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 privileged and the kernel emulates them |
12 | * for us. Instructions using problem state SPR can be executed |
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 | |
21 | static 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 | |
35 | int dscr_user(void) |
36 | { |
37 | int i; |
38 | |
39 | SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR)); |
40 | |
41 | check_dscr(str: "" ); |
42 | |
43 | for (i = 0; i < COUNT; i++) { |
44 | set_dscr(i); |
45 | if (check_dscr(str: "kernel" )) |
46 | return 1; |
47 | } |
48 | |
49 | for (i = 0; i < COUNT; i++) { |
50 | set_dscr_usr(i); |
51 | if (check_dscr(str: "user" )) |
52 | return 1; |
53 | } |
54 | return 0; |
55 | } |
56 | |
57 | int main(int argc, char *argv[]) |
58 | { |
59 | return test_harness(dscr_user, "dscr_user_test" ); |
60 | } |
61 | |