include/linux/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  * Types of misc cgroup entries supported by the host.
  13  */
  14 enum 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
  24 struct 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  * @failed: True if charged failed for the resource in a cgroup.
  35  */
  36 struct misc_res {
  37         unsigned long max;
  38         atomic_long_t usage;
  39         bool failed;
  40 };
  41
  42 /**
  43  * struct misc_cg - Miscellaneous controller's cgroup structure.
  44  * @css: cgroup subsys state object.
  45  * @res: Array of misc resources usage in the cgroup.
  46  */
  47 struct misc_cg {
  48         struct cgroup_subsys_state css;
  49         struct misc_res res[MISC_CG_RES_TYPES];
  50 };
  51
  52 unsigned long misc_cg_res_total_usage(enum misc_res_type type);
  53 int misc_cg_set_capacity(enum misc_res_type type, unsigned long capacity);
  54 int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg,
  55                        unsigned long amount);
  56 void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg,
  57                       unsigned long amount);
  58
  59 /**
  60  * css_misc() - Get misc cgroup from the css.
  61  * @css: cgroup subsys state object.
  62  *
  63  * Context: Any context.
  64  * Return:
  65  * * %NULL - If @css is null.
  66  * * struct misc_cg* - misc cgroup pointer of the passed css.
  67  */
  68 static inline struct misc_cg *css_misc(struct cgroup_subsys_state *css)
  69 {
  70         return css ? container_of(css, struct misc_cg, css) : NULL;
  71 }
  72
  73 /*
  74  * get_current_misc_cg() - Find and get the misc cgroup of the current task.
  75  *
  76  * Returned cgroup has its ref count increased by 1. Caller must call
  77  * put_misc_cg() to return the reference.
  78  *
  79  * Return: Misc cgroup to which the current task belongs to.
  80  */
  81 static inline struct misc_cg *get_current_misc_cg(void)
  82 {
  83         return css_misc(task_get_css(current, misc_cgrp_id));
  84 }
  85
  86 /*
  87  * put_misc_cg() - Put the misc cgroup and reduce its ref count.
  88  * @cg - cgroup to put.
  89  */
  90 static inline void put_misc_cg(struct misc_cg *cg)
  91 {
  92         if (cg)
  93                 css_put(&cg->css);
  94 }
  95
  96 #else /* !CONFIG_CGROUP_MISC */
  97
  98 static inline unsigned long misc_cg_res_total_usage(enum misc_res_type type)
  99 {
 100         return 0;
 101 }
 102
 103 static inline int misc_cg_set_capacity(enum misc_res_type type,
 104                                        unsigned long capacity)
 105 {
 106         return 0;
 107 }
 108
 109 static inline int misc_cg_try_charge(enum misc_res_type type,
 110                                      struct misc_cg *cg,
 111                                      unsigned long amount)
 112 {
 113         return 0;
 114 }
 115
 116 static inline void misc_cg_uncharge(enum misc_res_type type,
 117                                     struct misc_cg *cg,
 118                                     unsigned long amount)
 119 {
 120 }
 121
 122 static inline struct misc_cg *get_current_misc_cg(void)
 123 {
 124         return NULL;
 125 }
 126
 127 static inline void put_misc_cg(struct misc_cg *cg)
 128 {
 129 }
 130
 131 #endif /* CONFIG_CGROUP_MISC */
 132 #endif /* _MISC_CGROUP_H_ */