mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 22:16:39 +07:00
c3bb7fadaf
Finally clean up the odd spacing in these files. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
285 lines
7.5 KiB
C
285 lines
7.5 KiB
C
/*
|
|
* klist.c - Routines for manipulating klists.
|
|
*
|
|
* Copyright (C) 2005 Patrick Mochel
|
|
*
|
|
* This file is released under the GPL v2.
|
|
*
|
|
* This klist interface provides a couple of structures that wrap around
|
|
* struct list_head to provide explicit list "head" (struct klist) and list
|
|
* "node" (struct klist_node) objects. For struct klist, a spinlock is
|
|
* included that protects access to the actual list itself. struct
|
|
* klist_node provides a pointer to the klist that owns it and a kref
|
|
* reference count that indicates the number of current users of that node
|
|
* in the list.
|
|
*
|
|
* The entire point is to provide an interface for iterating over a list
|
|
* that is safe and allows for modification of the list during the
|
|
* iteration (e.g. insertion and removal), including modification of the
|
|
* current node on the list.
|
|
*
|
|
* It works using a 3rd object type - struct klist_iter - that is declared
|
|
* and initialized before an iteration. klist_next() is used to acquire the
|
|
* next element in the list. It returns NULL if there are no more items.
|
|
* Internally, that routine takes the klist's lock, decrements the
|
|
* reference count of the previous klist_node and increments the count of
|
|
* the next klist_node. It then drops the lock and returns.
|
|
*
|
|
* There are primitives for adding and removing nodes to/from a klist.
|
|
* When deleting, klist_del() will simply decrement the reference count.
|
|
* Only when the count goes to 0 is the node removed from the list.
|
|
* klist_remove() will try to delete the node from the list and block until
|
|
* it is actually removed. This is useful for objects (like devices) that
|
|
* have been removed from the system and must be freed (but must wait until
|
|
* all accessors have finished).
|
|
*/
|
|
|
|
#include <linux/klist.h>
|
|
#include <linux/module.h>
|
|
|
|
|
|
/**
|
|
* klist_init - Initialize a klist structure.
|
|
* @k: The klist we're initializing.
|
|
* @get: The get function for the embedding object (NULL if none)
|
|
* @put: The put function for the embedding object (NULL if none)
|
|
*
|
|
* Initialises the klist structure. If the klist_node structures are
|
|
* going to be embedded in refcounted objects (necessary for safe
|
|
* deletion) then the get/put arguments are used to initialise
|
|
* functions that take and release references on the embedding
|
|
* objects.
|
|
*/
|
|
void klist_init(struct klist *k, void (*get)(struct klist_node *),
|
|
void (*put)(struct klist_node *))
|
|
{
|
|
INIT_LIST_HEAD(&k->k_list);
|
|
spin_lock_init(&k->k_lock);
|
|
k->get = get;
|
|
k->put = put;
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_init);
|
|
|
|
static void add_head(struct klist *k, struct klist_node *n)
|
|
{
|
|
spin_lock(&k->k_lock);
|
|
list_add(&n->n_node, &k->k_list);
|
|
spin_unlock(&k->k_lock);
|
|
}
|
|
|
|
static void add_tail(struct klist *k, struct klist_node *n)
|
|
{
|
|
spin_lock(&k->k_lock);
|
|
list_add_tail(&n->n_node, &k->k_list);
|
|
spin_unlock(&k->k_lock);
|
|
}
|
|
|
|
static void klist_node_init(struct klist *k, struct klist_node *n)
|
|
{
|
|
INIT_LIST_HEAD(&n->n_node);
|
|
init_completion(&n->n_removed);
|
|
kref_init(&n->n_ref);
|
|
n->n_klist = k;
|
|
if (k->get)
|
|
k->get(n);
|
|
}
|
|
|
|
/**
|
|
* klist_add_head - Initialize a klist_node and add it to front.
|
|
* @n: node we're adding.
|
|
* @k: klist it's going on.
|
|
*/
|
|
void klist_add_head(struct klist_node *n, struct klist *k)
|
|
{
|
|
klist_node_init(k, n);
|
|
add_head(k, n);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_add_head);
|
|
|
|
/**
|
|
* klist_add_tail - Initialize a klist_node and add it to back.
|
|
* @n: node we're adding.
|
|
* @k: klist it's going on.
|
|
*/
|
|
void klist_add_tail(struct klist_node *n, struct klist *k)
|
|
{
|
|
klist_node_init(k, n);
|
|
add_tail(k, n);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_add_tail);
|
|
|
|
/**
|
|
* klist_add_after - Init a klist_node and add it after an existing node
|
|
* @n: node we're adding.
|
|
* @pos: node to put @n after
|
|
*/
|
|
void klist_add_after(struct klist_node *n, struct klist_node *pos)
|
|
{
|
|
struct klist *k = pos->n_klist;
|
|
|
|
klist_node_init(k, n);
|
|
spin_lock(&k->k_lock);
|
|
list_add(&n->n_node, &pos->n_node);
|
|
spin_unlock(&k->k_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_add_after);
|
|
|
|
/**
|
|
* klist_add_before - Init a klist_node and add it before an existing node
|
|
* @n: node we're adding.
