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

   1 /*
   2  * POWER Data Stream Control Register (DSCR) SPR test
   3  *
   4  * This test modifies the DSCR value through both the SPR number
   5  * based mtspr instruction and then makes sure that the same is
   6  * reflected through mfspr instruction using either of the SPR
   7  * numbers.
   8  *
   9  * When using the privilege state SPR, the instructions such as
  10  * mfspr or mtspr are priviledged and the kernel emulates them
  11  * for us. Instructions using problem state SPR can be exuecuted
  12  * directly without any emulation if the HW supports them. Else
  13  * they also get emulated by the kernel.
  14  *
  15  * Copyright 2013, Anton Blanchard, IBM Corporation.
  16  * Copyright 2015, Anshuman Khandual, IBM Corporation.
  17  *
  18  * This program is free software; you can redistribute it and/or modify it
  19  * under the terms of the GNU General Public License version 2 as published
  20  * by the Free Software Foundation.
  21  */
  22 #include "dscr.h"
  23
  24 static int check_dscr(char *str)
  25 {
  26         unsigned long cur_dscr, cur_dscr_usr;
  27
  28         cur_dscr = get_dscr();
  29         cur_dscr_usr = get_dscr_usr();
  30         if (cur_dscr != cur_dscr_usr) {
  31                 printf("%s set, kernel get %lx != user get %lx\n",
  32                                         str, cur_dscr, cur_dscr_usr);
  33                 return 1;
  34         }
  35         return 0;
  36 }
  37
  38 int dscr_user(void)
  39 {
  40         int i;
  41
  42         check_dscr("");
  43
  44         for (i = 0; i < COUNT; i++) {
  45                 set_dscr(i);
  46                 if (check_dscr("kernel"))
  47                         return 1;
  48         }
  49
  50         for (i = 0; i < COUNT; i++) {
  51                 set_dscr_usr(i);
  52                 if (check_dscr("user"))
  53                         return 1;
  54         }
  55         return 0;
  56 }
  57
  58 int main(int argc, char *argv[])
  59 {
  60         return test_harness(dscr_user, "dscr_user_test");
  61 }