[deliverable/linux.git] / kernel / resource.c

/*
 *	linux/kernel/resource.c
 *
 * Copyright (C) 1999	Linus Torvalds
 * Copyright (C) 1999	Martin Mares <mj@ucw.cz>
 *
 * Arbitrary resource management.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/io.h>


struct resource ioport_resource = {
	.name	= "PCI IO",
	.start	= 0x0000,
	.end	= IO_SPACE_LIMIT,
	.flags	= IORESOURCE_IO,
};

EXPORT_SYMBOL(ioport_resource);

struct resource iomem_resource = {
	.name	= "PCI mem",
	.start	= 0UL,
	.end	= ~0UL,
	.flags	= IORESOURCE_MEM,
};

EXPORT_SYMBOL(iomem_resource);

static DEFINE_RWLOCK(resource_lock);

#ifdef CONFIG_PROC_FS

enum { MAX_IORES_LEVEL = 5 };

static void *r_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct resource *p = v;
	(*pos)++;
	if (p->child)
		return p->child;
	while (!p->sibling && p->parent)
		p = p->parent;
	return p->sibling;
}

static void *r_start(struct seq_file *m, loff_t *pos)
	__acquires(resource_lock)
{
	struct resource *p = m->private;
	loff_t l = 0;
	read_lock(&resource_lock);
	for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
		;
	return p;
}

static void r_stop(struct seq_file *m, void *v)
	__releases(resource_lock)
{
	read_unlock(&resource_lock);
}

static int r_show(struct seq_file *m, void *v)
{
	struct resource *root = m->private;
	struct resource *r = v, *p;
	int width = root->end < 0x10000 ? 4 : 8;
	int depth;

	for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
		if (p->parent == root)
			break;
	seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
			depth * 2, "",
			width, (unsigned long long) r->start,
			width, (unsigned long long) r->end,
			r->name ? r->name : "<BAD>");
	return 0;
}

static struct seq_operations resource_op = {
	.start	= r_start,
	.next	= r_next,
	.stop	= r_stop,
	.show	= r_show,
};

static int ioports_open(struct inode *inode, struct file *file)
{
	int res = seq_open(file, &resource_op);
	if (!res) {
		struct seq_file *m = file->private_data;
		m->private = &ioport_resource;
	}
	return res;
}

static int iomem_open(struct inode *inode, struct file *file)
{
	int res = seq_open(file, &resource_op);
	if (!res) {
		struct seq_file *m = file->private_data;
		m->private = &iomem_resource;
	}
	return res;
}

static struct file_operations proc_ioports_operations = {
	.open		= ioports_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static struct file_operations proc_iomem_operations = {
	.open		= iomem_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static int __init ioresources_init(void)
{
	struct proc_dir_entry *entry;

	entry = create_proc_entry("ioports", 0, NULL);
	if (entry)
		entry->proc_fops = &proc_ioports_operations;
	entry = create_proc_entry("iomem", 0, NULL);
	if (entry)
		entry->proc_fops = &proc_iomem_operations;
	return 0;
}
__initcall(ioresources_init);

#endif /* CONFIG_PROC_FS */

/* Return the conflict entry if you can't request it */
static struct resource * __request_resource(struct resource *root, struct resource *new)
{
	resource_size_t start = new->start;
	resource_size_t end = new->end;
	struct resource *tmp, **p;

	if (end < start)
		return root;
	if (start < root->start)
		return root;
	if (end > root->end)
		return root;
	p = &root->child;
	for (;;) {
		tmp = *p;
		if (!tmp || tmp->start > end) {
			new->sibling = tmp;
			*p = new;
			new->parent = root;
			return NULL;
		}
		p = &tmp->sibling;
		if (tmp->end < start)
			continue;
		return tmp;
	}
}

static int __release_resource(struct resource *old)
{
	struct resource *tmp, **p;

	p = &old->parent->child;
	for (;;) {
		tmp = *p;
		if (!tmp)
			break;
		if (tmp == old) {
			*p = tmp->sibling;
			old->parent = NULL;
			return 0;
		}
		p = &tmp->sibling;
	}
	return -EINVAL;
}

int request_resource(struct resource *root, struct resource *new)
{
	struct resource *conflict;

	write_lock(&resource_lock);
	conflict = __request_resource(root, new);
	write_unlock(&resource_lock);
	return conflict ? -EBUSY : 0;
}

