/* * linux/drivers/firmware/memmap.c * Copyright (C) 2008 SUSE LINUX Products GmbH * by Bernhard Walle <bernhard.walle@gmx.de> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2.0 as published by * the Free Software Foundation * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #include <linux/string.h> #include <linux/firmware-map.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/types.h> #include <linux/bootmem.h> #include <linux/slab.h> /* * Data types ------------------------------------------------------------------ */ /* * Firmware map entry. Because firmware memory maps are flat and not * hierarchical, it's ok to organise them in a linked list. No parent * information is necessary as for the resource tree. */ struct firmware_map_entry { /* * start and end must be u64 rather than resource_size_t, because e820 * resources can lie at addresses above 4G. */ u64 start; /* start of the memory range */ u64 end; /* end of the memory range (incl.) */ const char *type; /* type of the memory range */ struct list_head list; /* entry for the linked list */ struct kobject kobj; /* kobject for each entry */ }; /* * Forward declarations -------------------------------------------------------- */ static ssize_t memmap_attr_show(struct kobject *kobj, struct attribute *attr, char *buf); static ssize_t start_show(struct firmware_map_entry *entry, char *buf); static ssize_t end_show(struct firmware_map_entry *entry, char *buf); static ssize_t type_show(struct firmware_map_entry *entry, char *buf); /* * Static data ----------------------------------------------------------------- */ struct memmap_attribute { struct attribute attr; ssize_t (*show)(struct firmware_map_entry *entry, char *buf); }; static struct memmap_attribute memmap_start_attr = __ATTR_RO(start); static struct memmap_attribute memmap_end_attr = __ATTR_RO(end); static struct memmap_attribute memmap_type_attr = __ATTR_RO(type); /* * These are default attributes that are added for every memmap entry. */ static struct attribute *def_attrs[] = { &memmap_start_attr.attr, &memmap_end_attr.attr, &memmap_type_attr.attr, NULL }; static const struct sysfs_ops memmap_attr_ops = { .show = memmap_attr_show, }; static struct kobj_type memmap_ktype = { .sysfs_ops = &memmap_attr_ops, .default_attrs = def_attrs, }; /* * Registration functions ------------------------------------------------------ */ /* * Firmware memory map entries. No locking is needed because the * firmware_map_add() and firmware_map_add_early() functions are called * in firmware initialisation code in one single thread of execution. */ static LIST_HEAD(map_entries); /** * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. * @start: Start of the memory range. * @end: End of the memory range (inclusive). * @type: Type of the memory range. * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised * entry. * * Common implementation of firmware_map_add() and firmware_map_add_early() * which expects a pre-allocated struct firmware_map_entry. **/ static int firmware_map_add_entry(u64 start, u64 end, const char *type, struct firmware_map_entry *entry) { BUG_ON(start > end); entry->start = start; entry->end = end; entry->type = type; INIT_LIST_HEAD(&entry->list); kobject_init(&entry->kobj, &memmap_ktype); list_add_tail(&entry->list, &map_entries); return 0; } /* * Add memmap entry on sysfs */ static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) { static int map_entries_nr; static struct kset *mmap_kset; if (!mmap_kset) { mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj); if (!mmap_kset) return -ENOMEM; } entry->kobj.kset = mmap_kset; if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++)) kobject_put(&entry->kobj); return 0; } /** * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do * memory hotplug. * @start: Start of the memory range. * @end: End of the memory range (inclusive). * @type: Type of the memory range. * * Adds a firmware mapping entry. This function is for memory hotplug, it is * similar to function firmware_map_add_early(). The only difference is that * it will create the syfs entry dynamically. * * Returns 0 on success, or -ENOMEM if no memory could be allocated. **/ int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type) { struct firmware_map_entry *entry; entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); if (!entry) return -ENOMEM; firmware_map_add_entry(start, end, type, entry); /* create the memmap entry */ add_sysfs_fw_map_entry(entry); return 0; } /** * firmware_map_add_early() - Adds a firmware mapping entry. * @start: Start of the memory range. * @end: End of the memory range (inclusive). * @type: Type of the memory range. * * Adds a firmware mapping entry. This function uses the bootmem allocator * for memory allocation. * * That function must be called before late_initcall. * * Returns 0 on success, or -ENOMEM if no memory could be allocated. **/ int __init firmware_map_add_early(u64 start, u64 end, const char *type) { struct firmware_map_entry *entry; entry = alloc_bootmem(sizeof(struct firmware_map_entry)); if (WARN_ON(!entry)) return -ENOMEM; return firmware_map_add_entry(start, end, type, entry); } /* * Sysfs functions ------------------------------------------------------------- */ static ssize_t start_show(struct firmware_map_entry *entry, char *buf) { return snprintf(buf, PAGE_SIZE, "0x%llx\n", (unsigned long long)entry->start); } static ssize_t end_show(struct firmware_map_entry *entry, char *buf) { return snprintf(buf, PAGE_SIZE, "0x%llx\n", (unsigned long long)entry->end); } static ssize_t type_show(struct firmware_map_entry *entry, char *buf) { return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); } #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) #define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) static ssize_t memmap_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { struct firmware_map_entry *entry = to_memmap_entry(kobj); struct memmap_attribute *memmap_attr = to_memmap_attr(attr); return memmap_attr->show(entry, buf); } /* * Initialises stuff and adds the entries in the map_entries list to * sysfs. Important is that firmware_map_add() and firmware_map_add_early() * must be called before late_initcall. That's just because that function * is called as late_initcall() function, which means that if you call * firmware_map_add() or firmware_map_add_early() afterwards, the entries * are not added to sysfs. */ static int __init memmap_init(void) { struct firmware_map_entry *entry; list_for_each_entry(entry, &map_entries, list) add_sysfs_fw_map_entry(entry); return 0; } late_initcall(memmap_init);