linux/tools/testing/selftests/bpf/bpf_util.h
Martin KaFai Lau aa5f0c96cc bpf: Refactor ARRAY_SIZE macro to bpf_util.h
This patch refactors the ARRAY_SIZE macro to bpf_util.h.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-11 01:58:46 +02:00

52 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __BPF_UTIL__
#define __BPF_UTIL__
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
static inline unsigned int bpf_num_possible_cpus(void)
{
static const char *fcpu = "/sys/devices/system/cpu/possible";
unsigned int start, end, possible_cpus = 0;
char buff[128];
FILE *fp;
int n;
fp = fopen(fcpu, "r");
if (!fp) {
printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno));
exit(1);
}
while (fgets(buff, sizeof(buff), fp)) {
n = sscanf(buff, "%u-%u", &start, &end);
if (n == 0) {
printf("Failed to retrieve # possible CPUs!\n");
exit(1);
} else if (n == 1) {
end = start;
}
possible_cpus = start == 0 ? end + 1 : 0;
break;
}
fclose(fp);
return possible_cpus;
}
#define __bpf_percpu_val_align __attribute__((__aligned__(8)))
#define BPF_DECLARE_PERCPU(type, name) \
struct { type v; /* padding */ } __bpf_percpu_val_align \
name[bpf_num_possible_cpus()]
#define bpf_percpu(name, cpu) name[(cpu)].v
#ifndef ARRAY_SIZE
# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif
#endif /* __BPF_UTIL__ */