1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /*
3 * Copyright (c) 2018, Mellanox Technologies inc. All rights reserved.
4 */
5
6 #include <linux/dim.h>
7 #include <linux/rtnetlink.h>
8
9 /*
10 * Net DIM profiles:
11 * There are different set of profiles for each CQ period mode.
12 * There are different set of profiles for RX/TX CQs.
13 * Each profile size must be of NET_DIM_PARAMS_NUM_PROFILES
14 */
15 #define NET_DIM_RX_EQE_PROFILES { \
16 {.usec = 1, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
17 {.usec = 8, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
18 {.usec = 64, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
19 {.usec = 128, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \
20 {.usec = 256, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,} \
21 }
22
23 #define NET_DIM_RX_CQE_PROFILES { \
24 {.usec = 2, .pkts = 256,}, \
25 {.usec = 8, .pkts = 128,}, \
26 {.usec = 16, .pkts = 64,}, \
27 {.usec = 32, .pkts = 64,}, \
28 {.usec = 64, .pkts = 64,} \
29 }
30
31 #define NET_DIM_TX_EQE_PROFILES { \
32 {.usec = 1, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \
33 {.usec = 8, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \
34 {.usec = 32, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \
35 {.usec = 64, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \
36 {.usec = 128, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,} \
37 }
38
39 #define NET_DIM_TX_CQE_PROFILES { \
40 {.usec = 5, .pkts = 128,}, \
41 {.usec = 8, .pkts = 64,}, \
42 {.usec = 16, .pkts = 32,}, \
43 {.usec = 32, .pkts = 32,}, \
44 {.usec = 64, .pkts = 32,} \
45 }
46
47 static const struct dim_cq_moder
48 rx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
49 NET_DIM_RX_EQE_PROFILES,
50 NET_DIM_RX_CQE_PROFILES,
51 };
52
53 static const struct dim_cq_moder
54 tx_profile[DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = {
55 NET_DIM_TX_EQE_PROFILES,
56 NET_DIM_TX_CQE_PROFILES,
57 };
58
59 struct dim_cq_moder
60 net_dim_get_rx_moderation(u8 cq_period_mode, int ix)
61 {
62 struct dim_cq_moder cq_moder = rx_profile[cq_period_mode][ix];
63
64 cq_moder.cq_period_mode = cq_period_mode;
65 return cq_moder;
66 }
67 EXPORT_SYMBOL(net_dim_get_rx_moderation);
68
69 struct dim_cq_moder
70 net_dim_get_def_rx_moderation(u8 cq_period_mode)
71 {
72 u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
73 NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;
74
75 return net_dim_get_rx_moderation(cq_period_mode, profile_ix);
76 }
77 EXPORT_SYMBOL(net_dim_get_def_rx_moderation);
78
79 struct dim_cq_moder
80 net_dim_get_tx_moderation(u8 cq_period_mode, int ix)
81 {
82 struct dim_cq_moder cq_moder = tx_profile[cq_period_mode][ix];
83
84 cq_moder.cq_period_mode = cq_period_mode;
85 return cq_moder;
86 }
87 EXPORT_SYMBOL(net_dim_get_tx_moderation);
88
89 struct dim_cq_moder
90 net_dim_get_def_tx_moderation(u8 cq_period_mode)
91 {
92 u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ?
