1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * POWER Data Stream Control Register (DSCR) sysfs thread test
4  *
5  * This test updates the system wide DSCR default value through
6  * sysfs interface which should then update all the CPU specific
7  * DSCR default values which must also be then visible to threads
8  * executing on individual CPUs on the system.
9  *
10  * Copyright 2015, Anshuman Khandual, IBM Corporation.
11  */
12 #define _GNU_SOURCE
13 #include "dscr.h"
14 
test_thread_dscr(unsigned long val)15 static int test_thread_dscr(unsigned long val)
16 {
17 	unsigned long cur_dscr, cur_dscr_usr;
18 
19 	cur_dscr = get_dscr();
20 	cur_dscr_usr = get_dscr_usr();
21 
22 	if (val != cur_dscr) {
23 		printf("[cpu %d] Kernel DSCR should be %ld but is %ld\n",
24 					sched_getcpu(), val, cur_dscr);
25 		return 1;
26 	}
27 
28 	if (val != cur_dscr_usr) {
29 		printf("[cpu %d] User DSCR should be %ld but is %ld\n",
30 					sched_getcpu(), val, cur_dscr_usr);
31 		return 1;
32 	}
33 	return 0;
34 }
35 
check_cpu_dscr_thread(unsigned long val)36 static int check_cpu_dscr_thread(unsigned long val)
37 {
38 	cpu_set_t mask;
39 	int cpu;
40 
41 	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
42 		CPU_ZERO(&mask);
43 		CPU_SET(cpu, &mask);
44 		if (sched_setaffinity(0, sizeof(mask), &mask))
45 			continue;
46 
47 		if (test_thread_dscr(val))
48 			return 1;
49 	}
50 	return 0;
51 
52 }
53 
dscr_sysfs_thread(void)54 int dscr_sysfs_thread(void)
55 {
56 	unsigned long orig_dscr_default;
57 	int i, j;
58 
59 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
60 
61 	orig_dscr_default = get_default_dscr();
62 	for (i = 0; i < COUNT; i++) {
63 		for (j = 0; j < DSCR_MAX; j++) {
64 			set_default_dscr(j);
65 			if (check_cpu_dscr_thread(j))
66 				goto fail;
67 		}
68 	}
69 	set_default_dscr(orig_dscr_default);
70 	return 0;
71 fail:
72 	set_default_dscr(orig_dscr_default);
73 	return 1;
74 }
75 
main(int argc,char * argv[])76 int main(int argc, char *argv[])
77 {
78 	return test_harness(dscr_sysfs_thread, "dscr_sysfs_thread_test");
79 }
80