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 
cma_sysfs_account_success_pages(struct cma * cma,unsigned long nr_pages)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 
cma_sysfs_account_fail_pages(struct cma * cma,unsigned long nr_pages)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 
cma_from_kobj(struct kobject * kobj)27 static inline struct cma *cma_from_kobj(struct kobject *kobj)
28 {
29 	return container_of(kobj, struct cma_kobject, kobj)->cma;
30 }
31 
alloc_pages_success_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)32 static ssize_t alloc_pages_success_show(struct kobject *kobj,
33 					struct kobj_attribute *attr, char *buf)
34 {
35 	struct cma *cma = cma_from_kobj(kobj);
36 
37 	return sysfs_emit(buf, "%llu\n",
38 			  atomic64_read(&cma->nr_pages_succeeded));
39 }
40 CMA_ATTR_RO(alloc_pages_success);
41 
alloc_pages_fail_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)42 static ssize_t alloc_pages_fail_show(struct kobject *kobj,
43 				     struct kobj_attribute *attr, char *buf)
44 {
45 	struct cma *cma = cma_from_kobj(kobj);
46 
47 	return sysfs_emit(buf, "%llu\n", atomic64_read(&cma->nr_pages_failed));
48 }
49 CMA_ATTR_RO(alloc_pages_fail);
50 
cma_kobj_release(struct kobject * kobj)51 static void cma_kobj_release(struct kobject *kobj)
52 {
53 	struct cma *cma = cma_from_kobj(kobj);
54 	struct cma_kobject *cma_kobj = cma->cma_kobj;
55 
56 	kfree(cma_kobj);
57 	cma->cma_kobj = NULL;
58 }
59 
60 static struct attribute *cma_attrs[] = {
61 	&alloc_pages_success_attr.attr,
62 	&alloc_pages_fail_attr.attr,
63 	NULL,
64 };
65 ATTRIBUTE_GROUPS(cma);
66 
67 static struct kobj_type cma_ktype = {
68 	.release = cma_kobj_release,
69 	.sysfs_ops = &kobj_sysfs_ops,
70 	.default_groups = cma_groups,
71 };
72 
cma_sysfs_init(void)73 static int __init cma_sysfs_init(void)
74 {
75 	struct kobject *cma_kobj_root;
76 	struct cma_kobject *cma_kobj;
77 	struct cma *cma;
78 	int i, err;
79 
80 	cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
81 	if (!cma_kobj_root)
82 		return -ENOMEM;
83 
84 	for (i = 0; i < cma_area_count; i++) {
85 		cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
86 		if (!cma_kobj) {
87 			err = -ENOMEM;
88 			goto out;
89 		}
90 
91 		cma = &cma_areas[i];
92 		cma->cma_kobj = cma_kobj;
93 		cma_kobj->cma = cma;
94 		err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype,
95 					   cma_kobj_root, "%s", cma->name);
96 		if (err) {
97 			kobject_put(&cma_kobj->kobj);
98 			goto out;
99 		}
100 	}
101 
102 	return 0;
103 out:
104 	while (--i >= 0) {
105 		cma = &cma_areas[i];
106 		kobject_put(&cma->cma_kobj->kobj);
107 	}
108 	kobject_put(cma_kobj_root);
109 
110 	return err;
111 }
112 subsys_initcall(cma_sysfs_init);
113