aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/resource.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/resource.c')
-rw-r--r--kernel/resource.c1132
1 files changed, 1132 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
new file mode 100644
index 00000000..3ff40178
--- /dev/null
+++ b/kernel/resource.c
@@ -0,0 +1,1132 @@
+/*
+ * 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/sched.h>
+#include <linux/seq_file.h>
+#include <linux/device.h>
+#include <linux/pfn.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);
+
+/* constraints to be met while allocating resources */
+struct resource_constraint {
+ resource_size_t min, max, align;
+ resource_size_t (*alignf)(void *, const struct resource *,
+ resource_size_t, resource_size_t);
+ void *alignf_data;
+};
+
+static DEFINE_RWLOCK(resource_lock);
+
+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;
+}
+
+#ifdef CONFIG_PROC_FS
+
+enum { MAX_IORES_LEVEL = 5 };
+
+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)
+{
+ proc_create("ioports", 0, NULL, &proc_ioports_operations);
+ proc_create("iomem", 0, NULL, &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;
+}
+
+static void __release_child_resources(struct resource *r)
+{
+ struct resource *tmp, *p;
+ resource_size_t size;
+
+ p = r->child;
+ r->child = NULL;
+ while (p) {
+ tmp = p;
+ p = p->sibling;
+
+ tmp->parent = NULL;
+ tmp->sibling = NULL;
+ __release_child_resources(tmp);
+
+ printk(KERN_DEBUG "release child resource %pR\n", tmp);
+ /* need to restore size, and keep flags */
+ size = resource_size(tmp);
+ tmp->start = 0;
+ tmp->end = size - 1;
+ }
+}
+
+void release_child_resources(struct resource *r)
+{
+ write_lock(&resource_lock);
+ __release_child_resources(r);
+ write_unlock(&resource_lock);
+}
+
+/**
+ * request_resource_conflict - request and reserve an I/O or memory resource
+ * @root: root resource descriptor
+ * @new: resource descriptor desired by caller
+ *
+ * Returns 0 for success, conflict resource on error.
+ */
+struct resource *request_resource_conflict(struct resource *root, struct resource *new)
+{
+ struct resource *conflict;
+
+ write_lock(&resource_lock);
+ conflict = __request_resource(root, new);
+ write_unlock(&resource_lock);
+ return conflict;
+}
+
+/**
+ * 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;
+
+ conflict = request_resource_conflict(root, new);
+ 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_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 and "name".
+ * If found, returns 0, res is overwritten, if not found, returns -1.
+ */
+static int find_next_system_ram(struct resource *res, char *name)
+{
+ 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 (name && strcmp(p->name, name))
+ 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;
+}
+
+/*
+ * This function calls callback against all memory range of "System RAM"
+ * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
+ * Now, this function is only for "System RAM".
+ */
+int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg, int (*func)(unsigned long, unsigned long, void *))
+{
+ struct resource res;
+ unsigned long pfn, end_pfn;
+ 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, "System RAM") >= 0)) {
+ pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ end_pfn = (res.end + 1) >> PAGE_SHIFT;
+ if (end_pfn > pfn)
+ ret = (*func)(pfn, end_pfn - pfn, arg);
+ if (ret)
+ break;
+ res.start = res.end + 1;
+ res.end = orig_end;
+ }
+ return ret;
+}
+
+#endif
+
+static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
+{
+ return 1;
+}
+/*
+ * This generic page_is_ram() returns true if specified address is
+ * registered as "System RAM" in iomem_resource list.
