1/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
2/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
3#pragma once
4
5#ifndef WRITE_ONCE
6#define WRITE_ONCE(x, val) ((*(volatile typeof(x) *) &(x)) = (val))
7#endif
8
9#ifndef NUMA_NO_NODE
10#define	NUMA_NO_NODE	(-1)
11#endif
12
13#ifndef arena_container_of
14#define arena_container_of(ptr, type, member)			\
15	({							\
16		void __arena *__mptr = (void __arena *)(ptr);	\
17		((type *)(__mptr - offsetof(type, member)));	\
18	})
19#endif
20
21#ifdef __BPF__ /* when compiled as bpf program */
22
23#ifndef PAGE_SIZE
24#define PAGE_SIZE __PAGE_SIZE
25/*
26 * for older kernels try sizeof(struct genradix_node)
27 * or flexible:
28 * static inline long __bpf_page_size(void) {
29 *   return bpf_core_enum_value(enum page_size_enum___l, __PAGE_SIZE___l) ?: sizeof(struct genradix_node);
30 * }
31 * but generated code is not great.
32 */
33#endif
34
35#if defined(__BPF_FEATURE_ADDR_SPACE_CAST) && !defined(BPF_ARENA_FORCE_ASM)
36#define __arena __attribute__((address_space(1)))
37#define cast_kern(ptr) /* nop for bpf prog. emitted by LLVM */
38#define cast_user(ptr) /* nop for bpf prog. emitted by LLVM */
39#else
40#define __arena
41#define cast_kern(ptr) bpf_addr_space_cast(ptr, 0, 1)
42#define cast_user(ptr) bpf_addr_space_cast(ptr, 1, 0)
43#endif
44
45void __arena* bpf_arena_alloc_pages(void *map, void __arena *addr, __u32 page_cnt,
46				    int node_id, __u64 flags) __ksym __weak;
47void bpf_arena_free_pages(void *map, void __arena *ptr, __u32 page_cnt) __ksym __weak;
48
49#else /* when compiled as user space code */
50
51#define __arena
52#define __arg_arena
53#define cast_kern(ptr) /* nop for user space */
54#define cast_user(ptr) /* nop for user space */
55__weak char arena[1];
56
57#ifndef offsetof
58#define offsetof(type, member)  ((unsigned long)&((type *)0)->member)
59#endif
60
61static inline void __arena* bpf_arena_alloc_pages(void *map, void *addr, __u32 page_cnt,
62						  int node_id, __u64 flags)
63{
64	return NULL;
65}
66static inline void bpf_arena_free_pages(void *map, void __arena *ptr, __u32 page_cnt)
67{
68}
69
70#endif
71