diff options
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/misc.rst | 4 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 73 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 70 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 1 | ||||
| -rw-r--r-- | include/linux/cgroup_subsys.h | 4 | ||||
| -rw-r--r-- | include/linux/misc_cgroup.h | 132 | ||||
| -rw-r--r-- | init/Kconfig | 14 | ||||
| -rw-r--r-- | kernel/cgroup/Makefile | 1 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 2 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset.c | 6 | ||||
| -rw-r--r-- | kernel/cgroup/misc.c | 407 |
12 files changed, 699 insertions, 16 deletions
diff --git a/Documentation/admin-guide/cgroup-v1/index.rst b/Documentation/admin-guide/cgroup-v1/index.rst index 226f64473e8e..99fbc8a64ba9 100644 --- a/Documentation/admin-guide/cgroup-v1/index.rst +++ b/Documentation/admin-guide/cgroup-v1/index.rst @@ -17,6 +17,7 @@ Control Groups version 1 hugetlb memcg_test memory + misc net_cls net_prio pids diff --git a/Documentation/admin-guide/cgroup-v1/misc.rst b/Documentation/admin-guide/cgroup-v1/misc.rst new file mode 100644 index 000000000000..661614c24df3 --- /dev/null +++ b/Documentation/admin-guide/cgroup-v1/misc.rst @@ -0,0 +1,4 @@ +=============== +Misc controller +=============== +Please refer "Misc" documentation in Documentation/admin-guide/cgroup-v2.rst diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 64c62b979f2f..b1e81aa8598a 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -65,8 +65,11 @@ v1 is available under :ref:`Documentation/admin-guide/cgroup-v1/index.rst <cgrou 5-7-1. RDMA Interface Files 5-8. HugeTLB 5.8-1. HugeTLB Interface Files - 5-8. Misc - 5-8-1. perf_event + 5-9. Misc + 5.9-1 Miscellaneous cgroup Interface Files + 5.9-2 Migration and Ownership + 5-10. Others + 5-10-1. perf_event 5-N. Non-normative information 5-N-1. CPU controller root cgroup process behaviour 5-N-2. IO controller root cgroup process behaviour @@ -2171,6 +2174,72 @@ HugeTLB Interface Files Misc ---- +The Miscellaneous cgroup provides the resource limiting and tracking +mechanism for the scalar resources which cannot be abstracted like the other +cgroup resources. Controller is enabled by the CONFIG_CGROUP_MISC config +option. + +A resource can be added to the controller via enum misc_res_type{} in the +include/linux/misc_cgroup.h file and the corresponding name via misc_res_name[] +in the kernel/cgroup/misc.c file. Provider of the resource must set its +capacity prior to using the resource by calling misc_cg_set_capacity(). + +Once a capacity is set then the resource usage can be updated using charge and +uncharge APIs. All of the APIs to interact with misc controller are in +include/linux/misc_cgroup.h. + +Misc Interface Files +~~~~~~~~~~~~~~~~~~~~ + +Miscellaneous controller provides 3 interface files. If two misc resources (res_a and res_b) are registered then: + + misc.capacity + A read-only flat-keyed file shown only in the root cgroup. It shows + miscellaneous scalar resources available on the platform along with + their quantities:: + + $ cat misc.capacity + res_a 50 + res_b 10 + + misc.current + A read-only flat-keyed file shown in the non-root cgroups. It shows + the current usage of the resources in the cgroup and its children.:: + + $ cat misc.current + res_a 3 + res_b 0 + + misc.max + A read-write flat-keyed file shown in the non root cgroups. Allowed + maximum usage of the resources in the cgroup and its children.:: + + $ cat misc.max + res_a max + res_b 4 + + Limit can be set by:: + + # echo res_a 1 > misc.max + + Limit can be set to max by:: + + # echo res_a max > misc.max + + Limits can be set higher than the capacity value in the misc.capacity + file. + +Migration and Ownership +~~~~~~~~~~~~~~~~~~~~~~~ + +A miscellaneous scalar resource is charged to the cgroup in which it is used +first, and stays charged to that cgroup until that resource is freed. Migrating +a process to a different cgroup does not move the charge to the destination +cgroup where the process has moved. + +Others +------ + perf_event ~~~~~~~~~~ diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 2b27a9452403..415a49b8b8f8 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -14,6 +14,7 @@ #include <linux/psp-sev.h> #include <linux/pagemap.h> #include <linux/swap.h> +#include <linux/misc_cgroup.h> #include <linux/processor.h> #include <linux/trace_events.h> #include <asm/fpu/internal.h> @@ -28,6 +29,21 @@ #define __ex(x) __kvm_handle_fault_on_reboot(x) +#ifndef CONFIG_KVM_AMD_SEV +/* + * When this config is not defined, SEV feature is not supported and APIs in + * this file are not used but this file still gets compiled into the KVM AMD + * module. + * + * We will not have MISC_CG_RES_SEV and MISC_CG_RES_SEV_ES entries in the enum + * misc_res_type {} defined in linux/misc_cgroup.h. + * + * Below macros allow compilation to succeed. + */ +#define MISC_CG_RES_SEV MISC_CG_RES_TYPES +#define MISC_CG_RES_SEV_ES MISC_CG_RES_TYPES +#endif + static u8 sev_enc_bit; static int sev_flush_asids(void); static DECLARE_RWSEM(sev_deactivate_lock); @@ -89,8 +105,19 @@ static bool __sev_recycle_asids(int min_asid, int max_asid) static int sev_asid_new(struct kvm_sev_info *sev) { - int pos, min_asid, max_asid; + int pos, min_asid, max_asid, ret; bool retry = true; + enum misc_res_type type; + + type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV; + WARN_ON(sev->misc_cg); + sev->misc_cg = get_current_misc_cg(); + ret = misc_cg_try_charge(type, sev->misc_cg, 1); + if (ret) { + put_misc_cg(sev->misc_cg); + sev->misc_cg = NULL; + return ret; + } mutex_lock(&sev_bitmap_lock); @@ -108,7 +135,8 @@ again: goto again; } mutex_unlock(&sev_bitmap_lock); - return -EBUSY; + ret = -EBUSY; + goto e_uncharge; } __set_bit(pos, sev_asid_bitmap); @@ -116,6 +144,11 @@ again: mutex_unlock(&sev_bitmap_lock); return pos + 1; +e_uncharge: + misc_cg_uncharge(type, sev->misc_cg, 1); + put_misc_cg(sev->misc_cg); + sev->misc_cg = NULL; + return ret; } static int sev_get_asid(struct kvm *kvm) @@ -125,14 +158,15 @@ static int sev_get_asid(struct kvm *kvm) return sev->asid; } -static void sev_asid_free(int asid) +static void sev_asid_free(struct kvm_sev_info *sev) { struct svm_cpu_data *sd; int cpu, pos; + enum misc_res_type type; mutex_lock(&sev_bitmap_lock); - pos = asid - 1; + pos = sev->asid - 1; __set_bit(pos, sev_reclaim_asid_bitmap); for_each_possible_cpu(cpu) { @@ -141,6 +175,11 @@ static void sev_asid_free(int asid) } mutex_unlock(&sev_bitmap_lock); + + type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV; + misc_cg_uncharge(type, sev->misc_cg, 1); + put_misc_cg(sev->misc_cg); + sev->misc_cg = NULL; } static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) @@ -188,19 +227,20 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) asid = sev_asid_new(sev); if (asid < 0) return ret; + sev->asid = asid; ret = sev_platform_init(&argp->error); if (ret) goto e_free; sev->active = true; - sev->asid = asid; INIT_LIST_HEAD(&sev->regions_list); return 0; e_free: - sev_asid_free(asid); + sev_asid_free(sev); + sev->asid = 0; return ret; } @@ -1315,12 +1355,12 @@ void sev_vm_destroy(struct kvm *kvm) mutex_unlock(&kvm->lock); sev_unbind_asid(kvm, sev->handle); - sev_asid_free(sev->asid); + sev_asid_free(sev); } void __init sev_hardware_setup(void) { - unsigned int eax, ebx, ecx, edx; + unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count; bool