Clients of the ida API routinely follow the
same steps to allocate and ida index, as well
as to free said index. These helper routines
should make it a little easier to use these
APIs.
Signed-off-by: Lee Duncan <lduncan@xxxxxxxx>
---
include/linux/idr.h | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 013fd9bc4cb6..5a9526dc6298 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -16,6 +16,8 @@
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/rcupdate.h>
+#include <linux/spinlock.h>
+#include <linux/gfp.h>
/*
* We want shallower trees and thus more bits covered at each layer. 8
@@ -183,4 +185,44 @@ static inline int ida_get_new(struct ida *ida, int *p_id)
void __init idr_init_cache(void);
+/**
+ * ida_get_index - allocate a ida index value
+ * @ida idr handle
+ * @lock spinlock handle protecting this index
+ * @p_id pointer to allocated index value
+ *
+ * A helper function for safely allocating an index value (id),
+ * returning a negative errno value on failure, else 0.
+ */
+static inline int ida_get_index(struct ida *ida, spinlock_t *lock, int *p_id)
+{
+ int error = -ENOMEM;
+
+ do {
+ if (!ida_pre_get(ida, GFP_KERNEL))
+ break;
+ spin_lock(lock);
+ error = ida_get_new(ida, p_id);
+ spin_unlock(lock);
+ } while (error == -EAGAIN);
+
+ return error;
+}
+
+/**
+ * ida_put_index - free an allocated ida index value
+ * @ida idr handle
+ * @lock spinlock handle protecting this index
+ * @id the value of the allocated index
+ *
+ * A helper function that goes with @ida_get_index, which safely
+ * frees a previously-allocated index value.
+ */
+static inline void ida_put_index(struct ida *ida, spinlock_t *lock, int id)
+{
+ spin_lock(lock);
+ ida_remove(ida, id);
+ spin_unlock(lock);
+}
+
#endif /* __IDR_H__ */
--
2.1.4
--
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