+ */
+int __weak page_is_ram(unsigned long pfn)
+{
+ return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
+}
+
+void __weak arch_remove_reservations(struct resource *avail)
+{
+}
+
+static resource_size_t simple_align_resource(void *data,
+ const struct resource *avail,
+ resource_size_t size,
+ resource_size_t align)
+{
+ return avail->start;
+}
+
+static void resource_clip(struct resource *res, resource_size_t min,
+ resource_size_t max)
+{
+ if (res->start < min)
+ res->start = min;
+ if (res->end > max)
+ res->end = max;
+}
+
+static bool resource_contains(struct resource *res1, struct resource *res2)
+{
+ return res1->start <= res2->start && res1->end >= res2->end;
+}
+
+/*
+ * Find empty slot in the resource tree with the given range and
+ * alignment constraints
+ */
+static int __find_resource(struct resource *root, struct resource *old,
+ struct resource *new,
+ resource_size_t size,
+ struct resource_constraint *constraint)
+{
+ struct resource *this = root->child;
+ struct resource tmp = *new, avail, alloc;
+
+ tmp.flags = new->flags;
+ tmp.start = root->start;
+ /*
+ * Skip past an allocated resource that starts at 0, since the assignment
+ * of this->start - 1 to tmp->end below would cause an underflow.
+ */
+ if (this && this->start == root->start) {
+ tmp.start = (this == old) ? old->start : this->end + 1;
+ this = this->sibling;
+ }
+ for(;;) {
+ if (this)
+ tmp.end = (this == old) ? this->end : this->start - 1;
+ else
+ tmp.end = root->end;
+
+ resource_clip(&tmp, constraint->min, constraint->max);
+ arch_remove_reservations(&tmp);
+
+ /* Check for overflow after ALIGN() */
+ avail = *new;
+ avail.start = ALIGN(tmp.start, constraint->align);
+ avail.end = tmp.end;
+ if (avail.start >= tmp.start) {
+ alloc.start = constraint->alignf(constraint->alignf_data, &avail,
+ size, constraint->align);
+ alloc.end = alloc.start + size - 1;
+ if (resource_contains(&avail, &alloc)) {
+ new->start = alloc.start;
+ new->end = alloc.end;
+ return 0;
+ }
+ }
+ if (!this)
+ break;
+ if (this != old)
+ tmp.start = this->end + 1;
+ this = this->sibling;
+ }
+ return -EBUSY;
+}
+
+/*
+ * 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,
+ struct resource_constraint *constraint)
+{
+ return __find_resource(root, NULL, new, size, constraint);
+}
+
+/**
+ * reallocate_resource - allocate a slot in the resource tree given range & alignment.
+ * The resource will be relocated if the new size cannot be reallocated in the
+ * current location.
+ *
+ * @root: root resource descriptor
+ * @old: resource descriptor desired by caller
+ * @newsize: new size of the resource descriptor
+ * @constraint: the size and alignment constraints to be met.
+ */
+int reallocate_resource(struct resource *root, struct resource *old,
+ resource_size_t newsize,
+ struct resource_constraint *constraint)
+{
+ int err=0;
+ struct resource new = *old;
+ struct resource *conflict;
+
+ write_lock(&resource_lock);
+
+ if ((err = __find_resource(root, old, &new, newsize, constraint)))
+ goto out;
+
+ if (resource_contains(&new, old)) {
+ old->start = new.start;
+ old->end = new.end;
+ goto out;
+ }
+
+ if (old->child) {
+ err = -EBUSY;
+ goto out;
+ }
+
+ if (resource_contains(old, &new)) {
+ old->start = new.start;
+ old->end = new.end;
+ } else {
+ __release_resource(old);
+ *old = new;
+ conflict = __request_resource(root, old);
+ BUG_ON(conflict);
+ }
+out:
+ write_unlock(&resource_lock);
+ return err;
+}
+
+
+/**
+ * allocate_resource - allocate empty slot in the resource tree given range & alignment.
