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 	int n;
16 
17 	fp = fopen(fcpu, "r");
18 	if (!fp) {
19 		printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno));
20 		exit(1);
21 	}
22 
23 	while (fgets(buff, sizeof(buff), fp)) {
24 		n = sscanf(buff, "%u-%u", &start, &end);
25 		if (n == 0) {
26 			printf("Failed to retrieve # possible CPUs!\n");
27 			exit(1);
28 		} else if (n == 1) {
29 			end = start;
30 		}
31 		possible_cpus = start == 0 ? end + 1 : 0;
32 		break;
33 	}
34 	fclose(fp);
35 
36 	return possible_cpus;
37 }
38 
39 #define __bpf_percpu_val_align	__attribute__((__aligned__(8)))
40 
41 #define BPF_DECLARE_PERCPU(type, name)				\
42 	struct { type v; /* padding */ } __bpf_percpu_val_align	\
43 		name[bpf_num_possible_cpus()]
44 #define bpf_percpu(name, cpu) name[(cpu)].v
45 
46 #endif /* __BPF_UTIL__ */
47