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![Adrian Bunk](/assets/img/avatar_default.png)
If a __deprecated is desired it should go to the prototype in the header (where it currently isn't). But at this place it's pointless. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
550 lines
12 KiB
C
550 lines
12 KiB
C
/*
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* linux/kernel/resource.c
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*
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* Copyright (C) 1999 Linus Torvalds
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* Copyright (C) 1999 Martin Mares <mj@ucw.cz>
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*
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* Arbitrary resource management.
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/fs.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <asm/io.h>
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struct resource ioport_resource = {
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.name = "PCI IO",
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.start = 0x0000,
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.end = IO_SPACE_LIMIT,
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.flags = IORESOURCE_IO,
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};
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EXPORT_SYMBOL(ioport_resource);
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struct resource iomem_resource = {
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.name = "PCI mem",
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.start = 0UL,
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.end = ~0UL,
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.flags = IORESOURCE_MEM,
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};
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EXPORT_SYMBOL(iomem_resource);
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static DEFINE_RWLOCK(resource_lock);
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#ifdef CONFIG_PROC_FS
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enum { MAX_IORES_LEVEL = 5 };
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static void *r_next(struct seq_file *m, void *v, loff_t *pos)
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{
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struct resource *p = v;
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(*pos)++;
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if (p->child)
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return p->child;
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while (!p->sibling && p->parent)
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p = p->parent;
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return p->sibling;
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}
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static void *r_start(struct seq_file *m, loff_t *pos)
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__acquires(resource_lock)
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{
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struct resource *p = m->private;
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loff_t l = 0;
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read_lock(&resource_lock);
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for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
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;
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return p;
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}
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static void r_stop(struct seq_file *m, void *v)
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__releases(resource_lock)
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{
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read_unlock(&resource_lock);
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}
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static int r_show(struct seq_file *m, void *v)
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{
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struct resource *root = m->private;
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struct resource *r = v, *p;
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int width = root->end < 0x10000 ? 4 : 8;
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int depth;
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for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
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if (p->parent == root)
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break;
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seq_printf(m, "%*s%0*lx-%0*lx : %s\n",
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depth * 2, "",
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width, r->start,
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width, r->end,
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r->name ? r->name : "<BAD>");
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return 0;
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}
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static struct seq_operations resource_op = {
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.start = r_start,
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.next = r_next,
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.stop = r_stop,
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.show = r_show,
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};
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static int ioports_open(struct inode *inode, struct file *file)
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{
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int res = seq_open(file, &resource_op);
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if (!res) {
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struct seq_file *m = file->private_data;
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m->private = &ioport_resource;
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}
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return res;
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}
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static int iomem_open(struct inode *inode, struct file *file)
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{
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int res = seq_open(file, &resource_op);
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if (!res) {
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struct seq_file *m = file->private_data;
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m->private = &iomem_resource;
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}
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return res;
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}
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static struct file_operations proc_ioports_operations = {
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.open = ioports_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static struct file_operations proc_iomem_operations = {
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.open = iomem_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static int __init ioresources_init(void)
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{
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struct proc_dir_entry *entry;
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entry = create_proc_entry("ioports", 0, NULL);
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if (entry)
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entry->proc_fops = &proc_ioports_operations;
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entry = create_proc_entry("iomem", 0, NULL);
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if (entry)
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entry->proc_fops = &proc_iomem_operations;
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return 0;
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}
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__initcall(ioresources_init);
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#endif /* CONFIG_PROC_FS */
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/* Return the conflict entry if you can't request it */
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static struct resource * __request_resource(struct resource *root, struct resource *new)
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{
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unsigned long start = new->start;
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unsigned long end = new->end;
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struct resource *tmp, **p;
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if (end < start)
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return root;
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if (start < root->start)
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return root;
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if (end > root->end)
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return root;
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p = &root->child;
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for (;;) {
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tmp = *p;
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if (!tmp || tmp->start > end) {
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new->sibling = tmp;
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*p = new;
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new->parent = root;
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return NULL;
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}
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p = &tmp->sibling;
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if (tmp->end < start)
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continue;
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return tmp;
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}
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}
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static int __release_resource(struct resource *old)
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{
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struct resource *tmp, **p;
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p = &old->parent->child;
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for (;;) {
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tmp = *p;
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if (!tmp)
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break;
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if (tmp == old) {
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*p = tmp->sibling;
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old->parent = NULL;
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return 0;
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}
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p = &tmp->sibling;
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}
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return -EINVAL;
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}
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int request_resource(struct resource *root, struct resource *new)
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{
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struct resource *conflict;
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write_lock(&resource_lock);
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conflict = __request_resource(root, new);
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write_unlock(&resource_lock);
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return conflict ? -EBUSY : 0;
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}
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EXPORT_SYMBOL(request_resource);
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struct resource *____request_resource(struct resource *root, struct resource *new)
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{
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struct resource *conflict;
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write_lock(&resource_lock);
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conflict = __request_resource(root, new);
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write_unlock(&resource_lock);
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return conflict;
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}
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EXPORT_SYMBOL(____request_resource);
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int release_resource(struct resource *old)
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{
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int retval;
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write_lock(&resource_lock);
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retval = __release_resource(old);
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write_unlock(&resource_lock);
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return retval;
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}
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EXPORT_SYMBOL(release_resource);
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/*
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* Find empty slot in the resource tree given range and alignment.
