsk_frames)
600                 xsk_tx_completed(bp, xsk_frames);
601 }
602
603 /**
604  * i40e_xsk_any_rx_ring_enabled - Checks if Rx rings have an AF_XDP
605  * buffer pool attached
606  * @vsi: vsi
607  *
608  * Returns true if any of the Rx rings has an AF_XDP buffer pool attached
609  **/
610 bool i40e_xsk_any_rx_ring_enabled(struct i40e_vsi *vsi)
611 {
612         struct net_device *netdev = vsi->netdev;
613         int i;
614
615         for (i = 0; i < vsi->num_queue_pairs; i++) {
616                 if (xsk_get_pool_from_qid(netdev, i))
617                         return true;
618         }
619
620         return false;
621 }