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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> | |
c570be0d | 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; | |
59 | switch (sync) { | |
60 | case COUNTER_SYNC_PER_CPU: | |
61 | { | |
62 | do { | |
63 | move_sum = 0; | |
64 | old = res; | |
65 | n = (int8_t) ((uint8_t) old + (uint8_t) v); | |
66 | if (unlikely(n > (int8_t) global_sum_step)) | |
67 | move_sum = (int8_t) global_sum_step / 2; | |
68 | else if (unlikely(n < -(int8_t) global_sum_step)) | |
69 | move_sum = -((int8_t) global_sum_step / 2); | |
70 | n -= move_sum; | |
71 | res = cmpxchg_local(int_p, old, n); | |
72 | } while (old != res); | |
73 | break; | |
74 | } | |
75 | case COUNTER_SYNC_GLOBAL: | |
76 | { | |
77 | do { | |
78 | old = res; | |
79 | n = (int8_t) ((uint8_t) old + (uint8_t) v); | |
80 | res = cmpxchg(int_p, old, n); | |
81 | } while (old != res); | |
82 | break; | |
83 | } | |
cf30b6d4 MD |
84 | default: |
85 | return -EINVAL; | |
a101fa10 MD |
86 | } |
87 | if (v > 0 && (v >= U8_MAX || n < old)) | |
88 | overflow = true; | |
f801323d | 89 | else if (v < 0 && (v <= -(s64) U8_MAX || n > old)) |
a101fa10 MD |
90 | underflow = true; |
91 | break; | |
92 | } | |
93 | case COUNTER_SIZE_16_BIT: | |
94 | { | |
95 | int16_t *int_p = (int16_t *) layout->counters + index; | |
96 | int16_t old, n, res; | |
97 | int16_t global_sum_step = counter->global_sum_step.s16; | |
98 | ||
99 | res = *int_p; | |
100 | switch (sync) { | |
101 | case COUNTER_SYNC_PER_CPU: | |
102 | { | |
103 | do { | |
104 | move_sum = 0; | |
105 | old = res; | |
106 | n = (int16_t) ((uint16_t) old + (uint16_t) v); | |
107 | if (unlikely(n > (int16_t) global_sum_step)) | |
108 | move_sum = (int16_t) global_sum_step / 2; | |
109 | else if (unlikely(n < -(int16_t) global_sum_step)) | |
110 | move_sum = -((int16_t) global_sum_step / 2); | |
111 | n -= move_sum; | |
112 | res = cmpxchg_local(int_p, old, n); | |
113 | } while (old != res); | |
114 | break; | |
115 | } | |
116 | case COUNTER_SYNC_GLOBAL: | |
117 | { | |
118 | do { | |
119 | old = res; | |
120 | n = (int16_t) ((uint16_t) old + (uint16_t) v); | |
121 | res = cmpxchg(int_p, old, n); | |
122 | } while (old != res); | |
123 | break; | |
124 | } | |
cf30b6d4 MD |
125 | default: |
126 | return -EINVAL; | |
a101fa10 MD |
127 | } |
128 | if (v > 0 && (v >= U16_MAX || n < old)) | |
129 | overflow = true; | |
f801323d | 130 | else if (v < 0 && (v <= -(s64) U16_MAX || n > old)) |
a101fa10 MD |
131 | underflow = true; |
132 | break; | |
133 | } | |
134 | case COUNTER_SIZE_32_BIT: | |
135 | { | |
136 | int32_t *int_p = (int32_t *) layout->counters + index; | |
137 | int32_t old, n, res; | |
138 | int32_t global_sum_step = counter->global_sum_step.s32; | |
139 | ||
140 | res = *int_p; | |
141 | switch (sync) { | |
142 | case COUNTER_SYNC_PER_CPU: | |
143 | { | |
144 | do { | |
145 | move_sum = 0; | |
146 | old = res; | |
147 | n = (int32_t) ((uint32_t) old + (uint32_t) v); | |
148 | if (unlikely(n > (int32_t) global_sum_step)) | |
149 | move_sum = (int32_t) global_sum_step / 2; | |
150 | else if (unlikely(n < -(int32_t) global_sum_step)) | |
151 | move_sum = -((int32_t) global_sum_step / 2); | |
152 | n -= move_sum; | |
153 | res = cmpxchg_local(int_p, old, n); | |
154 | } while (old != res); | |
155 | break; | |
156 | } | |
157 | case COUNTER_SYNC_GLOBAL: | |
158 | { | |
159 | do { | |
160 | old = res; | |
161 | n = (int32_t) ((uint32_t) old + (uint32_t) v); | |
162 | res = cmpxchg(int_p, old, n); | |
163 | } while (old != res); | |
164 | break; | |
165 | } | |
cf30b6d4 MD |
166 | default: |
167 | return -EINVAL; | |
a101fa10 MD |
168 | } |
169 | if (v > 0 && (v >= U32_MAX || n < old)) | |
170 | overflow = true; | |
f801323d | 171 | else if (v < 0 && (v <= -(s64) U32_MAX || n > old)) |
a101fa10 MD |
172 | underflow = true; |
173 | break; | |
174 | } | |
175 | #if BITS_PER_LONG == 64 | |
176 | case COUNTER_SIZE_64_BIT: | |
177 | { | |
178 | int64_t *int_p = (int64_t *) layout->counters + index; | |
