[GitHub/mt8127/android_kernel_alcatel_ttab.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/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	= 0,
	.end	= IO_SPACE_LIMIT,
	.flags	= IORESOURCE_IO,
};
EXPORT_SYMBOL(ioport_resource);

struct resource iomem_resource = {
	.name	= "PCI mem",
	.start	= 0,
	.end	= -1,
	.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);

#ifdef CONFIG_MEMORY_HOTPLUG
/*
 * Finds the lowest memory reosurce exists within [res->start.res->end)
 * the caller must specify res->start, res->end, res->flags.
 * If found, returns 0, res is overwritten, if not found, returns -1.
 */
int find_next_system_ram(struct resource *res)
{
	resource_size_t start, end;
	struct resource *p;

	BUG_ON(!res);

	start = res->start;
	end = res->end;

	read_lock(&resource_lock);
	for (p = iomem_resource.child; p ; p = p->sibling) {
		/* system ram is just marked as IORESOURCE_MEM */
		if (p->flags != res->flags)
			continue;
		if (p->start > end) {
			p = NULL;
			break;
		}
		if (p->start >= start)
			break;
	}
	read_unlock(&resource_lock);
	if (!p)
		return -1;
	/* copy data */
	res->start = p->start;
	res->end = p->end;
	return 0;
}
#endif

/*
 * 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;
}

/*
 * 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
1da177e4 LT	10	#include <linux/module.h>
	11	#include <linux/sched.h>
	12	#include <linux/errno.h>
	13	#include <linux/ioport.h>
	14	#include <linux/init.h>
	15	#include <linux/slab.h>
	16	#include <linux/spinlock.h>
	17	#include <linux/fs.h>
	18	#include <linux/proc_fs.h>
	19	#include <linux/seq_file.h>
	20	#include <asm/io.h>
	21
	22
	23	struct resource ioport_resource = {
	24	.name = "PCI IO",
6550e07f	25	.start = 0,
1da177e4 LT	26	.end = IO_SPACE_LIMIT,
	27	.flags = IORESOURCE_IO,
	28	};
1da177e4 LT	29	EXPORT_SYMBOL(ioport_resource);
	30
	31	struct resource iomem_resource = {
	32	.name = "PCI mem",
6550e07f GKH	33	.start = 0,
6550e07f GKH	34	.end = -1,
1da177e4 LT	35	.flags = IORESOURCE_MEM,
1da177e4 LT	36	};
1da177e4 LT	37	EXPORT_SYMBOL(iomem_resource);
	38
	39	static DEFINE_RWLOCK(resource_lock);
	40
	41	#ifdef CONFIG_PROC_FS
	42
	43	enum { MAX_IORES_LEVEL = 5 };
	44
	45	static void r_next(struct seq_file m, void v, loff_t pos)
	46	{
	47	struct resource *p = v;
	48	(*pos)++;
	49	if (p->child)
	50	return p->child;
	51	while (!p->sibling && p->parent)
	52	p = p->parent;
	53	return p->sibling;
	54	}
	55
	56	static void r_start(struct seq_file m, loff_t *pos)
	57	__acquires(resource_lock)
	58	{
	59	struct resource *p = m->private;
	60	loff_t l = 0;
	61	read_lock(&resource_lock);
	62	for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
	63	;
	64	return p;
	65	}
	66
	67	static void r_stop(struct seq_file m, void v)
	68	__releases(resource_lock)
	69	{
	70	read_unlock(&resource_lock);
	71	}
	72
	73	static int r_show(struct seq_file m, void v)
	74	{
	75	struct resource *root = m->private;
	76	struct resource r = v, p;
	77	int width = root->end < 0x10000 ? 4 : 8;
	78	int depth;
	79
	80	for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
	81	if (p->parent == root)
	82	break;
685143ac	83	seq_printf(m, "%s%0llx-%0*llx : %s\n",
1da177e4	84	depth * 2, "",
685143ac GKH	85	width, (unsigned long long) r->start,
685143ac GKH	86	width, (unsigned long long) r->end,
1da177e4 LT	87	r->name ? r->name : "<BAD>");
	88	return 0;
	89	}
	90
	91	static struct seq_operations resource_op = {
	92	.start = r_start,
	93	.next = r_next,
	94	.stop = r_stop,
