1 /* SPDX-License-Identifier: GPL-2.0 */ 1
2 #ifndef _LINUX_NET_QUEUES_H
3 #define _LINUX_NET_QUEUES_H
4
5 #include <linux/netdevice.h>
6
7 /* See the netdev.yaml spec for definition of
8 struct netdev_queue_stats_rx {
9 u64 bytes;
10 u64 packets;
11 u64 alloc_fail;
12
13 u64 hw_drops;
14 u64 hw_drop_overruns;
15
16 u64 csum_unnecessary;
17 u64 csum_none;
18 u64 csum_bad;
19
20 u64 hw_gro_packets;
21 u64 hw_gro_bytes;
22 u64 hw_gro_wire_packets;
23 u64 hw_gro_wire_bytes;
24
25 u64 hw_drop_ratelimits;
26 };
27
28 struct netdev_queue_stats_tx {
29 u64 bytes;
30 u64 packets;
31
32 u64 hw_drops;
33 u64 hw_drop_errors;
34
35 u64 csum_none;
36 u64 needs_csum;
37
38 u64 hw_gso_packets;
39 u64 hw_gso_bytes;
40 u64 hw_gso_wire_packets;
41 u64 hw_gso_wire_bytes;
42
43 u64 hw_drop_ratelimits;
44
45 u64 stop;
46 u64 wake;
47 };
48
49 /**
50 * struct netdev_stat_ops - netdev ops for fin
51 * @get_queue_stats_rx: get stats for a given
52 * @get_queue_stats_tx: get stats for a given
53 * @get_base_stats: get base stats (not be
54 *
55 * Query stats for a given object. The values
56 * on entry (specifically they are *not* zero-
57 * assign values only to the statistics they c
58 * collected must be left undefined.
59 *
60 * Queue objects are not necessarily persisten
61 * queues are queried by the per-queue callbac
62 * statistics will not generally add up to the
63 * the device. The @get_base_stats callback al
64 * between events for currently live queues an
65 * @get_base_stats can also be used to report
66 * transferred outside of the main set of queu
67 * When the statistics for the entire device a
68 * is issued to collect the delta, and then a
69 * Only statistics which are set in @get_base_
70 * at the device level, meaning that unlike in
71 * a statistic to zero in @get_base_stats is a
72 * This is because @get_base_stats has a secon
73 * statistics are in fact correct for the enti
74 * for some of the events is not maintained, a
75 * be provided).
76 *
77 * Device drivers can assume that when collect
78 * the @get_base_stats and subsequent per-queu
79 * "atomically" (without releasing the rtnl_lo
80 *
81 * Device drivers are encouraged to reset the
82 * number of queues change. This is because th
83 * per-queue statistics is currently to detect
84 */
85 struct netdev_stat_ops {
86 void (*get_queue_stats_rx)(struct net_
87 struct netd
88 void (*get_queue_stats_tx)(struct net_
89 struct netd
90 void (*get_base_stats)(struct net_devi
91 struct netdev_q
92 struct netdev_q
93 };
94
95 /**
96 * struct netdev_queue_mgmt_ops - netdev ops f
97 *
98 * @ndo_queue_mem_size: Size of the struct tha
99 *
100 * @ndo_queue_mem_alloc: Allocate memory for a
101 * The new memory is wri
102 *
103 * @ndo_queue_mem_free: Free memory from an RX
104 *
105 * @ndo_queue_start: Start an RX queue with
106 * specified index.
107 *
108 * @ndo_queue_stop: Stop the RX queue at t
109 * queue's memory is writ
110 */
111 struct netdev_queue_mgmt_ops {
112 size_t ndo_queue_mem_
113 int (*ndo_queue_me
114
115
116 void (*ndo_queue_me
117
118 int (*ndo_queue_st
119
120
121 int (*ndo_queue_st
122
123
124 };
125
126 /**
127 * DOC: Lockless queue stopping / waking helpe
128 *
129 * The netif_txq_maybe_stop() and __netif_txq_
130 * macros are designed to safely implement sto
131 * and waking netdev queues without full lock
132 *
133 * We assume that there can be no concurrent s
134 * wake attempts. The try-stop should happen f
135 * while wake up should be triggered from NAPI
136 * The two may run concurrently (single produc
137 *
138 * The try-stop side is expected to run from t
139 * it does not reschedule Tx (netif_tx_start_q
140 * netif_tx_wake_queue()). Uses of the ``stop`
141 * handler may lead to xmit queue being enable
142 * The waking side does not have similar conte
143 *
144 * The macros guarantee that rings will not re
145 * space available, but they do *not* prevent
146 * the ring is full! Drivers should check for
147 * for the xmit handler.
