From ff3cc952d3f009e6c376cc40651b87187ce364a6 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Wed, 9 Mar 2016 12:47:04 -0700 Subject: [PATCH] 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: Toshi Kani Cc: Ingo Molnar Cc: Borislav Petkov Cc: Andrew Morton Cc: Dan Williams Signed-off-by: Dan Williams --- include/linux/ioport.h | 1 + kernel/resource.c | 51 +++++++++++++++++++++++++++++++++++++----- 2 files changed, 47 insertions(+), 5 deletions(-) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index afb45597fb5f..8017b8bf45fa 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -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, diff --git a/kernel/resource.c b/kernel/resource.c index 5a56e8f24058..effb6ee2c3e8 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -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) { - *p = tmp->sibling; + 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) { -- 2.20.1