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