Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_PERCPU_COUNTER_H |
3 | #define _LINUX_PERCPU_COUNTER_H | |
4 | /* | |
5 | * A simple "approximate counter" for use in ext2 and ext3 superblocks. | |
6 | * | |
7 | * WARNING: these things are HUGE. 4 kbytes per counter on 32-way P4. | |
8 | */ | |
9 | ||
1da177e4 LT |
10 | #include <linux/spinlock.h> |
11 | #include <linux/smp.h> | |
c67ad917 | 12 | #include <linux/list.h> |
1da177e4 LT |
13 | #include <linux/threads.h> |
14 | #include <linux/percpu.h> | |
0216bfcf | 15 | #include <linux/types.h> |
908c7f19 | 16 | #include <linux/gfp.h> |
1da177e4 LT |
17 | |
18 | #ifdef CONFIG_SMP | |
19 | ||
20 | struct percpu_counter { | |
f032a450 | 21 | raw_spinlock_t lock; |
0216bfcf | 22 | s64 count; |
c67ad917 AM |
23 | #ifdef CONFIG_HOTPLUG_CPU |
24 | struct list_head list; /* All percpu_counters are on a list */ | |
25 | #endif | |
43cf38eb | 26 | s32 __percpu *counters; |
1da177e4 LT |
27 | }; |
28 | ||
179f7ebf | 29 | extern int percpu_counter_batch; |
1da177e4 | 30 | |
908c7f19 | 31 | int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, gfp_t gfp, |
ea319518 PZ |
32 | struct lock_class_key *key); |
33 | ||
908c7f19 | 34 | #define percpu_counter_init(fbc, value, gfp) \ |
ea319518 PZ |
35 | ({ \ |
36 | static struct lock_class_key __key; \ | |
37 | \ | |
908c7f19 | 38 | __percpu_counter_init(fbc, value, gfp, &__key); \ |
ea319518 PZ |
39 | }) |
40 | ||
c67ad917 | 41 | void percpu_counter_destroy(struct percpu_counter *fbc); |
3a587f47 | 42 | void percpu_counter_set(struct percpu_counter *fbc, s64 amount); |
104b4e51 NB |
43 | void percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, |
44 | s32 batch); | |
02d21168 | 45 | s64 __percpu_counter_sum(struct percpu_counter *fbc); |
80188b0d DC |
46 | int __percpu_counter_compare(struct percpu_counter *fbc, s64 rhs, s32 batch); |
47 | ||
48 | static inline int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs) | |
49 | { | |
50 | return __percpu_counter_compare(fbc, rhs, percpu_counter_batch); | |
51 | } | |
1da177e4 | 52 | |
20e89767 | 53 | static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount) |
252e0ba6 | 54 | { |
104b4e51 | 55 | percpu_counter_add_batch(fbc, amount, percpu_counter_batch); |
252e0ba6 PZ |
56 | } |
57 | ||
bf1d89c8 PZ |
58 | static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc) |
59 | { | |
02d21168 | 60 | s64 ret = __percpu_counter_sum(fbc); |
bf1d89c8 PZ |
61 | return ret < 0 ? 0 : ret; |
62 | } | |
63 | ||
64 | static inline s64 percpu_counter_sum(struct percpu_counter *fbc) | |
65 | { | |
02d21168 | 66 | return __percpu_counter_sum(fbc); |
bf1d89c8 PZ |
67 | } |
68 | ||
0216bfcf | 69 | static inline s64 percpu_counter_read(struct percpu_counter *fbc) |
1da177e4 LT |
70 | { |
71 | return fbc->count; | |
72 | } | |
73 | ||
74 | /* | |
75 | * It is possible for the percpu_counter_read() to return a small negative | |
76 | * number for some counter which should never be negative. | |
0216bfcf | 77 | * |
1da177e4 | 78 | */ |
0216bfcf | 79 | static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc) |
1da177e4 | 80 | { |
0216bfcf | 81 | s64 ret = fbc->count; |
1da177e4 LT |
82 | |
83 | barrier(); /* Prevent reloads of fbc->count */ | |
0216bfcf | 84 | if (ret >= 0) |
1da177e4 | 85 | return ret; |
c84598bb | 86 | return 0; |
1da177e4 LT |
87 | } |
88 | ||
