- 根目录:
- drivers
- firmware
- memmap.c
/*
* 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>
#include <linux/mm.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 struct firmware_map_entry * __meminit
firmware_map_find_entry(u64 start, u64 end, const char *type);
/*
* 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,
};
/* Firmware memory map entries. */
static LIST_HEAD(map_entries);
static DEFINE_SPINLOCK(map_entries_lock);
/*
* For memory hotplug, there is no way to free memory map entries allocated
* by boot mem after the system is up. So when we hot-remove memory whose
* map entry is allocated by bootmem, we need to remember the storage and
* reuse it when the memory is hot-added again.
*/
static LIST_HEAD(map_entries_bootmem);
static DEFINE_SPINLOCK(map_entries_bootmem_lock);
static inline struct firmware_map_entry *
to_memmap_entry(struct kobject *kobj)
{
return container_of(kobj, struct firmware_map_entry, kobj);
}
static void __meminit release_firmware_map_entry(struct kobject *kobj)
{
struct firmware_map_entry *entry = to_memmap_entry(kobj);
if (PageReserved(virt_to_page(entry))) {
/*
* Remember the storage allocated by bootmem, and reuse it when
* the memory is hot-added again. The entry will be added to
* map_entries_bootmem here, and deleted from &map_entries in
* firmware_map_remove_entry().
*/
spin_lock(&map_entries_bootmem_lock);
list_add(&entry->list, &map_entries_bootmem);
spin_unlock(&map_entries_bootmem_lock);
return;
}
kfree(entry);
}
static struct kobj_type __refdata memmap_ktype = {
.release = release_firmware_map_entry,
.sysfs_ops = &memmap_attr_ops,
.default_attrs = def_attrs,
};
/*
* Registration functions ------------------------------------------------------
*/
/**
* 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 (exclusive).
* @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 - 1;
entry->type = type;
INIT_LIST_HEAD(&entry->list);
kobject_init(&entry->kobj, &memmap_ktype);
spin_lock(&map_entries_lock);
list_add_tail(&entry->list, &map_entries);
spin_unlock(&map_entries_lock);
return 0;
}
/**
* firmware_map_remove_entry() - Does the real work to remove a firmware
* memmap entry.
* @entry: removed entry.
*
* The caller must hold map_entries_lock, and release it properly.
**/
static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
{
list_del(&entry->list);
}
/*
* 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;
}
/*
* Remove memmap entry on sysfs
*/
static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
{
kobject_put(&entry->kobj);
}
/*
* firmware_map_find_entry_in_list() - Search memmap entry in a given list.
* @start: Start of the memory range.
* @end: End of the memory range (exclusive).
* @type: Type of the memory range.
* @list: In which to find the entry.
*
* This function is to find the memmap entey of a given memory range in a
* given list. The caller must hold map_entries_lock, and must not release
* the lock until the processing of the returned entry has completed.
*
* Return: Pointer to the entry to be found on success, or NULL on failure.
*/
static struct firmware_map_entry * __meminit
firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
struct list_head *list)
{
struct firmware_map_entry *entry;
list_for_each_entry(entry, list, list)
if ((entry->start == start) && (entry->end == end) &&
(!strcmp(entry->type, type))) {
return entry;
}
return NULL;
}
/*
* firmware_map_find_entry() - Search memmap entry in map_entries.
* @start: Start of the memory range.
* @end: End of the memory range (exclusive).
* @type: Type of the memory range.
*
* This function is to find the memmap entey of a given memory range.
* The caller must hold map_entries_lock, and must not release the lock
* until the processing of the returned entry has completed.
*
* Return: Pointer to the entry to be found on success, or NULL on failure.
*/
static struct firmware_map_entry * __meminit
firmware_map_find_entry(u64 start, u64 end, const char *type)
{
return firmware_map_find_entry_in_list(start, end, type, &map_entries);
}
/*
* firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem.
* @start: Start of the memory range.
* @end: End of the memory range (exclusive).
* @type: Type of the memory range.
*
* This function is similar to firmware_map_find_entry except that it find the
* given entry in map_entries_bootmem.
*
* Return: Pointer to the entry to be found on success, or NULL on failure.
*/
static struct firmware_map_entry * __meminit
firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
{
return firmware_map_find_entry_in_list(start, end, type,
&map_entries_bootmem);
}
/**
* 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 (exclusive)
* @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 = firmware_map_find_entry_bootmem(start, end, type);
if (!entry) {
entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
if (!entry)
return -ENOMEM;
} else {
/* Reuse storage allocated by bootmem. */
spin_lock(&map_entries_bootmem_lock);
list_del(&entry->list);
spin_unlock(&map_entries_bootmem_lock);
memset(entry, 0, sizeof(*entry));
}
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.
* @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 = memblock_virt_alloc(sizeof(struct firmware_map_entry), 0);
if (WARN_ON(!entry))
return -ENOMEM;
return firmware_map_add_entry(start, end, type, entry);
}
/**
* firmware_map_remove() - remove a firmware mapping entry
* @start: Start of the memory range.
* @end: End of the memory range.
* @type: Type of the memory range.
*
* removes a firmware mapping entry.
*
* Returns 0 on success, or -EINVAL if no entry.
**/
int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
{
struct firmware_map_entry *entry;
spin_lock(&map_entries_lock);
entry = firmware_map_find_entry(start, end - 1, type);
if (!entry) {
spin_unlock(&map_entries_lock);
return -EINVAL;
}
firmware_map_remove_entry(entry);
spin_unlock(&map_entries_lock);
/* remove the memmap entry */
remove_sysfs_fw_map_entry(entry);
return 0;
}
/*
* 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);
}
static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
{
return container_of(attr, struct memmap_attribute, attr);
}
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 firmware_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(firmware_memmap_init);