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 #include <linux/slab.h> 24 25 /* 26 * Data types ------------------------------------------------------------------ 27 */ 28 29 /* 30 * Firmware map entry. Because firmware memory maps are flat and not 31 * hierarchical, it's ok to organise them in a linked list. No parent 32 * information is necessary as for the resource tree. 33 */ 34 struct firmware_map_entry { 35 /* 36 * start and end must be u64 rather than resource_size_t, because e820 37 * resources can lie at addresses above 4G. 38 */ 39 u64 start; /* start of the memory range */ 40 u64 end; /* end of the memory range (incl.) */ 41 const char *type; /* type of the memory range */ 42 struct list_head list; /* entry for the linked list */ 43 struct kobject kobj; /* kobject for each entry */ 44 }; 45 46 /* 47 * Forward declarations -------------------------------------------------------- 48 */ 49 static ssize_t memmap_attr_show(struct kobject *kobj, 50 struct attribute *attr, char *buf); 51 static ssize_t start_show(struct firmware_map_entry *entry, char *buf); 52 static ssize_t end_show(struct firmware_map_entry *entry, char *buf); 53 static ssize_t type_show(struct firmware_map_entry *entry, char *buf); 54 55 /* 56 * Static data ----------------------------------------------------------------- 57 */ 58 59 struct memmap_attribute { 60 struct attribute attr; 61 ssize_t (*show)(struct firmware_map_entry *entry, char *buf); 62 }; 63 64 static struct memmap_attribute memmap_start_attr = __ATTR_RO(start); 65 static struct memmap_attribute memmap_end_attr = __ATTR_RO(end); 66 static struct memmap_attribute memmap_type_attr = __ATTR_RO(type); 67 68 /* 69 * These are default attributes that are added for every memmap entry. 70 */ 71 static struct attribute *def_attrs[] = { 72 &memmap_start_attr.attr, 73 &memmap_end_attr.attr, 74 &memmap_type_attr.attr, 75 NULL 76 }; 77 78 static const struct sysfs_ops memmap_attr_ops = { 79 .show = memmap_attr_show, 80 }; 81 82 static struct kobj_type memmap_ktype = { 83 .sysfs_ops = &memmap_attr_ops, 84 .default_attrs = def_attrs, 85 }; 86 87 /* 88 * Registration functions ------------------------------------------------------ 89 */ 90 91 /* 92 * Firmware memory map entries. No locking is needed because the 93 * firmware_map_add() and firmware_map_add_early() functions are called 94 * in firmware initialisation code in one single thread of execution. 95 */ 96 static LIST_HEAD(map_entries); 97 98 /** 99 * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. 100 * @start: Start of the memory range. 101 * @end: End of the memory range (exclusive). 102 * @type: Type of the memory range. 103 * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised 104 * entry. 105 * 106 * Common implementation of firmware_map_add() and firmware_map_add_early() 107 * which expects a pre-allocated struct firmware_map_entry. 108 **/ 109 static int firmware_map_add_entry(u64 start, u64 end, 110 const char *type, 111 struct firmware_map_entry *entry) 112 { 113 BUG_ON(start > end); 114 115 entry->start = start; 116 entry->end = end - 1; 117 entry->type = type; 118 INIT_LIST_HEAD(&entry->list); 119 kobject_init(&entry->kobj, &memmap_ktype); 120 121 list_add_tail(&entry->list, &map_entries); 122 123 return 0; 124 } 125 126 /* 127 * Add memmap entry on sysfs 128 */ 129 static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) 130 { 131 static int map_entries_nr; 132 static struct kset *mmap_kset; 133 134 if (!mmap_kset) { 135 mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); 136 if (!mmap_kset) 137 return -ENOMEM; 138 } 139 140 entry->kobj.kset = mmap_kset; 141 if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++)) 142 kobject_put(&entry->kobj); 143 144 return 0; 145 } 146 147 /** 148 * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do 149 * memory hotplug. 150 * @start: Start of the memory range. 151 * @end: End of the memory range (exclusive) 152 * @type: Type of the memory range. 153 * 154 * Adds a firmware mapping entry. This function is for memory hotplug, it is 155 * similar to function firmware_map_add_early(). The only difference is that 156 * it will create the syfs entry dynamically. 157 * 158 * Returns 0 on success, or -ENOMEM if no memory could be allocated. 159 **/ 160 int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type) 161 { 162 struct firmware_map_entry *entry; 163 164 entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); 165 if (!entry) 166 return -ENOMEM; 167 168 firmware_map_add_entry(start, end, type, entry); 169 /* create the memmap entry */ 170 add_sysfs_fw_map_entry(entry); 171 172 return 0; 173 } 174 175 /** 176 * firmware_map_add_early() - Adds a firmware mapping entry. 177 * @start: Start of the memory range. 178 * @end: End of the memory range. 179 * @type: Type of the memory range. 180 * 181 * Adds a firmware mapping entry. This function uses the bootmem allocator 182 * for memory allocation. 183 * 184 * That function must be called before late_initcall. 185 * 186 * Returns 0 on success, or -ENOMEM if no memory could be allocated. 187 **/ 188 int __init firmware_map_add_early(u64 start, u64 end, const char *type) 189 { 190 struct firmware_map_entry *entry; 191 192 entry = alloc_bootmem(sizeof(struct firmware_map_entry)); 193 if (WARN_ON(!entry)) 194 return -ENOMEM; 195 196 return firmware_map_add_entry(start, end, type, entry); 197 } 198 199 /* 200 * Sysfs functions ------------------------------------------------------------- 201 */ 202 203 static ssize_t start_show(struct firmware_map_entry *entry, char *buf) 204 { 205 return snprintf(buf, PAGE_SIZE, "0x%llx\n", 206 (unsigned long long)entry->start); 207 } 208 209 static ssize_t end_show(struct firmware_map_entry *entry, char *buf) 210 { 211 return snprintf(buf, PAGE_SIZE, "0x%llx\n", 212 (unsigned long long)entry->end); 213 } 214 215 static ssize_t type_show(struct firmware_map_entry *entry, char *buf) 216 { 217 return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); 218 } 219 220 #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) 221 #define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) 222 223 static ssize_t memmap_attr_show(struct kobject *kobj, 224 struct attribute *attr, char *buf) 225 { 226 struct firmware_map_entry *entry = to_memmap_entry(kobj); 227 struct memmap_attribute *memmap_attr = to_memmap_attr(attr); 228 229 return memmap_attr->show(entry, buf); 230 } 231 232 /* 233 * Initialises stuff and adds the entries in the map_entries list to 234 * sysfs. Important is that firmware_map_add() and firmware_map_add_early() 235 * must be called before late_initcall. That's just because that function 236 * is called as late_initcall() function, which means that if you call 237 * firmware_map_add() or firmware_map_add_early() afterwards, the entries 238 * are not added to sysfs. 239 */ 240 static int __init memmap_init(void) 241 { 242 struct firmware_map_entry *entry; 243 244 list_for_each_entry(entry, &map_entries, list) 245 add_sysfs_fw_map_entry(entry); 246 247 return 0; 248 } 249 late_initcall(memmap_init); 250 251