+ * The resource will be reallocated with a new size if it was already allocated
+ * @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,
+ resource_size_t (*alignf)(void *,
+ const struct resource *,
+ resource_size_t,
+ resource_size_t),
+ void *alignf_data)
+{
+ int err;
+ struct resource_constraint constraint;
+
+ if (!alignf)
+ alignf = simple_align_resource;
+
+ constraint.min = min;
+ constraint.max = max;
+ constraint.align = align;
+ constraint.alignf = alignf;
+ constraint.alignf_data = alignf_data;
+
+ if ( new->parent ) {
+ /* resource is already allocated, try reallocating with
+ the new constraints */
+ return reallocate_resource(root, new, size, &constraint);
+ }
+
+ write_lock(&resource_lock);
+ err = find_resource(root, new, size, &constraint);
+ if (err >= 0 && __request_resource(root, new))
+ err = -EBUSY;
+ write_unlock(&resource_lock);
+ return err;
+}
+
+EXPORT_SYMBOL(allocate_resource);
+
+/*
+ * Insert a resource into the resource tree. If successful, return NULL,
+ * otherwise return the conflicting resource (compare to __request_resource())
+ */
+static struct resource * __insert_resource(struct resource *parent, struct resource *new)
+{
+ struct resource *first, *next;
+
+ for (;; parent = first) {
+ first = __request_resource(parent, new);
+ if (!first)
+ return first;
+
+ if (first == parent)
+ return first;
+ if (WARN_ON(first == new)) /* duplicated insertion */
+ return first;
+
+ 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)
+ return next;
+ if (!next->sibling)
+ break;
+ if (next->sibling->start > new->end)
+ break;
+ }
+
+ 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;
+ }
+ return NULL;
+}
+
+/**
+ * insert_resource_conflict - Inserts resource in the resource tree
+ * @parent: parent of the new resource
+ * @new: new resource to insert
+ *
+ * Returns 0 on success, conflict resource if the resource can't be inserted.
+ *
+ * This function is equivalent to request_resource_conflict 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.
+ */
+struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
+{
+ struct resource *conflict;
+
+ write_lock(&resource_lock);
+ conflict = __insert_resource(parent, new);
+ write_unlock(&resource_lock);
+ return conflict;
+}
+
+/**
+ * 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.
+ */
+int insert_resource(struct resource *parent, struct resource *new)
+{
+ struct resource *conflict;
+
+ conflict = insert_resource_conflict(parent, new);
+ return conflict ? -EBUSY : 0;
+}
+
+/**
+ * insert_resource_expand_to_fit - Insert a resource into the resource tree
+ * @root: root resource descriptor
+ * @new: new resource to insert
+ *
+ * Insert a resource into the resource tree, possibly expanding it in order
+ * to make it encompass any conflicting resources.
+ */
+void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
+{
+ if (new->parent)
+ return;
+
+ write_lock(&resource_lock);
+ for (;;) {
+ struct resource *conflict;
+
+ conflict = __insert_resource(root, new);
+ if (!conflict)
+ break;
+ if (conflict == root)
+ break;
+
+ /* Ok, expand resource to cover the conflict, then try again .. */
+ if (conflict->start < new->start)
+ new->start = conflict->start;
+ if (conflict->end > new->end)
+ new->end = conflict->end;
+
+ printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
+ }
+ write_unlock(&resource_lock);
+}
+
+/**
+ * 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;
+}
+
+static void __init __reserve_region_with_split(struct resource *root,
+ resource_size_t start, resource_size_t end,
+ const char *name)
+{
+ struct resource *parent = root;
+ struct resource *conflict;
+ struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
+
+ if (!res)
+ return;
+
+ res->name = name;
+ res->start = start;
+ res->end = end;
+ res->flags = IORESOURCE_BUSY;
+
+ conflict = __request_resource(parent, res);
+ if (!conflict)
+ return;
+
+ /* failed, split and try again */
+ kfree(res);
+
+ /* conflict covered whole area */
+ if (conflict->start <= start && conflict->end >= end)
+ return;
+
+ if (conflict->start > start)
+ __reserve_region_with_split(root, start, conflict->start-1, name);
+ if (conflict->end < end)
+ __reserve_region_with_split(root, conflict->end+1, end, name);
+}
+
+void __init reserve_region_with_split(struct resource *root,
+ resource_size_t start, resource_size_t end,
+ const char *name)
+{
+ write_lock(&resource_lock);
+ __reserve_region_with_split(root, start, end, name);
+ write_unlock(&resource_lock);
+}
+
+EXPORT_SYMBOL(adjust_resource);
+
+/**
+ * resource_alignment - calculate resource's alignment
+ * @res: resource pointer
+ *
+ * Returns alignment on success, 0 (invalid alignment) on failure.
