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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/resource.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'kernel/resource.c')
-rw-r--r--kernel/resource.c551
1 files changed, 551 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
new file mode 100644
index 000000000000..35c99ac02c7c
--- /dev/null
+++ b/kernel/resource.c
@@ -0,0 +1,551 @@
+/*
+ * linux/kernel/resource.c
+ *
+ * Copyright (C) 1999 Linus Torvalds
+ * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
+ *
+ * Arbitrary resource management.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/sched.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 <asm/io.h>
+
+
+struct resource ioport_resource = {
+ .name = "PCI IO",
+ .start = 0x0000,
+ .end = IO_SPACE_LIMIT,
+ .flags = IORESOURCE_IO,
+};
+
+EXPORT_SYMBOL(ioport_resource);
+
+struct resource iomem_resource = {
+ .name = "PCI mem",
+ .start = 0UL,
+ .end = ~0UL,
+ .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*lx-%0*lx : %s\n",
+ depth * 2, "",
+ width, r->start,
+ width, r->end,
+ r->name ? r->name : "<BAD>");
+ return 0;
+}
+
+static 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 struct file_operations proc_ioports_operations = {
+ .open = ioports_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static 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)
+{
+ 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;
+
+ 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;
+}
+
+EXPORT_SYMBOL(request_resource);
+
+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;
+}
+
+EXPORT_SYMBOL(____request_resource);
+
+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);
+
+/*
+ * 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 = (new->start + align - 1) & ~(align - 1);
+ if (alignf)
+ alignf(alignf_data, new, size, align);
+ if (new->start < new->end && new->end - new->start + 1 >= size) {
+ 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;
+}
+
+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 of 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 childs of
+ * the new resource. Otherwise the new resource becomes the child of
+ * the conflicting resource
+ */
+int insert_resource(struct resource *parent, struct resource *new)
+{
+ int result;
+ struct resource *first, *next;
+
+ write_lock(&resource_lock);
+ begin:
+ result = 0;
+ first = __request_resource(parent, new);
+ if (!first)
+ goto out;
+
+ result = -EBUSY;
+ if (first == parent)
+ goto out;
+
+ /* Resource fully contained by the clashing resource? Recurse into it */
+ if (first->start <= new->start && first->end >= new->end) {
+ parent = first;
+ goto begin;
+ }
+
+ 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;
+}
+
+EXPORT_SYMBOL(insert_resource);
+
+/*
+ * 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;
+}
+
+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.
+ */
+struct resource * __request_region(struct resource *parent, unsigned long start, unsigned long n, const char *name)
+{
+ struct resource *res = kmalloc(sizeof(*res), GFP_KERNEL);
+
+ if (res) {
+ memset(res, 0, sizeof(*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);
+
+int __deprecated __check_region(struct resource *parent, unsigned long start, unsigned long 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);
+
+void __release_region(struct resource *parent, unsigned long start, unsigned long n)
+{
+ struct resource **p;
+ unsigned long 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 <%08lx-%08lx>\n", start, end);
+}
+
+EXPORT_SYMBOL(__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);