1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * POWER Data Stream Control Register (DSCR) sysfs thread test 4 * 5 * This test updates the system wide DSCR default value through 6 * sysfs interface which should then update all the CPU specific 7 * DSCR default values which must also be then visible to threads 8 * executing on individual CPUs on the system. 9 * 10 * Copyright 2015, Anshuman Khandual, IBM Corporation. 11 */ 12 #define _GNU_SOURCE 13 #include "dscr.h" 14 15 static int test_thread_dscr(unsigned long val) 16 { 17 unsigned long cur_dscr, cur_dscr_usr; 18 19 cur_dscr = get_dscr(); 20 cur_dscr_usr = get_dscr_usr(); 21 22 if (val != cur_dscr) { 23 printf("[cpu %d] Kernel DSCR should be %ld but is %ld\n", 24 sched_getcpu(), val, cur_dscr); 25 return 1; 26 } 27 28 if (val != cur_dscr_usr) { 29 printf("[cpu %d] User DSCR should be %ld but is %ld\n", 30 sched_getcpu(), val, cur_dscr_usr); 31 return 1; 32 } 33 return 0; 34 } 35 36 static int check_cpu_dscr_thread(unsigned long val) 37 { 38 cpu_set_t mask; 39 int cpu; 40 41 for (cpu = 0; cpu < CPU_SETSIZE; cpu++) { 42 CPU_ZERO(&mask); 43 CPU_SET(cpu, &mask); 44 if (sched_setaffinity(0, sizeof(mask), &mask)) 45 continue; 46 47 if (test_thread_dscr(val)) 48 return 1; 49 } 50 return 0; 51 52 } 53 54 int dscr_sysfs_thread(void) 55 { 56 unsigned long orig_dscr_default; 57 int i, j; 58 59 SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR)); 60 61 orig_dscr_default = get_default_dscr(); 62 for (i = 0; i < COUNT; i++) { 63 for (j = 0; j < DSCR_MAX; j++) { 64 set_default_dscr(j); 65 if (check_cpu_dscr_thread(j)) 66 goto fail; 67 } 68 } 69 set_default_dscr(orig_dscr_default); 70 return 0; 71 fail: 72 set_default_dscr(orig_dscr_default); 73 return 1; 74 } 75 76 int main(int argc, char *argv[]) 77 { 78 return test_harness(dscr_sysfs_thread, "dscr_sysfs_thread_test"); 79 } 80