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426 lines
12 KiB
426 lines
12 KiB
/*
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* linux/drivers/firmware/memmap.c
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* Copyright (C) 2008 SUSE LINUX Products GmbH
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* by Bernhard Walle <bernhard.walle@gmx.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License v2.0 as published by
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* the Free Software Foundation
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/string.h>
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#include <linux/firmware-map.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/bootmem.h>
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#include <linux/slab.h>
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#include <linux/mm.h>
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/*
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* Data types ------------------------------------------------------------------
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*/
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/*
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* Firmware map entry. Because firmware memory maps are flat and not
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* hierarchical, it's ok to organise them in a linked list. No parent
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* information is necessary as for the resource tree.
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*/
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struct firmware_map_entry {
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/*
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* start and end must be u64 rather than resource_size_t, because e820
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* resources can lie at addresses above 4G.
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*/
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u64 start; /* start of the memory range */
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u64 end; /* end of the memory range (incl.) */
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const char *type; /* type of the memory range */
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struct list_head list; /* entry for the linked list */
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struct kobject kobj; /* kobject for each entry */
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};
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/*
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* Forward declarations --------------------------------------------------------
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*/
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static ssize_t memmap_attr_show(struct kobject *kobj,
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struct attribute *attr, char *buf);
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static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
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static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
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static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
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static struct firmware_map_entry * __meminit
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firmware_map_find_entry(u64 start, u64 end, const char *type);
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/*
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* Static data -----------------------------------------------------------------
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*/
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struct memmap_attribute {
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struct attribute attr;
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ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
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};
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static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
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static struct memmap_attribute memmap_end_attr = __ATTR_RO(end);
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static struct memmap_attribute memmap_type_attr = __ATTR_RO(type);
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/*
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* These are default attributes that are added for every memmap entry.
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*/
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static struct attribute *def_attrs[] = {
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&memmap_start_attr.attr,
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&memmap_end_attr.attr,
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&memmap_type_attr.attr,
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NULL
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};
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static const struct sysfs_ops memmap_attr_ops = {
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.show = memmap_attr_show,
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};
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/* Firmware memory map entries. */
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static LIST_HEAD(map_entries);
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static DEFINE_SPINLOCK(map_entries_lock);
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/*
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* For memory hotplug, there is no way to free memory map entries allocated
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* by boot mem after the system is up. So when we hot-remove memory whose
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* map entry is allocated by bootmem, we need to remember the storage and
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* reuse it when the memory is hot-added again.
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*/
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static LIST_HEAD(map_entries_bootmem);
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static DEFINE_SPINLOCK(map_entries_bootmem_lock);
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static inline struct firmware_map_entry *
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to_memmap_entry(struct kobject *kobj)
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{
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return container_of(kobj, struct firmware_map_entry, kobj);
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}
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static void __meminit release_firmware_map_entry(struct kobject *kobj)
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{
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struct firmware_map_entry *entry = to_memmap_entry(kobj);
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if (PageReserved(virt_to_page(entry))) {
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/*
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* Remember the storage allocated by bootmem, and reuse it when
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* the memory is hot-added again. The entry will be added to
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* map_entries_bootmem here, and deleted from &map_entries in
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* firmware_map_remove_entry().
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*/
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spin_lock(&map_entries_bootmem_lock);
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list_add(&entry->list, &map_entries_bootmem);
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spin_unlock(&map_entries_bootmem_lock);
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return;
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}
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kfree(entry);
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}
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static struct kobj_type __refdata memmap_ktype = {
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.release = release_firmware_map_entry,
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.sysfs_ops = &memmap_attr_ops,
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.default_attrs = def_attrs,
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};
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/*
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* Registration functions ------------------------------------------------------
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*/
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/**
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* firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
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* @start: Start of the memory range.
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* @end: End of the memory range (exclusive).
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* @type: Type of the memory range.
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* @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
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* entry.
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*
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* Common implementation of firmware_map_add() and firmware_map_add_early()
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* which expects a pre-allocated struct firmware_map_entry.
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*
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* Return: 0 always
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*/
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static int firmware_map_add_entry(u64 start, u64 end,
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const char *type,
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struct firmware_map_entry *entry)
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{
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BUG_ON(start > end);
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entry->start = start;
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entry->end = end - 1;
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entry->type = type;
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INIT_LIST_HEAD(&entry->list);
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kobject_init(&entry->kobj, &memmap_ktype);
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spin_lock(&map_entries_lock);
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list_add_tail(&entry->list, &map_entries);
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spin_unlock(&map_entries_lock);
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return 0;
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}
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/**
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* firmware_map_remove_entry() - Does the real work to remove a firmware
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* memmap entry.
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* @entry: removed entry.
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*
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* The caller must hold map_entries_lock, and release it properly.
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*/
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static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
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{
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list_del(&entry->list);
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}
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/*
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* Add memmap entry on sysfs
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*/
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static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
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{
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static int map_entries_nr;
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static struct kset *mmap_kset;
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if (entry->kobj.state_in_sysfs)
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return -EEXIST;
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if (!mmap_kset) {
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mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
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if (!mmap_kset)
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return -ENOMEM;
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}
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entry->kobj.kset = mmap_kset;
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if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
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kobject_put(&entry->kobj);
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return 0;
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}
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/*
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* Remove memmap entry on sysfs
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*/
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static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
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{
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kobject_put(&entry->kobj);
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}
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/**
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* firmware_map_find_entry_in_list() - Search memmap entry in a given list.
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* @start: Start of the memory range.
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* @end: End of the memory range (exclusive).
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* @type: Type of the memory range.
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* @list: In which to find the entry.
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*
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* This function is to find the memmap entey of a given memory range in a
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* given list. The caller must hold map_entries_lock, and must not release
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* the lock until the processing of the returned entry has completed.