+ */
+resource_size_t resource_alignment(struct resource *res)
+{
+ switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
+ case IORESOURCE_SIZEALIGN:
+ return resource_size(res);
+ case IORESOURCE_STARTALIGN:
+ return res->start;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * 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.
+ */
+
+static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
+
+/**
+ * __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
+ * @flags: IO resource flags
+ */
+struct resource * __request_region(struct resource *parent,
+ resource_size_t start, resource_size_t n,
+ const char *name, int flags)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
+
+ if (!res)
+ return NULL;
+
+ res->name = name;
+ res->start = start;
+ res->end = start + n - 1;
+ res->flags = IORESOURCE_BUSY;
+ res->flags |= flags;
+
+ 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;
+ }
+ if (conflict->flags & flags & IORESOURCE_MUXED) {
+ add_wait_queue(&muxed_resource_wait, &wait);
+ write_unlock(&resource_lock);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule();
+ remove_wait_queue(&muxed_resource_wait, &wait);
+ write_lock(&resource_lock);
+ 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", 0);
+ 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);
+ if (res->flags & IORESOURCE_MUXED)
+ wake_up(&muxed_resource_wait);
+ 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, 0);
+ 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 (;;) {
+ unsigned 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);
+
+/*
+ * Check if the requested addr and size spans more than any slot in the
+ * iomem resource tree.
+ */
+int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
+{
+ struct resource *p = &iomem_resource;
+ int err = 0;
+ loff_t l;
+
+ read_lock(&resource_lock);
+ for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+ /*
+ * We can probably skip the resources without
+ * IORESOURCE_IO attribute?
+ */
+ if (p->start >= addr + size)
+ continue;
+ if (p->end < addr)
+ continue;
+ if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
+ PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
+ continue;
+ /*
+ * if a resource is "BUSY", it's not a hardware resource
+ * but a driver mapping of such a resource; we don't want
+ * to warn for those; some drivers legitimately map only
+ * partial hardware resources. (example: vesafb)
+ */
+ if (p->flags & IORESOURCE_BUSY)
+ continue;
+
+ printk(KERN_WARNING "resource map sanity check conflict: "
+ "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
+ (unsigned long long)addr,
+ (unsigned long long)(addr + size - 1),
+ (unsigned long long)p->start,
+ (unsigned long long)p->end,
+ p->name);
+ err = -1;
+ break;
+ }
+ read_unlock(&resource_lock);
+
+ return err;
+}
+
+#ifdef CONFIG_STRICT_DEVMEM
+static int strict_iomem_checks = 1;
+#else
+static int strict_iomem_checks;
+#endif
+
+/*
+ * check if an address is reserved in the iomem resource tree
+ * returns 1 if reserved, 0 if not reserved.
+ */
+int iomem_is_exclusive(u64 addr)
+{
+ struct resource *p = &iomem_resource;
+ int err = 0;
+ loff_t l;
+ int size = PAGE_SIZE;
+
+ if (!strict_iomem_checks)
+ return 0;
+
+ addr = addr & PAGE_MASK;
+
+ read_lock(&resource_lock);
+ for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+ /*
+ * We can probably skip the resources without
+ * IORESOURCE_IO attribute?
+ */
+ if (p->start >= addr + size)
+ break;
+ if (p->end < addr)
+ continue;
+ if (p->flags & IORESOURCE_BUSY &&
+ p->flags & IORESOURCE_EXCLUSIVE) {
+ err = 1;
+ break;
+ }
+ }
+ read_unlock(&resource_lock);
+
+ return err;
+}
+
+static int __init strict_iomem(char *str)
+{
+ if (strstr(str, "relaxed"))
+ strict_iomem_checks = 0;
+ if (strstr(str, "strict"))
+ strict_iomem_checks = 1;
+ return 1;
+}
+
+__setup("iomem=", strict_iomem);
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 15:26:22 +0000