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 */