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1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright (c) 2019 Linus Walleij <linus.walleij@linaro.org>
4  */
5 
6 #ifndef LTP_IOPRIO_H
7 #define LTP_IOPRIO_H
8 
9 enum {
10 	IOPRIO_CLASS_NONE = 0,
11 	IOPRIO_CLASS_RT,
12 	IOPRIO_CLASS_BE,
13 	IOPRIO_CLASS_IDLE,
14 };
15 
16 enum {
17 	IOPRIO_WHO_PROCESS = 1,
18 	IOPRIO_WHO_PGRP,
19 	IOPRIO_WHO_USER,
20 };
21 
22 /* The I/O scheduler classes have 8 priorities 0..7 except for the IDLE class */
23 #define IOPRIO_PRIO_NUM		8
24 
25 #define IOPRIO_CLASS_SHIFT	(13)
26 #define IOPRIO_PRIO_MASK	((1UL << IOPRIO_CLASS_SHIFT) - 1)
27 
28 #define IOPRIO_PRIO_CLASS(data)	((data) >> IOPRIO_CLASS_SHIFT)
29 #define IOPRIO_PRIO_LEVEL(data)	((data) & IOPRIO_PRIO_MASK)
30 #define IOPRIO_PRIO_VALUE(class, data)	(((class) << IOPRIO_CLASS_SHIFT) | data)
31 
32 static const char * const to_class_str[] = {
33 	[IOPRIO_CLASS_NONE] = "NONE",
34 	[IOPRIO_CLASS_RT]   = "REALTIME",
35 	[IOPRIO_CLASS_BE]   = "BEST-EFFORT",
36 	[IOPRIO_CLASS_IDLE] = "IDLE"
37 };
38 
sys_ioprio_get(int which,int who)39 static inline int sys_ioprio_get(int which, int who)
40 {
41 	return tst_syscall(__NR_ioprio_get, which, who);
42 }
43 
sys_ioprio_set(int which,int who,int ioprio)44 static inline int sys_ioprio_set(int which, int who, int ioprio)
45 {
46 	return tst_syscall(__NR_ioprio_set, which, who, ioprio);
47 }
48 
49 /* Priority range from 0 (highest) to 7 (lowest) */
prio_in_range(int prio)50 static inline int prio_in_range(int prio)
51 {
52 	if ((prio < 0) || (prio > 7))
53 		return 0;
54 	return 1;
55 }
56 
57 /* Priority range from 0 to 3 using the enum */
class_in_range(int class)58 static inline int class_in_range(int class)
59 {
60 	if ((class < IOPRIO_CLASS_NONE) || (class > IOPRIO_CLASS_IDLE))
61 		return 0;
62 	return 1;
63 }
64 
ioprio_check_setting(int class,int prio,int report)65 static inline void ioprio_check_setting(int class, int prio, int report)
66 {
67 	int res;
68 	int newclass, newprio;
69 
70 	res = sys_ioprio_get(IOPRIO_WHO_PROCESS, 0);
71 	if (res == -1) {
72 		tst_res(TFAIL | TTERRNO,
73 			 "reading back prio failed");
74 		return;
75 	}
76 
77 	newclass = IOPRIO_PRIO_CLASS(res);
78 	newprio = IOPRIO_PRIO_LEVEL(res);
79 	if (newclass != class)
80 		tst_res(TFAIL,
81 			"wrong class after setting, expected %s got %s",
82 			to_class_str[class],
83 			to_class_str[newclass]);
84 	else if (newprio != prio)
85 		tst_res(TFAIL,
86 			"wrong prio after setting, expected %d got %d",
87 			prio, newprio);
88 	else if (report)
89 		tst_res(TPASS, "ioprio_set new class %s, new prio %d",
90 			to_class_str[newclass],
91 			newprio);
92 }
93 
94 #endif
95