tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c

   1 /*
   2  * POWER Data Stream Control Register (DSCR) sysfs interface test
   3  *
   4  * This test updates to system wide DSCR default through the sysfs interface
   5  * and then verifies that all the CPU specific DSCR defaults are updated as
   6  * well verified from their sysfs interfaces.
   7  *
   8  * Copyright 2015, Anshuman Khandual, IBM Corporation.
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License version 2 as published
  12  * by the Free Software Foundation.
  13  */
  14 #include "dscr.h"
  15
  16 static int check_cpu_dscr_default(char *file, unsigned long val)
  17 {
  18         char buf[10];
  19         int fd, rc;
  20
  21         fd = open(file, O_RDWR);
  22         if (fd == -1) {
  23                 perror("open() failed");
  24                 return 1;
  25         }
  26
  27         rc = read(fd, buf, sizeof(buf));
  28         if (rc == -1) {
  29                 perror("read() failed");
  30                 return 1;
  31         }
  32         close(fd);
  33
  34         buf[rc] = '\0';
  35         if (strtol(buf, NULL, 16) != val) {
  36                 printf("DSCR match failed: %ld (system) %ld (cpu)\n",
  37                                         val, strtol(buf, NULL, 16));
  38                 return 1;
  39         }
  40         return 0;
  41 }
  42
  43 static int check_all_cpu_dscr_defaults(unsigned long val)
  44 {
  45         DIR *sysfs;
  46         struct dirent *dp;
  47         char file[LEN_MAX];
  48
  49         sysfs = opendir(CPU_PATH);
  50         if (!sysfs) {
  51                 perror("opendir() failed");
  52                 return 1;
  53         }
  54
  55         while ((dp = readdir(sysfs))) {
  56                 if (!(dp->d_type & DT_DIR))
  57                         continue;
  58                 if (!strcmp(dp->d_name, "cpuidle"))
  59                         continue;
  60                 if (!strstr(dp->d_name, "cpu"))
  61                         continue;
  62
  63                 sprintf(file, "%s%s/dscr", CPU_PATH, dp->d_name);
  64                 if (access(file, F_OK))
  65                         continue;
  66
  67                 if (check_cpu_dscr_default(file, val))
  68                         return 1;
  69         }
  70         closedir(sysfs);
  71         return 0;
  72 }
  73
  74 int dscr_sysfs(void)
  75 {
  76         unsigned long orig_dscr_default;
  77         int i, j;
  78
  79         orig_dscr_default = get_default_dscr();
  80         for (i = 0; i < COUNT; i++) {
  81                 for (j = 0; j < DSCR_MAX; j++) {
  82                         set_default_dscr(j);
  83                         if (check_all_cpu_dscr_defaults(j))
  84                                 goto fail;
  85                 }
  86         }
  87         set_default_dscr(orig_dscr_default);
  88         return 0;
  89 fail:
  90         set_default_dscr(orig_dscr_default);
  91         return 1;
  92 }
  93
  94 int main(int argc, char *argv[])
  95 {
  96         return test_harness(dscr_sysfs, "dscr_sysfs_test");
  97 }