1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3
4 #ifndef _CPUMASK_COMMON_H
5 #define _CPUMASK_COMMON_H
6
7 #include "errno.h"
8 #include <stdbool.h>
9
10 /* Should use BTF_FIELDS_MAX, but it is not always available in vmlinux.h,
11 * so use the hard-coded number as a workaround.
12 */
13 #define CPUMASK_KPTR_FIELDS_MAX 11
14
15 int err;
16
17 #define private(name) SEC(".bss." #name) __attribute__((aligned(8)))
18 private(MASK) static struct bpf_cpumask __kptr * global_mask;
19
20 struct __cpumask_map_value {
21 struct bpf_cpumask __kptr * cpumask;
22 };
23
24 struct array_map {
25 __uint(type, BPF_MAP_TYPE_ARRAY);
26 __type(key, int);
27 __type(value, struct __cpumask_map_value);
28 __uint(max_entries, 1);
29 } __cpumask_map SEC(".maps");
30
31 struct bpf_cpumask *bpf_cpumask_create(void) __ksym __weak;
32 void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym __weak;
33 struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym __weak;
34 u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym __weak;
35 u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym __weak;
36 u32 bpf_cpumask_first_and(const struct cpumask *src1,
37 const struct cpumask *src2) __ksym __weak;
38 void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
39 void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
40 bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym __weak;
41 bool bpf_cpumask_test_and_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
42 bool bpf_cpumask_test_and_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
43 void bpf_cpumask_setall(struct bpf_cpumask *cpumask) __ksym __weak;
44 void bpf_cpumask_clear(struct bpf_cpumask *cpumask) __ksym __weak;
45 bool bpf_cpumask_and(struct bpf_cpumask *cpumask,
46 const struct cpumask *src1,
47 const struct cpumask *src2) __ksym __weak;
48 void bpf_cpumask_or(struct bpf_cpumask *cpumask,
49 const struct cpumask *src1,
50 const struct cpumask *src2) __ksym __weak;
51 void bpf_cpumask_xor(struct bpf_cpumask *cpumask,
52 const struct cpumask *src1,
53 const struct cpumask *src2) __ksym __weak;
54 bool bpf_cpumask_equal(const struct cpumask *src1, const struct cpumask *src2) __ksym __weak;
55 bool bpf_cpumask_intersects(const struct cpumask *src1, const struct cpumask *src2) __ksym __weak;
56 bool bpf_cpumask_subset(const struct cpumask *src1, const struct cpumask *src2) __ksym __weak;
57 bool bpf_cpumask_empty(const struct cpumask *cpumask) __ksym __weak;
58 bool bpf_cpumask_full(const struct cpumask *cpumask) __ksym __weak;
59 void bpf_cpumask_copy(struct bpf_cpumask *dst, const struct cpumask *src) __ksym __weak;
60 u32 bpf_cpumask_any_distribute(const struct cpumask *src) __ksym __weak;
61 u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1,
62 const struct cpumask *src2) __ksym __weak;
63 u32 bpf_cpumask_weight(const struct cpumask *cpumask) __ksym __weak;
64
65 void bpf_rcu_read_lock(void) __ksym __weak;
66 void bpf_rcu_read_unlock(void) __ksym __weak;
67
cast(struct bpf_cpumask * cpumask)68 static inline const struct cpumask *cast(struct bpf_cpumask *cpumask)
69 {
70 return (const struct cpumask *)cpumask;
71 }
72
create_cpumask(void)73 static inline struct bpf_cpumask *create_cpumask(void)
74 {
75 struct bpf_cpumask *cpumask;
76
77 cpumask = bpf_cpumask_create();
78 if (!cpumask) {
79 err = 1;
80 return NULL;
81 }
82
83 if (!bpf_cpumask_empty(cast(cpumask))) {
84 err = 2;
85 bpf_cpumask_release(cpumask);
86 return NULL;
87 }
88
89 return cpumask;
90 }
91
cpumask_map_value_lookup(void)92 static inline struct __cpumask_map_value *cpumask_map_value_lookup(void)
93 {
94 u32 key = 0;
95
96 return bpf_map_lookup_elem(&__cpumask_map, &key);
97 }
98
cpumask_map_insert(struct bpf_cpumask * mask)99 static inline int cpumask_map_insert(struct bpf_cpumask *mask)
100 {
101 struct __cpumask_map_value local, *v;
102 long status;
103 struct bpf_cpumask *old;
104 u32 key = 0;
105
106 local.cpumask = NULL;
107 status = bpf_map_update_elem(&__cpumask_map, &key, &local, 0);
108 if (status) {
109 bpf_cpumask_release(mask);
110 return status;
111 }
112
113 v = bpf_map_lookup_elem(&__cpumask_map, &key);
114 if (!v) {
115 bpf_cpumask_release(mask);
116 return -ENOENT;
117 }
118
119 old = bpf_kptr_xchg(&v->cpumask, mask);
120 if (old) {
121 bpf_cpumask_release(old);
122 return -EEXIST;
123 }
124
125 return 0;
126 }
127
128 #endif /* _CPUMASK_COMMON_H */
129