LXR linux/tools/testing/selftests/powerpc/dscr/dscr_sysfs

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * POWER Data Stream Control Register (DSCR) sysfs interface test
   4 *
   5 * This test updates to system wide DSCR default through the sysfs interface
   6 * and then verifies that all the CPU specific DSCR defaults are updated as
   7 * well verified from their sysfs interfaces.
   8 *
   9 * Copyright 2015, Anshuman Khandual, IBM Corporation.
  10 */
  11#include "dscr.h"
  12
  13static int check_cpu_dscr_default(char *file, unsigned long val)
  14{
  15        char buf[10];
  16        int fd, rc;
  17
  18        fd = open(file, O_RDWR);
  19        if (fd == -1) {
  20                perror("open() failed");
  21                return 1;
  22        }
  23
  24        rc = read(fd, buf, sizeof(buf));
  25        if (rc == -1) {
  26                perror("read() failed");
  27                return 1;
  28        }
  29        close(fd);
  30
  31        buf[rc] = '\0';
  32        if (strtol(buf, NULL, 16) != val) {
  33                printf("DSCR match failed: %ld (system) %ld (cpu)\n",
  34                                        val, strtol(buf, NULL, 16));
  35                return 1;
  36        }
  37        return 0;
  38}
  39
  40static int check_all_cpu_dscr_defaults(unsigned long val)
  41{
  42        DIR *sysfs;
  43        struct dirent *dp;
  44        char file[LEN_MAX];
  45
  46        sysfs = opendir(CPU_PATH);
  47        if (!sysfs) {
  48                perror("opendir() failed");
  49                return 1;
  50        }
  51
  52        while ((dp = readdir(sysfs))) {
  53                int len;
  54
  55                if (!(dp->d_type & DT_DIR))
  56                        continue;
  57                if (!strcmp(dp->d_name, "cpuidle"))
  58                        continue;
  59                if (!strstr(dp->d_name, "cpu"))
  60                        continue;
  61
  62                len = snprintf(file, LEN_MAX, "%s%s/dscr", CPU_PATH, dp->d_name);
  63                if (len >= LEN_MAX)
  64                        continue;
  65                if (access(file, F_OK))
  66                        continue;
  67
  68                if (check_cpu_dscr_default(file, val))
  69                        return 1;
  70        }
  71        closedir(sysfs);
  72        return 0;
  73}
  74
  75int dscr_sysfs(void)
  76{
  77        unsigned long orig_dscr_default;
  78        int i, j;
  79
  80        SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
  81
  82        orig_dscr_default = get_default_dscr();
  83        for (i = 0; i < COUNT; i++) {
  84                for (j = 0; j < DSCR_MAX; j++) {
  85                        set_default_dscr(j);
  86                        if (check_all_cpu_dscr_defaults(j))
  87                                goto fail;
  88                }
  89        }
  90        set_default_dscr(orig_dscr_default);
  91        return 0;
  92fail:
  93        set_default_dscr(orig_dscr_default);
  94        return 1;
  95}
  96
  97int main(int argc, char *argv[])
  98{
  99        return test_harness(dscr_sysfs, "dscr_sysfs_test");
 100}
 101