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
10int err;
11
12#define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8)))
13private(MASK) static struct bpf_cpumask __kptr * global_mask;
14
15struct __cpumask_map_value {
16	struct bpf_cpumask __kptr * cpumask;
17};
18
19struct 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
26struct bpf_cpumask *bpf_cpumask_create(void) __ksym __weak;
27void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym __weak;
28struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym __weak;
29u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym __weak;
30u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym __weak;
31u32 bpf_cpumask_first_and(const struct cpumask *src1,
32			  const struct cpumask *src2) __ksym __weak;
33void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
34void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
35bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym __weak;
36bool bpf_cpumask_test_and_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
37bool bpf_cpumask_test_and_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym __weak;
38void bpf_cpumask_setall(struct bpf_cpumask *cpumask) __ksym __weak;
39void bpf_cpumask_clear(struct bpf_cpumask *cpumask) __ksym __weak;
40bool bpf_cpumask_and(struct bpf_cpumask *cpumask,
41		     const struct cpumask *src1,
42		     const struct cpumask *src2) __ksym __weak;
43void bpf_cpumask_or(struct bpf_cpumask *cpumask,
44		    const struct cpumask *src1,
45		    const struct cpumask *src2) __ksym __weak;
46void bpf_cpumask_xor(struct bpf_cpumask *cpumask,
47		     const struct cpumask *src1,
48		     const struct cpumask *src2) __ksym __weak;
49bool bpf_cpumask_equal(const struct cpumask *src1, const struct cpumask *src2) __ksym __weak;
50bool bpf_cpumask_intersects(const struct cpumask *src1, const struct cpumask *src2) __ksym __weak;
51bool bpf_cpumask_subset(const struct cpumask *src1, const struct cpumask *src2) __ksym __weak;
52bool bpf_cpumask_empty(const struct cpumask *cpumask) __ksym __weak;
53bool bpf_cpumask_full(const struct cpumask *cpumask) __ksym __weak;
54void bpf_cpumask_copy(struct bpf_cpumask *dst, const struct cpumask *src) __ksym __weak;
55u32 bpf_cpumask_any_distribute(const struct cpumask *src) __ksym __weak;
56u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1,
57				   const struct cpumask *src2) __ksym __weak;
58u32 bpf_cpumask_weight(const struct cpumask *cpumask) __ksym __weak;
59
60void bpf_rcu_read_lock(void) __ksym __weak;
61void bpf_rcu_read_unlock(void) __ksym __weak;
62
63static inline const struct cpumask *cast(struct bpf_cpumask *cpumask)
64{
65	return (const struct cpumask *)cpumask;
66}
67
68static inline struct bpf_cpumask *create_cpumask(void)
69{
70	struct bpf_cpumask *cpumask;
71
72	cpumask = bpf_cpumask_create();
73	if (!cpumask) {
74		err = 1;
75		return NULL;
76	}
77
78	if (!bpf_cpumask_empty(cast(cpumask))) {
79		err = 2;
80		bpf_cpumask_release(cpumask);
81		return NULL;
82	}
83
84	return cpumask;
85}
86
87static inline struct __cpumask_map_value *cpumask_map_value_lookup(void)
88{
89	u32 key = 0;
90
91	return bpf_map_lookup_elem(&__cpumask_map, &key);
92}
93
94static inline int cpumask_map_insert(struct bpf_cpumask *mask)
95{
96	struct __cpumask_map_value local, *v;
97	long status;
98	struct bpf_cpumask *old;
99	u32 key = 0;
100
101	local.cpumask = NULL;
102	status = bpf_map_update_elem(&__cpumask_map, &key, &local, 0);
103	if (status) {
104		bpf_cpumask_release(mask);
105		return status;
106	}
107
108	v = bpf_map_lookup_elem(&__cpumask_map, &key);
109	if (!v) {
110		bpf_cpumask_release(mask);
111		return -ENOENT;
112	}
113
114	old = bpf_kptr_xchg(&v->cpumask, mask);
115	if (old) {
116		bpf_cpumask_release(old);
117		return -EEXIST;
118	}
119
120	return 0;
121}
122
123#endif /* _CPUMASK_COMMON_H */
124