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