EXPORT_SYMBOL(request_resource);

struct resource *____request_resource(struct resource *root, struct resource *new)
{
	struct resource *conflict;

	write_lock(&resource_lock);
	conflict = __request_resource(root, new);
	write_unlock(&resource_lock);
	return conflict;
}

EXPORT_SYMBOL(____request_resource);

int release_resource(struct resource *old)
{
	int retval;

	write_lock(&resource_lock);
	retval = __release_resource(old);
	write_unlock(&resource_lock);
	return retval;
}

EXPORT_SYMBOL(release_resource);

/*
 * Find empty slot in the resource tree given range and alignment.
 */
static int find_resource(struct resource *root, struct resource *new,
			 resource_size_t size, resource_size_t min,
			 resource_size_t max, resource_size_t align,
			 void (*alignf)(void *, struct resource *,
					resource_size_t, resource_size_t),
			 void *alignf_data)
{
	struct resource *this = root->child;

	new->start = root->start;
	/*
	 * Skip past an allocated resource that starts at 0, since the assignment
	 * of this->start - 1 to new->end below would cause an underflow.
	 */
	if (this && this->start == 0) {
		new->start = this->end + 1;
		this = this->sibling;
	}
	for(;;) {
		if (this)
			new->end = this->start - 1;
		else
			new->end = root->end;
		if (new->start < min)
			new->start = min;
		if (new->end > max)
			new->end = max;
		new->start = ALIGN(new->start, align);
		if (alignf)
			alignf(alignf_data, new, size, align);
		if (new->start < new->end && new->end - new->start >= size - 1) {
			new->end = new->start + size - 1;
			return 0;
		}
		if (!this)
			break;
		new->start = this->end + 1;
		this = this->sibling;
	}
	return -EBUSY;
}

/*
 * Allocate empty slot in the resource tree given range and alignment.
 */
int allocate_resource(struct resource *root, struct resource *new,
		      resource_size_t size, resource_size_t min,
		      resource_size_t max, resource_size_t align,
		      void (*alignf)(void *, struct resource *,
				     resource_size_t, resource_size_t),
		      void *alignf_data)
{
	int err;

	write_lock(&resource_lock);
	err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
	if (err >= 0 && __request_resource(root, new))
		err = -EBUSY;
	write_unlock(&resource_lock);
	return err;
}

EXPORT_SYMBOL(allocate_resource);

/**
 * insert_resource - Inserts a resource in the resource tree
 * @parent: parent of the new resource
 * @new: new resource to insert
 *
 * Returns 0 on success, -EBUSY if the resource can't be inserted.
 *
 * This function is equivalent of request_resource when no conflict
 * happens. If a conflict happens, and the conflicting resources
 * entirely fit within the range of the new resource, then the new
 * resource is inserted and the conflicting resources become childs of
 * the new resource.  Otherwise the new resource becomes the child of
 * the conflicting resource
 */
int insert_resource(struct resource *parent, struct resource *new)
{
	int result;
	struct resource *first, *next;

	write_lock(&resource_lock);
 begin:
 	result = 0;
	first = __request_resource(parent, new);
	if (!first)
		goto out;

	result = -EBUSY;
	if (first == parent)
		goto out;

	/* Resource fully contained by the clashing resource? Recurse into it */
	if (first->start <= new->start && first->end >= new->end) {
		parent = first;
		goto begin;
	}

	for (next = first; ; next = next->sibling) {
		/* Partial overlap? Bad, and unfixable */
		if (next->start < new->start || next->end > new->end)
			goto out;
		if (!next->sibling)
			break;
		if (next->sibling->start > new->end)
			break;
	}

	result = 0;

	new->parent = parent;
	new->sibling = next->sibling;
	new->child = first;

	next->sibling = NULL;
	for (next = first; next; next = next->sibling)
		next->parent = new;

	if (parent->child == first) {
		parent->child = new;
	} else {
		next = parent->child;
		while (next->sibling != first)
			next = next->sibling;
		next->sibling = new;
	}

 out:
	write_unlock(&resource_lock);
	return result;
}

EXPORT_SYMBOL(insert_resource);

