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