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 int err;
11 
12 #define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8)))
13 private(MASK) static struct bpf_cpumask __kptr * global_mask;
14 
15 struct __cpumask_map_value {
16 	struct bpf_cpumask __kptr * cpumask;
17 };
18 
19 struct array_map {
20 	__uint(type, BPF_MAP_TYPE_ARRAY);
21 	__type(key, int);
22 	__type(value, struct __cpumask_map_value);
23 	__uint(max_entries, 1);
24 } __cpumask_map SEC(".maps");
25 
26 struct bpf_cpumask *bpf_cpumask_create(void) __ksym;
27 void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym;
28 struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym;
29 u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym;
30 u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym;
31 void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
32 void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
33 bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym;
34 bool bpf_cpumask_test_and_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
35 bool bpf_cpumask_test_and_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
36 void bpf_cpumask_setall(struct bpf_cpumask *cpumask) __ksym;
37 void bpf_cpumask_clear(struct bpf_cpumask *cpumask) __ksym;
38 bool bpf_cpumask_and(struct bpf_cpumask *cpumask,
39 		     const struct cpumask *src1,
40 		     const struct cpumask *src2) __ksym;
41 void bpf_cpumask_or(struct bpf_cpumask *cpumask,
42 		    const struct cpumask *src1,
43 		    const struct cpumask *src2) __ksym;
44 void bpf_cpumask_xor(struct bpf_cpumask *cpumask,
45 		     const struct cpumask *src1,
46 		     const struct cpumask *src2) __ksym;
47 bool bpf_cpumask_equal(const struct cpumask *src1, const struct cpumask *src2) __ksym;
48 bool bpf_cpumask_intersects(const struct cpumask *src1, const struct cpumask *src2) __ksym;
49 bool bpf_cpumask_subset(const struct cpumask *src1, const struct cpumask *src2) __ksym;
50 bool bpf_cpumask_empty(const struct cpumask *cpumask) __ksym;
51 bool bpf_cpumask_full(const struct cpumask *cpumask) __ksym;
52 void bpf_cpumask_copy(struct bpf_cpumask *dst, const struct cpumask *src) __ksym;
53 u32 bpf_cpumask_any(const struct cpumask *src) __ksym;
54 u32 bpf_cpumask_any_and(const struct cpumask *src1, const struct cpumask *src2) __ksym;
55 
56 void bpf_rcu_read_lock(void) __ksym;
57 void bpf_rcu_read_unlock(void) __ksym;
58 
59 static inline const struct cpumask *cast(struct bpf_cpumask *cpumask)
60 {
61 	return (const struct cpumask *)cpumask;
62 }
63 
64 static inline struct bpf_cpumask *create_cpumask(void)
65 {
66 	struct bpf_cpumask *cpumask;
67 
68 	cpumask = bpf_cpumask_create();
69 	if (!cpumask) {
70 		err = 1;
71 		return NULL;
72 	}
73 
74 	if (!bpf_cpumask_empty(cast(cpumask))) {
75 		err = 2;
76 		bpf_cpumask_release(cpumask);
77 		return NULL;
78 	}
79 
80 	return cpumask;
81 }
82 
83 static inline struct __cpumask_map_value *cpumask_map_value_lookup(void)
84 {
85 	u32 key = 0;
86 
87 	return bpf_map_lookup_elem(&__cpumask_map, &key);
88 }
89 
90 static inline int cpumask_map_insert(struct bpf_cpumask *mask)
91 {
92 	struct __cpumask_map_value local, *v;
93 	long status;
94 	struct bpf_cpumask *old;
95 	u32 key = 0;
96 
97 	local.cpumask = NULL;
98 	status = bpf_map_update_elem(&__cpumask_map, &key, &local, 0);
99 	if (status) {
100 		bpf_cpumask_release(mask);
101 		return status;
102 	}
103 
104 	v = bpf_map_lookup_elem(&__cpumask_map, &key);
105 	if (!v) {
106 		bpf_cpumask_release(mask);
107 		return -ENOENT;
108 	}
109 
110 	old = bpf_kptr_xchg(&v->cpumask, mask);
111 	if (old) {
112 		bpf_cpumask_release(old);
113 		return -EEXIST;
114 	}
115 
116 	return 0;
117 }
118 
119 #endif /* _CPUMASK_COMMON_H */
120