/*
 * Given an existing resource, change its start and size to match the
 * arguments.  Returns -EBUSY if it can't fit.  Existing children of
 * the resource are assumed to be immutable.
 */
int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
{
	struct resource *tmp, *parent = res->parent;
	resource_size_t end = start + size - 1;
	int result = -EBUSY;

	write_lock(&resource_lock);

	if ((start < parent->start) || (end > parent->end))
		goto out;

	for (tmp = res->child; tmp; tmp = tmp->sibling) {
		if ((tmp->start < start) || (tmp->end > end))
			goto out;
	}

	if (res->sibling && (res->sibling->start <= end))
		goto out;

	tmp = parent->child;
	if (tmp != res) {
		while (tmp->sibling != res)
			tmp = tmp->sibling;
		if (start <= tmp->end)
			goto out;
	}

	res->start = start;
	res->end = end;
	result = 0;

 out:
	write_unlock(&resource_lock);
	return result;
}

EXPORT_SYMBOL(adjust_resource);

/*
 * This is compatibility stuff for IO resources.
 *
 * Note how this, unlike the above, knows about
 * the IO flag meanings (busy etc).
 *
 * Request-region creates a new busy region.
 *
 * Check-region returns non-zero if the area is already busy
 *
 * Release-region releases a matching busy region.
 */
struct resource * __request_region(struct resource *parent,
				   resource_size_t start, resource_size_t n,
				   const char *name)
{
	struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);

	if (res) {
		res->name = name;
		res->start = start;
		res->end = start + n - 1;
		res->flags = IORESOURCE_BUSY;

		write_lock(&resource_lock);

		for (;;) {
			struct resource *conflict;

			conflict = __request_resource(parent, res);
			if (!conflict)
				break;
			if (conflict != parent) {
				parent = conflict;
				if (!(conflict->flags & IORESOURCE_BUSY))
					continue;
			}

			/* Uhhuh, that didn't work out.. */
			kfree(res);
			res = NULL;
			break;
		}
		write_unlock(&resource_lock);
	}
	return res;
}

EXPORT_SYMBOL(__request_region);

int __check_region(struct resource *parent, resource_size_t start,
			resource_size_t n)
{
	struct resource * res;

	res = __request_region(parent, start, n, "check-region");
	if (!res)
		return -EBUSY;

	release_resource(res);
	kfree(res);
	return 0;
}

EXPORT_SYMBOL(__check_region);

void __release_region(struct resource *parent, resource_size_t start,
			resource_size_t n)
{
	struct resource **p;
	resource_size_t end;

	p = &parent->child;
	end = start + n - 1;

	write_lock(&resource_lock);

	for (;;) {
		struct resource *res = *p;

		if (!res)
			break;
		if (res->start <= start && res->end >= end) {
			if (!(res->flags & IORESOURCE_BUSY)) {
				p = &res->child;
				continue;
			}
			if (res->start != start || res->end != end)
				break;
			*p = res->sibling;
			write_unlock(&resource_lock);
			kfree(res);
			return;
		}
		p = &res->sibling;
	}

	write_unlock(&resource_lock);

	printk(KERN_WARNING "Trying to free nonexistent resource "
		"<%016llx-%016llx>\n", (unsigned long long)start,
		(unsigned long long)end);
}

EXPORT_SYMBOL(__release_region);

/*
 * Called from init/main.c to reserve IO ports.
 */
#define MAXRESERVE 4
static int __init reserve_setup(char *str)
{
	static int reserved;
	static struct resource reserve[MAXRESERVE];

	for (;;) {
		int io_start, io_num;
		int x = reserved;

		if (get_option (&str, &io_start) != 2)
			break;
		if (get_option (&str, &io_num)   == 0)
			break;
		if (x < MAXRESERVE) {
			struct resource *res = reserve + x;
			res->name = "reserved";
			res->start = io_start;
			res->end = io_start + io_num - 1;
			res->flags = IORESOURCE_BUSY;
			res->child = NULL;
			if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
				reserved = x+1;
		}
	}
	return 1;
}