179 | int64_t old, n, res; | |
180 | int64_t global_sum_step = counter->global_sum_step.s64; | |
181 | ||
182 | res = *int_p; | |
183 | switch (sync) { | |
184 | case COUNTER_SYNC_PER_CPU: | |
185 | { | |
186 | do { | |
187 | move_sum = 0; | |
188 | old = res; | |
189 | n = (int64_t) ((uint64_t) old + (uint64_t) v); | |
190 | if (unlikely(n > (int64_t) global_sum_step)) | |
191 | move_sum = (int64_t) global_sum_step / 2; | |
192 | else if (unlikely(n < -(int64_t) global_sum_step)) | |
193 | move_sum = -((int64_t) global_sum_step / 2); | |
194 | n -= move_sum; | |
195 | res = cmpxchg_local(int_p, old, n); | |
196 | } while (old != res); | |
197 | break; | |
198 | } | |
199 | case COUNTER_SYNC_GLOBAL: | |
200 | { | |
201 | do { | |
202 | old = res; | |
203 | n = (int64_t) ((uint64_t) old + (uint64_t) v); | |
204 | res = cmpxchg(int_p, old, n); | |
205 | } while (old != res); | |
206 | break; | |
207 | } | |
cf30b6d4 MD |
208 | default: |
209 | return -EINVAL; | |
a101fa10 MD |
210 | } |
211 | if (v > 0 && n < old) | |
212 | overflow = true; | |
213 | else if (v < 0 && n > old) | |
214 | underflow = true; | |
215 | break; | |
216 | } | |
217 | #endif | |
218 | default: | |
219 | return -EINVAL; | |
220 | } | |
221 | if (unlikely(overflow && !test_bit(index, layout->overflow_bitmap))) | |
222 | set_bit(index, layout->overflow_bitmap); | |
223 | else if (unlikely(underflow && !test_bit(index, layout->underflow_bitmap))) | |
224 | set_bit(index, layout->underflow_bitmap); | |
225 | if (remainder) | |
226 | *remainder = move_sum; | |
227 | return 0; | |
228 | } | |
229 | ||
2b8161a4 | 230 | static __always_inline int __lttng_counter_add_percpu(const struct lib_counter_config *config, |
a101fa10 MD |
231 | struct lib_counter *counter, |
232 | const size_t *dimension_indexes, int64_t v) | |
233 | { | |
234 | int64_t move_sum; | |
235 | int ret; | |
236 | ||
237 | ret = __lttng_counter_add(config, COUNTER_ALLOC_PER_CPU, config->sync, | |
238 | counter, dimension_indexes, v, &move_sum); | |
239 | if (unlikely(ret)) | |
240 | return ret; | |
241 | if (unlikely(move_sum)) | |
242 | return __lttng_counter_add(config, COUNTER_ALLOC_GLOBAL, COUNTER_SYNC_GLOBAL, | |
243 | counter, dimension_indexes, move_sum, NULL); | |
244 | return 0; | |
245 | } | |
246 | ||
2b8161a4 | 247 | static __always_inline int __lttng_counter_add_global(const struct lib_counter_config *config, |
a101fa10 MD |
248 | struct lib_counter *counter, |
249 | const size_t *dimension_indexes, int64_t v) | |
250 | { | |
251 | return __lttng_counter_add(config, COUNTER_ALLOC_GLOBAL, config->sync, counter, | |
252 | dimension_indexes, v, NULL); | |
253 | } | |
254 | ||
2b8161a4 | 255 | static __always_inline int lttng_counter_add(const struct lib_counter_config *config, |
a101fa10 MD |
256 | struct lib_counter *counter, |
257 | const size_t *dimension_indexes, int64_t v) | |
258 | { | |
259 | switch (config->alloc) { | |
c570be0d MJ |
260 | case COUNTER_ALLOC_PER_CPU: |
261 | lttng_fallthrough; | |
a101fa10 MD |
262 | case COUNTER_ALLOC_PER_CPU | COUNTER_ALLOC_GLOBAL: |
263 | return __lttng_counter_add_percpu(config, counter, dimension_indexes, v); | |
264 | case COUNTER_ALLOC_GLOBAL: | |
265 | return __lttng_counter_add_global(config, counter, dimension_indexes, v); | |
266 | default: | |
267 | return -EINVAL; | |
268 | } | |
269 | } | |
270 | ||
2b8161a4 | 271 | static __always_inline int lttng_counter_inc(const struct lib_counter_config *config, |
a101fa10 MD |
272 | struct lib_counter *counter, |
273 | const size_t *dimension_indexes) | |
274 | { | |
275 | return lttng_counter_add(config, counter, dimension_indexes, 1); | |
276 | } | |
277 | ||
2b8161a4 | 278 | static __always_inline int lttng_counter_dec(const struct lib_counter_config *config, |
a101fa10 MD |
279 | struct lib_counter *counter, |
280 | const size_t *dimension_indexes) | |
281 | { | |
282 | return lttng_counter_add(config, counter, dimension_indexes, -1); | |
283 | } | |
284 | ||
285 | #endif /* _LTTNG_COUNTER_API_H */ |