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a101fa10 MD |
1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
2 | * | |
3 | * counter/counter-api.h | |
4 | * | |
5 | * LTTng Counters API, requiring counter/config.h | |
6 | * | |
7 | * Copyright (C) 2020 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
8 | */ | |
9 | ||
10 | #ifndef _LTTNG_COUNTER_API_H | |
11 | #define _LTTNG_COUNTER_API_H | |
12 | ||
13 | #include <linux/types.h> | |
14 | #include <linux/percpu.h> | |
15 | #include <linux/bitops.h> | |
16 | #include <counter/counter.h> | |
17 | #include <counter/counter-internal.h> | |
c190d76e | 18 | #include <wrapper/compiler_attributes.h> |
236233f7 | 19 | #include <wrapper/limits.h> |
a101fa10 MD |
20 | |
21 | /* | |
22 | * Using unsigned arithmetic because overflow is defined. | |
23 | */ | |
2b8161a4 | 24 | static __always_inline int __lttng_counter_add(const struct lib_counter_config *config, |
a101fa10 MD |
25 | enum lib_counter_config_alloc alloc, |
26 | enum lib_counter_config_sync sync, | |
27 | struct lib_counter *counter, | |
28 | const size_t *dimension_indexes, int64_t v, | |
29 | int64_t *remainder) | |
30 | { | |
31 | size_t index; | |
32 | bool overflow = false, underflow = false; | |
33 | struct lib_counter_layout *layout; | |
34 | int64_t move_sum = 0; | |
35 | ||
36 | if (unlikely(lttng_counter_validate_indexes(config, counter, dimension_indexes))) | |
37 | return -EOVERFLOW; | |
38 | index = lttng_counter_get_index(config, counter, dimension_indexes); | |
39 | ||
40 | switch (alloc) { | |
41 | case COUNTER_ALLOC_PER_CPU: | |
42 | layout = per_cpu_ptr(counter->percpu_counters, smp_processor_id()); | |
43 | break; | |
44 | case COUNTER_ALLOC_GLOBAL: | |
45 | layout = &counter->global_counters; | |
46 | break; | |
47 | default: | |
48 | return -EINVAL; | |
49 | } | |
50 | ||
51 | switch (config->counter_size) { | |
52 | case COUNTER_SIZE_8_BIT: | |
53 | { | |
54 | int8_t *int_p = (int8_t *) layout->counters + index; | |
55 | int8_t old, n, res; | |
56 | int8_t global_sum_step = counter->global_sum_step.s8; | |
57 | ||
58 | res = *int_p; | |
bc826918 MD |
59 | switch (alloc) { |
60 | case COUNTER_ALLOC_PER_CPU: | |
a101fa10 MD |
61 | { |
62 | do { | |
63 | move_sum = 0; | |
64 | old = res; | |
65 | n = (int8_t) ((uint8_t) old + (uint8_t) v); | |
bf59e80c MD |
66 | if (unlikely(global_sum_step)) { |
67 | if (unlikely(n > (int8_t) global_sum_step)) | |
68 | move_sum = (int8_t) global_sum_step / 2; | |
69 | else if (unlikely(n < -(int8_t) global_sum_step)) | |
70 | move_sum = -((int8_t) global_sum_step / 2); | |
71 | n -= move_sum; | |
72 | } | |
a101fa10 MD |
73 | res = cmpxchg_local(int_p, old, n); |
74 | } while (old != res); | |
75 | break; | |
76 | } | |
bc826918 | 77 | case COUNTER_ALLOC_GLOBAL: |
a101fa10 MD |
78 | { |
79 | do { | |
80 | old = res; | |
81 | n = (int8_t) ((uint8_t) old + (uint8_t) v); | |
82 | res = cmpxchg(int_p, old, n); | |
83 | } while (old != res); | |
84 | break; | |
85 | } | |
cf30b6d4 MD |
86 | default: |
87 | return -EINVAL; | |
a101fa10 MD |
88 | } |
89 | if (v > 0 && (v >= U8_MAX || n < old)) | |
90 | overflow = true; | |
f801323d | 91 | else if (v < 0 && (v <= -(s64) U8_MAX || n > old)) |
a101fa10 MD |
92 | underflow = true; |
93 | break; | |
94 | } | |
95 | case COUNTER_SIZE_16_BIT: | |
96 | { | |
97 | int16_t *int_p = (int16_t *) layout->counters + index; | |
98 | int16_t old, n, res; | |
99 | int16_t global_sum_step = counter->global_sum_step.s16; | |
100 | ||
