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 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 close(fd); 28 return 1; 29 } 30 close(fd); 31 32 buf[rc] = '\0'; 33 if (strtol(buf, NULL, 16) != val) { 34 printf("DSCR match failed: %ld (system) %ld (cpu)\n", 35 val, strtol(buf, NULL, 16)); 36 return 1; 37 } 38 return 0; 39 } 40 41 static int check_all_cpu_dscr_defaults(unsigned long val) 42 { 43 DIR *sysfs; 44 struct dirent *dp; 45 char file[LEN_MAX]; 46 47 sysfs = opendir(CPU_PATH); 48 if (!sysfs) { 49 perror("opendir() failed"); 50 return 1; 51 } 52 53 while ((dp = readdir(sysfs))) { 54 int len; 55 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 len = snprintf(file, LEN_MAX, "%s%s/dscr", CPU_PATH, dp->d_name); 64 if (len >= LEN_MAX) 65 continue; 66 if (access(file, F_OK)) 67 continue; 68 69 if (check_cpu_dscr_default(file, val)) { 70 closedir(sysfs); 71 return 1; 72 } 73 } 74 closedir(sysfs); 75 return 0; 76 } 77 78 int dscr_sysfs(void) 79 { 80 unsigned long orig_dscr_default; 81 int i, j; 82 83 SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR)); 84 85 orig_dscr_default = get_default_dscr(); 86 for (i = 0; i < COUNT; i++) { 87 for (j = 0; j < DSCR_MAX; j++) { 88 set_default_dscr(j); 89 if (check_all_cpu_dscr_defaults(j)) 90 goto fail; 91 } 92 } 93 set_default_dscr(orig_dscr_default); 94 return 0; 95 fail: 96 set_default_dscr(orig_dscr_default); 97 return 1; 98 } 99 100 int main(int argc, char *argv[]) 101 { 102 return test_harness(dscr_sysfs, "dscr_sysfs_test"); 103 } 104