LXR linux/tools/testing/selftests/bpf/bpf

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __BPF_UTIL__
   3#define __BPF_UTIL__
   4
   5#include <stdio.h>
   6#include <stdlib.h>
   7#include <string.h>
   8#include <errno.h>
   9
  10static inline unsigned int bpf_num_possible_cpus(void)
  11{
  12        static const char *fcpu = "/sys/devices/system/cpu/possible";
  13        unsigned int start, end, possible_cpus = 0;
  14        char buff[128];
  15        FILE *fp;
  16        int n;
  17
  18        fp = fopen(fcpu, "r");
  19        if (!fp) {
  20                printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno));
  21                exit(1);
  22        }
  23
  24        while (fgets(buff, sizeof(buff), fp)) {
  25                n = sscanf(buff, "%u-%u", &start, &end);
  26                if (n == 0) {
  27                        printf("Failed to retrieve # possible CPUs!\n");
  28                        exit(1);
  29                } else if (n == 1) {
  30                        end = start;
  31                }
  32                possible_cpus = start == 0 ? end + 1 : 0;
  33                break;
  34        }
  35        fclose(fp);
  36
  37        return possible_cpus;
  38}
  39
  40#define __bpf_percpu_val_align  __attribute__((__aligned__(8)))
  41
  42#define BPF_DECLARE_PERCPU(type, name)                          \
  43        struct { type v; /* padding */ } __bpf_percpu_val_align \
  44                name[bpf_num_possible_cpus()]
  45#define bpf_percpu(name, cpu) name[(cpu)].v
  46
  47#endif /* __BPF_UTIL__ */
  48