Implement device resource management, in short, devres. A device driver can allocate arbirary size of devres data which is associated with a release function. On driver detach, release function is invoked on the devres data, then, devres data is freed. devreses are typed by associated release functions. Some devreses are better represented by single instance of the type while others need multiple instances sharing the same release function. Both usages are supported. devreses can be grouped using devres group such that a device driver can easily release acquired resources halfway through initialization or selectively release resources (e.g. resources for port 1 out of 4 ports). This patch adds devres core including documentation and the following managed interfaces. * alloc/free : devm_kzalloc(), devm_kzfree() * IO region : devm_request_region(), devm_release_region() * IRQ : devm_request_irq(), devm_free_irq() * DMA : dmam_alloc_coherent(), dmam_free_coherent(), dmam_declare_coherent_memory(), dmam_pool_create(), dmam_pool_destroy() * PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed() * iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(), devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(), pcim_iomap(), pcim_iounmap() Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
713 lines
16 KiB
C
713 lines
16 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/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 <linux/device.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 = 0,
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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 = 0,
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.end = -1,
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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*llx-%0*llx : %s\n",
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depth * 2, "",
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width, (unsigned long long) r->start,
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width, (unsigned long long) 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 const 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 const 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 const 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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resource_size_t start = new->start;
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resource_size_t 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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/**
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* request_resource - request and reserve an I/O or memory resource
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* @root: root resource descriptor
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* @new: resource descriptor desired by caller
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*
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* Returns 0 for success, negative error code on error.
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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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/**
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* ____request_resource - reserve a resource, with resource conflict returned
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* @root: root resource descriptor
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* @new: resource descriptor desired by caller
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*
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* Returns:
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* On success, NULL is returned.
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* On error, a pointer to the conflicting resource is returned.
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*/
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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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/**
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* release_resource - release a previously reserved resource
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* @old: resource pointer
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*/
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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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#ifdef CONFIG_MEMORY_HOTPLUG
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/*
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* Finds the lowest memory reosurce exists within [res->start.res->end)
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* the caller must specify res->start, res->end, res->flags.
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* If found, returns 0, res is overwritten, if not found, returns -1.
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*/
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int find_next_system_ram(struct resource *res)
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{
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resource_size_t start, end;
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struct resource *p;
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BUG_ON(!res);
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start = res->start;
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end = res->end;
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BUG_ON(start >= end);
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read_lock(&resource_lock);
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for (p = iomem_resource.child; p ; p = p->sibling) {
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/* system ram is just marked as IORESOURCE_MEM */
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if (p->flags != res->flags)
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continue;
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if (p->start > end) {
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p = NULL;
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break;
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}
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if ((p->end >= start) && (p->start < end))
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break;
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}
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read_unlock(&resource_lock);
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if (!p)
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return -1;
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/* copy data */
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if (res->start < p->start)
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res->start = p->start;
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if (res->end > p->end)
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res->end = p->end;
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return 0;
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}
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#endif
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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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resource_size_t size, resource_size_t min,
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resource_size_t max, resource_size_t align,
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void (*alignf)(void *, struct resource *,
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resource_size_t, resource_size_t),
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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_resource - allocate empty slot in the resource tree given range & alignment
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* @root: root resource descriptor
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* @new: resource descriptor desired by caller
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* @size: requested resource region size
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* @min: minimum size to allocate
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* @max: maximum size to allocate
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* @align: alignment requested, in bytes
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* @alignf: alignment function, optional, called if not NULL
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* @alignf_data: arbitrary data to pass to the @alignf function
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*/
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int allocate_resource(struct resource *root, struct resource *new,
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resource_size_t size, resource_size_t min,
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resource_size_t max, resource_size_t align,
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void (*alignf)(void *, struct resource *,
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resource_size_t, resource_size_t),
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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 to 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 children of
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* the new 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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for (;; parent = first) {
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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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if ((first->start > new->start) || (first->end < new->end))
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break;
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if ((first->start == new->start) && (first->end == new->end))
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break;
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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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/**
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* adjust_resource - modify a resource's start and size
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* @res: resource to modify
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* @start: new start value
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* @size: new size
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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 0 on success, -EBUSY if it can't fit.
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* Existing children of the resource are assumed to be immutable.
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*/
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int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
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{
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struct resource *tmp, *parent = res->parent;
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resource_size_t 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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/**
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* __request_region - create a new busy resource region
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* @parent: parent resource descriptor
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* @start: resource start address
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* @n: resource region size
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* @name: reserving caller's ID string
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*/
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struct resource * __request_region(struct resource *parent,
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resource_size_t start, resource_size_t n,
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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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/**
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* __check_region - check if a resource region is busy or free
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* @parent: parent resource descriptor
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* @start: resource start address
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* @n: resource region size
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|
*
|
|
* Returns 0 if the region is free at the moment it is checked,
|
|
* returns %-EBUSY if the region is busy.
|
|
*
|
|
* NOTE:
|
|
* This function is deprecated because its use is racy.
|
|
* Even if it returns 0, a subsequent call to request_region()
|
|
* may fail because another driver etc. just allocated the region.
|
|
* Do NOT use it. It will be removed from the kernel.
|
|
*/
|
|
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);
|
|
|
|
/**
|
|
* __release_region - release a previously reserved resource region
|
|
* @parent: parent resource descriptor
|
|
* @start: resource start address
|
|
* @n: resource region size
|
|
*
|
|
* The described resource region must match a currently busy 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);
|
|
|
|
/*
|
|
* Managed region resource
|
|
*/
|
|
struct region_devres {
|
|
struct resource *parent;
|
|
resource_size_t start;
|
|
resource_size_t n;
|
|
};
|
|
|
|
static void devm_region_release(struct device *dev, void *res)
|
|
{
|
|
struct region_devres *this = res;
|
|
|
|
__release_region(this->parent, this->start, this->n);
|
|
}
|
|
|
|
static int devm_region_match(struct device *dev, void *res, void *match_data)
|
|
{
|
|
struct region_devres *this = res, *match = match_data;
|
|
|
|
return this->parent == match->parent &&
|
|
this->start == match->start && this->n == match->n;
|
|
}
|
|
|
|
struct resource * __devm_request_region(struct device *dev,
|
|
struct resource *parent, resource_size_t start,
|
|
resource_size_t n, const char *name)
|
|
{
|
|
struct region_devres *dr = NULL;
|
|
struct resource *res;
|
|
|
|
dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
|
|
GFP_KERNEL);
|
|
if (!dr)
|
|
return NULL;
|
|
|
|
dr->parent = parent;
|
|
dr->start = start;
|
|
dr->n = n;
|
|
|
|
res = __request_region(parent, start, n, name);
|
|
if (res)
|
|
devres_add(dev, dr);
|
|
else
|
|
devres_free(dr);
|
|
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(__devm_request_region);
|
|
|
|
void __devm_release_region(struct device *dev, struct resource *parent,
|
|
resource_size_t start, resource_size_t n)
|
|
{
|
|
struct region_devres match_data = { parent, start, n };
|
|
|
|
__release_region(parent, start, n);
|
|
WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
|
|
&match_data));
|
|
}
|
|
EXPORT_SYMBOL(__devm_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);
|