	95	.show = r_show,
	96	};
	97
	98	static int ioports_open(struct inode inode, struct file file)
	99	{
	100	int res = seq_open(file, &resource_op);
	101	if (!res) {
	102	struct seq_file *m = file->private_data;
	103	m->private = &ioport_resource;
	104	}
	105	return res;
	106	}
	107
	108	static int iomem_open(struct inode inode, struct file file)
	109	{
	110	int res = seq_open(file, &resource_op);
	111	if (!res) {
	112	struct seq_file *m = file->private_data;
	113	m->private = &iomem_resource;
	114	}
	115	return res;
	116	}
	117
	118	static struct file_operations proc_ioports_operations = {
	119	.open = ioports_open,
	120	.read = seq_read,
	121	.llseek = seq_lseek,
	122	.release = seq_release,
	123	};
	124
	125	static struct file_operations proc_iomem_operations = {
	126	.open = iomem_open,
	127	.read = seq_read,
	128	.llseek = seq_lseek,
	129	.release = seq_release,
	130	};
	131
	132	static int __init ioresources_init(void)
	133	{
	134	struct proc_dir_entry *entry;
	135
	136	entry = create_proc_entry("ioports", 0, NULL);
	137	if (entry)
	138	entry->proc_fops = &proc_ioports_operations;
	139	entry = create_proc_entry("iomem", 0, NULL);
	140	if (entry)
	141	entry->proc_fops = &proc_iomem_operations;
	142	return 0;
	143	}
	144	__initcall(ioresources_init);
	145
	146	#endif /* CONFIG_PROC_FS */
	147
	148	/* Return the conflict entry if you can't request it */
	149	static struct resource * __request_resource(struct resource root, struct resource new)
	150	{
d75fc8bb GKH	151	resource_size_t start = new->start;
d75fc8bb GKH	152	resource_size_t end = new->end;
1da177e4 LT	153	struct resource tmp, *p;
	154
	155	if (end < start)
	156	return root;
	157	if (start < root->start)
	158	return root;
	159	if (end > root->end)
	160	return root;
	161	p = &root->child;
	162	for (;;) {
	163	tmp = *p;
	164	if (!tmp \|\| tmp->start > end) {
	165	new->sibling = tmp;
	166	*p = new;
	167	new->parent = root;
	168	return NULL;
	169	}
	170	p = &tmp->sibling;
	171	if (tmp->end < start)
	172	continue;
	173	return tmp;
	174	}
	175	}
	176
	177	static int __release_resource(struct resource *old)
	178	{
	179	struct resource tmp, *p;
	180
	181	p = &old->parent->child;
	182	for (;;) {
	183	tmp = *p;
	184	if (!tmp)
	185	break;
	186	if (tmp == old) {
	187	*p = tmp->sibling;
	188	old->parent = NULL;
	189	return 0;
	190	}
	191	p = &tmp->sibling;
	192	}
	193	return -EINVAL;
	194	}
	195
	196	int request_resource(struct resource root, struct resource new)
	197	{
	198	struct resource *conflict;
	199
	200	write_lock(&resource_lock);
	201	conflict = __request_resource(root, new);
	202	write_unlock(&resource_lock);
	203	return conflict ? -EBUSY : 0;
	204	}
	205
	206	EXPORT_SYMBOL(request_resource);
	207
	208	struct resource ____request_resource(struct resource root, struct resource *new)
	209	{
	210	struct resource *conflict;
	211
	212	write_lock(&resource_lock);
	213	conflict = __request_resource(root, new);
	214	write_unlock(&resource_lock);
	215	return conflict;
	216	}
217
218	EXPORT_SYMBOL(____request_resource);
219
220	int release_resource(struct resource *old)
221	{
222	int retval;
223
224	write_lock(&resource_lock);
225	retval = __release_resource(old);
226	write_unlock(&resource_lock);
227	return retval;
228	}
229
230	EXPORT_SYMBOL(release_resource);
231
2842f114 KH	232	#ifdef CONFIG_MEMORY_HOTPLUG
	233	/*
	234	* Finds the lowest memory reosurce exists within [res->start.res->end)
	235	* the caller must specify res->start, res->end, res->flags.
