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 13 static int check_cpu_dscr_default(char *file, unsigned long val) 14 { 15 unsigned long cpu_dscr; 16 int err; 17 18 err = read_ulong(file, &cpu_dscr, 16); 19 if (err) 20 return err; 21 22 if (cpu_dscr != val) { 23 printf("DSCR match failed: %ld (system) %ld (cpu)\n", 24 val, cpu_dscr); 25 return 1; 26 } 27 return 0; 28 } 29 30 static int check_all_cpu_dscr_defaults(unsigned long val) 31 { 32 DIR *sysfs; 33 struct dirent *dp; 34 char file[LEN_MAX]; 35 36 sysfs = opendir(CPU_PATH); 37 if (!sysfs) { 38 perror("opendir() failed"); 39 return 1; 40 } 41 42 while ((dp = readdir(sysfs))) { 43 int len; 44 45 if (!(dp->d_type & DT_DIR)) 46 continue; 47 if (!strcmp(dp->d_name, "cpuidle")) 48 continue; 49 if (!strstr(dp->d_name, "cpu")) 50 continue; 51 52 len = snprintf(file, LEN_MAX, "%s%s/dscr", CPU_PATH, dp->d_name); 53 if (len >= LEN_MAX) 54 continue; 55 if (access(file, F_OK)) 56 continue; 57 58 if (check_cpu_dscr_default(file, val)) { 59 closedir(sysfs); 60 return 1; 61 } 62 } 63 closedir(sysfs); 64 return 0; 65 } 66 67 int dscr_sysfs(void) 68 { 69 unsigned long orig_dscr_default; 70 71 SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR)); 72 73 orig_dscr_default = get_default_dscr(); 74 for (int i = 0; i < DSCR_MAX; i++) { 75 set_default_dscr(i); 76 if (check_all_cpu_dscr_defaults(i)) 77 goto fail; 78 } 79 set_default_dscr(orig_dscr_default); 80 return 0; 81 fail: 82 set_default_dscr(orig_dscr_default); 83 return 1; 84 } 85 86 int main(int argc, char *argv[]) 87 { 88 return test_harness(dscr_sysfs, "dscr_sysfs_test"); 89 } 90