litmus-rt.git - The LITMUS^RT kernel.

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author	Linus Torvalds <torvalds@linux-foundation.org>	2010-03-14 14:15:45 -0400
committer	Linus Torvalds <torvalds@linux-foundation.org>	2010-03-14 14:15:45 -0400
commit	bca14dd14f3b0c5e3e2d1d314679f85b67871365 (patch)
tree	e2da281ecf99e9ea009c71cea947440d2b06afed /include/linux/parser.h
parent	02ca6c407e0d43e6de5d646d26d87fc2eaa7a98b (diff)
parent	2aa2b50dd62b5d0675bd7453fbeb5732dc2d7866 (diff)

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86/mce: Fix build bug with CONFIG_PROVE_LOCKING=y && CONFIG_X86_MCE_INTEL=y

Diffstat (limited to 'include/linux/parser.h')

0 files changed, 0 insertions, 0 deletions

/* * 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/export.h> #include <linux/sched.h> /* * Use the lowest bit of n_klist to mark deleted nodes and exclude * dead ones from iteration. */ #define KNODE_DEAD 1LU #define KNODE_KLIST_MASK ~KNODE_DEAD static struct klist *knode_klist(struct klist_node *knode) { return (struct klist *) ((unsigned long)knode->n_klist & KNODE_KLIST_MASK); } static bool knode_dead(struct klist_node *knode) { return (unsigned long)knode->n_klist & KNODE_DEAD; } static void knode_set_klist(struct klist_node *knode, struct klist *klist) { knode->n_klist = klist; /* no knode deserves to start its life dead */ WARN_ON(knode_dead(knode)); } static void knode_kill(struct klist_node *knode) { /* and no knode should die twice ever either, see we're very humane */ WARN_ON(knode_dead(knode)); *(unsigned long *)&knode->n_klist |= KNODE_DEAD; } /** * 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); kref_init(&n->n_ref); knode_set_klist(n, 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 = knode_klist(pos); 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 = knode_klist(pos); 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); struct klist_waiter { struct list_head list; struct klist_node *node; struct task_struct *process; int woken; }; static DEFINE_SPINLOCK(klist_remove_lock); static LIST_HEAD(klist_remove_waiters); static void klist_release(struct kref *kref) { struct klist_waiter *waiter, *tmp; struct klist_node *n = container_of(kref, struct klist_node, n_ref); WARN_ON(!knode_dead(n)); list_del(&n->n_node); spin_lock(&klist_remove_lock); list_for_each_entry_safe(waiter, tmp, &klist_remove_waiters, list) { if (waiter->node != n) continue; waiter->woken = 1;


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