__setup("reserve=", reserve_setup);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/kernel/resource.c
	3	*
	4	* Copyright (C) 1999 Linus Torvalds
	5	* Copyright (C) 1999 Martin Mares <mj@ucw.cz>
	6	*
	7	* Arbitrary resource management.
	8	*/
	9
	10	#include <linux/config.h>
	11	#include <linux/module.h>
	12	#include <linux/sched.h>
	13	#include <linux/errno.h>
	14	#include <linux/ioport.h>
	15	#include <linux/init.h>
	16	#include <linux/slab.h>
	17	#include <linux/spinlock.h>
	18	#include <linux/fs.h>
	19	#include <linux/proc_fs.h>
	20	#include <linux/seq_file.h>
	21	#include <asm/io.h>
	22
	23
	24	struct resource ioport_resource = {
	25	.name = "PCI IO",
	26	.start = 0x0000,
	27	.end = IO_SPACE_LIMIT,
	28	.flags = IORESOURCE_IO,
	29	};
	30
	31	EXPORT_SYMBOL(ioport_resource);
	32
	33	struct resource iomem_resource = {
	34	.name = "PCI mem",
	35	.start = 0UL,
	36	.end = ~0UL,
	37	.flags = IORESOURCE_MEM,
	38	};
	39
	40	EXPORT_SYMBOL(iomem_resource);
	41
	42	static DEFINE_RWLOCK(resource_lock);
	43
	44	#ifdef CONFIG_PROC_FS
	45
	46	enum { MAX_IORES_LEVEL = 5 };
	47
	48	static void r_next(struct seq_file m, void v, loff_t pos)
	49	{
	50	struct resource *p = v;
	51	(*pos)++;
	52	if (p->child)
	53	return p->child;
	54	while (!p->sibling && p->parent)
	55	p = p->parent;
	56	return p->sibling;
	57	}
	58
	59	static void r_start(struct seq_file m, loff_t *pos)
	60	__acquires(resource_lock)
	61	{
	62	struct resource *p = m->private;
	63	loff_t l = 0;
	64	read_lock(&resource_lock);
65	for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
66	;
67	return p;
68	}
69
70	static void r_stop(struct seq_file m, void v)
71	__releases(resource_lock)
72	{
73	read_unlock(&resource_lock);
74	}
75
76	static int r_show(struct seq_file m, void v)
77	{
78	struct resource *root = m->private;
79	struct resource r = v, p;
80	int width = root->end < 0x10000 ? 4 : 8;
81	int depth;
82
83	for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
84	if (p->parent == root)
85	break;
685143ac	86	seq_printf(m, "%s%0llx-%0*llx : %s\n",
1da177e4	87	depth * 2, "",
685143ac GKH	88	width, (unsigned long long) r->start,
685143ac GKH	89	width, (unsigned long long) r->end,
1da177e4 LT	90	r->name ? r->name : "<BAD>");
	91	return 0;
	92	}
	93
	94	static struct seq_operations resource_op = {
	95	.start = r_start,
	96	.next = r_next,
	97	.stop = r_stop,
	98	.show = r_show,
	99	};
	100
	101	static int ioports_open(struct inode inode, struct file file)
	102	{
	103	int res = seq_open(file, &resource_op);
	104	if (!res) {
	105	struct seq_file *m = file->private_data;
	106	m->private = &ioport_resource;
	107	}
	108	return res;
	109	}
	110
	111	static int iomem_open(struct inode inode, struct file file)
	112	{
	113	int res = seq_open(file, &resource_op);
	114	if (!res) {
	115	struct seq_file *m = file->private_data;
	116	m->private = &iomem_resource;
	117	}
	118	return res;
	119	}
	120
	121	static struct file_operations proc_ioports_operations = {
	122	.open = ioports_open,
	123	.read = seq_read,
	124	.llseek = seq_lseek,
	125	.release = seq_release,
	126	};
	127
	128	static struct file_operations proc_iomem_operations = {
	129	.open = iomem_open,
	130	.read = seq_read,
	131	.llseek = seq_lseek,
	132	.release = seq_release,
	133	};
	134
	135	static int __init ioresources_init(void)
	136	{
	137	struct proc_dir_entry *entry;
	138
	139	entry = create_proc_entry("ioports", 0, NULL);
	140	if (entry)
	141	entry->proc_fops = &proc_ioports_operations;
	142	entry = create_proc_entry("iomem", 0, NULL);
	143	if (entry)
	144	entry->proc_fops = &proc_iomem_operations;