	236	* If found, returns 0, res is overwritten, if not found, returns -1.
	237	*/
	238	int find_next_system_ram(struct resource *res)
	239	{
	240	resource_size_t start, end;
	241	struct resource *p;
	242
	243	BUG_ON(!res);
	244
	245	start = res->start;
	246	end = res->end;
	247
	248	read_lock(&resource_lock);
	249	for (p = iomem_resource.child; p ; p = p->sibling) {
	250	/* system ram is just marked as IORESOURCE_MEM */
	251	if (p->flags != res->flags)
	252	continue;
	253	if (p->start > end) {
	254	p = NULL;
	255	break;
	256	}
	257	if (p->start >= start)
	258	break;
	259	}
	260	read_unlock(&resource_lock);
	261	if (!p)
	262	return -1;
	263	/* copy data */
	264	res->start = p->start;
	265	res->end = p->end;
	266	return 0;
	267	}
	268	#endif
	269
1da177e4 LT	270	/*
	271	* Find empty slot in the resource tree given range and alignment.
	272	*/
	273	static int find_resource(struct resource root, struct resource new,
d75fc8bb GKH	274	resource_size_t size, resource_size_t min,
d75fc8bb GKH	275	resource_size_t max, resource_size_t align,
1da177e4	276	void (alignf)(void , struct resource *,
d75fc8bb	277	resource_size_t, resource_size_t),
1da177e4 LT	278	void *alignf_data)
	279	{
	280	struct resource *this = root->child;
	281
	282	new->start = root->start;
	283	/*
	284	* Skip past an allocated resource that starts at 0, since the assignment
	285	* of this->start - 1 to new->end below would cause an underflow.
	286	*/
	287	if (this && this->start == 0) {
	288	new->start = this->end + 1;
	289	this = this->sibling;
	290	}
	291	for(;;) {
	292	if (this)
	293	new->end = this->start - 1;
	294	else
	295	new->end = root->end;
	296	if (new->start < min)
	297	new->start = min;
	298	if (new->end > max)
	299	new->end = max;
8c0e33c1	300	new->start = ALIGN(new->start, align);
1da177e4 LT	301	if (alignf)
1da177e4 LT	302	alignf(alignf_data, new, size, align);
b52402c7	303	if (new->start < new->end && new->end - new->start >= size - 1) {
1da177e4 LT	304	new->end = new->start + size - 1;
	305	return 0;
	306	}
	307	if (!this)
	308	break;
	309	new->start = this->end + 1;
	310	this = this->sibling;
	311	}
	312	return -EBUSY;
	313	}
	314
	315	/*
	316	* Allocate empty slot in the resource tree given range and alignment.
	317	*/
	318	int allocate_resource(struct resource root, struct resource new,
d75fc8bb GKH	319	resource_size_t size, resource_size_t min,
d75fc8bb GKH	320	resource_size_t max, resource_size_t align,
1da177e4	321	void (alignf)(void , struct resource *,
d75fc8bb	322	resource_size_t, resource_size_t),
1da177e4 LT	323	void *alignf_data)
	324	{
	325	int err;
	326
	327	write_lock(&resource_lock);
	328	err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
	329	if (err >= 0 && __request_resource(root, new))
	330	err = -EBUSY;
	331	write_unlock(&resource_lock);
	332	return err;
	333	}
	334
	335	EXPORT_SYMBOL(allocate_resource);
	336
	337	/**
	338	* insert_resource - Inserts a resource in the resource tree
	339	* @parent: parent of the new resource
	340	* @new: new resource to insert
	341	*
	342	* Returns 0 on success, -EBUSY if the resource can't be inserted.
