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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-09-01 01:38:43 (GMT)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-09-01 01:38:43 (GMT)
commitef5f5de069bd9081a7ddf6998269b58fc65e27ef (patch)
tree21d53507543248f81725cbc486625f77562f935d /lib
parent73990fc810bf84c5338d9596f8af8d70fe90ac72 (diff)
parente91a398c31cef2d51786642e372c503cd43fba90 (diff)
Merge branch 'acpi-pm'
* acpi-pm: ACPI / bus: Move duplicate code to a separate new function mfd: Add support for Intel Sunrisepoint LPSS devices dmaengine: add a driver for Intel integrated DMA 64-bit mfd: make mfd_remove_devices() iterate in reverse order driver core: implement device_for_each_child_reverse() klist: implement klist_prev() Driver core: wakeup the parent device before trying probe ACPI / PM: Attach ACPI power domain only once PM / QoS: Make it possible to expose device latency tolerance to userspace ACPI / PM: Update the copyright notice and description of power.c
Diffstat (limited to 'lib')
-rw-r--r--lib/klist.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/lib/klist.c b/lib/klist.c
index 89b485a..d74cf7a 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -324,6 +324,47 @@ static struct klist_node *to_klist_node(struct list_head *n)
}
/**
+ * klist_prev - Ante up prev node in list.
+ * @i: Iterator structure.
+ *
+ * First grab list lock. Decrement the reference count of the previous
+ * node, if there was one. Grab the prev node, increment its reference
+ * count, drop the lock, and return that prev node.
+ */
+struct klist_node *klist_prev(struct klist_iter *i)
+{
+ void (*put)(struct klist_node *) = i->i_klist->put;
+ struct klist_node *last = i->i_cur;
+ struct klist_node *prev;
+
+ spin_lock(&i->i_klist->k_lock);
+
+ if (last) {
+ prev = to_klist_node(last->n_node.prev);
+ if (!klist_dec_and_del(last))
+ put = NULL;
+ } else
+ prev = to_klist_node(i->i_klist->k_list.prev);
+
+ i->i_cur = NULL;
+ while (prev != to_klist_node(&i->i_klist->k_list)) {
+ if (likely(!knode_dead(prev))) {
+ kref_get(&prev->n_ref);
+ i->i_cur = prev;
+ break;
+ }
+ prev = to_klist_node(prev->n_node.prev);
+ }
+
+ spin_unlock(&i->i_klist->k_lock);
+
+ if (put && last)
+ put(last);
+ return i->i_cur;
+}
+EXPORT_SYMBOL_GPL(klist_prev);
+
+/**
* klist_next - Ante up next node in list.
* @i: Iterator structure.
*

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