mm/cma_sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * CMA SysFS Interface
   4  *
   5  * Copyright (c) 2021 Minchan Kim <minchan@kernel.org>
   6  */
   7
   8 #include <linux/cma.h>
   9 #include <linux/kernel.h>
  10 #include <linux/slab.h>
  11
  12 #include "cma.h"
  13
  14 #define CMA_ATTR_RO(_name) \
  15         static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
  16
  17 void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages)
  18 {
  19         atomic64_add(nr_pages, &cma->nr_pages_succeeded);
  20 }
  21
  22 void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages)
  23 {
  24         atomic64_add(nr_pages, &cma->nr_pages_failed);
  25 }
  26
  27 void cma_sysfs_account_release_pages(struct cma *cma, unsigned long nr_pages)
  28 {
  29         atomic64_add(nr_pages, &cma->nr_pages_released);
  30 }
  31
  32 static inline struct cma *cma_from_kobj(struct kobject *kobj)
  33 {
  34         return container_of(kobj, struct cma_kobject, kobj)->cma;
  35 }
  36
  37 static ssize_t alloc_pages_success_show(struct kobject *kobj,
  38                                         struct kobj_attribute *attr, char *buf)
  39 {
  40         struct cma *cma = cma_from_kobj(kobj);
  41
  42         return sysfs_emit(buf, "%llu\n",
  43                           atomic64_read(&cma->nr_pages_succeeded));
  44 }
  45 CMA_ATTR_RO(alloc_pages_success);
  46
  47 static ssize_t alloc_pages_fail_show(struct kobject *kobj,
  48                                      struct kobj_attribute *attr, char *buf)
  49 {
  50         struct cma *cma = cma_from_kobj(kobj);
  51
  52         return sysfs_emit(buf, "%llu\n", atomic64_read(&cma->nr_pages_failed));
  53 }
  54 CMA_ATTR_RO(alloc_pages_fail);
  55
  56 static ssize_t release_pages_success_show(struct kobject *kobj,
  57                                           struct kobj_attribute *attr, char *buf)
  58 {
  59         struct cma *cma = cma_from_kobj(kobj);
  60
  61         return sysfs_emit(buf, "%llu\n", atomic64_read(&cma->nr_pages_released));
  62 }
  63 CMA_ATTR_RO(release_pages_success);
  64
  65 static void cma_kobj_release(struct kobject *kobj)
  66 {
  67         struct cma *cma = cma_from_kobj(kobj);
  68         struct cma_kobject *cma_kobj = cma->cma_kobj;
  69
  70         kfree(cma_kobj);
  71         cma->cma_kobj = NULL;
  72 }
  73
  74 static struct attribute *cma_attrs[] = {
  75         &alloc_pages_success_attr.attr,
  76         &alloc_pages_fail_attr.attr,
  77         &release_pages_success_attr.attr,
  78         NULL,
  79 };
  80 ATTRIBUTE_GROUPS(cma);
  81
  82 static const struct kobj_type cma_ktype = {
  83         .release = cma_kobj_release,
  84         .sysfs_ops = &kobj_sysfs_ops,
  85         .default_groups = cma_groups,
  86 };
  87
  88 static int __init cma_sysfs_init(void)
  89 {
  90         struct kobject *cma_kobj_root;
  91         struct cma_kobject *cma_kobj;
  92         struct cma *cma;
  93         int i, err;
  94
  95         cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
  96         if (!cma_kobj_root)
  97                 return -ENOMEM;
  98
  99         for (i = 0; i < cma_area_count; i++) {
 100                 cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
 101                 if (!cma_kobj) {
 102                         err = -ENOMEM;
 103                         goto out;
 104                 }
 105
 106                 cma = &cma_areas[i];
 107                 cma->cma_kobj = cma_kobj;
 108                 cma_kobj->cma = cma;
 109                 err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype,
 110                                            cma_kobj_root, "%s", cma->name);
 111                 if (err) {
 112                         kobject_put(&cma_kobj->kobj);
 113                         goto out;
 114                 }
 115         }
 116
 117         return 0;
 118 out:
 119         while (--i >= 0) {
 120                 cma = &cma_areas[i];
 121                 kobject_put(&cma->cma_kobj->kobj);
 122         }
 123         kobject_put(cma_kobj_root);
 124
 125         return err;
 126 }
 127 subsys_initcall(cma_sysfs_init);