sev_es_supported = false; bool sev_supported = false; @@ -1352,7 +1392,11 @@ void __init sev_hardware_setup(void) if (!sev_reclaim_asid_bitmap) goto out; - pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1); + sev_asid_count = max_sev_asid - min_sev_asid + 1; + if (misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count)) + goto out; + + pr_info("SEV supported: %u ASIDs\n", sev_asid_count); sev_supported = true; /* SEV-ES support requested? */ @@ -1367,7 +1411,11 @@ void __init sev_hardware_setup(void) if (min_sev_asid == 1) goto out; - pr_info("SEV-ES supported: %u ASIDs\n", min_sev_asid - 1); + sev_es_asid_count = min_sev_asid - 1; + if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count)) + goto out; + + pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count); sev_es_supported = true; out: @@ -1382,6 +1430,8 @@ void sev_hardware_teardown(void) bitmap_free(sev_asid_bitmap); bitmap_free(sev_reclaim_asid_bitmap); + misc_cg_set_capacity(MISC_CG_RES_SEV, 0); + misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0); sev_flush_asids(); } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 39e071fdab0c..9806aaebc37f 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -65,6 +65,7 @@ struct kvm_sev_info { unsigned long pages_locked; /* Number of pages locked */ struct list_head regions_list; /* List of registered regions */ u64 ap_jump_table; /* SEV-ES AP Jump Table address */ + struct misc_cg *misc_cg; /* For misc cgroup accounting */ }; struct kvm_svm { diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h index acb77dcff3b4..445235487230 100644 --- a/include/linux/cgroup_subsys.h +++ b/include/linux/cgroup_subsys.h @@ -61,6 +61,10 @@ SUBSYS(pids) SUBSYS(rdma) #endif +#if IS_ENABLED(CONFIG_CGROUP_MISC) +SUBSYS(misc) +#endif + /* * The following subsystems are not supported on the default hierarchy. */ diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h new file mode 100644 index 000000000000..da2367e2ac1e --- /dev/null +++ b/include/linux/misc_cgroup.h @@ -0,0 +1,132 @@ +/* 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 { +#ifdef CONFIG_KVM_AMD_SEV + /* AMD SEV ASIDs resource */ + MISC_CG_RES_SEV, + /* AMD SEV-ES ASIDs resource */ + MISC_CG_RES_SEV_ES, +#endif + 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 */ + +static inline 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_ */ diff --git a/init/Kconfig b/init/Kconfig index 5babea38e346..1097b9d9691b 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1110,6 +1110,20 @@ config CGROUP_BPF BPF_CGROUP_INET_INGRESS will be executed on the ingress path of inet sockets. +config CGROUP_MISC + bool "Misc resource controller" + default n + help + Provides a controller for miscellaneous resources on a host. + + Miscellaneous scalar resources are the resources on the host system + which cannot be abstracted like the other cgroups. This controller + tracks and limits the miscellaneous resources used by a process + attached to a cgroup hierarchy. + + For more information, please check misc cgroup section in + /Documentation/admin-guide/cgroup-v2.rst. + config CGROUP_DEBUG bool "Debug controller" default n diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile index 5d7a76bfbbb7..12f8457ad1f9 100644 --- a/kernel/cgroup/Makefile +++ b/kernel/cgroup/Makefile @@ -5,4 +5,5 @@ obj-$(CONFIG_CGROUP_FREEZER) += legacy_freezer.o obj-$(CONFIG_CGROUP_PIDS) += pids.o obj-$(CONFIG_CGROUP_RDMA) += rdma.o obj-$(CONFIG_CPUSETS) += cpuset.o +obj-$(CONFIG_CGROUP_MISC) += misc.o obj-$(CONFIG_CGROUP_DEBUG) += debug.o diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index a5751784ad74..391aa570369b 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -727,7 +727,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) stats->nr_stopped++; break; default: - if (delayacct_is_task_waiting_on_io(tsk)) + if (tsk->in_iowait) stats->nr_io_wait++; break; } diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 5258b68153e0..a945504c0ae7 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -585,7 +585,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial) par = parent_cs(cur); - /* On legacy hiearchy, we must be a subset of our parent cpuset. */ + /* On legacy hierarchy, we must be a subset of our parent cpuset. */ ret = -EACCES; if (!is_in_v2_mode() && !is_cpuset_subset(trial, par)) goto out; @@ -1726,7 +1726,7 @@ static void update_tasks_nodemask(struct cpuset *cs) * When configured nodemask is changed, the effective nodemasks of this cpuset * and all its descendants need to be updated. * - * On legacy hiearchy, effective_mems will be the same with mems_allowed. + * On legacy hierarchy, effective_mems will be the same with mems_allowed. * * Called with cpuset_mutex held */ @@ -2500,7 +2500,7 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft) BUG(); } - /* Unrechable but makes gcc happy */ + /* Unreachable but makes gcc happy */ return 0; } diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c new file mode 100644 index 000000000000..ec02d963cad1 --- /dev/null +++ b/kernel/cgroup/misc.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Miscellaneous cgroup controller + * + * Copyright 2020 Google LLC + * Author: Vipin Sharma <vipinsh@google.com> + */ + +#include <linux/limits.h> +#include <linux/cgroup.h> +#include <linux/errno.h> +#include <linux/atomic.h> +#include <linux/slab.h> +#include <linux/misc_cgroup.h> + +#define MAX_STR "max" +#define MAX_NUM ULONG_MAX + +/* Miscellaneous res name, keep it in sync with enum misc_res_type */ +static const char *const misc_res_name[] = { +#ifdef CONFIG_KVM_AMD_SEV + /* AMD SEV ASIDs resource */ + "sev", + /* AMD SEV-ES ASIDs resource */ + "sev_es", +#endif +}; + +/* Root misc cgroup */ +static struct misc_cg root_cg; + +/* + * Miscellaneous resources capacity for the entire machine. 0 capacity means + * resource is not initialized or not present in the host. + * + * root_cg.max and capacity are independent of each other. root_cg.max can be + * more than the actual capacity. We are using Limits resource distribution + * model of cgroup for miscellaneous controller. + */ +static unsigned long misc_res_capacity[MISC_CG_RES_TYPES]; + +/** + * parent_misc() - Get the parent of the passed misc cgroup. + * @cgroup: cgroup whose parent needs to be fetched. + * + * Context: Any context. + * Return: + * * struct misc_cg* - Parent of the @cgroup. + * * %NULL - If @cgroup is null or the passed cgroup does not have a parent. + */ +static struct misc_cg *parent_misc(struct misc_cg *cgroup) +{ + return cgroup ? css_misc(cgroup->css.parent) : NULL; +} + +/** + * valid_type() - Check if @type is valid or not. + * @type: misc res type. + * + * Context: Any context. + * Return: + * * true - If valid type. + * * false - If not valid type. + */ +static inline bool valid_type(enum misc_res_type type) +{ + return type >= 0 && type < MISC_CG_RES_TYPES; +} + +/** + * misc_cg_res_total_usage() - Get the current total usage of the resource. + * @type: misc res type. + * + * Context: Any context. + * Return: Current total usage of the resource. + */ +unsigned long misc_cg_res_total_usage(enum misc_res_type type) +{ + if (valid_type(type)) + return atomic_long_read(&root_cg.res[type].usage); + + return 0; +} +EXPORT_SYMBOL_GPL(misc_cg_res_total_usage); + +/** + * misc_cg_set_capacity() - Set the capacity of the misc cgroup res. + * @type: Type of the misc res. + * @capacity: Supported capacity of the misc res on the host. + * + * If