1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
3 *
4 * RMNET Data virtual network driver
5 */
6
7#include <linux/etherdevice.h>
8#include <linux/ethtool.h>
9#include <linux/if_arp.h>
10#include <net/pkt_sched.h>
11#include "rmnet_config.h"
12#include "rmnet_handlers.h"
13#include "rmnet_private.h"
14#include "rmnet_map.h"
15#include "rmnet_vnd.h"
16
17/* RX/TX Fixup */
18
19void rmnet_vnd_rx_fixup(struct sk_buff *skb, struct net_device *dev)
20{
21 struct rmnet_priv *priv = netdev_priv(dev);
22 struct rmnet_pcpu_stats *pcpu_ptr;
23
24 pcpu_ptr = this_cpu_ptr(priv->pcpu_stats);
25
26 u64_stats_update_begin(syncp: &pcpu_ptr->syncp);
27 pcpu_ptr->stats.rx_pkts++;
28 pcpu_ptr->stats.rx_bytes += skb->len;
29 u64_stats_update_end(syncp: &pcpu_ptr->syncp);
30}
31
32void rmnet_vnd_tx_fixup_len(unsigned int len, struct net_device *dev)
33{
34 struct rmnet_priv *priv = netdev_priv(dev);
35 struct rmnet_pcpu_stats *pcpu_ptr;
36
37 pcpu_ptr = this_cpu_ptr(priv->pcpu_stats);
38
39 u64_stats_update_begin(syncp: &pcpu_ptr->syncp);
40 pcpu_ptr->stats.tx_pkts++;
41 pcpu_ptr->stats.tx_bytes += len;
42 u64_stats_update_end(syncp: &pcpu_ptr->syncp);
43}
44
45void rmnet_vnd_tx_fixup(struct sk_buff *skb, struct net_device *dev)
46{
47 rmnet_vnd_tx_fixup_len(len: skb->len, dev);
48}
49
50/* Network Device Operations */
51
52static netdev_tx_t rmnet_vnd_start_xmit(struct sk_buff *skb,
53 struct net_device *dev)
54{
55 struct rmnet_priv *priv;
56
57 priv = netdev_priv(dev);
58 if (priv->real_dev) {
59 rmnet_egress_handler(skb);
60 } else {
61 this_cpu_inc(priv->pcpu_stats->stats.tx_drops);
62 kfree_skb(skb);
63 }
64 return NETDEV_TX_OK;
65}
66
67static int rmnet_vnd_headroom(struct rmnet_port *port)
68{
69 u32 headroom;
70
71 headroom = sizeof(struct rmnet_map_header);
72
73 if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)
74 headroom += sizeof(struct rmnet_map_ul_csum_header);
75
76 return headroom;
77}
78
79static int rmnet_vnd_change_mtu(struct net_device *rmnet_dev, int new_mtu)
80{
81 struct rmnet_priv *priv = netdev_priv(dev: rmnet_dev);
82 struct rmnet_port *port;
83 u32 headroom;
84
85 port = rmnet_get_port_rtnl(real_dev: priv->real_dev);
86
87 headroom = rmnet_vnd_headroom(port);
88
89 if (new_mtu < 0 || new_mtu > RMNET_MAX_PACKET_SIZE ||
90 new_mtu > (priv->real_dev->mtu - headroom))
91 return -EINVAL;
92
93 WRITE_ONCE(rmnet_dev->mtu, new_mtu);
94 return 0;
95}
96
97static int rmnet_vnd_get_iflink(const struct net_device *dev)
98{
99 struct rmnet_priv *priv = netdev_priv(dev);
100
101 return READ_ONCE(priv->real_dev->ifindex);
102}
103
104static int rmnet_vnd_init(struct net_device *dev)
105{
106 struct rmnet_priv *priv = netdev_priv(dev);
107 int err;
108
109 priv->pcpu_stats = alloc_percpu(struct rmnet_pcpu_stats);
110 if (!priv->pcpu_stats)
111 return -ENOMEM;
112
113 err = gro_cells_init(gcells: &priv->gro_cells, dev);
114 if (err) {
115 free_percpu(pdata: priv->pcpu_stats);
116 return err;
117 }
118
119 return 0;
120}
121
122static void rmnet_vnd_uninit(struct net_device *dev)
123{
124 struct rmnet_priv *priv = netdev_priv(dev);
125
126 gro_cells_destroy(gcells: &priv->gro_cells);
127 free_percpu(pdata: priv->pcpu_stats);
128}
129
130static void rmnet_get_stats64(struct net_device *dev,
131 struct rtnl_link_stats64 *s)
132{
133 struct rmnet_priv *priv = netdev_priv(dev);
134 struct rmnet_vnd_stats total_stats = { };
135 struct rmnet_pcpu_stats *pcpu_ptr;
136 struct rmnet_vnd_stats snapshot;
137 unsigned int cpu, start;
138
139 for_each_possible_cpu(cpu) {
140 pcpu_ptr = per_cpu_ptr(priv->pcpu_stats, cpu);
141
142 do {
143 start = u64_stats_fetch_begin(syncp: &pcpu_ptr->syncp);
144 snapshot = pcpu_ptr->stats; /* struct assignment */
145 } while (u64_stats_fetch_retry(syncp: &pcpu_ptr->syncp, start));
146
147 total_stats.rx_pkts += snapshot.rx_pkts;