	145	return 0;
	146	}
	147	__initcall(ioresources_init);
	148
	149	#endif /* CONFIG_PROC_FS */
	150
	151	/* Return the conflict entry if you can't request it */
	152	static struct resource * __request_resource(struct resource root, struct resource new)
	153	{
d75fc8bb GKH	154	resource_size_t start = new->start;
d75fc8bb GKH	155	resource_size_t end = new->end;
1da177e4 LT	156	struct resource tmp, *p;
	157
	158	if (end < start)
	159	return root;
	160	if (start < root->start)
	161	return root;
	162	if (end > root->end)
	163	return root;
	164	p = &root->child;
	165	for (;;) {
	166	tmp = *p;
	167	if (!tmp \|\| tmp->start > end) {
	168	new->sibling = tmp;
	169	*p = new;
	170	new->parent = root;
	171	return NULL;
	172	}
	173	p = &tmp->sibling;
	174	if (tmp->end < start)
	175	continue;
	176	return tmp;
	177	}
	178	}
	179
	180	static int __release_resource(struct resource *old)
	181	{
	182	struct resource tmp, *p;
	183
	184	p = &old->parent->child;
	185	for (;;) {
	186	tmp = *p;
	187	if (!tmp)
	188	break;
	189	if (tmp == old) {
	190	*p = tmp->sibling;
	191	old->parent = NULL;
	192	return 0;
	193	}
	194	p = &tmp->sibling;
	195	}
	196	return -EINVAL;
	197	}
	198
	199	int request_resource(struct resource root, struct resource new)
	200	{
	201	struct resource *conflict;
	202
	203	write_lock(&resource_lock);
	204	conflict = __request_resource(root, new);
	205	write_unlock(&resource_lock);
	206	return conflict ? -EBUSY : 0;
	207	}
	208
	209	EXPORT_SYMBOL(request_resource);
	210
	211	struct resource ____request_resource(struct resource root, struct resource *new)
	212	{
	213	struct resource *conflict;
	214
	215	write_lock(&resource_lock);
	216	conflict = __request_resource(root, new);
	217	write_unlock(&resource_lock);
	218	return conflict;
	219	}
220
221	EXPORT_SYMBOL(____request_resource);
222
223	int release_resource(struct resource *old)
224	{
225	int retval;
226
227	write_lock(&resource_lock);
228	retval = __release_resource(old);
229	write_unlock(&resource_lock);
230	return retval;
231	}
232
233	EXPORT_SYMBOL(release_resource);
234
235	/*
236	* Find empty slot in the resource tree given range and alignment.
237	*/
238	static int find_resource(struct resource root, struct resource new,
d75fc8bb GKH	239	resource_size_t size, resource_size_t min,
d75fc8bb GKH	240	resource_size_t max, resource_size_t align,
1da177e4	241	void (alignf)(void , struct resource *,
d75fc8bb	242	resource_size_t, resource_size_t),
1da177e4 LT	243	void *alignf_data)
	244	{
	245	struct resource *this = root->child;
	246
	247	new->start = root->start;
	248	/*
	249	* Skip past an allocated resource that starts at 0, since the assignment
	250	* of this->start - 1 to new->end below would cause an underflow.
	251	*/
	252	if (this && this->start == 0) {
	253	new->start = this->end + 1;
	254	this = this->sibling;
	255	}
	256	for(;;) {
	257	if (this)
	258	new->end = this->start - 1;
	259	else
	260	new->end = root->end;
	261	if (new->start < min)
	262	new->start = min;
	263	if (new->end > max)
	264	new->end = max;
8c0e33c1	265	new->start = ALIGN(new->start, align);
1da177e4 LT	266	if (alignf)
1da177e4 LT	267	alignf(alignf_data, new, size, align);
b52402c7	268	if (new->start < new->end && new->end - new->start >= size - 1) {
1da177e4 LT	269	new->end = new->start + size - 1;
	270	return 0;
	271	}
	272	if (!this)
	273	break;
	274	new->start = this->end + 1;
	275	this = this->sibling;
	276	}
	277	return -EBUSY;
	278	}
	279
	280	/*
	281	* Allocate empty slot in the resource tree given range and alignment.
	282	*/
	283	int allocate_resource(struct resource root, struct resource new,