capacity is 0 then the charging a misc cgroup fails for that type. + * + * Context: Any context. + * Return: + * * %0 - Successfully registered the capacity. + * * %-EINVAL - If @type is invalid. + */ +int misc_cg_set_capacity(enum misc_res_type type, unsigned long capacity) +{ + if (!valid_type(type)) + return -EINVAL; + + WRITE_ONCE(misc_res_capacity[type], capacity); + return 0; +} +EXPORT_SYMBOL_GPL(misc_cg_set_capacity); + +/** + * misc_cg_cancel_charge() - Cancel the charge from the misc cgroup. + * @type: Misc res type in misc cg to cancel the charge from. + * @cg: Misc cgroup to cancel charge from. + * @amount: Amount to cancel. + * + * Context: Any context. + */ +static void misc_cg_cancel_charge(enum misc_res_type type, struct misc_cg *cg, + unsigned long amount) +{ + WARN_ONCE(atomic_long_add_negative(-amount, &cg->res[type].usage), + "misc cgroup resource %s became less than 0", + misc_res_name[type]); +} + +/** + * misc_cg_try_charge() - Try charging the misc cgroup. + * @type: Misc res type to charge. + * @cg: Misc cgroup which will be charged. + * @amount: Amount to charge. + * + * Charge @amount to the misc cgroup. Caller must use the same cgroup during + * the uncharge call. + * + * Context: Any context. + * Return: + * * %0 - If successfully charged. + * * -EINVAL - If @type is invalid or misc res has 0 capacity. + * * -EBUSY - If max limit will be crossed or total usage will be more than the + * capacity. + */ +int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, + unsigned long amount) +{ + struct misc_cg *i, *j; + int ret; + struct misc_res *res; + int new_usage; + + if (!(valid_type(type) && cg && READ_ONCE(misc_res_capacity[type]))) + return -EINVAL; + + if (!amount) + return 0; + + for (i = cg; i; i = parent_misc(i)) { + res = &i->res[type]; + + new_usage = atomic_long_add_return(amount, &res->usage); + if (new_usage > READ_ONCE(res->max) || + new_usage > READ_ONCE(misc_res_capacity[type])) { + if (!res->failed) { + pr_info("cgroup: charge rejected by the misc controller for %s resource in ", + misc_res_name[type]); + pr_cont_cgroup_path(i->css.cgroup); + pr_cont("\n"); + res->failed = true; + } + ret = -EBUSY; + goto err_charge; + } + } + return 0; + +err_charge: + for (j = cg; j != i; j = parent_misc(j)) + misc_cg_cancel_charge(type, j, amount); + misc_cg_cancel_charge(type, i, amount); + return ret; +} +EXPORT_SYMBOL_GPL(misc_cg_try_charge); + +/** + * misc_cg_uncharge() - Uncharge the misc cgroup. + * @type: Misc res type which was charged. + * @cg: Misc cgroup which will be uncharged. + * @amount: Charged amount. + * + * Context: Any context. + */ +void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg, + unsigned long amount) +{ + struct misc_cg *i; + + if (!(amount && valid_type(type) && cg)) + return; + + for (i = cg; i; i = parent_misc(i)) + misc_cg_cancel_charge(type, i, amount); +} +EXPORT_SYMBOL_GPL(misc_cg_uncharge); + +/** + * misc_cg_max_show() - Show the misc cgroup max limit. + * @sf: Interface file + * @v: Arguments passed + * + * Context: Any context. + * Return: 0 to denote successful print. + */ +static int misc_cg_max_show(struct seq_file *sf, void *v) +{ + int i; + struct misc_cg *cg = css_misc(seq_css(sf)); + unsigned long max; + + for (i = 0; i < MISC_CG_RES_TYPES; i++) { + if (READ_ONCE(misc_res_capacity[i])) { + max = READ_ONCE(cg->res[i].max); + if (max == MAX_NUM) + seq_printf(sf, "%s max\n", misc_res_name[i]); + else + seq_printf(sf, "%s %lu\n", misc_res_name[i], + max); + } + } + + return 0; +} + +/** + * misc_cg_max_write() - Update the maximum limit of the cgroup. + * @of: Handler for the file. + * @buf: Data from the user. It should be either "max", 0, or a positive + * integer. + * @nbytes: Number of bytes of the data. + * @off: Offset in the file. + * + * User can pass data like: + * echo sev 23 > misc.max, OR + * echo sev max > misc.max + * + * Context: Any context. + * Return: + * * >= 0 - Number of bytes processed in the input. + * * -EINVAL - If buf is not valid. + * * -ERANGE - If number is bigger than the unsigned long capacity. + */ +static ssize_t misc_cg_max_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + struct misc_cg *cg; + unsigned long max; + int ret = 0, i; + enum misc_res_type type = MISC_CG_RES_TYPES; + char *token; + + buf = strstrip(buf); + token = strsep(&buf, " "); + + if (!token || !buf) + return -EINVAL; + + for (i = 0; i < MISC_CG_RES_TYPES; i++) { + if (!strcmp(misc_res_name[i], token)) { + type = i; + break; + } + } + + if (type == MISC_CG_RES_TYPES) + return -EINVAL; + + if (!strcmp(MAX_STR, buf)) { + max = MAX_NUM; + } else { + ret = kstrtoul(buf, 0, &max); + if (ret) + return ret; + } + + cg = css_misc(of_css(of)); + + if (READ_ONCE(misc_res_capacity[type])) + WRITE_ONCE(cg->res[type].max, max); + else + ret = -EINVAL; + + return ret ? ret : nbytes; +} + +/** + * misc_cg_current_show() - Show the current usage of the misc cgroup. + * @sf: Interface file + * @v: Arguments passed + * + * Context: Any context. + * Return: 0 to denote successful print. + */ +static int misc_cg_current_show(struct seq_file *sf, void *v) +{ + int i; + unsigned long usage; + struct misc_cg *cg = css_misc(seq_css(sf)); + + for (i = 0; i < MISC_CG_RES_TYPES; i++) { + usage = atomic_long_read(&cg->res[i].usage); + if (READ_ONCE(misc_res_capacity[i]) || usage) + seq_printf(sf, "%s %lu\n", misc_res_name[i], usage); + } + + return 0; +} + +/** + * misc_cg_capacity_show() - Show the total capacity of misc res on the host. + * @sf: Interface file + * @v: Arguments passed + * + * Only present in the root cgroup directory. + * + * Context: Any context. + * Return: 0 to denote successful print. + */ +static int misc_cg_capacity_show(struct seq_file *sf, void *v) +{ + int i; + unsigned long cap; + + for (i = 0; i < MISC_CG_RES_TYPES; i++) { + cap = READ_ONCE(misc_res_capacity[i]); + if (cap) + seq_printf(sf, "%s %lu\n", misc_res_name[i], cap); + } + + return 0; +} + +/* Misc cgroup interface files */ +static struct cftype misc_cg_files[] = { + { + .name = "max", + .write = misc_cg_max_write, + .seq_show = misc_cg_max_show, + .flags = CFTYPE_NOT_ON_ROOT, + }, + { + .name = "current", + .seq_show = misc_cg_current_show, + .flags = CFTYPE_NOT_ON_ROOT, + }, + { + .name = "capacity", + .seq_show = misc_cg_capacity_show, + .flags = CFTYPE_ONLY_ON_ROOT, + }, + {} +}; + +/** + * misc_cg_alloc() - Allocate misc cgroup. + * @parent_css: Parent cgroup. + * + * Context: Process context. + * Return: + * * struct cgroup_subsys_state* - css of the allocated cgroup. + * * ERR_PTR(-ENOMEM) - No memory available to allocate. + */ +static struct cgroup_subsys_state * +misc_cg_alloc(struct cgroup_subsys_state *parent_css) +{ + enum misc_res_type i; + struct misc_cg *cg; + + if (!parent_css) { + cg = &root_cg; + } else { + cg = kzalloc(sizeof(*cg), GFP_KERNEL); + if (!cg) + return ERR_PTR(-ENOMEM); + } + + for (i = 0; i < MISC_CG_RES_TYPES; i++) { + WRITE_ONCE(cg->res[i].max, MAX_NUM); + atomic_long_set(&cg->res[i].usage, 0); + } + + return &cg->css; +} + +/** + * misc_cg_free() - Free the misc cgroup. + * @css: cgroup subsys object. + * + * Context: Any context. + */ +static void misc_cg_free(struct cgroup_subsys_state *css) +{ + kfree(css_misc(css)); +} + +/* Cgroup controller callbacks */ +struct cgroup_subsys misc_cgrp_subsys = { + .css_alloc = misc_cg_alloc, + .css_free = misc_cg_free, + .legacy_cftypes = misc_cg_files, + .dfl_cftypes = misc_cg_files, +}; |