148 total_stats.rx_bytes += snapshot.rx_bytes;
149 total_stats.tx_pkts += snapshot.tx_pkts;
150 total_stats.tx_bytes += snapshot.tx_bytes;
151 total_stats.tx_drops += snapshot.tx_drops;
152 }
153
154 s->rx_packets = total_stats.rx_pkts;
155 s->rx_bytes = total_stats.rx_bytes;
156 s->tx_packets = total_stats.tx_pkts;
157 s->tx_bytes = total_stats.tx_bytes;
158 s->tx_dropped = total_stats.tx_drops;
159}
160
161static const struct net_device_ops rmnet_vnd_ops = {
162 .ndo_start_xmit = rmnet_vnd_start_xmit,
163 .ndo_change_mtu = rmnet_vnd_change_mtu,
164 .ndo_get_iflink = rmnet_vnd_get_iflink,
165 .ndo_add_slave = rmnet_add_bridge,
166 .ndo_del_slave = rmnet_del_bridge,
167 .ndo_init = rmnet_vnd_init,
168 .ndo_uninit = rmnet_vnd_uninit,
169 .ndo_get_stats64 = rmnet_get_stats64,
170};
171
172static const char rmnet_gstrings_stats[][ETH_GSTRING_LEN] = {
173 "Checksum ok",
174 "Bad IPv4 header checksum",
175 "Checksum valid bit not set",
176 "Checksum validation failed",
177 "Checksum error bad buffer",
178 "Checksum error bad ip version",
179 "Checksum error bad transport",
180 "Checksum skipped on ip fragment",
181 "Checksum skipped",
182 "Checksum computed in software",
183 "Checksum computed in hardware",
184};
185
186static void rmnet_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
187{
188 switch (stringset) {
189 case ETH_SS_STATS:
190 memcpy(buf, &rmnet_gstrings_stats,
191 sizeof(rmnet_gstrings_stats));
192 break;
193 }
194}
195
196static int rmnet_get_sset_count(struct net_device *dev, int sset)
197{
198 switch (sset) {
199 case ETH_SS_STATS:
200 return ARRAY_SIZE(rmnet_gstrings_stats);
201 default:
202 return -EOPNOTSUPP;
203 }
204}
205
206static void rmnet_get_ethtool_stats(struct net_device *dev,
207 struct ethtool_stats *stats, u64 *data)
208{
209 struct rmnet_priv *priv = netdev_priv(dev);
210 struct rmnet_priv_stats *st = &priv->stats;
211
212 if (!data)
213 return;
214
215 memcpy(data, st, ARRAY_SIZE(rmnet_gstrings_stats) * sizeof(u64));
216}
217
218static int rmnet_get_coalesce(struct net_device *dev,
219 struct ethtool_coalesce *coal,
220 struct kernel_ethtool_coalesce *kernel_coal,
221 struct netlink_ext_ack *extack)
222{
223 struct rmnet_priv *priv = netdev_priv(dev);
224 struct rmnet_port *port;
225
226 port = rmnet_get_port_rtnl(real_dev: priv->real_dev);
227
228 memset(kernel_coal, 0, sizeof(*kernel_coal));
229 kernel_coal->tx_aggr_max_bytes = port->egress_agg_params.bytes;
230 kernel_coal->tx_aggr_max_frames = port->egress_agg_params.count;
231 kernel_coal->tx_aggr_time_usecs = div_u64(dividend: port->egress_agg_params.time_nsec,
232 NSEC_PER_USEC);
233
234 return 0;
235}
236
237static int rmnet_set_coalesce(struct net_device *dev,
238 struct ethtool_coalesce *coal,
239 struct kernel_ethtool_coalesce *kernel_coal,
240 struct netlink_ext_ack *extack)
241{
242 struct rmnet_priv *priv = netdev_priv(dev);
243 struct rmnet_port *port;
244
245 port = rmnet_get_port_rtnl(real_dev: priv->real_dev);
246
247 if (kernel_coal->tx_aggr_max_frames < 1 || kernel_coal->tx_aggr_max_frames > 64)
248 return -EINVAL;
249
250 if (kernel_coal->tx_aggr_max_bytes > 32768)
251 return -EINVAL;
252
253 rmnet_map_update_ul_agg_config(port, size: kernel_coal->tx_aggr_max_bytes,
254 count: kernel_coal->tx_aggr_max_frames,
255 time: kernel_coal->tx_aggr_time_usecs);
256
257 return 0;
258}
259
260static const struct ethtool_ops rmnet_ethtool_ops = {
261 .supported_coalesce_params = ETHTOOL_COALESCE_TX_AGGR,
262 .get_coalesce = rmnet_get_coalesce,
263 .set_coalesce = rmnet_set_coalesce,
264 .get_ethtool_stats = rmnet_get_ethtool_stats,
265 .get_strings = rmnet_get_strings,
266 .get_sset_count = rmnet_get_sset_count,
267};
268
269/* Called by kernel whenever a new rmnet<n> device is created. Sets MTU,
270 * flags, ARP type, needed headroom, etc...
