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