xref: /linux/include/linux/misc_cgroup.h (revision 55d0969c451159cff86949b38c39171cab962069)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Miscellaneous cgroup controller.
4  *
5  * Copyright 2020 Google LLC
6  * Author: Vipin Sharma <vipinsh@google.com>
7  */
8 #ifndef _MISC_CGROUP_H_
9 #define _MISC_CGROUP_H_
10 
11 /**
12  * enum misc_res_type - Types of misc cgroup entries supported by the host.
13  */
14 enum misc_res_type {
15 #ifdef CONFIG_KVM_AMD_SEV
16 	/** @MISC_CG_RES_SEV: AMD SEV ASIDs resource */
17 	MISC_CG_RES_SEV,
18 	/** @MISC_CG_RES_SEV_ES: AMD SEV-ES ASIDs resource */
19 	MISC_CG_RES_SEV_ES,
20 #endif
21 	/** @MISC_CG_RES_TYPES: count of enum misc_res_type constants */
22 	MISC_CG_RES_TYPES
23 };
24 
25 struct misc_cg;
26 
27 #ifdef CONFIG_CGROUP_MISC
28 
29 #include <linux/cgroup.h>
30 
31 /**
32  * struct misc_res: Per cgroup per misc type resource
33  * @max: Maximum limit on the resource.
34  * @watermark: Historical maximum usage of the resource.
35  * @usage: Current usage of the resource.
36  * @events: Number of times, the resource limit exceeded.
37  */
38 struct misc_res {
39 	u64 max;
40 	atomic64_t watermark;
41 	atomic64_t usage;
42 	atomic64_t events;
43 	atomic64_t events_local;
44 };
45 
46 /**
47  * struct misc_cg - Miscellaneous controller's cgroup structure.
48  * @css: cgroup subsys state object.
49  * @events_file: Handle for the misc resources events file.
50  * @res: Array of misc resources usage in the cgroup.
51  */
52 struct misc_cg {
53 	struct cgroup_subsys_state css;
54 
55 	/* misc.events */
56 	struct cgroup_file events_file;
57 	/* misc.events.local */
58 	struct cgroup_file events_local_file;
59 
60 	struct misc_res res[MISC_CG_RES_TYPES];
61 };
62 
63 u64 misc_cg_res_total_usage(enum misc_res_type type);
64 int misc_cg_set_capacity(enum misc_res_type type, u64 capacity);
65 int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, u64 amount);
66 void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg, u64 amount);
67 
68 /**
69  * css_misc() - Get misc cgroup from the css.
70  * @css: cgroup subsys state object.
71  *
72  * Context: Any context.
73  * Return:
74  * * %NULL - If @css is null.
75  * * struct misc_cg* - misc cgroup pointer of the passed css.
76  */
77 static inline struct misc_cg *css_misc(struct cgroup_subsys_state *css)
78 {
79 	return css ? container_of(css, struct misc_cg, css) : NULL;
80 }
81 
82 /*
83  * get_current_misc_cg() - Find and get the misc cgroup of the current task.
84  *
85  * Returned cgroup has its ref count increased by 1. Caller must call
86  * put_misc_cg() to return the reference.
87  *
88  * Return: Misc cgroup to which the current task belongs to.
89  */
90 static inline struct misc_cg *get_current_misc_cg(void)
91 {
92 	return css_misc(task_get_css(current, misc_cgrp_id));
93 }
94 
95 /*
96  * put_misc_cg() - Put the misc cgroup and reduce its ref count.
97  * @cg - cgroup to put.
98  */
99 static inline void put_misc_cg(struct misc_cg *cg)
100 {
101 	if (cg)
102 		css_put(&cg->css);
103 }
104 
105 #else /* !CONFIG_CGROUP_MISC */
106 
107 static inline u64 misc_cg_res_total_usage(enum misc_res_type type)
108 {
109 	return 0;
110 }
111 
112 static inline int misc_cg_set_capacity(enum misc_res_type type, u64 capacity)
113 {
114 	return 0;
115 }
116 
117 static inline int misc_cg_try_charge(enum misc_res_type type,
118 				     struct misc_cg *cg,
119 				     u64 amount)
120 {
121 	return 0;
122 }
123 
124 static inline void misc_cg_uncharge(enum misc_res_type type,
125 				    struct misc_cg *cg,
126 				    u64 amount)
127 {
128 }
129 
130 static inline struct misc_cg *get_current_misc_cg(void)
131 {
132 	return NULL;
133 }
134 
135 static inline void put_misc_cg(struct misc_cg *cg)
136 {
137 }
138 
139 #endif /* CONFIG_CGROUP_MISC */
140 #endif /* _MISC_CGROUP_H_ */
141