1 /* 2 * linux/drivers/firmware/memmap.c 3 * Copyright (C) 2008 SUSE LINUX Products GmbH 4 * by Bernhard Walle <bernhard.walle@gmx.de> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License v2.0 as published by 8 * the Free Software Foundation 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 */ 16 17 #include <linux/string.h> 18 #include <linux/firmware-map.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/types.h> 22 #include <linux/bootmem.h> 23 24 /* 25 * Data types ------------------------------------------------------------------ 26 */ 27 28 /* 29 * Firmware map entry. Because firmware memory maps are flat and not 30 * hierarchical, it's ok to organise them in a linked list. No parent 31 * information is necessary as for the resource tree. 32 */ 33 struct firmware_map_entry { 34 /* 35 * start and end must be u64 rather than resource_size_t, because e820 36 * resources can lie at addresses above 4G. 37 */ 38 u64 start; /* start of the memory range */ 39 u64 end; /* end of the memory range (incl.) */ 40 const char *type; /* type of the memory range */ 41 struct list_head list; /* entry for the linked list */ 42 struct kobject kobj; /* kobject for each entry */ 43 }; 44 45 /* 46 * Forward declarations -------------------------------------------------------- 47 */ 48 static ssize_t memmap_attr_show(struct kobject *kobj, 49 struct attribute *attr, char *buf); 50 static ssize_t start_show(struct firmware_map_entry *entry, char *buf); 51 static ssize_t end_show(struct firmware_map_entry *entry, char *buf); 52 static ssize_t type_show(struct firmware_map_entry *entry, char *buf); 53 54 /* 55 * Static data ----------------------------------------------------------------- 56 */ 57 58 struct memmap_attribute { 59 struct attribute attr; 60 ssize_t (*show)(struct firmware_map_entry *entry, char *buf); 61 }; 62 63 static struct memmap_attribute memmap_start_attr = __ATTR_RO(start); 64 static struct memmap_attribute memmap_end_attr = __ATTR_RO(end); 65 static struct memmap_attribute memmap_type_attr = __ATTR_RO(type); 66 67 /* 68 * These are default attributes that are added for every memmap entry. 69 */ 70 static struct attribute *def_attrs[] = { 71 &memmap_start_attr.attr, 72 &memmap_end_attr.attr, 73 &memmap_type_attr.attr, 74 NULL 75 }; 76 77 static const struct sysfs_ops memmap_attr_ops = { 78 .show = memmap_attr_show, 79 }; 80 81 static struct kobj_type memmap_ktype = { 82 .sysfs_ops = &memmap_attr_ops, 83 .default_attrs = def_attrs, 84 }; 85 86 /* 87 * Registration functions ------------------------------------------------------ 88 */ 89 90 /* 91 * Firmware memory map entries. No locking is needed because the 92 * firmware_map_add() and firmware_map_add_early() functions are called 93 * in firmware initialisation code in one single thread of execution. 94 */ 95 static LIST_HEAD(map_entries); 96 97 /** 98 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. 99 * @start: Start of the memory range. 100 * @end: End of the memory range (inclusive). 101 * @type: Type of the memory range. 102 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised 103 * entry. 104 * 105 * Common implementation of firmware_map_add() and firmware_map_add_early() 106 * which expects a pre-allocated struct firmware_map_entry. 107 **/ 108 static int firmware_map_add_entry(u64 start, u64 end, 109 const char *type, 110 struct firmware_map_entry *entry) 111 { 112 BUG_ON(start > end); 113 114 entry->start = start; 115 entry->end = end; 116 entry->type = type; 117 INIT_LIST_HEAD(&entry->list); 118 kobject_init(&entry->kobj, &memmap_ktype); 119 120 list_add_tail(&entry->list, &map_entries); 121 122 return 0; 123 } 124 125 /* 126 * Add memmap entry on sysfs 127 */ 128 static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) 129 { 130 static int map_entries_nr; 131 static struct kset *mmap_kset; 132 133 if (!mmap_kset) { 134 mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); 135 if (!mmap_kset) 136 return -ENOMEM; 137 } 138 139 entry->kobj.kset = mmap_kset; 140 if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++)) 141 kobject_put(&entry->kobj); 142 143 return 0; 144 } 145 146 /** 147 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do 148 * memory hotplug. 149 * @start: Start of the memory range. 150 * @end: End of the memory range (inclusive). 151 * @type: Type of the memory range. 152 * 153 * Adds a firmware mapping entry. This function is for memory hotplug, it is 154 * similar to function firmware_map_add_early(). The only difference is that 155 * it will create the syfs entry dynamically. 156 * 157 * Returns 0 on success, or -ENOMEM if no memory could be allocated. 158 **/ 159 int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type) 160 { 161 struct firmware_map_entry *entry; 162 163 entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); 164 if (!entry) 165 return -ENOMEM; 166 167 firmware_map_add_entry(start, end, type, entry); 168 /* create the memmap entry */ 169 add_sysfs_fw_map_entry(entry); 170 171 return 0; 172 } 173 174 /** 175 * firmware_map_add_early() - Adds a firmware mapping entry. 176 * @start: Start of the memory range. 177 * @end: End of the memory range (inclusive). 178 * @type: Type of the memory range. 179 * 180 * Adds a firmware mapping entry. This function uses the bootmem allocator 181 * for memory allocation. 182 * 183 * That function must be called before late_initcall. 184 * 185 * Returns 0 on success, or -ENOMEM if no memory could be allocated. 186 **/ 187 int __init firmware_map_add_early(u64 start, u64 end, const char *type) 188 { 189 struct firmware_map_entry *entry; 190 191 entry = alloc_bootmem(sizeof(struct firmware_map_entry)); 192 if (WARN_ON(!entry)) 193 return -ENOMEM; 194 195 return firmware_map_add_entry(start, end, type, entry); 196 } 197 198 /* 199 * Sysfs functions ------------------------------------------------------------- 200 */ 201 202 static ssize_t start_show(struct firmware_map_entry *entry, char *buf) 203 { 204 return snprintf(buf, PAGE_SIZE, "0x%llx\n", 205 (unsigned long long)entry->start); 206 } 207 208 static ssize_t end_show(struct firmware_map_entry *entry, char *buf) 209 { 210 return snprintf(buf, PAGE_SIZE, "0x%llx\n", 211 (unsigned long long)entry->end); 212 } 213 214 static ssize_t type_show(struct firmware_map_entry *entry, char *buf) 215 { 216 return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); 217 } 218 219 #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) 220 #define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) 221 222 static ssize_t memmap_attr_show(struct kobject *kobj, 223 struct attribute *attr, char *buf) 224 { 225 struct firmware_map_entry *entry = to_memmap_entry(kobj); 226 struct memmap_attribute *memmap_attr = to_memmap_attr(attr); 227 228 return memmap_attr->show(entry, buf); 229 } 230 231 /* 232 * Initialises stuff and adds the entries in the map_entries list to 233 * sysfs. Important is that firmware_map_add() and firmware_map_add_early() 234 * must be called before late_initcall. That's just because that function 235 * is called as late_initcall() function, which means that if you call 236 * firmware_map_add() or firmware_map_add_early() afterwards, the entries 237 * are not added to sysfs. 238 */ 239 static int __init memmap_init(void) 240 { 241 struct firmware_map_entry *entry; 242 243 list_for_each_entry(entry, &map_entries, list) 244 add_sysfs_fw_map_entry(entry); 245 246 return 0; 247 } 248 late_initcall(memmap_init); 249 250