101 | res = *int_p; | |
bc826918 MD |
102 | switch (alloc) { |
103 | case COUNTER_ALLOC_PER_CPU: | |
a101fa10 MD |
104 | { |
105 | do { | |
106 | move_sum = 0; | |
107 | old = res; | |
108 | n = (int16_t) ((uint16_t) old + (uint16_t) v); | |
bf59e80c MD |
109 | if (unlikely(global_sum_step)) { |
110 | if (unlikely(n > (int16_t) global_sum_step)) | |
111 | move_sum = (int16_t) global_sum_step / 2; | |
112 | else if (unlikely(n < -(int16_t) global_sum_step)) | |
113 | move_sum = -((int16_t) global_sum_step / 2); | |
114 | n -= move_sum; | |
115 | } | |
a101fa10 MD |
116 | res = cmpxchg_local(int_p, old, n); |
117 | } while (old != res); | |
118 | break; | |
119 | } | |
bc826918 | 120 | case COUNTER_ALLOC_GLOBAL: |
a101fa10 MD |
121 | { |
122 | do { | |
123 | old = res; | |
124 | n = (int16_t) ((uint16_t) old + (uint16_t) v); | |
125 | res = cmpxchg(int_p, old, n); | |
126 | } while (old != res); | |
127 | break; | |
128 | } | |
cf30b6d4 MD |
129 | default: |
130 | return -EINVAL; | |
a101fa10 MD |
131 | } |
132 | if (v > 0 && (v >= U16_MAX || n < old)) | |
133 | overflow = true; | |
f801323d | 134 | else if (v < 0 && (v <= -(s64) U16_MAX || n > old)) |
a101fa10 MD |
135 | underflow = true; |
136 | break; | |
137 | } | |
138 | case COUNTER_SIZE_32_BIT: | |
139 | { | |
140 | int32_t *int_p = (int32_t *) layout->counters + index; | |
141 | int32_t old, n, res; | |
142 | int32_t global_sum_step = counter->global_sum_step.s32; | |
143 | ||
144 | res = *int_p; | |
bc826918 MD |
145 | switch (alloc) { |
146 | case COUNTER_ALLOC_PER_CPU: | |
a101fa10 MD |
147 | { |
148 | do { | |
149 | move_sum = 0; | |
150 | old = res; | |
151 | n = (int32_t) ((uint32_t) old + (uint32_t) v); | |
bf59e80c MD |
152 | if (unlikely(global_sum_step)) { |
153 | if (unlikely(n > (int32_t) global_sum_step)) | |
154 | move_sum = (int32_t) global_sum_step / 2; | |
155 | else if (unlikely(n < -(int32_t) global_sum_step)) | |
156 | move_sum = -((int32_t) global_sum_step / 2); | |
157 | n -= move_sum; | |
158 | } | |
a101fa10 MD |
159 | res = cmpxchg_local(int_p, old, n); |
160 | } while (old != res); | |
161 | break; | |
162 | } | |
bc826918 | 163 | case COUNTER_ALLOC_GLOBAL: |
a101fa10 MD |
164 | { |
165 | do { | |
166 | old = res; | |
167 | n = (int32_t) ((uint32_t) old + (uint32_t) v); | |
168 | res = cmpxchg(int_p, old, n); | |
169 | } while (old != res); | |
170 | break; | |
171 | } | |
cf30b6d4 MD |
172 | default: |
173 | return -EINVAL; | |
a101fa10 MD |
174 | } |
175 | if (v > 0 && (v >= U32_MAX || n < old)) | |
176 | overflow = true; | |
f801323d | 177 | else if (v < 0 && (v <= -(s64) U32_MAX || n > old)) |
a101fa10 MD |
178 | underflow = true; |
179 | break; | |
180 | } | |
181 | #if BITS_PER_LONG == 64 | |
182 | case COUNTER_SIZE_64_BIT: | |
183 | { | |
184 | int64_t *int_p = (int64_t *) layout->counters + index; | |
185 | int64_t old, n, res; | |
186 | int64_t global_sum_step = counter->global_sum_step.s64; | |
187 | ||
188 | res = *int_p; | |
bc826918 MD |
189 | switch (alloc) { |
190 | case COUNTER_ALLOC_PER_CPU: | |
a101fa10 MD |
191 | { |
192 | do { | |
193 | move_sum = 0; | |
194 | old = res; | |
195 | n = (int64_t) ((uint64_t) old + (uint64_t) v); | |
bf59e80c MD |
196 | if (unlikely(global_sum_step)) { |
197 | if (unlikely(n > (int64_t) global_sum_step)) | |
198 | move_sum = (int64_t) global_sum_step / 2; | |
199 | else if (unlikely(n < -(int64_t) global_sum_step)) | |
200 | move_sum = -((int64_t) global_sum_step / 2); | |
201 | n -= move_sum; | |
