misc_cgroup.h

  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 */
 14enum 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	/** @MISC_CG_RES_TDX: 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
 29struct 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 */
 42struct 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 */
 56struct 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
 67int misc_cg_set_capacity(enum misc_res_type type, u64 capacity);
 68int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, u64 amount);
 69void 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 */
 80static 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 */
 93static 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 */
102static 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
110static inline int misc_cg_set_capacity(enum misc_res_type type, u64 capacity)
111{
112	return 0;
113}
114
115static 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
122static inline void misc_cg_uncharge(enum misc_res_type type,
123				    struct misc_cg *cg,
124				    u64 amount)
125{
126}
127
128static inline struct misc_cg *get_current_misc_cg(void)
129{
130	return NULL;
131}
132
133static inline void put_misc_cg(struct misc_cg *cg)
134{
135}
136
137#endif /* CONFIG_CGROUP_MISC */
138#endif /* _MISC_CGROUP_H_ */