// SPDX-License-Identifier: GPL-2.0-only /* * POWER Data Stream Control Register (DSCR) explicit test * * This test modifies the DSCR value using mtspr instruction and * verifies the change with mfspr instruction. It uses both the * privilege state SPR and the problem state SPR for this purpose. * * When using the privilege state SPR, the instructions such as * mfspr or mtspr are priviledged and the kernel emulates them * for us. Instructions using problem state SPR can be exuecuted * directly without any emulation if the HW supports them. Else * they also get emulated by the kernel. * * Copyright 2012, Anton Blanchard, IBM Corporation. * Copyright 2015, Anshuman Khandual, IBM Corporation. */ #include "dscr.h" int dscr_explicit(void) { unsigned long i, dscr = 0; srand(getpid()); set_dscr(dscr); for (i = 0; i < COUNT; i++) { unsigned long cur_dscr, cur_dscr_usr; double ret = uniform_deviate(rand()); if (ret < 0.001) { dscr++; if (dscr > DSCR_MAX) dscr = 0; set_dscr(dscr); } cur_dscr = get_dscr(); if (cur_dscr != dscr) { fprintf(stderr, "Kernel DSCR should be %ld but " "is %ld\n", dscr, cur_dscr); return 1; } ret = uniform_deviate(rand()); if (ret < 0.001) { dscr++; if (dscr > DSCR_MAX) dscr = 0; set_dscr_usr(dscr); } cur_dscr_usr = get_dscr_usr(); if (cur_dscr_usr != dscr) { fprintf(stderr, "User DSCR should be %ld but " "is %ld\n", dscr, cur_dscr_usr); return 1; } } return 0; } int main(int argc, char *argv[]) { return test_harness(dscr_explicit, "dscr_explicit_test"); }