|
|
* @pos: node to put @n after
|
|
*/
|
|
void klist_add_before(struct klist_node *n, struct klist_node *pos)
|
|
{
|
|
struct klist *k = pos->n_klist;
|
|
|
|
klist_node_init(k, n);
|
|
spin_lock(&k->k_lock);
|
|
list_add_tail(&n->n_node, &pos->n_node);
|
|
spin_unlock(&k->k_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_add_before);
|
|
|
|
static void klist_release(struct kref *kref)
|
|
{
|
|
struct klist_node *n = container_of(kref, struct klist_node, n_ref);
|
|
|
|
list_del(&n->n_node);
|
|
complete(&n->n_removed);
|
|
n->n_klist = NULL;
|
|
}
|
|
|
|
static int klist_dec_and_del(struct klist_node *n)
|
|
{
|
|
return kref_put(&n->n_ref, klist_release);
|
|
}
|
|
|
|
/**
|
|
* klist_del - Decrement the reference count of node and try to remove.
|
|
* @n: node we're deleting.
|
|
*/
|
|
void klist_del(struct klist_node *n)
|
|
{
|
|
struct klist *k = n->n_klist;
|
|
void (*put)(struct klist_node *) = k->put;
|
|
|
|
spin_lock(&k->k_lock);
|
|
if (!klist_dec_and_del(n))
|
|
put = NULL;
|
|
spin_unlock(&k->k_lock);
|
|
if (put)
|
|
put(n);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_del);
|
|
|
|
/**
|
|
* klist_remove - Decrement the refcount of node and wait for it to go away.
|
|
* @n: node we're removing.
|
|
*/
|
|
void klist_remove(struct klist_node *n)
|
|
{
|
|
klist_del(n);
|
|
wait_for_completion(&n->n_removed);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_remove);
|
|
|
|
/**
|
|
* klist_node_attached - Say whether a node is bound to a list or not.
|
|
* @n: Node that we're testing.
|
|
*/
|
|
int klist_node_attached(struct klist_node *n)
|
|
{
|
|
return (n->n_klist != NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_node_attached);
|
|
|
|
/**
|
|
* klist_iter_init_node - Initialize a klist_iter structure.
|
|
* @k: klist we're iterating.
|
|
* @i: klist_iter we're filling.
|
|
* @n: node to start with.
|
|
*
|
|
* Similar to klist_iter_init(), but starts the action off with @n,
|
|
* instead of with the list head.
|
|
*/
|
|
void klist_iter_init_node(struct klist *k, struct klist_iter *i,
|
|
struct klist_node *n)
|
|
{
|
|
i->i_klist = k;
|
|
i->i_head = &k->k_list;
|
|
i->i_cur = n;
|
|
if (n)
|
|
kref_get(&n->n_ref);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_iter_init_node);
|
|
|
|
/**
|
|
* klist_iter_init - Iniitalize a klist_iter structure.
|
|
* @k: klist we're iterating.
|
|
* @i: klist_iter structure we're filling.
|
|
*
|
|
* Similar to klist_iter_init_node(), but start with the list head.
|
|
*/
|
|
void klist_iter_init(struct klist *k, struct klist_iter *i)
|
|
{
|
|
klist_iter_init_node(k, i, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_iter_init);
|
|
|
|
/**
|
|
* klist_iter_exit - Finish a list iteration.
|
|
* @i: Iterator structure.
|
|
*
|
|
* Must be called when done iterating over list, as it decrements the
|
|
* refcount of the current node. Necessary in case iteration exited before
|
|
* the end of the list was reached, and always good form.
|
|
*/
|
|
void klist_iter_exit(struct klist_iter *i)
|
|
{
|
|
if (i->i_cur) {
|
|
klist_del(i->i_cur);
|
|
i->i_cur = NULL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_iter_exit);
|
|
|
|
static struct klist_node *to_klist_node(struct list_head *n)
|
|
{
|
|
return container_of(n, struct klist_node, n_node);
|
|
}
|
|
|
|
/**
|
|
* klist_next - Ante up next node in list.
|
|
* @i: Iterator structure.
|
|
*
|
|
* First grab list lock. Decrement the reference count of the previous
|
|
* node, if there was one. Grab the next node, increment its reference
|
|
* count, drop the lock, and return that next node.
|
|
*/
|
|
struct klist_node *klist_next(struct klist_iter *i)
|
|
{
|
|
struct list_head *next;
|
|
struct klist_node *lnode = i->i_cur;
|
|
struct klist_node *knode = NULL;
|
|
void (*put)(struct klist_node *) = i->i_klist->put;
|
|
|
|
spin_lock(&i->i_klist->k_lock);
|
|
if (lnode) {
|
|
next = lnode->n_node.next;
|
|
if (!klist_dec_and_del(lnode))
|
|
put = NULL;
|
|
} else
|
|
next = i->i_head->next;
|
|
|
|
if (next != i->i_head) {
|
|
knode = to_klist_node(next);
|
|
kref_get(&knode->n_ref);
|
|
}
|
|
i->i_cur = knode;
|
|
spin_unlock(&i->i_klist->k_lock);
|
|
if (put && lnode)
|
|
put(lnode);
|
|
return knode;
|
|
}
|
|
EXPORT_SYMBOL_GPL(klist_next);
|