1 /* 2 * POWER Data Stream Control Register (DSCR) explicit test 3 * 4 * This test modifies the DSCR value using mtspr instruction and 5 * verifies the change with mfspr instruction. It uses both the 6 * privilege state SPR and the problem state SPR for this purpose. 7 * 8 * When using the privilege state SPR, the instructions such as 9 * mfspr or mtspr are priviledged and the kernel emulates them 10 * for us. Instructions using problem state SPR can be exuecuted 11 * directly without any emulation if the HW supports them. Else 12 * they also get emulated by the kernel. 13 * 14 * Copyright 2012, Anton Blanchard, IBM Corporation. 15 * Copyright 2015, Anshuman Khandual, IBM Corporation. 16 * 17 * This program is free software; you can redistribute it and/or modify it 18 * under the terms of the GNU General Public License version 2 as published 19 * by the Free Software Foundation. 20 */ 21 #include "dscr.h" 22 23 int dscr_explicit(void) 24 { 25 unsigned long i, dscr = 0; 26 27 srand(getpid()); 28 set_dscr(dscr); 29 30 for (i = 0; i < COUNT; i++) { 31 unsigned long cur_dscr, cur_dscr_usr; 32 double ret = uniform_deviate(rand()); 33 34 if (ret < 0.001) { 35 dscr++; 36 if (dscr > DSCR_MAX) 37 dscr = 0; 38 39 set_dscr(dscr); 40 } 41 42 cur_dscr = get_dscr(); 43 if (cur_dscr != dscr) { 44 fprintf(stderr, "Kernel DSCR should be %ld but " 45 "is %ld\n", dscr, cur_dscr); 46 return 1; 47 } 48 49 ret = uniform_deviate(rand()); 50 if (ret < 0.001) { 51 dscr++; 52 if (dscr > DSCR_MAX) 53 dscr = 0; 54 55 set_dscr_usr(dscr); 56 } 57 58 cur_dscr_usr = get_dscr_usr(); 59 if (cur_dscr_usr != dscr) { 60 fprintf(stderr, "User DSCR should be %ld but " 61 "is %ld\n", dscr, cur_dscr_usr); 62 return 1; 63 } 64 } 65 return 0; 66 } 67 68 int main(int argc, char *argv[]) 69 { 70 return test_harness(dscr_explicit, "dscr_explicit_test"); 71 } 72
