LXR linux/tools/testing/selftests/powerpc/dscr/dscr_user

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * POWER Data Stream Control Register (DSCR) SPR test
   4 *
   5 * This test modifies the DSCR value through both the SPR number
   6 * based mtspr instruction and then makes sure that the same is
   7 * reflected through mfspr instruction using either of the SPR
   8 * numbers.
   9 *
  10 * When using the privilege state SPR, the instructions such as
  11 * mfspr or mtspr are priviledged and the kernel emulates them
  12 * for us. Instructions using problem state SPR can be exuecuted
  13 * directly without any emulation if the HW supports them. Else
  14 * they also get emulated by the kernel.
  15 *
  16 * Copyright 2013, Anton Blanchard, IBM Corporation.
  17 * Copyright 2015, Anshuman Khandual, IBM Corporation.
  18 */
  19#include "dscr.h"
  20
  21static int check_dscr(char *str)
  22{
  23        unsigned long cur_dscr, cur_dscr_usr;
  24
  25        cur_dscr = get_dscr();
  26        cur_dscr_usr = get_dscr_usr();
  27        if (cur_dscr != cur_dscr_usr) {
  28                printf("%s set, kernel get %lx != user get %lx\n",
  29                                        str, cur_dscr, cur_dscr_usr);
  30                return 1;
  31        }
  32        return 0;
  33}
  34
  35int dscr_user(void)
  36{
  37        int i;
  38
  39        SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
  40
  41        check_dscr("");
  42
  43        for (i = 0; i < COUNT; i++) {
  44                set_dscr(i);
  45                if (check_dscr("kernel"))
  46                        return 1;
  47        }
  48
  49        for (i = 0; i < COUNT; i++) {
  50                set_dscr_usr(i);
  51                if (check_dscr("user"))
  52                        return 1;
  53        }
  54        return 0;
  55}
  56
  57int main(int argc, char *argv[])
  58{
  59        return test_harness(dscr_user, "dscr_user_test");
  60}
  61