1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2013 Red Hat, Inc., Dave Young <dyoung@redhat.com> 4 */ 5 6 #include <linux/string.h> 7 #include <linux/kernel.h> 8 #include <linux/module.h> 9 #include <linux/types.h> 10 #include <linux/efi.h> 11 #include <linux/slab.h> 12 13 #include <asm/efi.h> 14 #include <asm/setup.h> 15 16 struct efi_runtime_map_entry { 17 efi_memory_desc_t md; 18 struct kobject kobj; /* kobject for each entry */ 19 }; 20 21 static struct efi_runtime_map_entry **map_entries; 22 23 struct map_attribute { 24 struct attribute attr; 25 ssize_t (*show)(struct efi_runtime_map_entry *entry, char *buf); 26 }; 27 28 static inline struct map_attribute *to_map_attr(struct attribute *attr) 29 { 30 return container_of(attr, struct map_attribute, attr); 31 } 32 33 static ssize_t type_show(struct efi_runtime_map_entry *entry, char *buf) 34 { 35 return snprintf(buf, PAGE_SIZE, "0x%x\n", entry->md.type); 36 } 37 38 #define EFI_RUNTIME_FIELD(var) entry->md.var 39 40 #define EFI_RUNTIME_U64_ATTR_SHOW(name) \ 41 static ssize_t name##_show(struct efi_runtime_map_entry *entry, char *buf) \ 42 { \ 43 return snprintf(buf, PAGE_SIZE, "0x%llx\n", EFI_RUNTIME_FIELD(name)); \ 44 } 45 46 EFI_RUNTIME_U64_ATTR_SHOW(phys_addr); 47 EFI_RUNTIME_U64_ATTR_SHOW(virt_addr); 48 EFI_RUNTIME_U64_ATTR_SHOW(num_pages); 49 EFI_RUNTIME_U64_ATTR_SHOW(attribute); 50 51 static inline struct efi_runtime_map_entry *to_map_entry(struct kobject *kobj) 52 { 53 return container_of(kobj, struct efi_runtime_map_entry, kobj); 54 } 55 56 static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr, 57 char *buf) 58 { 59 struct efi_runtime_map_entry *entry = to_map_entry(kobj); 60 struct map_attribute *map_attr = to_map_attr(attr); 61 62 return map_attr->show(entry, buf); 63 } 64 65 static struct map_attribute map_type_attr = __ATTR_RO_MODE(type, 0400); 66 static struct map_attribute map_phys_addr_attr = __ATTR_RO_MODE(phys_addr, 0400); 67 static struct map_attribute map_virt_addr_attr = __ATTR_RO_MODE(virt_addr, 0400); 68 static struct map_attribute map_num_pages_attr = __ATTR_RO_MODE(num_pages, 0400); 69 static struct map_attribute map_attribute_attr = __ATTR_RO_MODE(attribute, 0400); 70 71 /* 72 * These are default attributes that are added for every memmap entry. 73 */ 74 static struct attribute *def_attrs[] = { 75 &map_type_attr.attr, 76 &map_phys_addr_attr.attr, 77 &map_virt_addr_attr.attr, 78 &map_num_pages_attr.attr, 79 &map_attribute_attr.attr, 80 NULL 81 }; 82 ATTRIBUTE_GROUPS(def); 83 84 static const struct sysfs_ops map_attr_ops = { 85 .show = map_attr_show, 86 }; 87 88 static 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 96 static const struct kobj_type __refconst map_ktype = { 97 .sysfs_ops = &map_attr_ops, 98 .default_groups = def_groups, 99 .release = map_release, 100 }; 101 102 static struct kset *map_kset; 103 104 static struct efi_runtime_map_entry * 105 add_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 } 138 139 int efi_get_runtime_map_size(void) 140 { 141 return efi.memmap.nr_map * efi.memmap.desc_size; 142 } 143 144 int efi_get_runtime_map_desc_size(void) 145 { 146 return efi.memmap.desc_size; 147 } 148 149 int 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 } 159 160 static int __init efi_runtime_map_init(void) 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) || !efi_kobj) 167 return 0; 168 169 map_entries = kcalloc(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; 186 out_add_entry: 187 for (j = i - 1; j >= 0; j--) { 188 entry = *(map_entries + j); 189 kobject_put(&entry->kobj); 190 } 191 out: 192 return ret; 193 } 194 subsys_initcall_sync(efi_runtime_map_init); 195