202 | } | |
a101fa10 MD |
203 | res = cmpxchg_local(int_p, old, n); |
204 | } while (old != res); | |
205 | break; | |
206 | } | |
bc826918 | 207 | case COUNTER_ALLOC_GLOBAL: |
a101fa10 MD |
208 | { |
209 | do { | |
210 | old = res; | |
211 | n = (int64_t) ((uint64_t) old + (uint64_t) v); | |
212 | res = cmpxchg(int_p, old, n); | |
213 | } while (old != res); | |
214 | break; | |
215 | } | |
cf30b6d4 MD |
216 | default: |
217 | return -EINVAL; | |
a101fa10 MD |
218 | } |
219 | if (v > 0 && n < old) | |
220 | overflow = true; | |
221 | else if (v < 0 && n > old) | |
222 | underflow = true; | |
223 | break; | |
224 | } | |
225 | #endif | |
226 | default: | |
227 | return -EINVAL; | |
228 | } | |
229 | if (unlikely(overflow && !test_bit(index, layout->overflow_bitmap))) | |
230 | set_bit(index, layout->overflow_bitmap); | |
231 | else if (unlikely(underflow && !test_bit(index, layout->underflow_bitmap))) | |
232 | set_bit(index, layout->underflow_bitmap); | |
233 | if (remainder) | |
234 | *remainder = move_sum; | |
235 | return 0; | |
236 | } | |
237 | ||
2b8161a4 | 238 | static __always_inline int __lttng_counter_add_percpu(const struct lib_counter_config *config, |
a101fa10 MD |
239 | struct lib_counter *counter, |
240 | const size_t *dimension_indexes, int64_t v) | |
241 | { | |
242 | int64_t move_sum; | |
243 | int ret; | |
244 | ||
245 | ret = __lttng_counter_add(config, COUNTER_ALLOC_PER_CPU, config->sync, | |
246 | counter, dimension_indexes, v, &move_sum); | |
247 | if (unlikely(ret)) | |
248 | return ret; | |
249 | if (unlikely(move_sum)) | |
250 | return __lttng_counter_add(config, COUNTER_ALLOC_GLOBAL, COUNTER_SYNC_GLOBAL, | |
251 | counter, dimension_indexes, move_sum, NULL); | |
252 | return 0; | |
253 | } | |
254 | ||
2b8161a4 | 255 | static __always_inline int __lttng_counter_add_global(const struct lib_counter_config *config, |
a101fa10 MD |
256 | struct lib_counter *counter, |
257 | const size_t *dimension_indexes, int64_t v) | |
258 | { | |
259 | return __lttng_counter_add(config, COUNTER_ALLOC_GLOBAL, config->sync, counter, | |
260 | dimension_indexes, v, NULL); | |
261 | } | |
262 | ||
2b8161a4 | 263 | static __always_inline int lttng_counter_add(const struct lib_counter_config *config, |
a101fa10 MD |
264 | struct lib_counter *counter, |
265 | const size_t *dimension_indexes, int64_t v) | |
266 | { | |
267 | switch (config->alloc) { | |
c190d76e MJ |
268 | case COUNTER_ALLOC_PER_CPU: |
269 | lttng_fallthrough; | |
a101fa10 MD |
270 | case COUNTER_ALLOC_PER_CPU | COUNTER_ALLOC_GLOBAL: |
271 | return __lttng_counter_add_percpu(config, counter, dimension_indexes, v); | |
272 | case COUNTER_ALLOC_GLOBAL: | |
273 | return __lttng_counter_add_global(config, counter, dimension_indexes, v); | |
274 | default: | |
275 | return -EINVAL; | |
276 | } | |
277 | } | |
278 | ||
2b8161a4 | 279 | static __always_inline int lttng_counter_inc(const struct lib_counter_config *config, |
a101fa10 MD |
280 | struct lib_counter *counter, |
281 | const size_t *dimension_indexes) | |
282 | { | |
283 | return lttng_counter_add(config, counter, dimension_indexes, 1); | |
284 | } | |
285 | ||
2b8161a4 | 286 | static __always_inline int lttng_counter_dec(const struct lib_counter_config *config, |
a101fa10 MD |
287 | struct lib_counter *counter, |
288 | const size_t *dimension_indexes) | |
289 | { | |
290 | return lttng_counter_add(config, counter, dimension_indexes, -1); | |
291 | } | |
292 | ||
293 | #endif /* _LTTNG_COUNTER_API_H */ |