mm/damon/sysfs-common.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Common Primitives for DAMON Sysfs Interface
   4  *
   5  * Author: SeongJae Park <sj@kernel.org>
   6  */
   7
   8 #include <linux/slab.h>
   9
  10 #include "sysfs-common.h"
  11
  12 DEFINE_MUTEX(damon_sysfs_lock);
  13
  14 /*
  15  * unsigned long range directory
  16  */
  17
  18 struct damon_sysfs_ul_range *damon_sysfs_ul_range_alloc(
  19                 unsigned long min,
  20                 unsigned long max)
  21 {
  22         struct damon_sysfs_ul_range *range = kmalloc(sizeof(*range),
  23                         GFP_KERNEL);
  24
  25         if (!range)
  26                 return NULL;
  27         range->kobj = (struct kobject){};
  28         range->min = min;
  29         range->max = max;
  30
  31         return range;
  32 }
  33
  34 static ssize_t min_show(struct kobject *kobj, struct kobj_attribute *attr,
  35                 char *buf)
  36 {
  37         struct damon_sysfs_ul_range *range = container_of(kobj,
  38                         struct damon_sysfs_ul_range, kobj);
  39
  40         return sysfs_emit(buf, "%lu\n", range->min);
  41 }
  42
  43 static ssize_t min_store(struct kobject *kobj, struct kobj_attribute *attr,
  44                 const char *buf, size_t count)
  45 {
  46         struct damon_sysfs_ul_range *range = container_of(kobj,
  47                         struct damon_sysfs_ul_range, kobj);
  48         unsigned long min;
  49         int err;
  50
  51         err = kstrtoul(buf, 0, &min);
  52         if (err)
  53                 return err;
  54
  55         range->min = min;
  56         return count;
  57 }
  58
  59 static ssize_t max_show(struct kobject *kobj, struct kobj_attribute *attr,
  60                 char *buf)
  61 {
  62         struct damon_sysfs_ul_range *range = container_of(kobj,
  63                         struct damon_sysfs_ul_range, kobj);
  64
  65         return sysfs_emit(buf, "%lu\n", range->max);
  66 }
  67
  68 static ssize_t max_store(struct kobject *kobj, struct kobj_attribute *attr,
  69                 const char *buf, size_t count)
  70 {
  71         struct damon_sysfs_ul_range *range = container_of(kobj,
  72                         struct damon_sysfs_ul_range, kobj);
  73         unsigned long max;
  74         int err;
  75
  76         err = kstrtoul(buf, 0, &max);
  77         if (err)
  78                 return err;
  79
  80         range->max = max;
  81         return count;
  82 }
  83
  84 void damon_sysfs_ul_range_release(struct kobject *kobj)
  85 {
  86         kfree(container_of(kobj, struct damon_sysfs_ul_range, kobj));
  87 }
  88
  89 static struct kobj_attribute damon_sysfs_ul_range_min_attr =
  90                 __ATTR_RW_MODE(min, 0600);
  91
  92 static struct kobj_attribute damon_sysfs_ul_range_max_attr =
  93                 __ATTR_RW_MODE(max, 0600);
  94
  95 static struct attribute *damon_sysfs_ul_range_attrs[] = {
  96         &damon_sysfs_ul_range_min_attr.attr,
  97         &damon_sysfs_ul_range_max_attr.attr,
  98         NULL,
  99 };
 100 ATTRIBUTE_GROUPS(damon_sysfs_ul_range);
 101
 102 const struct kobj_type damon_sysfs_ul_range_ktype = {
 103         .release = damon_sysfs_ul_range_release,
 104         .sysfs_ops = &kobj_sysfs_ops,
 105         .default_groups = damon_sysfs_ul_range_groups,
 106 };
 107