93 NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE;
94
95 return net_dim_get_tx_moderation(cq_period_mode, profile_ix);
96 }
97 EXPORT_SYMBOL(net_dim_get_def_tx_moderation);
98
99 int net_dim_init_irq_moder(struct net_device *dev, u8 profile_flags,
100 u8 coal_flags, u8 rx_mode, u8 tx_mode,
101 void (*rx_dim_work)(struct work_struct *work),
102 void (*tx_dim_work)(struct work_struct *work))
103 {
104 struct dim_cq_moder *rxp = NULL, *txp;
105 struct dim_irq_moder *moder;
106 int len;
107
108 dev->irq_moder = kzalloc(sizeof(*dev->irq_moder), GFP_KERNEL);
109 if (!dev->irq_moder)
110 return -ENOMEM;
111
112 moder = dev->irq_moder;
113 len = NET_DIM_PARAMS_NUM_PROFILES * sizeof(*moder->rx_profile);
114
115 moder->coal_flags = coal_flags;
116 moder->profile_flags = profile_flags;
117
118 if (profile_flags & DIM_PROFILE_RX) {
119 moder->rx_dim_work = rx_dim_work;
120 moder->dim_rx_mode = rx_mode;
121 rxp = kmemdup(rx_profile[rx_mode], len, GFP_KERNEL);
122 if (!rxp)
123 goto free_moder;
124
125 rcu_assign_pointer(moder->rx_profile, rxp);
126 }
127
128 if (profile_flags & DIM_PROFILE_TX) {
129 moder->tx_dim_work = tx_dim_work;
130 moder->dim_tx_mode = tx_mode;
131 txp = kmemdup(tx_profile[tx_mode], len, GFP_KERNEL);
132 if (!txp)
133 goto free_rxp;
134
135 rcu_assign_pointer(moder->tx_profile, txp);
136 }
137
138 return 0;
139
140 free_rxp:
141 kfree(rxp);
142 free_moder:
143 kfree(moder);
144 return -ENOMEM;
145 }
146 EXPORT_SYMBOL(net_dim_init_irq_moder);
147
148 /* RTNL lock is held. */
149 void net_dim_free_irq_moder(struct net_device *dev)
150 {
151 struct dim_cq_moder *rxp, *txp;
152
153 if (!dev->irq_moder)
154 return;
155
156 rxp = rtnl_dereference(dev->irq_moder->rx_profile);
157 txp = rtnl_dereference(dev->irq_moder->tx_profile);
158
159 rcu_assign_pointer(dev->irq_moder->rx_profile, NULL);
160 rcu_assign_pointer(dev->irq_moder->tx_profile, NULL);
161
162 kfree_rcu(rxp, rcu);
163 kfree_rcu(txp, rcu);
164 kfree(dev->irq_moder);
165 }
166 EXPORT_SYMBOL(net_dim_free_irq_moder);
167
168 void net_dim_setting(struct net_device *dev, struct dim *dim, bool is_tx)
169 {
170 struct dim_irq_moder *irq_moder = dev->irq_moder;
171
172 if (!irq_moder)
173 return;
174
175 if (is_tx) {
176 INIT_WORK(&dim->work, irq_moder->tx_dim_work);
177 dim->mode = READ_ONCE(irq_moder->dim_tx_mode);
178 return;
179 }
180
181 INIT_WORK(&dim->work, irq_moder->rx_dim_work);
182 dim->mode = READ_ONCE(irq_moder->dim_rx_mode);
183 }
184 EXPORT_SYMBOL(net_dim_setting);
185
186 void net_dim_work_cancel(struct dim *dim)
187 {
188 cancel_work_sync(&dim->work);
189 }
190 EXPORT_SYMBOL(net_dim_work_cancel);
191
192 struct dim_cq_moder net_dim_get_rx_irq_moder(struct net_device *dev,
193 struct dim *dim)
194 {
195 struct dim_cq_moder res, *profile;
196
197 rcu_read_lock();
198 profile = rcu_dereference(dev->irq_moder->rx_profile);
199 res = profile[dim->profile_ix];
200 rcu_read_unlock();
201
202 res.cq_period_mode = dim->mode;
203
204 return res;
205 }
206 EXPORT_SYMBOL(net_dim_get_rx_irq_moder);
207
208 struct dim_cq_moder net_dim_get_tx_irq_moder(struct net_device *dev,
209 struct dim *dim)
210 {
211 struct dim_cq_moder res, *profile;
212
213 rcu_read_lock();
214 profile = rcu_dereference(dev->irq_moder->tx_profile);
215 res = profile[dim->profile_ix];
216 rcu_read_unlock();
217
218 res.cq_period_mode = dim->mode;
219
220 return res;
221 }
222 EXPORT_SYMBOL(net_dim_get_tx_irq_moder);
223
224 void net_dim_set_rx_mode(struct net_device *dev, u8 rx_mode)
225 {
226 WRITE_ONCE(dev->irq_moder->dim_rx_mode, rx_mode);
227 }
228 EXPORT_SYMBOL(net_dim_set_rx_mode);
229
230 void net_dim_set_tx_mode(struct net_device *dev, u8 tx_mode)
231 {
232 WRITE_ONCE(dev->irq_moder->dim_tx_mode, tx_mode);