85dcbba3 | 89 | static inline bool percpu_counter_initialized(struct percpu_counter *fbc) |
7f93cff9 TT |
90 | { |
91 | return (fbc->counters != NULL); | |
92 | } | |
93 | ||
7fa4cf92 | 94 | #else /* !CONFIG_SMP */ |
1da177e4 LT |
95 | |
96 | struct percpu_counter { | |
0216bfcf | 97 | s64 count; |
1da177e4 LT |
98 | }; |
99 | ||
908c7f19 TH |
100 | static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount, |
101 | gfp_t gfp) | |
1da177e4 | 102 | { |
0216bfcf | 103 | fbc->count = amount; |
833f4077 | 104 | return 0; |
1da177e4 LT |
105 | } |
106 | ||
107 | static inline void percpu_counter_destroy(struct percpu_counter *fbc) | |
108 | { | |
109 | } | |
110 | ||
3a587f47 PZ |
111 | static inline void percpu_counter_set(struct percpu_counter *fbc, s64 amount) |
112 | { | |
113 | fbc->count = amount; | |
114 | } | |
115 | ||
27f5e0f6 TC |
116 | static inline int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs) |
117 | { | |
118 | if (fbc->count > rhs) | |
119 | return 1; | |
120 | else if (fbc->count < rhs) | |
121 | return -1; | |
122 | else | |
123 | return 0; | |
124 | } | |
125 | ||
80188b0d DC |
126 | static inline int |
127 | __percpu_counter_compare(struct percpu_counter *fbc, s64 rhs, s32 batch) | |
128 | { | |
129 | return percpu_counter_compare(fbc, rhs); | |
130 | } | |
131 | ||
1da177e4 | 132 | static inline void |
20e89767 | 133 | percpu_counter_add(struct percpu_counter *fbc, s64 amount) |
1da177e4 LT |
134 | { |
135 | preempt_disable(); | |
136 | fbc->count += amount; | |
137 | preempt_enable(); | |
138 | } | |
139 | ||
0c9cf2ef | 140 | static inline void |
104b4e51 | 141 | percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, s32 batch) |
0c9cf2ef AB |
142 | { |
143 | percpu_counter_add(fbc, amount); | |
144 | } | |
145 | ||
0216bfcf | 146 | static inline s64 percpu_counter_read(struct percpu_counter *fbc) |
1da177e4 LT |
147 | { |
148 | return fbc->count; | |
149 | } | |
150 | ||
c84598bb SL |
151 | /* |
152 | * percpu_counter is intended to track positive numbers. In the UP case the | |
153 | * number should never be negative. | |
154 | */ | |
0216bfcf | 155 | static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc) |
1da177e4 LT |
156 | { |
157 | return fbc->count; | |
158 | } | |
159 | ||
52d9f3b4 | 160 | static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc) |
e2bab3d9 AM |
161 | { |
162 | return percpu_counter_read_positive(fbc); | |
163 | } | |
164 | ||
bf1d89c8 PZ |
165 | static inline s64 percpu_counter_sum(struct percpu_counter *fbc) |
166 | { | |
167 | return percpu_counter_read(fbc); | |
168 | } | |
169 | ||
85dcbba3 | 170 | static inline bool percpu_counter_initialized(struct percpu_counter *fbc) |
7f93cff9 | 171 | { |
85dcbba3 | 172 | return true; |
7f93cff9 TT |
173 | } |
174 | ||
1da177e4 LT |
175 | #endif /* CONFIG_SMP */ |
176 | ||
177 | static inline void percpu_counter_inc(struct percpu_counter *fbc) | |
178 | { | |
aa0dff2d | 179 | percpu_counter_add(fbc, 1); |
1da177e4 LT |
180 | } |
181 | ||
182 | static inline void percpu_counter_dec(struct percpu_counter *fbc) | |
183 | { | |
aa0dff2d | 184 | percpu_counter_add(fbc, -1); |
1da177e4 LT |
185 | } |
186 | ||
3cb4f9fa PZ |
187 | static inline void percpu_counter_sub(struct percpu_counter *fbc, s64 amount) |
188 | { | |
189 | percpu_counter_add(fbc, -amount); | |
190 | } | |
191 | ||
1da177e4 | 192 | #endif /* _LINUX_PERCPU_COUNTER_H */ |