--- /dev/null
+/*
+ * linux/kernel/resource.c
+ *
+ * Copyright (C) 1999 Linus Torvalds
+ * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
+ *
+ * Arbitrary resource management.
+ */
+
+#include <lwk/errno.h>
+#include <lwk/resource.h>
+#include <lwk/init.h>
+#include <lwk/spinlock.h>
+#include <arch/io.h>
+
+struct resource ioport_resource = {
+ .name = "PCI IO",
+ .start = 0x0000,
+ .end = IO_SPACE_LIMIT,
+ .flags = IORESOURCE_IO,
+};
+
+struct resource iomem_resource = {
+ .name = "PCI mem",
+ .start = 0UL,
+ .end = ~0UL,
+ .flags = IORESOURCE_MEM,
+};
+
+static DEFINE_RWLOCK(resource_lock);
+
+/* Return the conflict entry if you can't request it */
+static struct resource * __request_resource(struct resource *root, struct resource *new)
+{
+ unsigned long start = new->start;
+ unsigned long 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;
+
+ BUG_ON(old->child);
+
+ p = &old->parent->child;
+ for (;;) {
+ tmp = *p;
+ if (!tmp)
+ break;
+ if (tmp == old) {
+ *p = tmp->sibling;
+ old->parent = NULL;
+ return 0;
+ }
+ p = &tmp->sibling;
+ }
+ return -EINVAL;
+}
+
+int request_resource(struct resource *root, struct resource *new)
+{
+ struct resource *conflict;
+
+ write_lock(&resource_lock);
+ conflict = __request_resource(root, new);
+ write_unlock(&resource_lock);
+ return conflict ? -EBUSY : 0;
+}
+
+struct resource *____request_resource(struct resource *root, struct resource *new)
+{
+ struct resource *conflict;
+
+ write_lock(&resource_lock);
+ conflict = __request_resource(root, new);
+ write_unlock(&resource_lock);
+ return conflict;
+}
+
+int release_resource(struct resource *old)
+{
+ int retval;
+
+ write_lock(&resource_lock);
+ retval = __release_resource(old);
+ write_unlock(&resource_lock);
+ return retval;
+}
+
+/*
+ * Find empty slot in the resource tree given range and alignment.
+ */
+static int find_resource(struct resource *root, struct resource *new,
+ unsigned long size,
+ unsigned long min, unsigned long max,
+ unsigned long align,
+ void (*alignf)(void *, struct resource *,
+ unsigned long, unsigned long),
+ void *alignf_data)
+{
+ struct resource *this = root->child;
+
+ new->start = root->start;
+ /*
+ * Skip past an allocated resource that starts at 0, since the assignment
+ * of this->start - 1 to new->end below would cause an underflow.
+ */
+ if (this && this->start == 0) {
+ new->start = this->end + 1;
+ this = this->sibling;
+ }
+ for(;;) {
+ if (this)
+ new->end = this->start - 1;
+ else
+ new->end = root->end;
+ if (new->start < min)
+ new->start = min;
+ if (new->end > max)
+ new->end = max;
+ new->start = ALIGN(new->start, align);
+ if (alignf)
+ alignf(alignf_data, new, size, align);
+ if (new->start < new->end && new->end - new->start >= size - 1) {
+ new->end = new->start + size - 1;
+ return 0;
+ }
+ if (!this)
+ break;
+ new->start = this->end + 1;
+ this = this->sibling;
+ }
+ return -EBUSY;
+}
+
+/*
+ * Allocate empty slot in the resource tree given range and alignment.
+ */
+int allocate_resource(struct resource *root, struct resource *new,
+ unsigned long size,
+ unsigned long min, unsigned long max,
+ unsigned long align,
+ void (*alignf)(void *, struct resource *,
+ unsigned long, unsigned long),
+ 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;
+}
+
+/**
+ * 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;
+}
+
+/*
+ * Given an existing resource, change its start and size to match the
+ * arguments. Returns -EBUSY if it can't fit. Existing children of
+ * the resource are assumed to be immutable.
+ */
+int adjust_resource(struct resource *res, unsigned long start, unsigned long size)
+{
+ struct resource *tmp, *parent = res->parent;
+ unsigned long 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;
+}
+
