[go: nahoru, domu]
1/*
2 * linux/drivers/efi/runtime-map.c
3 * Copyright (C) 2013 Red Hat, Inc., Dave Young <dyoung@redhat.com>
4 *
5 * This file is released under the GPLv2.
6 */
7
8#include <linux/string.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/types.h>
12#include <linux/efi.h>
13#include <linux/slab.h>
14
15#include <asm/setup.h>
16
17static void *efi_runtime_map;
18static int nr_efi_runtime_map;
19static u32 efi_memdesc_size;
20
21struct efi_runtime_map_entry {
22	efi_memory_desc_t md;
23	struct kobject kobj;   /* kobject for each entry */
24};
25
26static struct efi_runtime_map_entry **map_entries;
27
28struct map_attribute {
29	struct attribute attr;
30	ssize_t (*show)(struct efi_runtime_map_entry *entry, char *buf);
31};
32
33static inline struct map_attribute *to_map_attr(struct attribute *attr)
34{
35	return container_of(attr, struct map_attribute, attr);
36}
37
38static ssize_t type_show(struct efi_runtime_map_entry *entry, char *buf)
39{
40	return snprintf(buf, PAGE_SIZE, "0x%x\n", entry->md.type);
41}
42
43#define EFI_RUNTIME_FIELD(var) entry->md.var
44
45#define EFI_RUNTIME_U64_ATTR_SHOW(name) \
46static ssize_t name##_show(struct efi_runtime_map_entry *entry, char *buf) \
47{ \
48	return snprintf(buf, PAGE_SIZE, "0x%llx\n", EFI_RUNTIME_FIELD(name)); \
49}
50
51EFI_RUNTIME_U64_ATTR_SHOW(phys_addr);
52EFI_RUNTIME_U64_ATTR_SHOW(virt_addr);
53EFI_RUNTIME_U64_ATTR_SHOW(num_pages);
54EFI_RUNTIME_U64_ATTR_SHOW(attribute);
55
56static inline struct efi_runtime_map_entry *to_map_entry(struct kobject *kobj)
57{
58	return container_of(kobj, struct efi_runtime_map_entry, kobj);
59}
60
61static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr,
62			      char *buf)
63{
64	struct efi_runtime_map_entry *entry = to_map_entry(kobj);
65	struct map_attribute *map_attr = to_map_attr(attr);
66
67	return map_attr->show(entry, buf);
68}
69
70static struct map_attribute map_type_attr = __ATTR_RO(type);
71static struct map_attribute map_phys_addr_attr   = __ATTR_RO(phys_addr);
72static struct map_attribute map_virt_addr_attr  = __ATTR_RO(virt_addr);
73static struct map_attribute map_num_pages_attr  = __ATTR_RO(num_pages);
74static struct map_attribute map_attribute_attr  = __ATTR_RO(attribute);
75
76/*
77 * These are default attributes that are added for every memmap entry.
78 */
79static struct attribute *def_attrs[] = {
80	&map_type_attr.attr,
81	&map_phys_addr_attr.attr,
82	&map_virt_addr_attr.attr,
83	&map_num_pages_attr.attr,
84	&map_attribute_attr.attr,
85	NULL
86};
87
88static const struct sysfs_ops map_attr_ops = {
89	.show = map_attr_show,
90};
91
92static void map_release(struct kobject *kobj)
93{
94	struct efi_runtime_map_entry *entry;
95
96	entry = to_map_entry(kobj);
97	kfree(entry);
98}
99
100static struct kobj_type __refdata map_ktype = {
101	.sysfs_ops	= &map_attr_ops,
102	.default_attrs	= def_attrs,
103	.release	= map_release,
104};
105
106static struct kset *map_kset;
107
108static struct efi_runtime_map_entry *
109add_sysfs_runtime_map_entry(struct kobject *kobj, int nr)
110{
111	int ret;
112	struct efi_runtime_map_entry *entry;
113
114	if (!map_kset) {
115		map_kset = kset_create_and_add("runtime-map", NULL, kobj);
116		if (!map_kset)
117			return ERR_PTR(-ENOMEM);
118	}
119
120	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
121	if (!entry) {
122		kset_unregister(map_kset);
123		return entry;
124	}
125
126	memcpy(&entry->md, efi_runtime_map + nr * efi_memdesc_size,
127	       sizeof(efi_memory_desc_t));
128
129	kobject_init(&entry->kobj, &map_ktype);
130	entry->kobj.kset = map_kset;
131	ret = kobject_add(&entry->kobj, NULL, "%d", nr);
132	if (ret) {
133		kobject_put(&entry->kobj);
134		kset_unregister(map_kset);
135		return ERR_PTR(ret);
136	}
137
138	return entry;
139}
140
141int efi_get_runtime_map_size(void)
142{
143	return nr_efi_runtime_map * efi_memdesc_size;
144}
145
146int efi_get_runtime_map_desc_size(void)
147{
148	return efi_memdesc_size;
149}
150
151int efi_runtime_map_copy(void *buf, size_t bufsz)
152{
153	size_t sz = efi_get_runtime_map_size();
154
155	if (sz > bufsz)
156		sz = bufsz;
157
158	memcpy(buf, efi_runtime_map, sz);
159	return 0;
160}
161
162void efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size)
163{
164	efi_runtime_map = map;
165	nr_efi_runtime_map = nr_entries;
166	efi_memdesc_size = desc_size;
167}
168
169int __init efi_runtime_map_init(struct kobject *efi_kobj)
170{
171	int i, j, ret = 0;
172	struct efi_runtime_map_entry *entry;
173
174	if (!efi_runtime_map)
175		return 0;
176
177	map_entries = kzalloc(nr_efi_runtime_map * sizeof(entry), GFP_KERNEL);
178	if (!map_entries) {
179		ret = -ENOMEM;
180		goto out;
181	}
182
183	for (i = 0; i < nr_efi_runtime_map; i++) {
184		entry = add_sysfs_runtime_map_entry(efi_kobj, i);
185		if (IS_ERR(entry)) {
186			ret = PTR_ERR(entry);
187			goto out_add_entry;
188		}
189		*(map_entries + i) = entry;
190	}
191
192	return 0;
193out_add_entry:
194	for (j = i - 1; j > 0; j--) {
195		entry = *(map_entries + j);
196		kobject_put(&entry->kobj);
197	}
198	if (map_kset)
199		kset_unregister(map_kset);
200out:
201	return ret;
202}
203