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