]> Git Repo - J-linux.git/blob - drivers/net/ethernet/sfc/rx.c
Merge tag 'vfs-6.13-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
[J-linux.git] / drivers / net / ethernet / sfc / rx.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /****************************************************************************
3  * Driver for Solarflare network controllers and boards
4  * Copyright 2005-2006 Fen Systems Ltd.
5  * Copyright 2005-2013 Solarflare Communications Inc.
6  */
7
8 #include <linux/socket.h>
9 #include <linux/in.h>
10 #include <linux/slab.h>
11 #include <linux/ip.h>
12 #include <linux/ipv6.h>
13 #include <linux/tcp.h>
14 #include <linux/udp.h>
15 #include <linux/prefetch.h>
16 #include <linux/moduleparam.h>
17 #include <linux/iommu.h>
18 #include <net/ip.h>
19 #include <net/checksum.h>
20 #include <net/xdp.h>
21 #include <linux/bpf_trace.h>
22 #include "net_driver.h"
23 #include "efx.h"
24 #include "rx_common.h"
25 #include "filter.h"
26 #include "nic.h"
27 #include "selftest.h"
28 #include "workarounds.h"
29
30 /* Preferred number of descriptors to fill at once */
31 #define EFX_RX_PREFERRED_BATCH 8U
32
33 /* Maximum rx prefix used by any architecture. */
34 #define EFX_MAX_RX_PREFIX_SIZE 16
35
36 /* Size of buffer allocated for skb header area. */
37 #define EFX_SKB_HEADERS  128u
38
39 /* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
40 #define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
41                                       EFX_RX_USR_BUF_SIZE)
42
43 static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
44                                      struct efx_rx_buffer *rx_buf,
45                                      int len)
46 {
47         struct efx_nic *efx = rx_queue->efx;
48         unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
49
50         if (likely(len <= max_len))
51                 return;
52
53         /* The packet must be discarded, but this is only a fatal error
54          * if the caller indicated it was
55          */
56         rx_buf->flags |= EFX_RX_PKT_DISCARD;
57
58         if (net_ratelimit())
59                 netif_err(efx, rx_err, efx->net_dev,
60                           "RX queue %d overlength RX event (%#x > %#x)\n",
61                           efx_rx_queue_index(rx_queue), len, max_len);
62
63         efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
64 }
65
66 /* Allocate and construct an SKB around page fragments */
67 static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
68                                      struct efx_rx_buffer *rx_buf,
69                                      unsigned int n_frags,
70                                      u8 *eh, int hdr_len)
71 {
72         struct efx_nic *efx = channel->efx;
73         struct sk_buff *skb;
74
75         /* Allocate an SKB to store the headers */
76         skb = netdev_alloc_skb(efx->net_dev,
77                                efx->rx_ip_align + efx->rx_prefix_size +
78                                hdr_len);
79         if (unlikely(skb == NULL)) {
80                 atomic_inc(&efx->n_rx_noskb_drops);
81                 return NULL;
82         }
83
84         EFX_WARN_ON_ONCE_PARANOID(rx_buf->len < hdr_len);
85
86         memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
87                efx->rx_prefix_size + hdr_len);
88         skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
89         __skb_put(skb, hdr_len);
90
91         /* Append the remaining page(s) onto the frag list */
92         if (rx_buf->len > hdr_len) {
93                 rx_buf->page_offset += hdr_len;
94                 rx_buf->len -= hdr_len;
95
96                 for (;;) {
97                         skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
98                                         rx_buf->page, rx_buf->page_offset,
99                                         rx_buf->len, efx->rx_buffer_truesize);
100                         rx_buf->page = NULL;
101
102                         if (skb_shinfo(skb)->nr_frags == n_frags)
103                                 break;
104
105                         rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
106                 }
107         } else {
108                 __free_pages(rx_buf->page, efx->rx_buffer_order);
109                 rx_buf->page = NULL;
110                 n_frags = 0;
111         }
112
113         /* Move past the ethernet header */
114         skb->protocol = eth_type_trans(skb, efx->net_dev);
115
116         skb_mark_napi_id(skb, &channel->napi_str);
117
118         return skb;
119 }
120
121 void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
122                    unsigned int n_frags, unsigned int len, u16 flags)
123 {
124         struct efx_nic *efx = rx_queue->efx;
125         struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
126         struct efx_rx_buffer *rx_buf;
127
128         rx_buf = efx_rx_buffer(rx_queue, index);
129         rx_buf->flags |= flags;
130
131         /* Validate the number of fragments and completed length */
132         if (n_frags == 1) {
133                 if (!(flags & EFX_RX_PKT_PREFIX_LEN))
134                         efx_rx_packet__check_len(rx_queue, rx_buf, len);
135         } else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
136                    unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
137                    unlikely(len > n_frags * efx->rx_dma_len) ||
138                    unlikely(!efx->rx_scatter)) {
139                 /* If this isn't an explicit discard request, either
140                  * the hardware or the driver is broken.