233 }
234 EXPORT_SYMBOL(net_dim_set_tx_mode);
235
236 static int net_dim_step(struct dim *dim)
237 {
238 if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2))
239 return DIM_TOO_TIRED;
240
241 switch (dim->tune_state) {
242 case DIM_PARKING_ON_TOP:
243 case DIM_PARKING_TIRED:
244 break;
245 case DIM_GOING_RIGHT:
246 if (dim->profile_ix == (NET_DIM_PARAMS_NUM_PROFILES - 1))
247 return DIM_ON_EDGE;
248 dim->profile_ix++;
249 dim->steps_right++;
250 break;
251 case DIM_GOING_LEFT:
252 if (dim->profile_ix == 0)
253 return DIM_ON_EDGE;
254 dim->profile_ix--;
255 dim->steps_left++;
256 break;
257 }
258
259 dim->tired++;
260 return DIM_STEPPED;
261 }
262
263 static void net_dim_exit_parking(struct dim *dim)
264 {
265 dim->tune_state = dim->profile_ix ? DIM_GOING_LEFT : DIM_GOING_RIGHT;
266 net_dim_step(dim);
267 }
268
269 static int net_dim_stats_compare(struct dim_stats *curr,
270 struct dim_stats *prev)
271 {
272 if (!prev->bpms)
273 return curr->bpms ? DIM_STATS_BETTER : DIM_STATS_SAME;
274
275 if (IS_SIGNIFICANT_DIFF(curr->bpms, prev->bpms))
276 return (curr->bpms > prev->bpms) ? DIM_STATS_BETTER :
277 DIM_STATS_WORSE;
278
279 if (!prev->ppms)
280 return curr->ppms ? DIM_STATS_BETTER :
281 DIM_STATS_SAME;
282
283 if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms))
284 return (curr->ppms > prev->ppms) ? DIM_STATS_BETTER :
285 DIM_STATS_WORSE;
286
287 if (!prev->epms)
288 return DIM_STATS_SAME;
289
290 if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms))
291 return (curr->epms < prev->epms) ? DIM_STATS_BETTER :
292 DIM_STATS_WORSE;
293
294 return DIM_STATS_SAME;
295 }
296
297 static bool net_dim_decision(struct dim_stats *curr_stats, struct dim *dim)
298 {
299 int prev_state = dim->tune_state;
300 int prev_ix = dim->profile_ix;
301 int stats_res;
302 int step_res;
303
304 switch (dim->tune_state) {
305 case DIM_PARKING_ON_TOP:
306 stats_res = net_dim_stats_compare(curr_stats,
307 &dim->prev_stats);
308 if (stats_res != DIM_STATS_SAME)
309 net_dim_exit_parking(dim);
310 break;
311
312 case DIM_PARKING_TIRED:
313 dim->tired--;
314 if (!dim->tired)
315 net_dim_exit_parking(dim);
316 break;
317
318 case DIM_GOING_RIGHT:
319 case DIM_GOING_LEFT:
320 stats_res = net_dim_stats_compare(curr_stats,
321 &dim->prev_stats);
322 if (stats_res != DIM_STATS_BETTER)
323 dim_turn(dim);
324
325 if (dim_on_top(dim)) {
326 dim_park_on_top(dim);
327 break;
328 }
329
330 step_res = net_dim_step(dim);
331 switch (step_res) {
332 case DIM_ON_EDGE:
333 dim_park_on_top(dim);
334 break;
335 case DIM_TOO_TIRED:
336 dim_park_tired(dim);
337 break;
338 }
339
340 break;
341 }
342
343 if (prev_state != DIM_PARKING_ON_TOP ||
344 dim->tune_state != DIM_PARKING_ON_TOP)
345 dim->prev_stats = *curr_stats;
346
347 return dim->profile_ix != prev_ix;
348 }
349
350 void net_dim(struct dim *dim, struct dim_sample end_sample)
351 {
352 struct dim_stats curr_stats;
353 u16 nevents;
354
355 switch (dim->state) {
356 case DIM_MEASURE_IN_PROGRESS:
357 nevents = BIT_GAP(BITS_PER_TYPE(u16),
358 end_sample.event_ctr,
359 dim->start_sample.event_ctr);
360 if (nevents < DIM_NEVENTS)
361 break;
362 if (!dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats))
363 break;
364 if (net_dim_decision(&curr_stats, dim)) {
365 dim->state = DIM_APPLY_NEW_PROFILE;
366 schedule_work(&dim->work);
367 break;
368 }
369 fallthrough;
370 case DIM_START_MEASURE:
371 dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr,
372 end_sample.byte_ctr, &dim->start_sample);
373 dim->state = DIM_MEASURE_IN_PROGRESS;
374 break;
375 case DIM_APPLY_NEW_PROFILE:
376 break;
377 }
378 }
379 EXPORT_SYMBOL(net_dim);
380
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