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/* *	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/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 <linux/device.h>#include <linux/pfn.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); 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;} #ifdef CONFIG_PROC_FS enum { MAX_IORES_LEVEL = 5 }; 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 const 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 const struct file_operations proc_ioports_operations = {	.open		= ioports_open,	.read		= seq_read,	.llseek		= seq_lseek,	.release	= seq_release,}; static const struct file_operations proc_iomem_operations = {	.open		= iomem_open,	.read		= seq_read,	.llseek		= seq_lseek,	.release	= seq_release,}; static int __init ioresources_init(void){	proc_create("ioports", 0, NULL, &proc_ioports_operations);	proc_create("iomem", 0, NULL, &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;} /** * request_resource - request and reserve an I/O or memory resource * @root: root resource descriptor * @new: resource descriptor desired by caller * * Returns 0 for success, negative error code on error. */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); /** * release_resource - release a previously reserved resource * @old: resource pointer */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); #if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY)/* * 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. */static 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;	BUG_ON(start >= 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->end >= start) && (p->start < end))			break;	}	read_unlock(&resource_lock);	if (!p)		return -1;	/* copy data */	if (res->start < p->start)		res->start = p->start;	if (res->end > p->end)		res->end = p->end;	return 0;}intwalk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,			int (*func)(unsigned long, unsigned long, void *)){	struct resource res;	unsigned long pfn, len;	u64 orig_end;	int ret = -1;	res.start = (u64) start_pfn << PAGE_SHIFT;	res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;	res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;	orig_end = res.end;	while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {		pfn = (unsigned long)(res.start >> PAGE_SHIFT);		len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);		ret = (*func)(pfn, len, arg);		if (ret)			break;		res.start = res.end + 1;		res.end = orig_end;	}	return ret;} #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_resource - allocate empty slot in the resource tree given range & alignment * @root: root resource descriptor * @new: resource descriptor desired by caller * @size: requested resource region size * @min: minimum size to allocate * @max: maximum size to allocate * @align: alignment requested, in bytes * @alignf: alignment function, optional, called if not NULL * @alignf_data: arbitrary data to pass to the @alignf function */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 a resource into the resource tree. If successful, return NULL, * otherwise return the conflicting resource (compare to __request_resource()) */static struct resource * __insert_resource(struct resource *parent, struct resource *new){	struct resource *first, *next; 	for (;; parent = first) {		first = __request_resource(parent, new);		if (!first)			return first; 		if (first == parent)			return first; 		if ((first->start > new->start) || (first->end < new->end))			break;		if ((first->start == new->start) && (first->end == new->end))			break;	} 	for (next = first; ; next = next->sibling) {		/* Partial overlap? Bad, and unfixable */		if (next->start < new->start || next->end > new->end)			return next;		if (!next->sibling)			break;		if (next->sibling->start > new->end)			break;	} 	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;	}	return NULL;} /** * 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 to 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 children of * the new resource. */int insert_resource(struct resource *parent, struct resource *new){	struct resource *conflict; 	write_lock(&resource_lock);	conflict = __insert_resource(parent, new);	write_unlock(&resource_lock);	return conflict ? -EBUSY : 0;} /** * insert_resource_expand_to_fit - Insert a resource into the resource tree * @root: root resource descriptor * @new: new resource to insert * * Insert a resource into the resource tree, possibly expanding it in order * to make it encompass any conflicting resources. */void insert_resource_expand_to_fit(struct resource *root, struct resource *new){	if (new->parent)		return; 	write_lock(&resource_lock);	for (;;) {		struct resource *conflict; 		conflict = __insert_resource(root, new);		if (!conflict)			break;		if (conflict == root)			break; 		/* Ok, expand resource to cover the conflict, then try again .. */		if (conflict->start < new->start)			new->start = conflict->start;		if (conflict->end > new->end)			new->end = conflict->end; 		printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);	}	write_unlock(&resource_lock);} /** * adjust_resource - modify a resource's start and size * @res: resource to modify * @start: new start value * @size: new size * * Given an existing resource, change its start and size to match the * arguments.  Returns 0 on success, -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))

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