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 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 40 static 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 75 int 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; 92 fail: 93 set_default_dscr(orig_dscr_default); 94 return 1; 95 } 96 97 int main(int argc, char *argv[]) 98 { 99 return test_harness(dscr_sysfs, "dscr_sysfs_test"); 100 } 101