1 #ifndef __BPF_UTIL__
2 #define __BPF_UTIL__
3 
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <errno.h>
8 
9 static inline unsigned int bpf_num_possible_cpus(void)
10 {
11 	static const char *fcpu = "/sys/devices/system/cpu/possible";
12 	unsigned int start, end, possible_cpus = 0;
13 	char buff[128];
14 	FILE *fp;
15 
16 	fp = fopen(fcpu, "r");
17 	if (!fp) {
18 		printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno));
19 		exit(1);
20 	}
21 
22 	while (fgets(buff, sizeof(buff), fp)) {
23 		if (sscanf(buff, "%u-%u", &start, &end) == 2) {
24 			possible_cpus = start == 0 ? end + 1 : 0;
25 			break;
26 		}
27 	}
28 
29 	fclose(fp);
30 	if (!possible_cpus) {
31 		printf("Failed to retrieve # possible CPUs!\n");
32 		exit(1);
33 	}
34 
35 	return possible_cpus;
36 }
37 
38 #define __bpf_percpu_val_align	__attribute__((__aligned__(8)))
39 
40 #define BPF_DECLARE_PERCPU(type, name)				\
41 	struct { type v; /* padding */ } __bpf_percpu_val_align	\
42 		name[bpf_num_possible_cpus()]
43 #define bpf_percpu(name, cpu) name[(cpu)].v
44 
45 #endif /* __BPF_UTIL__ */
46