* Arbitrary resource management.
*/
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/init.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>
};
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)
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 - request and reserve an I/O or memory resource
+ * 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, negative error code on error.
+ * Returns 0 for success, conflict resource on error.
*/
-int request_resource(struct resource *root, struct resource *new)
+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;
}
void *arg, int (*func)(unsigned long, unsigned long, void *))
{
struct resource res;
- unsigned long pfn, len;
+ unsigned long pfn, end_pfn;
u64 orig_end;
int ret = -1;
orig_end = res.end;
while ((res.start < res.end) &&
(find_next_system_ram(&res, "System RAM") >= 0)) {
- pfn = (unsigned long)(res.start >> PAGE_SHIFT);
- len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
- ret = (*func)(pfn, len, arg);
+ 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;
#endif
+static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
+{
+ return 1;
+}
/*
- * Find empty slot in the resource tree given range and alignment.
+ * This generic page_is_ram() returns true if specified address is
+ * registered as "System RAM" in iomem_resource list.
*/
-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)
+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;
+ 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 == 0) {
- tmp.start = this->end + 1;
+ if (this && this->start == root->start) {
+ tmp.start = (this == old) ? old->start : this->end + 1;
this = this->sibling;
}
for(;;) {
if (this)
- tmp.end = this->start - 1;
+ tmp.end = (this == old) ? this->end : this->start - 1;
else
tmp.end = root->end;
- if (tmp.start < min)
- tmp.start = min;
- if (tmp.end > max)
- tmp.end = max;
- tmp.start = ALIGN(tmp.start, align);
- if (alignf)
- alignf(alignf_data, &tmp, size, align);
- if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
- new->start = tmp.start;
- new->end = tmp.start + size - 1;
- return 0;
+
+ if (tmp.end < tmp.start)
+ goto next;
+
+ 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)
+
+next: if (!this || this->end == root->end)
break;
- tmp.start = this->end + 1;
+
+ 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
+ * 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
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),
+ 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, min, max, align, alignf, alignf_data);
+ err = find_resource(root, new, size, &constraint);
if (err >= 0 && __request_resource(root, new))
err = -EBUSY;
write_unlock(&resource_lock);
EXPORT_SYMBOL(allocate_resource);
+/**
+ * lookup_resource - find an existing resource by a resource start address
+ * @root: root resource descriptor
+ * @start: resource start address
+ *
+ * Returns a pointer to the resource if found, NULL otherwise
+ */
+struct resource *lookup_resource(struct resource *root, resource_size_t start)
+{
+ struct resource *res;
+
+ read_lock(&resource_lock);
+ for (res = root->child; res; res = res->sibling) {
+ if (res->start == start)
+ break;
+ }
+ read_unlock(&resource_lock);
+
+ return res;
+}
+
/*
* Insert a resource into the resource tree. If successful, return NULL,
* otherwise return the conflicting resource (compare to __request_resource())
if (first == parent)
return first;
+ if (WARN_ON(first == new)) /* duplicated insertion */
+ return first;
if ((first->start > new->start) || (first->end < new->end))
break;
}
/**
- * insert_resource - Inserts a resource in the resource tree
+ * insert_resource_conflict - Inserts 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.
+ * Returns 0 on success, conflict resource if the resource can't be inserted.
*
- * This function is equivalent to request_resource when no conflict
+ * 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.
*/
-int insert_resource(struct resource *parent, struct resource *new)
+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;
}
* 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
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)
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;
*p = res->sibling;
write_unlock(&resource_lock);
+ if (res->flags & IORESOURCE_MUXED)
+ wake_up(&muxed_resource_wait);
kfree(res);
return;
}
projects / linux-flexiantxendom0-3.2.10.git / blobdiff