cregit-Linux how code gets into the kernel

Release 4.10 tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c

/*
 * 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.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */
#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; }

Contributors

PersonTokensPropCommitsCommitProp
anshuman khandualanshuman khandual175100.00%1100.00%
Total175100.00%1100.00%


int main(int argc, char *argv[]) { return test_harness(dscr_explicit, "dscr_explicit_test"); }

Contributors

PersonTokensPropCommitsCommitProp
anshuman khandualanshuman khandual21100.00%1100.00%
Total21100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
anshuman khandualanshuman khandual200100.00%1100.00%
Total200100.00%1100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.