tools/testing/selftests/bpf/bpf_util.h

   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
  10 static 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 len, n, i, j = 0;
  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         if (!fgets(buff, sizeof(buff), fp)) {
  25                 printf("Failed to read %s!\n", fcpu);
  26                 exit(1);
  27         }
  28
  29         len = strlen(buff);
  30         for (i = 0; i <= len; i++) {
  31                 if (buff[i] == ',' || buff[i] == '\0') {
  32                         buff[i] = '\0';
  33                         n = sscanf(&buff[j], "%u-%u", &start, &end);
  34                         if (n <= 0) {
  35                                 printf("Failed to retrieve # possible CPUs!\n");
  36                                 exit(1);
  37                         } else if (n == 1) {
  38                                 end = start;
  39                         }
  40                         possible_cpus += end - start + 1;
  41                         j = i + 1;
  42                 }
  43         }
  44
  45         fclose(fp);
  46
  47         return possible_cpus;
  48 }
  49
  50 #define __bpf_percpu_val_align  __attribute__((__aligned__(8)))
  51
  52 #define BPF_DECLARE_PERCPU(type, name)                          \
  53         struct { type v; /* padding */ } __bpf_percpu_val_align \
  54                 name[bpf_num_possible_cpus()]
  55 #define bpf_percpu(name, cpu) name[(cpu)].v
  56
  57 #ifndef ARRAY_SIZE
  58 # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  59 #endif
  60
  61 #endif /* __BPF_UTIL__ */