[linux-block.git] / include / linux / misc_cgroup.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Miscellaneous cgroup controller.
 *
 * Copyright 2020 Google LLC
 * Author: Vipin Sharma <vipinsh@google.com>
 */
#ifndef _MISC_CGROUP_H_
#define _MISC_CGROUP_H_

/**
 * Types of misc cgroup entries supported by the host.
 */
enum misc_res_type {
	MISC_CG_RES_TYPES
};

struct misc_cg;

#ifdef CONFIG_CGROUP_MISC

#include <linux/cgroup.h>

/**
 * struct misc_res: Per cgroup per misc type resource
 * @max: Maximum limit on the resource.
 * @usage: Current usage of the resource.
 * @failed: True if charged failed for the resource in a cgroup.
 */
struct misc_res {
	unsigned long max;
	atomic_long_t usage;
	bool failed;
};

/**
 * struct misc_cg - Miscellaneous controller's cgroup structure.
 * @css: cgroup subsys state object.
 * @res: Array of misc resources usage in the cgroup.
 */
struct misc_cg {
	struct cgroup_subsys_state css;
	struct misc_res res[MISC_CG_RES_TYPES];
};

unsigned long misc_cg_res_total_usage(enum misc_res_type type);
int misc_cg_set_capacity(enum misc_res_type type, unsigned long capacity);
int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg,
		       unsigned long amount);
void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg,
		      unsigned long amount);

/**
 * css_misc() - Get misc cgroup from the css.
 * @css: cgroup subsys state object.
 *
 * Context: Any context.
 * Return:
 * * %NULL - If @css is null.
 * * struct misc_cg* - misc cgroup pointer of the passed css.
 */
static inline struct misc_cg *css_misc(struct cgroup_subsys_state *css)
{
	return css ? container_of(css, struct misc_cg, css) : NULL;
}

/*
 * get_current_misc_cg() - Find and get the misc cgroup of the current task.
 *
 * Returned cgroup has its ref count increased by 1. Caller must call
 * put_misc_cg() to return the reference.
 *
 * Return: Misc cgroup to which the current task belongs to.
 */
static inline struct misc_cg *get_current_misc_cg(void)
{
	return css_misc(task_get_css(current, misc_cgrp_id));
}

/*
 * put_misc_cg() - Put the misc cgroup and reduce its ref count.
 * @cg - cgroup to put.
 */
static inline void put_misc_cg(struct misc_cg *cg)
{
	if (cg)
		css_put(&cg->css);
}

#else /* !CONFIG_CGROUP_MISC */

unsigned long misc_cg_res_total_usage(enum misc_res_type type)
{
	return 0;
}

static inline int misc_cg_set_capacity(enum misc_res_type type,
				       unsigned long capacity)
{
	return 0;
}

static inline int misc_cg_try_charge(enum misc_res_type type,
				     struct misc_cg *cg,
				     unsigned long amount)
{
	return 0;
}

static inline void misc_cg_uncharge(enum misc_res_type type,
				    struct misc_cg *cg,
				    unsigned long amount)
{
}

static inline struct misc_cg *get_current_misc_cg(void)
{
	return NULL;
}

static inline void put_misc_cg(struct misc_cg *cg)
{
}

#endif /* CONFIG_CGROUP_MISC */
#endif /* _MISC_CGROUP_H_ */
Commit	Line	Data
a72232ea VS	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	*/
	14	enum misc_res_type {
	15	MISC_CG_RES_TYPES
	16	};
	17
	18	struct misc_cg;
	19
	20	#ifdef CONFIG_CGROUP_MISC
	21
	22	#include <linux/cgroup.h>
	23
	24	/**
	25	* struct misc_res: Per cgroup per misc type resource
	26	* @max: Maximum limit on the resource.
	27	* @usage: Current usage of the resource.
	28	* @failed: True if charged failed for the resource in a cgroup.
	29	*/
	30	struct misc_res {
	31	unsigned long max;
	32	atomic_long_t usage;
	33	bool failed;
	34	};
	35
	36	/**
	37	* struct misc_cg - Miscellaneous controller's cgroup structure.
	38	* @css: cgroup subsys state object.
	39	* @res: Array of misc resources usage in the cgroup.
	40	*/
	41	struct misc_cg {
	42	struct cgroup_subsys_state css;
	43	struct misc_res res[MISC_CG_RES_TYPES];
	44	};
	45
	46	unsigned long misc_cg_res_total_usage(enum misc_res_type type);
	47	int misc_cg_set_capacity(enum misc_res_type type, unsigned long capacity);
	48	int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg,
	49	unsigned long amount);
	50	void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg,
	51	unsigned long amount);
	52
	53	/**
	54	* css_misc() - Get misc cgroup from the css.
	55	* @css: cgroup subsys state object.
	56	*
	57	* Context: Any context.
	58	* Return:
	59	* * %NULL - If @css is null.
	60	* * struct misc_cg* - misc cgroup pointer of the passed css.
	61	*/
	62	static inline struct misc_cg css_misc(struct cgroup_subsys_state css)
	63	{
	64	return css ? container_of(css, struct misc_cg, css) : NULL;
65	}
66
67	/*
68	* get_current_misc_cg() - Find and get the misc cgroup of the current task.
69	*
70	* Returned cgroup has its ref count increased by 1. Caller must call
71	* put_misc_cg() to return the reference.
72	*
73	* Return: Misc cgroup to which the current task belongs to.
74	*/
75	static inline struct misc_cg *get_current_misc_cg(void)
76	{
77	return css_misc(task_get_css(current, misc_cgrp_id));
78	}
79
80	/*
81	* put_misc_cg() - Put the misc cgroup and reduce its ref count.
82	* @cg - cgroup to put.
83	*/
84	static inline void put_misc_cg(struct misc_cg *cg)
85	{
86	if (cg)
87	css_put(&cg->css);
88	}
89
90	#else /* !CONFIG_CGROUP_MISC */
91
92	unsigned long misc_cg_res_total_usage(enum misc_res_type type)
93	{
94	return 0;
95	}
96
97	static inline int misc_cg_set_capacity(enum misc_res_type type,
98	unsigned long capacity)
99	{
100	return 0;
101	}
102
103	static inline int misc_cg_try_charge(enum misc_res_type type,
104	struct misc_cg *cg,
105	unsigned long amount)
106	{
107	return 0;
108	}
109
110	static inline void misc_cg_uncharge(enum misc_res_type type,
111	struct misc_cg *cg,
112	unsigned long amount)
113	{
114	}
115
116	static inline struct misc_cg *get_current_misc_cg(void)
117	{
118	return NULL;
119	}
120
121	static inline void put_misc_cg(struct misc_cg *cg)
122	{
123	}
124
125	#endif /* CONFIG_CGROUP_MISC */
126	#endif /* _MISC_CGROUP_H_ */