	343	*
	344	* This function is equivalent of request_resource when no conflict
	345	* happens. If a conflict happens, and the conflicting resources
	346	* entirely fit within the range of the new resource, then the new
	347	* resource is inserted and the conflicting resources become childs of
	348	* the new resource. Otherwise the new resource becomes the child of
	349	* the conflicting resource
	350	*/
	351	int insert_resource(struct resource parent, struct resource new)
	352	{
	353	int result;
	354	struct resource first, next;
	355
	356	write_lock(&resource_lock);
	357	begin:
	358	result = 0;
	359	first = __request_resource(parent, new);
	360	if (!first)
	361	goto out;
	362
	363	result = -EBUSY;
	364	if (first == parent)
	365	goto out;
	366
	367	/* Resource fully contained by the clashing resource? Recurse into it */
	368	if (first->start <= new->start && first->end >= new->end) {
	369	parent = first;
	370	goto begin;
	371	}
	372
	373	for (next = first; ; next = next->sibling) {
	374	/* Partial overlap? Bad, and unfixable */
	375	if (next->start < new->start \|\| next->end > new->end)
	376	goto out;
	377	if (!next->sibling)
	378	break;
	379	if (next->sibling->start > new->end)
	380	break;
	381	}
	382
	383	result = 0;
	384
	385	new->parent = parent;
	386	new->sibling = next->sibling;
387	new->child = first;
388
389	next->sibling = NULL;
390	for (next = first; next; next = next->sibling)
391	next->parent = new;
392
393	if (parent->child == first) {
394	parent->child = new;
395	} else {
396	next = parent->child;
397	while (next->sibling != first)
398	next = next->sibling;
399	next->sibling = new;
400	}
401
402	out:
403	write_unlock(&resource_lock);
404	return result;
405	}
406
1da177e4 LT	407	/*
	408	* Given an existing resource, change its start and size to match the
	409	* arguments. Returns -EBUSY if it can't fit. Existing children of
	410	* the resource are assumed to be immutable.
	411	*/
d75fc8bb	412	int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
1da177e4 LT	413	{
1da177e4 LT	414	struct resource tmp, parent = res->parent;
d75fc8bb	415	resource_size_t end = start + size - 1;
1da177e4 LT	416	int result = -EBUSY;
	417
	418	write_lock(&resource_lock);
	419
	420	if ((start < parent->start) \|\| (end > parent->end))
	421	goto out;
	422
	423	for (tmp = res->child; tmp; tmp = tmp->sibling) {
	424	if ((tmp->start < start) \|\| (tmp->end > end))
	425	goto out;
	426	}
	427
	428	if (res->sibling && (res->sibling->start <= end))
	429	goto out;
	430
	431	tmp = parent->child;
	432	if (tmp != res) {
	433	while (tmp->sibling != res)
	434	tmp = tmp->sibling;
	435	if (start <= tmp->end)
	436	goto out;
	437	}
	438
	439	res->start = start;
	440	res->end = end;
	441	result = 0;
	442
	443	out:
	444	write_unlock(&resource_lock);
	445	return result;
	446	}
	447
	448	EXPORT_SYMBOL(adjust_resource);
	449
	450	/*
	451	* This is compatibility stuff for IO resources.
	452	*
	453	* Note how this, unlike the above, knows about
	454	* the IO flag meanings (busy etc).
	455	*
	456	* Request-region creates a new busy region.
	457	*
	458	* Check-region returns non-zero if the area is already busy
	459	*
	460	* Release-region releases a matching busy region.