271 */
272void rmnet_vnd_setup(struct net_device *rmnet_dev)
273{
274 rmnet_dev->netdev_ops = &rmnet_vnd_ops;
275 rmnet_dev->mtu = RMNET_DFLT_PACKET_SIZE;
276 rmnet_dev->needed_headroom = RMNET_NEEDED_HEADROOM;
277 eth_hw_addr_random(dev: rmnet_dev);
278 rmnet_dev->tx_queue_len = RMNET_TX_QUEUE_LEN;
279
280 /* Raw IP mode */
281 rmnet_dev->header_ops = NULL; /* No header */
282 rmnet_dev->type = ARPHRD_RAWIP;
283 rmnet_dev->hard_header_len = 0;
284 rmnet_dev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
285
286 rmnet_dev->needs_free_netdev = true;
287 rmnet_dev->ethtool_ops = &rmnet_ethtool_ops;
288
289 rmnet_dev->lltx = true;
290
291 /* This perm addr will be used as interface identifier by IPv6 */
292 rmnet_dev->addr_assign_type = NET_ADDR_RANDOM;
293 eth_random_addr(addr: rmnet_dev->perm_addr);
294}
295
296/* Exposed API */
297
298int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
299 struct rmnet_port *port,
300 struct net_device *real_dev,
301 struct rmnet_endpoint *ep,
302 struct netlink_ext_ack *extack)
303
304{
305 struct rmnet_priv *priv = netdev_priv(dev: rmnet_dev);
306 u32 headroom;
307 int rc;
308
309 if (rmnet_get_endpoint(port, mux_id: id)) {
310 NL_SET_ERR_MSG_MOD(extack, "MUX ID already exists");
311 return -EBUSY;
312 }
313
314 rmnet_dev->hw_features = NETIF_F_RXCSUM;
315 rmnet_dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
316 rmnet_dev->hw_features |= NETIF_F_SG;
317
318 priv->real_dev = real_dev;
319
320 headroom = rmnet_vnd_headroom(port);
321
322 if (rmnet_vnd_change_mtu(rmnet_dev, new_mtu: real_dev->mtu - headroom)) {
323 NL_SET_ERR_MSG_MOD(extack, "Invalid MTU on real dev");
324 return -EINVAL;
325 }
326
327 rc = register_netdevice(dev: rmnet_dev);
328 if (!rc) {
329 ep->egress_dev = rmnet_dev;
330 ep->mux_id = id;
331 port->nr_rmnet_devs++;
332
333 rmnet_dev->rtnl_link_ops = &rmnet_link_ops;
334
335 priv->mux_id = id;
336
337 netdev_dbg(rmnet_dev, "rmnet dev created\n");
338 }
339
340 return rc;
341}
342
343int rmnet_vnd_dellink(u8 id, struct rmnet_port *port,
344 struct rmnet_endpoint *ep)
345{
346 if (id >= RMNET_MAX_LOGICAL_EP || !ep->egress_dev)
347 return -EINVAL;
348
349 ep->egress_dev = NULL;
350 port->nr_rmnet_devs--;
351 return 0;
352}
353
354int rmnet_vnd_do_flow_control(struct net_device *rmnet_dev, int enable)
355{
356 netdev_dbg(rmnet_dev, "Setting VND TX queue state to %d\n", enable);
357 /* Although we expect similar number of enable/disable
358 * commands, optimize for the disable. That is more
359 * latency sensitive than enable
360 */
361 if (unlikely(enable))
362 netif_wake_queue(dev: rmnet_dev);
363 else
364 netif_stop_queue(dev: rmnet_dev);
365
366 return 0;
367}
368
369int rmnet_vnd_validate_real_dev_mtu(struct net_device *real_dev)
370{
371 struct hlist_node *tmp_ep;
372 struct rmnet_endpoint *ep;
373 struct rmnet_port *port;
374 unsigned long bkt_ep;
375 u32 headroom;
376
377 port = rmnet_get_port_rtnl(real_dev);
378
379 headroom = rmnet_vnd_headroom(port);
380
381 hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
382 if (ep->egress_dev->mtu > (real_dev->mtu - headroom))
383 return -1;
384 }
385
386 return 0;
387}
388
389int rmnet_vnd_update_dev_mtu(struct rmnet_port *port,
390 struct net_device *real_dev)
391{
392 struct hlist_node *tmp_ep;
393 struct rmnet_endpoint *ep;
394 unsigned long bkt_ep;
395 u32 headroom;
396
397 headroom = rmnet_vnd_headroom(port);
398
399 hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
400 if (ep->egress_dev->mtu <= (real_dev->mtu - headroom))
401 continue;
402
403 if (rmnet_vnd_change_mtu(rmnet_dev: ep->egress_dev,
404 new_mtu: real_dev->mtu - headroom))
405 return -1;
406 }
407
408 return 0;
409}
410

source code of linux/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c