235 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			235 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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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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/*
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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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/*
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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 struct sysfs_ops memmap_attr_ops = {
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	.show = memmap_attr_show,
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};
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static struct kobj_type memmap_ktype = {
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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 memory map entries. No locking is needed because the
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 * firmware_map_add() and firmware_map_add_early() functions are called
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 * in firmware initialisation code in one single thread of execution.
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 */
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static LIST_HEAD(map_entries);
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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 (inclusive).
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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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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;
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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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	list_add_tail(&entry->list, &map_entries);
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	return 0;
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}
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/**
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 * firmware_map_add() - 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 (inclusive).
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 * @type:  Type of the memory range.
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 *
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 * This function uses kmalloc() for memory
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 * allocation. Use firmware_map_add_early() if you want to use the bootmem
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 * allocator.
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 *
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 * That function must be called before late_initcall.
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 *
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 * Returns 0 on success, or -ENOMEM if no memory could be allocated.
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 **/
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int firmware_map_add(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 = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
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	if (!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_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 (inclusive).
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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. Use firmware_map_add() if you want to use kmalloc().
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 *
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 * That function must be called before late_initcall.
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 *
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 * Returns 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 = alloc_bootmem(sizeof(struct firmware_map_entry));
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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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 * 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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#define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr)
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#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj)
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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 memmap_init(void)
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{
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	int i = 0;
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	struct firmware_map_entry *entry;
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	struct kset *memmap_kset;
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	memmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
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	if (WARN_ON(!memmap_kset))
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		return -ENOMEM;
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	list_for_each_entry(entry, &map_entries, list) {
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		entry->kobj.kset = memmap_kset;
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		if (kobject_add(&entry->kobj, NULL, "%d", i++))
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			kobject_put(&entry->kobj);
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	}
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	return 0;
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}
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late_initcall(memmap_init);
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