d75fc8bb GKH	284	resource_size_t size, resource_size_t min,
d75fc8bb GKH	285	resource_size_t max, resource_size_t align,
1da177e4	286	void (alignf)(void , struct resource *,
d75fc8bb	287	resource_size_t, resource_size_t),
1da177e4 LT	288	void *alignf_data)
	289	{
	290	int err;
	291
	292	write_lock(&resource_lock);
	293	err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
	294	if (err >= 0 && __request_resource(root, new))
	295	err = -EBUSY;
	296	write_unlock(&resource_lock);
	297	return err;
	298	}
	299
	300	EXPORT_SYMBOL(allocate_resource);
	301
	302	/**
	303	* insert_resource - Inserts a resource in the resource tree
	304	* @parent: parent of the new resource
	305	* @new: new resource to insert
	306	*
	307	* Returns 0 on success, -EBUSY if the resource can't be inserted.
	308	*
	309	* This function is equivalent of request_resource when no conflict
	310	* happens. If a conflict happens, and the conflicting resources
	311	* entirely fit within the range of the new resource, then the new
	312	* resource is inserted and the conflicting resources become childs of
	313	* the new resource. Otherwise the new resource becomes the child of
	314	* the conflicting resource
	315	*/
	316	int insert_resource(struct resource parent, struct resource new)
	317	{
	318	int result;
	319	struct resource first, next;
	320
	321	write_lock(&resource_lock);
	322	begin:
	323	result = 0;
	324	first = __request_resource(parent, new);
	325	if (!first)
	326	goto out;
	327
	328	result = -EBUSY;
	329	if (first == parent)
	330	goto out;
	331
	332	/* Resource fully contained by the clashing resource? Recurse into it */
	333	if (first->start <= new->start && first->end >= new->end) {
	334	parent = first;
	335	goto begin;
	336	}
	337
	338	for (next = first; ; next = next->sibling) {
	339	/* Partial overlap? Bad, and unfixable */
	340	if (next->start < new->start \|\| next->end > new->end)
	341	goto out;
	342	if (!next->sibling)
	343	break;
	344	if (next->sibling->start > new->end)
	345	break;
	346	}
	347
	348	result = 0;
	349
	350	new->parent = parent;
	351	new->sibling = next->sibling;
352	new->child = first;
353
354	next->sibling = NULL;
355	for (next = first; next; next = next->sibling)
356	next->parent = new;
357
358	if (parent->child == first) {
359	parent->child = new;
360	} else {
361	next = parent->child;
362	while (next->sibling != first)
363	next = next->sibling;
364	next->sibling = new;
365	}
366
367	out:
368	write_unlock(&resource_lock);
369	return result;
370	}
371
372	EXPORT_SYMBOL(insert_resource);
373
374	/*
375	* Given an existing resource, change its start and size to match the
376	* arguments. Returns -EBUSY if it can't fit. Existing children of
377	* the resource are assumed to be immutable.
378	*/
d75fc8bb	379	int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
1da177e4 LT	380	{
1da177e4 LT	381	struct resource tmp, parent = res->parent;
d75fc8bb	382	resource_size_t end = start + size - 1;
1da177e4 LT	383	int result = -EBUSY;
	384
	385	write_lock(&resource_lock);
	386
	387	if ((start < parent->start) \|\| (end > parent->end))
	388	goto out;
	389
	390	for (tmp = res->child; tmp; tmp = tmp->sibling) {
	391	if ((tmp->start < start) \|\| (tmp->end > end))
	392	goto out;
	393	}
	394
	395	if (res->sibling && (res->sibling->start <= end))
	396	goto out;
	397
	398	tmp = parent->child;
	399	if (tmp != res) {
	400	while (tmp->sibling != res)
	401	tmp = tmp->sibling;
	402	if (start <= tmp->end)
	403	goto out;
	404	}
	405
	406	res->start = start;
	407	res->end = end;
	408	result = 0;
	409
	410	out:
