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 map_kset = NULL; 124 return ERR_PTR(-ENOMEM); 125 } 126 127 memcpy(&entry->md, efi_runtime_map + nr * efi_memdesc_size, 128 sizeof(efi_memory_desc_t)); 129 130 kobject_init(&entry->kobj, &map_ktype); 131 entry->kobj.kset = map_kset; 132 ret = kobject_add(&entry->kobj, NULL, "%d", nr); 133 if (ret) { 134 kobject_put(&entry->kobj); 135 kset_unregister(map_kset); 136 map_kset = NULL; 137 return ERR_PTR(ret); 138 } 139 140 return entry; 141} 142 143int efi_get_runtime_map_size(void) 144{ 145 return nr_efi_runtime_map * efi_memdesc_size; 146} 147 148int efi_get_runtime_map_desc_size(void) 149{ 150 return efi_memdesc_size; 151} 152 153int efi_runtime_map_copy(void *buf, size_t bufsz) 154{ 155 size_t sz = efi_get_runtime_map_size(); 156 157 if (sz > bufsz) 158 sz = bufsz; 159 160 memcpy(buf, efi_runtime_map, sz); 161 return 0; 162} 163 164void efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size) 165{ 166 efi_runtime_map = map; 167 nr_efi_runtime_map = nr_entries; 168 efi_memdesc_size = desc_size; 169} 170 171int __init efi_runtime_map_init(struct kobject *efi_kobj) 172{ 173 int i, j, ret = 0; 174 struct efi_runtime_map_entry *entry; 175 176 if (!efi_runtime_map) 177 return 0; 178 179 map_entries = kzalloc(nr_efi_runtime_map * sizeof(entry), GFP_KERNEL); 180 if (!map_entries) { 181 ret = -ENOMEM; 182 goto out; 183 } 184 185 for (i = 0; i < nr_efi_runtime_map; i++) { 186 entry = add_sysfs_runtime_map_entry(efi_kobj, i); 187 if (IS_ERR(entry)) { 188 ret = PTR_ERR(entry); 189 goto out_add_entry; 190 } 191 *(map_entries + i) = entry; 192 } 193 194 return 0; 195out_add_entry: 196 for (j = i - 1; j >= 0; j--) { 197 entry = *(map_entries + j); 198 kobject_put(&entry->kobj); 199 } 200out: 201 return ret; 202} 203