tools/testing/selftests/bpf/bpf_arena_common.h

   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 __arena_global __attribute__((address_space(1)))
  38 #define cast_kern(ptr) /* nop for bpf prog. emitted by LLVM */
  39 #define cast_user(ptr) /* nop for bpf prog. emitted by LLVM */
  40 #else
  41 #define __arena
  42 #define __arena_global SEC(".addr_space.1")
  43 #define cast_kern(ptr) bpf_addr_space_cast(ptr, 0, 1)
  44 #define cast_user(ptr) bpf_addr_space_cast(ptr, 1, 0)
  45 #endif
  46
  47 void __arena* bpf_arena_alloc_pages(void *map, void __arena *addr, __u32 page_cnt,
  48                                     int node_id, __u64 flags) __ksym __weak;
  49 void bpf_arena_free_pages(void *map, void __arena *ptr, __u32 page_cnt) __ksym __weak;
  50
  51 #else /* when compiled as user space code */
  52
  53 #define __arena
  54 #define __arg_arena
  55 #define cast_kern(ptr) /* nop for user space */
  56 #define cast_user(ptr) /* nop for user space */
  57 __weak char arena[1];
  58
  59 #ifndef offsetof
  60 #define offsetof(type, member)  ((unsigned long)&((type *)0)->member)
  61 #endif
  62
  63 static inline void __arena* bpf_arena_alloc_pages(void *map, void *addr, __u32 page_cnt,
  64                                                   int node_id, __u64 flags)
  65 {
  66         return NULL;
  67 }
  68 static inline void bpf_arena_free_pages(void *map, void __arena *ptr, __u32 page_cnt)
  69 {
  70 }
  71
  72 #endif