cregit-Linux how code gets into the kernel

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

/*
 * POWER Data Stream Control Register (DSCR) SPR test
 *
 * This test modifies the DSCR value through both the SPR number
 * based mtspr instruction and then makes sure that the same is
 * reflected through mfspr instruction using either of the SPR
 * numbers.
 *
 * 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 2013, 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"


static int check_dscr(char *str) { unsigned long cur_dscr, cur_dscr_usr; cur_dscr = get_dscr(); cur_dscr_usr = get_dscr_usr(); if (cur_dscr != cur_dscr_usr) { printf("%s set, kernel get %lx != user get %lx\n", str, cur_dscr, cur_dscr_usr); return 1; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
anshuman khandualanshuman khandual51100.00%1100.00%
Total51100.00%1100.00%


int dscr_user(void) { int i; check_dscr(""); for (i = 0; i < COUNT; i++) { set_dscr(i); if (check_dscr("kernel")) return 1; } for (i = 0; i < COUNT; i++) { set_dscr_usr(i); if (check_dscr("user")) return 1; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
anshuman khandualanshuman khandual78100.00%1100.00%
Total78100.00%1100.00%


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

Contributors

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


Overall Contributors

PersonTokensPropCommitsCommitProp
anshuman khandualanshuman khandual154100.00%1100.00%
Total154100.00%1100.00%
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