141                  */
142                 WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
143                 rx_buf->flags |= EFX_RX_PKT_DISCARD;
144         }
145
146         netif_vdbg(efx, rx_status, efx->net_dev,
147                    "RX queue %d received ids %x-%x len %d %s%s\n",
148                    efx_rx_queue_index(rx_queue), index,
149                    (index + n_frags - 1) & rx_queue->ptr_mask, len,
150                    (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
151                    (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
152
153         /* Discard packet, if instructed to do so.  Process the
154          * previous receive first.
155          */
156         if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
157                 efx_rx_flush_packet(channel);
158                 efx_discard_rx_packet(channel, rx_buf, n_frags);
159                 return;
160         }
161
162         if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))
163                 rx_buf->len = len;
164
165         /* Release and/or sync the DMA mapping - assumes all RX buffers
166          * consumed in-order per RX queue.
167          */
168         efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
169
170         /* Prefetch nice and early so data will (hopefully) be in cache by
171          * the time we look at it.
172          */
173         prefetch(efx_rx_buf_va(rx_buf));
174
175         rx_buf->page_offset += efx->rx_prefix_size;
176         rx_buf->len -= efx->rx_prefix_size;
177
178         if (n_frags > 1) {
179                 /* Release/sync DMA mapping for additional fragments.
180                  * Fix length for last fragment.
181                  */
182                 unsigned int tail_frags = n_frags - 1;
183
184                 for (;;) {
185                         rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
186                         if (--tail_frags == 0)
187                                 break;
188                         efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
189                 }
190                 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
191                 efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
192         }
193
194         /* All fragments have been DMA-synced, so recycle pages. */
195         rx_buf = efx_rx_buffer(rx_queue, index);
196         efx_recycle_rx_pages(channel, rx_buf, n_frags);
197
198         /* Pipeline receives so that we give time for packet headers to be
199          * prefetched into cache.
200          */
201         efx_rx_flush_packet(channel);
202         channel->rx_pkt_n_frags = n_frags;
203         channel->rx_pkt_index = index;
204 }
205
206 static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
207                            struct efx_rx_buffer *rx_buf,
208                            unsigned int n_frags)
209 {
210         struct sk_buff *skb;
211         u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
212
213         skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
214         if (unlikely(skb == NULL)) {
215                 struct efx_rx_queue *rx_queue;
216
217                 rx_queue = efx_channel_get_rx_queue(channel);
218                 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
219                 return;
220         }
221         skb_record_rx_queue(skb, channel->rx_queue.core_index);
222
223         /* Set the SKB flags */
224         skb_checksum_none_assert(skb);
225         if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED)) {
226                 skb->ip_summed = CHECKSUM_UNNECESSARY;
227                 skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
228         }
229
230         efx_rx_skb_attach_timestamp(channel, skb);
231
232         if (channel->type->receive_skb)
233                 if (channel->type->receive_skb(channel, skb))
234                         return;
235
236         /* Pass the packet up */
237         if (channel->rx_list != NULL)
238                 /* Add to list, will pass up later */
239                 list_add_tail(&skb->list, channel->rx_list);
240         else
241                 /* No list, so pass it up now */
242                 netif_receive_skb(skb);
243 }
244
245 /** efx_do_xdp: perform XDP processing on a received packet
246  *
247  * Returns true if packet should still be delivered.