	411	write_unlock(&resource_lock);
	412	return result;
	413	}
	414
	415	EXPORT_SYMBOL(adjust_resource);
	416
	417	/*
	418	* This is compatibility stuff for IO resources.
	419	*
	420	* Note how this, unlike the above, knows about
	421	* the IO flag meanings (busy etc).
	422	*
	423	* Request-region creates a new busy region.
	424	*
	425	* Check-region returns non-zero if the area is already busy
	426	*
	427	* Release-region releases a matching busy region.
	428	*/
d75fc8bb GKH	429	struct resource * __request_region(struct resource *parent,
	430	resource_size_t start, resource_size_t n,
	431	const char *name)
1da177e4	432	{
dd392710	433	struct resource res = kzalloc(sizeof(res), GFP_KERNEL);
1da177e4 LT	434
1da177e4 LT	435	if (res) {
1da177e4 LT	436	res->name = name;
	437	res->start = start;
	438	res->end = start + n - 1;
	439	res->flags = IORESOURCE_BUSY;
	440
	441	write_lock(&resource_lock);
	442
	443	for (;;) {
	444	struct resource *conflict;
	445
	446	conflict = __request_resource(parent, res);
	447	if (!conflict)
	448	break;
	449	if (conflict != parent) {
	450	parent = conflict;
	451	if (!(conflict->flags & IORESOURCE_BUSY))
	452	continue;
	453	}
	454
	455	/* Uhhuh, that didn't work out.. */
	456	kfree(res);
	457	res = NULL;
	458	break;
	459	}
	460	write_unlock(&resource_lock);
	461	}
	462	return res;
	463	}
	464
	465	EXPORT_SYMBOL(__request_region);
	466
d75fc8bb GKH	467	int __check_region(struct resource *parent, resource_size_t start,
d75fc8bb GKH	468	resource_size_t n)
1da177e4 LT	469	{
	470	struct resource * res;
	471
	472	res = __request_region(parent, start, n, "check-region");
	473	if (!res)
	474	return -EBUSY;
	475
	476	release_resource(res);
	477	kfree(res);
	478	return 0;
	479	}
	480
	481	EXPORT_SYMBOL(__check_region);
	482
d75fc8bb GKH	483	void __release_region(struct resource *parent, resource_size_t start,
d75fc8bb GKH	484	resource_size_t n)
1da177e4 LT	485	{
1da177e4 LT	486	struct resource **p;
d75fc8bb	487	resource_size_t end;
1da177e4 LT	488
	489	p = &parent->child;
	490	end = start + n - 1;
	491
	492	write_lock(&resource_lock);
	493
	494	for (;;) {
	495	struct resource res = p;
	496
	497	if (!res)
	498	break;
	499	if (res->start <= start && res->end >= end) {
	500	if (!(res->flags & IORESOURCE_BUSY)) {
	501	p = &res->child;
	502	continue;
	503	}
	504	if (res->start != start \|\| res->end != end)
	505	break;
	506	*p = res->sibling;
	507	write_unlock(&resource_lock);
	508	kfree(res);
	509	return;
	510	}
	511	p = &res->sibling;
	512	}
	513
	514	write_unlock(&resource_lock);
	515
685143ac GKH	516	printk(KERN_WARNING "Trying to free nonexistent resource "
	517	"<%016llx-%016llx>\n", (unsigned long long)start,
	518	(unsigned long long)end);
1da177e4 LT	519	}
	520
	521	EXPORT_SYMBOL(__release_region);
	522
	523	/*
	524	* Called from init/main.c to reserve IO ports.
	525	*/
	526	#define MAXRESERVE 4
	527	static int __init reserve_setup(char *str)
	528	{
	529	static int reserved;
	530	static struct resource reserve[MAXRESERVE];
	531
	532	for (;;) {
	533	int io_start, io_num;
	534	int x = reserved;
	535
	536	if (get_option (&str, &io_start) != 2)
	537	break;
	538	if (get_option (&str, &io_num) == 0)
	539	break;
	540	if (x < MAXRESERVE) {
	541	struct resource *res = reserve + x;
	542	res->name = "reserved";
	543	res->start = io_start;
	544	res->end = io_start + io_num - 1;
	545	res->flags = IORESOURCE_BUSY;
	546	res->child = NULL;
	547	if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
	548	reserved = x+1;
	549	}
	550	}
	551	return 1;
	552	}
	553
	554	__setup("reserve=", reserve_setup);