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