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 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
74static 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};
80ATTRIBUTE_GROUPS(cma);
81
82static const struct kobj_type cma_ktype = {
83	.release = cma_kobj_release,
84	.sysfs_ops = &kobj_sysfs_ops,
85	.default_groups = cma_groups,
86};
87
88static 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;
118out:
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}
127subsys_initcall(cma_sysfs_init);
128