1/*
2 * POWER Data Stream Control Register (DSCR) explicit test
3 *
4 * This test modifies the DSCR value using mtspr instruction and
5 * verifies the change with mfspr instruction. It uses both the
6 * privilege state SPR and the problem state SPR for this purpose.
7 *
8 * When using the privilege state SPR, the instructions such as
9 * mfspr or mtspr are priviledged and the kernel emulates them
10 * for us. Instructions using problem state SPR can be exuecuted
11 * directly without any emulation if the HW supports them. Else
12 * they also get emulated by the kernel.
13 *
14 * Copyright 2012, Anton Blanchard, IBM Corporation.
15 * Copyright 2015, Anshuman Khandual, IBM Corporation.
16 *
17 * This program is free software; you can redistribute it and/or modify it
18 * under the terms of the GNU General Public License version 2 as published
19 * by the Free Software Foundation.
20 */
21#include "dscr.h"
22
23int dscr_explicit(void)
24{
25	unsigned long i, dscr = 0;
26
27	srand(getpid());
28	set_dscr(dscr);
29
30	for (i = 0; i < COUNT; i++) {
31		unsigned long cur_dscr, cur_dscr_usr;
32		double ret = uniform_deviate(rand());
33
34		if (ret < 0.001) {
35			dscr++;
36			if (dscr > DSCR_MAX)
37				dscr = 0;
38
39			set_dscr(dscr);
40		}
41
42		cur_dscr = get_dscr();
43		if (cur_dscr != dscr) {
44			fprintf(stderr, "Kernel DSCR should be %ld but "
45					"is %ld\n", dscr, cur_dscr);
46			return 1;
47		}
48
49		ret = uniform_deviate(rand());
50		if (ret < 0.001) {
51			dscr++;
52			if (dscr > DSCR_MAX)
53				dscr = 0;
54
55			set_dscr_usr(dscr);
56		}
57
58		cur_dscr_usr = get_dscr_usr();
59		if (cur_dscr_usr != dscr) {
60			fprintf(stderr, "User DSCR should be %ld but "
61					"is %ld\n", dscr, cur_dscr_usr);
62			return 1;
63		}
64	}
65	return 0;
66}
67
68int main(int argc, char *argv[])
69{
70	return test_harness(dscr_explicit, "dscr_explicit_test");
71}
72