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
141void efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size)
142{
143	efi_runtime_map = map;
144	nr_efi_runtime_map = nr_entries;
145	efi_memdesc_size = desc_size;
146}
147
148int __init efi_runtime_map_init(struct kobject *efi_kobj)
149{
150	int i, j, ret = 0;
151	struct efi_runtime_map_entry *entry;
152
153	if (!efi_runtime_map)
154		return 0;
155
156	map_entries = kzalloc(nr_efi_runtime_map * sizeof(entry), GFP_KERNEL);
157	if (!map_entries) {
158		ret = -ENOMEM;
159		goto out;
160	}
161
162	for (i = 0; i < nr_efi_runtime_map; i++) {
163		entry = add_sysfs_runtime_map_entry(efi_kobj, i);
164		if (IS_ERR(entry)) {
165			ret = PTR_ERR(entry);
166			goto out_add_entry;
167		}
168		*(map_entries + i) = entry;
169	}
170
171	return 0;
172out_add_entry:
173	for (j = i - 1; j > 0; j--) {
174		entry = *(map_entries + j);
175		kobject_put(&entry->kobj);
176	}
177	if (map_kset)
178		kset_unregister(map_kset);
179out:
180	return ret;
181}