Commit ff3cc952 authored by Toshi Kani's avatar Toshi Kani Committed by Dan Williams
Browse files

resource: Add remove_resource interface 



insert_resource() and insert_resource_conflict() are called
by resource producers to insert a new resource.  When there
is any conflict, they move conflicting resources down to the
children of the new resource.  There is no destructor of these
interfaces, however.

Add remove_resource(), which removes a resource previously
inserted by insert_resource() or insert_resource_conflict(),
and moves the children up to where they were before.

__release_resource() is changed to have @release_child, so
that this function can be used for remove_resource() as well.

Also add comments to clarify that these functions are intended
for producers of resources to avoid any confusion with
request/release_resource() for consumers.

Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 4e0d8f7e

include/linux/ioport.h

+1 −0
Original line number Diff line number Diff line
@@ -174,6 +174,7 @@ extern void reserve_region_with_split(struct resource *root, 
extern struct resource *insert_resource_conflict(struct resource *parent, struct resource *new);

extern int insert_resource(struct resource *parent, struct resource *new);

extern void insert_resource_expand_to_fit(struct resource *root, struct resource *new);

extern int remove_resource(struct resource *old);

extern void arch_remove_reservations(struct resource *avail);

extern int allocate_resource(struct resource *root, struct resource *new,

			     resource_size_t size, resource_size_t min,

kernel/resource.c

+46 −5
Original line number Diff line number Diff line
@@ -233,9 +233,9 @@ static struct resource * __request_resource(struct resource *root, struct resour 
	}

}



static int __release_resource(struct resource *old)

static int __release_resource(struct resource *old, bool release_child)

{

	struct resource *tmp, **p;

	struct resource *tmp, **p, *chd;



	p = &old->parent->child;

	for (;;) {
@@ -243,7 +243,17 @@ static int __release_resource(struct resource *old) 
		if (!tmp)

			break;

		if (tmp == old) {

			if (release_child || !(tmp->child)) {

				*p = tmp->sibling;

			} else {

				for (chd = tmp->child;; chd = chd->sibling) {

					chd->parent = tmp->parent;

					if (!(chd->sibling))

						break;

				}

				*p = tmp->child;

				chd->sibling = tmp->sibling;

			}

			old->parent = NULL;

			return 0;

		}
@@ -325,7 +335,7 @@ int release_resource(struct resource *old) 
	int retval;



	write_lock(&resource_lock);

	retval = __release_resource(old);

	retval = __release_resource(old, true);

	write_unlock(&resource_lock);

	return retval;

}
@@ -679,7 +689,7 @@ static int reallocate_resource(struct resource *root, struct resource *old, 
		old->start = new.start;

		old->end = new.end;

	} else {

		__release_resource(old);

		__release_resource(old, true);

		*old = new;

		conflict = __request_resource(root, old);

		BUG_ON(conflict);
@@ -825,6 +835,9 @@ static struct resource * __insert_resource(struct resource *parent, struct resou 
 * 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.

 *

 * This function is intended for producers of resources, such as FW modules

 * and bus drivers.

 */

struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)

{
@@ -842,6 +855,9 @@ struct resource *insert_resource_conflict(struct resource *parent, struct resour 
 * @new: new resource to insert

 *

 * Returns 0 on success, -EBUSY if the resource can't be inserted.

 *

 * This function is intended for producers of resources, such as FW modules

 * and bus drivers.

 */

int insert_resource(struct resource *parent, struct resource *new)

{
@@ -885,6 +901,31 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new) 
	write_unlock(&resource_lock);

}



/**

 * remove_resource - Remove a resource in the resource tree

 * @old: resource to remove

 *

 * Returns 0 on success, -EINVAL if the resource is not valid.

 *

 * This function removes a resource previously inserted by insert_resource()

 * or insert_resource_conflict(), and moves the children (if any) up to

 * where they were before.  insert_resource() and insert_resource_conflict()

 * insert a new resource, and move any conflicting resources down to the

 * children of the new resource.

 *

 * insert_resource(), insert_resource_conflict() and remove_resource() are

 * intended for producers of resources, such as FW modules and bus drivers.

 */

int remove_resource(struct resource *old)

{

	int retval;



	write_lock(&resource_lock);

	retval = __release_resource(old, false);

	write_unlock(&resource_lock);

	return retval;

}



static int __adjust_resource(struct resource *res, resource_size_t start,

				resource_size_t size)

{

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