148 *
149 * All descriptor ring indexes (and other rele
150 * be updated before invoking the macros.
151 */
152
153 #define netif_txq_try_stop(txq, get_desc, star
154 ({
155 int _res;
156
157 netif_tx_stop_queue(txq);
158 /* Producer index and stop bit
159 * to consumer before we reche
160 * Pairs with a barrier in __n
161 */
162 smp_mb__after_atomic();
163
164 /* We need to check again in a
165 * CPU has just made room avai
166 */
167 _res = 0;
168 if (unlikely(get_desc >= start
169 netif_tx_start_queue(t
170 _res = -1;
171 }
172 _res;
173 })
174
175 /**
176 * netif_txq_maybe_stop() - locklessly stop a
177 * @txq: struct netdev_queue to stop/st
178 * @get_desc: get current number of free des
179 * @stop_thrs: minimal number of available de
180 * enabled
181 * @start_thrs: minimal number of descriptors
182 * equal to @stop_thrs or higher
183 *
184 * All arguments may be evaluated multiple tim
185 * @get_desc must be a formula or a function c
186 * return up-to-date information when evaluate
187 * Expected to be used from ndo_start_xmit, se
188 *
189 * Returns:
190 * 0 if the queue was stopped
191 * 1 if the queue was left enabled
192 * -1 if the queue was re-enabled (raced
193 */
194 #define netif_txq_maybe_stop(txq, get_desc, st
195 ({
196 int _res;
197
198 _res = 1;
199 if (unlikely(get_desc < stop_t
200 _res = netif_txq_try_s
201 _res;
202 })
203
204 /* Variant of netdev_tx_completed_queue() whic
205 * @bytes != 0, regardless of kernel config.
206 */
207 static inline void
208 netdev_txq_completed_mb(struct netdev_queue *d
209 unsigned int pkts, uns
210 {
211 if (IS_ENABLED(CONFIG_BQL))
212 netdev_tx_completed_queue(dev_
213 else if (bytes)
214 smp_mb();
215 }
216
217 /**
218 * __netif_txq_completed_wake() - locklessly w
219 * @txq: struct netdev_queue to stop/st
220 * @pkts: number of packets completed
221 * @bytes: number of bytes completed
222 * @get_desc: get current number of free des
223 * @start_thrs: minimal number of descriptors
224 * @down_cond: down condition, predicate indi
225 * not be woken up even if descri
226 *
227 * All arguments may be evaluated multiple tim
228 * @get_desc must be a formula or a function c
229 * return up-to-date information when evaluate
230 * Reports completed pkts/bytes to BQL.
231 *
232 * Returns:
233 * 0 if the queue was woken up
234 * 1 if the queue was already enabled (o
235 * -1 if the queue was left unchanged (@s
236 */
237 #define __netif_txq_completed_wake(txq, pkts,
238 get_desc, s
239 ({
240 int _res;
241
242 /* Report to BQL and piggy bac
243 * Barrier makes sure that any
244 * after this point sees the n
245 * Pairs with barrier in netif
246 */
247 netdev_txq_completed_mb(txq, p
248
249 _res = -1;
250 if (pkts && likely(get_desc >=
251 _res = 1;
252 if (unlikely(netif_tx_
253 !(down_cond)) {
254 netif_tx_wake_
255 _res = 0;
256 }
257 }
258 _res;
259 })
260
261 #define netif_txq_completed_wake(txq, pkts, by
262 __netif_txq_completed_wake(txq, pkts,
263
264 /* subqueue variants follow */
265
266 #define netif_subqueue_try_stop(dev, idx, get_
267 ({
268 struct netdev_queue *txq;
269
270 txq = netdev_get_tx_queue(dev,
271 netif_txq_try_stop(txq, get_de
272 })
273
274 #define netif_subqueue_maybe_stop(dev, idx, ge
275 ({
276 struct netdev_queue *txq;
277
278 txq = netdev_get_tx_queue(dev,
279 netif_txq_maybe_stop(txq, get_
280 })
281
282 #define netif_subqueue_completed_wake(dev, idx
283 get_desc
284 ({
285 struct netdev_queue *txq;
286
287 txq = netdev_get_tx_queue(dev,
288 netif_txq_completed_wake(txq,
289 get_d
290 })
291
292 #endif
293
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