	461	*/
d75fc8bb GKH	462	struct resource * __request_region(struct resource *parent,
	463	resource_size_t start, resource_size_t n,
	464	const char *name)
1da177e4	465	{
dd392710	466	struct resource res = kzalloc(sizeof(res), GFP_KERNEL);
1da177e4 LT	467
1da177e4 LT	468	if (res) {
1da177e4 LT	469	res->name = name;
	470	res->start = start;
	471	res->end = start + n - 1;
	472	res->flags = IORESOURCE_BUSY;
	473
	474	write_lock(&resource_lock);
	475
	476	for (;;) {
	477	struct resource *conflict;
	478
	479	conflict = __request_resource(parent, res);
	480	if (!conflict)
	481	break;
	482	if (conflict != parent) {
	483	parent = conflict;
	484	if (!(conflict->flags & IORESOURCE_BUSY))
	485	continue;
	486	}
	487
	488	/* Uhhuh, that didn't work out.. */
	489	kfree(res);
	490	res = NULL;
	491	break;
	492	}
	493	write_unlock(&resource_lock);
	494	}
	495	return res;
	496	}
	497
	498	EXPORT_SYMBOL(__request_region);
	499
d75fc8bb GKH	500	int __check_region(struct resource *parent, resource_size_t start,
d75fc8bb GKH	501	resource_size_t n)
1da177e4 LT	502	{
	503	struct resource * res;
	504
	505	res = __request_region(parent, start, n, "check-region");
	506	if (!res)
	507	return -EBUSY;
	508
	509	release_resource(res);
	510	kfree(res);
	511	return 0;
	512	}
	513
	514	EXPORT_SYMBOL(__check_region);
	515
d75fc8bb GKH	516	void __release_region(struct resource *parent, resource_size_t start,
d75fc8bb GKH	517	resource_size_t n)
1da177e4 LT	518	{
1da177e4 LT	519	struct resource **p;
d75fc8bb	520	resource_size_t end;
1da177e4 LT	521
	522	p = &parent->child;
	523	end = start + n - 1;
	524
	525	write_lock(&resource_lock);
	526
	527	for (;;) {
	528	struct resource res = p;
	529
	530	if (!res)
	531	break;
	532	if (res->start <= start && res->end >= end) {
	533	if (!(res->flags & IORESOURCE_BUSY)) {
	534	p = &res->child;
	535	continue;
	536	}
	537	if (res->start != start \|\| res->end != end)
	538	break;
	539	*p = res->sibling;
	540	write_unlock(&resource_lock);
	541	kfree(res);
	542	return;
	543	}
	544	p = &res->sibling;
	545	}
	546
	547	write_unlock(&resource_lock);
	548
685143ac GKH	549	printk(KERN_WARNING "Trying to free nonexistent resource "
	550	"<%016llx-%016llx>\n", (unsigned long long)start,
	551	(unsigned long long)end);
1da177e4 LT	552	}
	553
	554	EXPORT_SYMBOL(__release_region);
	555
	556	/*
	557	* Called from init/main.c to reserve IO ports.
	558	*/
	559	#define MAXRESERVE 4
	560	static int __init reserve_setup(char *str)
	561	{
	562	static int reserved;
	563	static struct resource reserve[MAXRESERVE];
	564
	565	for (;;) {
	566	int io_start, io_num;
	567	int x = reserved;
	568
	569	if (get_option (&str, &io_start) != 2)
	570	break;
	571	if (get_option (&str, &io_num) == 0)
	572	break;
	573	if (x < MAXRESERVE) {
	574	struct resource *res = reserve + x;
	575	res->name = "reserved";
	576	res->start = io_start;
	577	res->end = io_start + io_num - 1;
	578	res->flags = IORESOURCE_BUSY;
	579	res->child = NULL;
	580	if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
	581	reserved = x+1;
	582	}
	583	}
	584	return 1;
	585	}
	586
	587	__setup("reserve=", reserve_setup);