1 /* 2 * linux/drivers/firmware/memmap.c 3 * Copyright (C) 2008 SUSE LINUX Products GmbH 4 * by Bernhard Walle <bwalle@suse.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 struct memmap_attribute memmap_start_attr = __ATTR_RO(start); 60 struct memmap_attribute memmap_end_attr = __ATTR_RO(end); 61 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 88 */ 89 static LIST_HEAD(map_entries); 90 91 /** 92 * Common implementation of firmware_map_add() and firmware_map_add_early() 93 * which expects a pre-allocated struct firmware_map_entry. 94 * 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 static int firmware_map_add_entry(resource_size_t start, resource_size_t end, 102 const char *type, 103 struct firmware_map_entry *entry) 104 { 105 BUG_ON(start > end); 106 107 entry->start = start; 108 entry->end = end; 109 entry->type = type; 110 INIT_LIST_HEAD(&entry->list); 111 kobject_init(&entry->kobj, &memmap_ktype); 112 113 list_add_tail(&entry->list, &map_entries); 114 115 return 0; 116 } 117 118 /* 119 * See <linux/firmware-map.h> for documentation. 120 */ 121 int firmware_map_add(resource_size_t start, resource_size_t end, 122 const char *type) 123 { 124 struct firmware_map_entry *entry; 125 126 entry = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); 127 WARN_ON(!entry); 128 if (!entry) 129 return -ENOMEM; 130 131 return firmware_map_add_entry(start, end, type, entry); 132 } 133 134 /* 135 * See <linux/firmware-map.h> for documentation. 136 */ 137 int __init firmware_map_add_early(resource_size_t start, resource_size_t end, 138 const char *type) 139 { 140 struct firmware_map_entry *entry; 141 142 entry = alloc_bootmem_low(sizeof(struct firmware_map_entry)); 143 WARN_ON(!entry); 144 if (!entry) 145 return -ENOMEM; 146 147 return firmware_map_add_entry(start, end, type, entry); 148 } 149 150 /* 151 * Sysfs functions ------------------------------------------------------------- 152 */ 153 154 static ssize_t start_show(struct firmware_map_entry *entry, char *buf) 155 { 156 return snprintf(buf, PAGE_SIZE, "0x%llx\n", 157 (unsigned long long)entry->start); 158 } 159 160 static ssize_t end_show(struct firmware_map_entry *entry, char *buf) 161 { 162 return snprintf(buf, PAGE_SIZE, "0x%llx\n", 163 (unsigned long long)entry->end); 164 } 165 166 static ssize_t type_show(struct firmware_map_entry *entry, char *buf) 167 { 168 return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); 169 } 170 171 #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) 172 #define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) 173 174 static ssize_t memmap_attr_show(struct kobject *kobj, 175 struct attribute *attr, char *buf) 176 { 177 struct firmware_map_entry *entry = to_memmap_entry(kobj); 178 struct memmap_attribute *memmap_attr = to_memmap_attr(attr); 179 180 return memmap_attr->show(entry, buf); 181 } 182 183 /* 184 * Initialises stuff and adds the entries in the map_entries list to 185 * sysfs. Important is that firmware_map_add() and firmware_map_add_early() 186 * must be called before late_initcall. 187 */ 188 static int __init memmap_init(void) 189 { 190 int i = 0; 191 struct firmware_map_entry *entry; 192 struct kset *memmap_kset; 193 194 memmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); 195 WARN_ON(!memmap_kset); 196 if (!memmap_kset) 197 return -ENOMEM; 198 199 list_for_each_entry(entry, &map_entries, list) { 200 entry->kobj.kset = memmap_kset; 201 kobject_add(&entry->kobj, NULL, "%d", i++); 202 } 203 204 return 0; 205 } 206 late_initcall(memmap_init); 207 208