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*/
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static int find_resource(struct resource *root, struct resource *new,
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unsigned long size,
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unsigned long min, unsigned long max,
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unsigned long align,
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void (*alignf)(void *, struct resource *,
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unsigned long, unsigned long),
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void *alignf_data)
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{
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struct resource *this = root->child;
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new->start = root->start;
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/*
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* Skip past an allocated resource that starts at 0, since the assignment
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* of this->start - 1 to new->end below would cause an underflow.
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*/
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if (this && this->start == 0) {
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new->start = this->end + 1;
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this = this->sibling;
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}
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for(;;) {
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if (this)
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new->end = this->start - 1;
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else
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new->end = root->end;
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if (new->start < min)
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new->start = min;
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if (new->end > max)
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new->end = max;
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new->start = ALIGN(new->start, align);
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if (alignf)
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alignf(alignf_data, new, size, align);
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if (new->start < new->end && new->end - new->start >= size - 1) {
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new->end = new->start + size - 1;
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return 0;
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}
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if (!this)
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break;
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new->start = this->end + 1;
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this = this->sibling;
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}
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return -EBUSY;
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}
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/*
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* Allocate empty slot in the resource tree given range and alignment.
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*/
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int allocate_resource(struct resource *root, struct resource *new,
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unsigned long size,
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unsigned long min, unsigned long max,
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unsigned long align,
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void (*alignf)(void *, struct resource *,
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unsigned long, unsigned long),
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void *alignf_data)
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{
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int err;
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write_lock(&resource_lock);
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err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
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if (err >= 0 && __request_resource(root, new))
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err = -EBUSY;
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write_unlock(&resource_lock);
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return err;
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}
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EXPORT_SYMBOL(allocate_resource);
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/**
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* insert_resource - Inserts a resource in the resource tree
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* @parent: parent of the new resource
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* @new: new resource to insert
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*
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* Returns 0 on success, -EBUSY if the resource can't be inserted.
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*
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* This function is equivalent of request_resource when no conflict
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* happens. If a conflict happens, and the conflicting resources
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* entirely fit within the range of the new resource, then the new
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* resource is inserted and the conflicting resources become childs of
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* the new resource. Otherwise the new resource becomes the child of
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* the conflicting resource
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*/
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int insert_resource(struct resource *parent, struct resource *new)
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{
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int result;
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struct resource *first, *next;
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write_lock(&resource_lock);
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begin:
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result = 0;
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first = __request_resource(parent, new);
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if (!first)
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goto out;
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result = -EBUSY;
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if (first == parent)
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goto out;
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/* Resource fully contained by the clashing resource? Recurse into it */
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if (first->start <= new->start && first->end >= new->end) {
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parent = first;
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goto begin;
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}
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for (next = first; ; next = next->sibling) {
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/* Partial overlap? Bad, and unfixable */
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if (next->start < new->start || next->end > new->end)
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goto out;
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if (!next->sibling)
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break;
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if (next->sibling->start > new->end)
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break;
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}
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result = 0;
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new->parent = parent;
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new->sibling = next->sibling;
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new->child = first;
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next->sibling = NULL;
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for (next = first; next; next = next->sibling)
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next->parent = new;
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if (parent->child == first) {
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parent->child = new;
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} else {
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next = parent->child;
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while (next->sibling != first)
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next = next->sibling;
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next->sibling = new;
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}
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out:
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write_unlock(&resource_lock);
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return result;
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}
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EXPORT_SYMBOL(insert_resource);
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/*
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* Given an existing resource, change its start and size to match the
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* arguments. Returns -EBUSY if it can't fit. Existing children of
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* the resource are assumed to be immutable.
