Initial commit

kernel/resource.c

@@ -0,0 +1,715 @@
+/*
+ *	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 <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 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)
+{
+	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;
+}
+
+/**
+ * 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;
+}
+int
+walk_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_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)
+{
+	int result;
+	struct resource *first, *next;
+
+	write_lock(&resource_lock);
+
+	for (;; parent = first) {
+	 	result = 0;
+		first = __request_resource(parent, new);
+		if (!first)
+			goto out;
+
+		result = -EBUSY;
+		if (first == parent)
+			goto out;
+
+		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)
+			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;
+}
+
+/**
+ * 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))
+		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.
+ */
+
+/**
+ * __request_region - create a new busy resource region
+ * @parent: parent resource descriptor
+ * @start: resource start address
+ * @n: resource region size
+ * @name: reserving caller's ID string
+ */
+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);
+
+/**
+ * __check_region - check if a resource region is busy or free
+ * @parent: parent resource descriptor
+ * @start: resource start address
+ * @n: resource region size
+ *
+ * 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);