248  */
249 static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
250                        struct efx_rx_buffer *rx_buf, u8 **ehp)
251 {
252         u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE];
253         struct efx_rx_queue *rx_queue;
254         struct bpf_prog *xdp_prog;
255         struct xdp_frame *xdpf;
256         struct xdp_buff xdp;
257         u32 xdp_act;
258         s16 offset;
259         int err;
260
261         xdp_prog = rcu_dereference_bh(efx->xdp_prog);
262         if (!xdp_prog)
263                 return true;
264
265         rx_queue = efx_channel_get_rx_queue(channel);
266
267         if (unlikely(channel->rx_pkt_n_frags > 1)) {
268                 /* We can't do XDP on fragmented packets - drop. */
269                 efx_free_rx_buffers(rx_queue, rx_buf,
270                                     channel->rx_pkt_n_frags);
271                 if (net_ratelimit())
272                         netif_err(efx, rx_err, efx->net_dev,
273                                   "XDP is not possible with multiple receive fragments (%d)\n",
274                                   channel->rx_pkt_n_frags);
275                 channel->n_rx_xdp_bad_drops++;
276                 return false;
277         }
278
279         dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr,
280                                 rx_buf->len, DMA_FROM_DEVICE);
281
282         /* Save the rx prefix. */
283         EFX_WARN_ON_PARANOID(efx->rx_prefix_size > EFX_MAX_RX_PREFIX_SIZE);
284         memcpy(rx_prefix, *ehp - efx->rx_prefix_size,
285                efx->rx_prefix_size);
286
287         xdp_init_buff(&xdp, efx->rx_page_buf_step, &rx_queue->xdp_rxq_info);
288         /* No support yet for XDP metadata */
289         xdp_prepare_buff(&xdp, *ehp - EFX_XDP_HEADROOM, EFX_XDP_HEADROOM,
290                          rx_buf->len, false);
291
292         xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp);
293
294         offset = (u8 *)xdp.data - *ehp;
295
296         switch (xdp_act) {
297         case XDP_PASS:
298                 /* Fix up rx prefix. */
299                 if (offset) {
300                         *ehp += offset;
301                         rx_buf->page_offset += offset;
302                         rx_buf->len -= offset;
303                         memcpy(*ehp - efx->rx_prefix_size, rx_prefix,
304                                efx->rx_prefix_size);
305                 }
306                 break;
307
308         case XDP_TX:
309                 /* Buffer ownership passes to tx on success. */
310                 xdpf = xdp_convert_buff_to_frame(&xdp);
311                 err = efx_xdp_tx_buffers(efx, 1, &xdpf, true);
312                 if (unlikely(err != 1)) {
313                         efx_free_rx_buffers(rx_queue, rx_buf, 1);
314                         if (net_ratelimit())
315                                 netif_err(efx, rx_err, efx->net_dev,
316                                           "XDP TX failed (%d)\n", err);
317                         channel->n_rx_xdp_bad_drops++;
318                         trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
319                 } else {
320                         channel->n_rx_xdp_tx++;
321                 }
322                 break;
323
324         case XDP_REDIRECT:
325                 err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog);
326                 if (unlikely(err)) {
327                         efx_free_rx_buffers(rx_queue, rx_buf, 1);
328                         if (net_ratelimit())
329                                 netif_err(efx, rx_err, efx->net_dev,
330                                           "XDP redirect failed (%d)\n", err);
331                         channel->n_rx_xdp_bad_drops++;
332                         trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
333                 } else {
334                         channel->n_rx_xdp_redirect++;
335                 }
336                 break;
337
338         default:
339                 bpf_warn_invalid_xdp_action(efx->net_dev, xdp_prog, xdp_act);
340                 efx_free_rx_buffers(rx_queue, rx_buf, 1);
341                 channel->n_rx_xdp_bad_drops++;
342                 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
343                 break;
344
345         case XDP_ABORTED:
346                 trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
347                 fallthrough;
348         case XDP_DROP:
349                 efx_free_rx_buffers(rx_queue, rx_buf, 1);
350                 channel->n_rx_xdp_drops++;
351                 break;
352         }
353
354         return xdp_act == XDP_PASS;
355 }
356
357 /* Handle a received packet.  Second half: Touches packet payload. */
358 void __efx_rx_packet(struct efx_channel *channel)
359 {
360         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
361         struct efx_nic *efx = channel->efx;
362         struct efx_rx_buffer *rx_buf =
363                 efx_rx_buffer(rx_queue, channel->rx_pkt_index);
364         u8 *eh = efx_rx_buf_va(rx_buf);
365
366         /* Read length from the prefix if necessary.  This already
367          * excludes the length of the prefix itself.
368          */
369         if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN) {
370                 rx_buf->len = le16_to_cpup((__le16 *)
371                                            (eh + efx->rx_packet_len_offset));
372                 /* A known issue may prevent this being filled in;
373                  * if that happens, just drop the packet.
374                  * Must do that in the driver since passing a zero-length
375                  * packet up to the stack may cause a crash.
376                  */
377                 if (unlikely(!rx_buf->len)) {
378                         efx_free_rx_buffers(rx_queue, rx_buf,
379                                             channel->rx_pkt_n_frags);
380                         channel->n_rx_frm_trunc++;
381                         goto out;
382                 }
383         }
384
385         /* If we're in loopback test, then pass the packet directly to the
386          * loopback layer, and free the rx_buf here
387          */
388         if (unlikely(efx->loopback_selftest)) {
389                 efx_loopback_rx_packet(efx, eh, rx_buf->len);
390                 efx_free_rx_buffers(rx_queue, rx_buf,
391                                     channel->rx_pkt_n_frags);
392                 goto out;
393         }
394
395         rx_queue->rx_packets++;
396         rx_queue->rx_bytes += rx_buf->len;
397
398         if (!efx_do_xdp(efx, channel, rx_buf, &eh))
399                 goto out;
400
401         if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
402                 rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
403
404         if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)
405                 efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh, 0);
406         else
407                 efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
408 out:
409         channel->rx_pkt_n_frags = 0;
410 }
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