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*/
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int adjust_resource(struct resource *res, unsigned long start, unsigned long size)
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{
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struct resource *tmp, *parent = res->parent;
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unsigned long end = start + size - 1;
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int result = -EBUSY;
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write_lock(&resource_lock);
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if ((start < parent->start) || (end > parent->end))
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goto out;
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for (tmp = res->child; tmp; tmp = tmp->sibling) {
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if ((tmp->start < start) || (tmp->end > end))
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goto out;
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}
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if (res->sibling && (res->sibling->start <= end))
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goto out;
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tmp = parent->child;
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if (tmp != res) {
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while (tmp->sibling != res)
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tmp = tmp->sibling;
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if (start <= tmp->end)
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goto out;
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}
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res->start = start;
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res->end = end;
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result = 0;
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out:
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write_unlock(&resource_lock);
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return result;
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}
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EXPORT_SYMBOL(adjust_resource);
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/*
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* This is compatibility stuff for IO resources.
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*
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* Note how this, unlike the above, knows about
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* the IO flag meanings (busy etc).
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*
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* Request-region creates a new busy region.
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*
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* Check-region returns non-zero if the area is already busy
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*
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* Release-region releases a matching busy region.
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*/
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struct resource * __request_region(struct resource *parent, unsigned long start, unsigned long n, const char *name)
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{
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struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
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if (res) {
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res->name = name;
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res->start = start;
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res->end = start + n - 1;
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res->flags = IORESOURCE_BUSY;
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write_lock(&resource_lock);
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for (;;) {
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struct resource *conflict;
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conflict = __request_resource(parent, res);
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if (!conflict)
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break;
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if (conflict != parent) {
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parent = conflict;
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if (!(conflict->flags & IORESOURCE_BUSY))
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continue;
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}
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/* Uhhuh, that didn't work out.. */
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kfree(res);
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res = NULL;
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break;
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}
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write_unlock(&resource_lock);
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}
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return res;
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}
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EXPORT_SYMBOL(__request_region);
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int __check_region(struct resource *parent, unsigned long start, unsigned long n)
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{
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struct resource * res;
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res = __request_region(parent, start, n, "check-region");
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if (!res)
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return -EBUSY;
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release_resource(res);
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kfree(res);
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return 0;
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}
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EXPORT_SYMBOL(__check_region);
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void __release_region(struct resource *parent, unsigned long start, unsigned long n)
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{
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struct resource **p;
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unsigned long end;
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p = &parent->child;
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end = start + n - 1;
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write_lock(&resource_lock);
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for (;;) {
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struct resource *res = *p;
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if (!res)
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break;
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if (res->start <= start && res->end >= end) {
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if (!(res->flags & IORESOURCE_BUSY)) {
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p = &res->child;
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continue;
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}
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if (res->start != start || res->end != end)
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break;
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*p = res->sibling;
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write_unlock(&resource_lock);
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kfree(res);
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return;
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}
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p = &res->sibling;
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}
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write_unlock(&resource_lock);
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printk(KERN_WARNING "Trying to free nonexistent resource <%08lx-%08lx>\n", start, end);
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}
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EXPORT_SYMBOL(__release_region);
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/*
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* Called from init/main.c to reserve IO ports.
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*/
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#define MAXRESERVE 4
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static int __init reserve_setup(char *str)
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{
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static int reserved;
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static struct resource reserve[MAXRESERVE];
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for (;;) {
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int io_start, io_num;
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int x = reserved;
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if (get_option (&str, &io_start) != 2)
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break;
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if (get_option (&str, &io_num) == 0)
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break;
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if (x < MAXRESERVE) {
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struct resource *res = reserve + x;
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res->name = "reserved";
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res->start = io_start;
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res->end = io_start + io_num - 1;
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res->flags = IORESOURCE_BUSY;
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res->child = NULL;
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if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
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reserved = x+1;
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}
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}
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return 1;
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}
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__setup("reserve=", reserve_setup);
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