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*
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* Return: Pointer to the entry to be found on success, or NULL on failure.
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*/
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static struct firmware_map_entry * __meminit
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firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
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struct list_head *list)
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{
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struct firmware_map_entry *entry;
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list_for_each_entry(entry, list, list)
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if ((entry->start == start) && (entry->end == end) &&
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(!strcmp(entry->type, type))) {
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return entry;
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}
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return NULL;
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}
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/**
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* firmware_map_find_entry() - Search memmap entry in map_entries.
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* @start: Start of the memory range.
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* @end: End of the memory range (exclusive).
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* @type: Type of the memory range.
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*
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* This function is to find the memmap entey of a given memory range.
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* The caller must hold map_entries_lock, and must not release the lock
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* until the processing of the returned entry has completed.
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*
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* Return: Pointer to the entry to be found on success, or NULL on failure.
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*/
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static struct firmware_map_entry * __meminit
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firmware_map_find_entry(u64 start, u64 end, const char *type)
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{
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return firmware_map_find_entry_in_list(start, end, type, &map_entries);
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}
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/**
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* firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem.
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* @start: Start of the memory range.
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* @end: End of the memory range (exclusive).
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* @type: Type of the memory range.
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*
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* This function is similar to firmware_map_find_entry except that it find the
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* given entry in map_entries_bootmem.
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*
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* Return: Pointer to the entry to be found on success, or NULL on failure.
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*/
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static struct firmware_map_entry * __meminit
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firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
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{
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return firmware_map_find_entry_in_list(start, end, type,
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&map_entries_bootmem);
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}
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/**
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* firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
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* memory hotplug.
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* @start: Start of the memory range.
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* @end: End of the memory range (exclusive)
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* @type: Type of the memory range.
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*
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* Adds a firmware mapping entry. This function is for memory hotplug, it is
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* similar to function firmware_map_add_early(). The only difference is that
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* it will create the syfs entry dynamically.
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*
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* Return: 0 on success, or -ENOMEM if no memory could be allocated.
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*/
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int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
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{
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struct firmware_map_entry *entry;
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entry = firmware_map_find_entry(start, end - 1, type);
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if (entry)
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return 0;
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entry = firmware_map_find_entry_bootmem(start, end - 1, type);
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if (!entry) {
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entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
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if (!entry)
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return -ENOMEM;
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} else {
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/* Reuse storage allocated by bootmem. */
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spin_lock(&map_entries_bootmem_lock);
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list_del(&entry->list);
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spin_unlock(&map_entries_bootmem_lock);
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memset(entry, 0, sizeof(*entry));
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}
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firmware_map_add_entry(start, end, type, entry);
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/* create the memmap entry */
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add_sysfs_fw_map_entry(entry);
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return 0;
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}
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/**
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* firmware_map_add_early() - Adds a firmware mapping entry.
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* @start: Start of the memory range.
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* @end: End of the memory range.
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* @type: Type of the memory range.
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*
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* Adds a firmware mapping entry. This function uses the bootmem allocator
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* for memory allocation.
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*
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* That function must be called before late_initcall.
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*
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* Return: 0 on success, or -ENOMEM if no memory could be allocated.
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*/
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int __init firmware_map_add_early(u64 start, u64 end, const char *type)
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{
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struct firmware_map_entry *entry;
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entry = memblock_virt_alloc(sizeof(struct firmware_map_entry), 0);
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if (WARN_ON(!entry))
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return -ENOMEM;
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return firmware_map_add_entry(start, end, type, entry);
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}
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/**
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* firmware_map_remove() - remove a firmware mapping entry
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* @start: Start of the memory range.
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* @end: End of the memory range.
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* @type: Type of the memory range.
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*
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* removes a firmware mapping entry.
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*
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* Return: 0 on success, or -EINVAL if no entry.
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*/
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int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
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{
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struct firmware_map_entry *entry;
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spin_lock(&map_entries_lock);
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entry = firmware_map_find_entry(start, end - 1, type);
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if (!entry) {
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spin_unlock(&map_entries_lock);
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return -EINVAL;
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}
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firmware_map_remove_entry(entry);
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spin_unlock(&map_entries_lock);
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/* remove the memmap entry */
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remove_sysfs_fw_map_entry(entry);
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return 0;
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}
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/*
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* Sysfs functions -------------------------------------------------------------
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*/
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static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
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{
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return snprintf(buf, PAGE_SIZE, "0x%llx\n",
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(unsigned long long)entry->start);
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}
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static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
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{
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return snprintf(buf, PAGE_SIZE, "0x%llx\n",
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(unsigned long long)entry->end);
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}
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static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
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{
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return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
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}
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static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
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{
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return container_of(attr, struct memmap_attribute, attr);
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}
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static ssize_t memmap_attr_show(struct kobject *kobj,
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struct attribute *attr, char *buf)
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{
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struct firmware_map_entry *entry = to_memmap_entry(kobj);
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struct memmap_attribute *memmap_attr = to_memmap_attr(attr);
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return memmap_attr->show(entry, buf);
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}
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/*
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* Initialises stuff and adds the entries in the map_entries list to
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* sysfs. Important is that firmware_map_add() and firmware_map_add_early()
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* must be called before late_initcall. That's just because that function
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* is called as late_initcall() function, which means that if you call
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* firmware_map_add() or firmware_map_add_early() afterwards, the entries
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* are not added to sysfs.
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*/
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static int __init firmware_memmap_init(void)
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{
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struct firmware_map_entry *entry;
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list_for_each_entry(entry, &map_entries, list)
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add_sysfs_fw_map_entry(entry);
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return 0;
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}
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late_initcall(firmware_memmap_init);
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