arena_spin_lock.c

 1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
 3#include <vmlinux.h>
 4#include <bpf/bpf_tracing.h>
 5#include <bpf/bpf_helpers.h>
 6#include "bpf_misc.h"
 7#include "bpf_arena_spin_lock.h"
 8
 9struct {
10	__uint(type, BPF_MAP_TYPE_ARENA);
11	__uint(map_flags, BPF_F_MMAPABLE);
12	__uint(max_entries, 100); /* number of pages */
13#ifdef __TARGET_ARCH_arm64
14	__ulong(map_extra, 0x1ull << 32); /* start of mmap() region */
15#else
16	__ulong(map_extra, 0x1ull << 44); /* start of mmap() region */
17#endif
18} arena SEC(".maps");
19
20int cs_count;
21
22#if defined(ENABLE_ATOMICS_TESTS) && defined(__BPF_FEATURE_ADDR_SPACE_CAST)
23arena_spinlock_t __arena lock;
24int test_skip = 1;
25#else
26int test_skip = 2;
27#endif
28
29int counter;
30int limit;
31
32SEC("tc")
33int prog(void *ctx)
34{
35	int ret = -2;
36
37#if defined(ENABLE_ATOMICS_TESTS) && defined(__BPF_FEATURE_ADDR_SPACE_CAST)
38	unsigned long flags;
39
40	if ((ret = arena_spin_lock_irqsave(&lock, flags))) {
41		if (ret == -EOPNOTSUPP)
42			test_skip = 3;
43		return ret;
44	}
45	if (counter != limit)
46		counter++;
47	bpf_repeat(cs_count);
48	ret = 0;
49	arena_spin_unlock_irqrestore(&lock, flags);
50#endif
51	return ret;
52}
53
54char _license[] SEC("license") = "GPL";