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
 17void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages)
 18{
 19	atomic64_add(nr_pages, &cma->nr_pages_succeeded);
 20}
 21
 22void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages)
 23{
 24	atomic64_add(nr_pages, &cma->nr_pages_failed);
 25}
 26
 27void cma_sysfs_account_release_pages(struct cma *cma, unsigned long nr_pages)
 28{
 29	atomic64_add(nr_pages, &cma->nr_pages_released);
 30}
 31
 32static inline struct cma *cma_from_kobj(struct kobject *kobj)
 33{
 34	return container_of(kobj, struct cma_kobject, kobj)->cma;
 35}
 36
 37static 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}
 45CMA_ATTR_RO(alloc_pages_success);
 46
 47static 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}
 54CMA_ATTR_RO(alloc_pages_fail);
 55
 56static 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}
 63CMA_ATTR_RO(release_pages_success);
 64
 65static ssize_t total_pages_show(struct kobject *kobj,
 66					  struct kobj_attribute *attr, char *buf)
 67{
 68	struct cma *cma = cma_from_kobj(kobj);
 69
 70	return sysfs_emit(buf, "%lu\n", cma->count);
 71}
 72CMA_ATTR_RO(total_pages);
 73
 74static ssize_t available_pages_show(struct kobject *kobj,
 75					  struct kobj_attribute *attr, char *buf)
 76{
 77	struct cma *cma = cma_from_kobj(kobj);
 78
 79	return sysfs_emit(buf, "%lu\n", cma->available_count);
 80}
 81CMA_ATTR_RO(available_pages);
 82
 83static void cma_kobj_release(struct kobject *kobj)
 84{
 85	struct cma *cma = cma_from_kobj(kobj);
 86	struct cma_kobject *cma_kobj = cma->cma_kobj;
 87
 88	kfree(cma_kobj);
 89	cma->cma_kobj = NULL;
 90}
 91
 92static struct attribute *cma_attrs[] = {
 93	&alloc_pages_success_attr.attr,
 94	&alloc_pages_fail_attr.attr,
 95	&release_pages_success_attr.attr,
 96	&total_pages_attr.attr,
 97	&available_pages_attr.attr,
 98	NULL,
 99};
100ATTRIBUTE_GROUPS(cma);
101
102static const struct kobj_type cma_ktype = {
103	.release = cma_kobj_release,
104	.sysfs_ops = &kobj_sysfs_ops,
105	.default_groups = cma_groups,
106};
107
108static int __init cma_sysfs_init(void)
109{
110	struct kobject *cma_kobj_root;
111	struct cma_kobject *cma_kobj;
112	struct cma *cma;
113	int i, err;
114
115	cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
116	if (!cma_kobj_root)
117		return -ENOMEM;
118
119	for (i = 0; i < cma_area_count; i++) {
120		cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
121		if (!cma_kobj) {
122			err = -ENOMEM;
123			goto out;
124		}
125
126		cma = &cma_areas[i];
127		cma->cma_kobj = cma_kobj;
128		cma_kobj->cma = cma;
129		err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype,
130					   cma_kobj_root, "%s", cma->name);
131		if (err) {
132			kobject_put(&cma_kobj->kobj);
133			goto out;
134		}
135	}
136
137	return 0;
138out:
139	while (--i >= 0) {
140		cma = &cma_areas[i];
141		kobject_put(&cma->cma_kobj->kobj);
142	}
143	kobject_put(cma_kobj_root);
144
145	return err;
146}
147subsys_initcall(cma_sysfs_init);