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-rw-r--r--include/linux/idr.h59
-rw-r--r--lib/idr.c70
2 files changed, 87 insertions, 42 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h
index e856f4e0ab35..cd339da0b1aa 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -230,15 +230,68 @@ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id);
void ida_remove(struct ida *ida, int id);
void ida_destroy(struct ida *ida);
-int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
- gfp_t gfp_mask);
-void ida_simple_remove(struct ida *ida, unsigned int id);
+int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t);
+void ida_free(struct ida *, unsigned int id);
+
+/**
+ * ida_alloc() - Allocate an unused ID.
+ * @ida: IDA handle.
+ * @gfp: Memory allocation flags.
+ *
+ * Allocate an ID between 0 and %INT_MAX, inclusive.
+ *
+ * Context: Any context.
+ * Return: The allocated ID, or %-ENOMEM if memory could not be allocated,
+ * or %-ENOSPC if there are no free IDs.
+ */
+static inline int ida_alloc(struct ida *ida, gfp_t gfp)
+{
+ return ida_alloc_range(ida, 0, ~0, gfp);
+}
+
+/**
+ * ida_alloc_min() - Allocate an unused ID.
+ * @ida: IDA handle.
+ * @min: Lowest ID to allocate.
+ * @gfp: Memory allocation flags.
+ *
+ * Allocate an ID between @min and %INT_MAX, inclusive.
+ *
+ * Context: Any context.
+ * Return: The allocated ID, or %-ENOMEM if memory could not be allocated,
+ * or %-ENOSPC if there are no free IDs.
+ */
+static inline int ida_alloc_min(struct ida *ida, unsigned int min, gfp_t gfp)
+{
+ return ida_alloc_range(ida, min, ~0, gfp);
+}
+
+/**
+ * ida_alloc_max() - Allocate an unused ID.
+ * @ida: IDA handle.
+ * @max: Highest ID to allocate.
+ * @gfp: Memory allocation flags.
+ *
+ * Allocate an ID between 0 and @max, inclusive.
+ *
+ * Context: Any context.
+ * Return: The allocated ID, or %-ENOMEM if memory could not be allocated,
+ * or %-ENOSPC if there are no free IDs.
+ */
+static inline int ida_alloc_max(struct ida *ida, unsigned int max, gfp_t gfp)
+{
+ return ida_alloc_range(ida, 0, max, gfp);
+}
static inline void ida_init(struct ida *ida)
{
INIT_RADIX_TREE(&ida->ida_rt, IDR_RT_MARKER | GFP_NOWAIT);
}
+#define ida_simple_get(ida, start, end, gfp) \
+ ida_alloc_range(ida, start, (end) - 1, gfp)
+#define ida_simple_remove(ida, id) ida_free(ida, id)
+
/**
* ida_get_new - allocate new ID
* @ida: idr handle
diff --git a/lib/idr.c b/lib/idr.c
index 352c6160e2e0..760fce92f1fb 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -317,7 +317,8 @@ EXPORT_SYMBOL(idr_replace);
* bit per ID, and so is more space efficient than an IDR. To use an IDA,
* define it using DEFINE_IDA() (or embed a &struct ida in a data structure,
* then initialise it using ida_init()). To allocate a new ID, call
- * ida_simple_get(). To free an ID, call ida_simple_remove().
+ * ida_alloc(), ida_alloc_min(), ida_alloc_max() or ida_alloc_range().
+ * To free an ID, call ida_free().
*
* If you have more complex locking requirements, use a loop around
* ida_pre_get() and ida_get_new() to allocate a new ID. Then use
@@ -378,7 +379,7 @@ EXPORT_SYMBOL(idr_replace);
* Allocate new ID above or equal to @start. It should be called
* with any required locks to ensure that concurrent calls to
* ida_get_new_above() / ida_get_new() / ida_remove() are not allowed.
- * Consider using ida_simple_get() if you do not have complex locking
+ * Consider using ida_alloc_range() if you do not have complex locking
* requirements.
*
* If memory is required, it will return %-EAGAIN, you should unlock
@@ -551,43 +552,34 @@ void ida_destroy(struct ida *ida)
EXPORT_SYMBOL(ida_destroy);
/**
- * ida_simple_get - get a new id.
- * @ida: the (initialized) ida.
- * @start: the minimum id (inclusive, < 0x8000000)
- * @end: the maximum id (exclusive, < 0x8000000 or 0)
- * @gfp_mask: memory allocation flags
- *
- * Allocates an id in the range start <= id < end, or returns -ENOSPC.
- * On memory allocation failure, returns -ENOMEM.
+ * ida_alloc_range() - Allocate an unused ID.
+ * @ida: IDA handle.
+ * @min: Lowest ID to allocate.
+ * @max: Highest ID to allocate.
+ * @gfp: Memory allocation flags.
*
- * Compared to ida_get_new_above() this function does its own locking, and
- * should be used unless there are special requirements.
+ * Allocate an ID between @min and @max, inclusive. The allocated ID will
+ * not exceed %INT_MAX, even if @max is larger.
*
- * Use ida_simple_remove() to get rid of an id.
+ * Context: Any context.
+ * Return: The allocated ID, or %-ENOMEM if memory could not be allocated,
+ * or %-ENOSPC if there are no free IDs.
*/
-int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
- gfp_t gfp_mask)
+int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max,
+ gfp_t gfp)
{
int ret, id;
- unsigned int max;
unsigned long flags;
- BUG_ON((int)start < 0);
- BUG_ON((int)end < 0);
+ if ((int)min < 0)
+ return -ENOSPC;
- if (end == 0)
- max = 0x80000000;
- else {
- BUG_ON(end < start);
- max = end - 1;
- }
+ if ((int)max < 0)
+ max = INT_MAX;
again:
- if (!ida_pre_get(ida, gfp_mask))
- return -ENOMEM;
-
xa_lock_irqsave(&ida->ida_rt, flags);
- ret = ida_get_new_above(ida, start, &id);
+ ret = ida_get_new_above(ida, min, &id);
if (!ret) {
if (id > max) {
ida_remove(ida, id);
@@ -598,24 +590,24 @@ again:
}
xa_unlock_irqrestore(&ida->ida_rt, flags);
- if (unlikely(ret == -EAGAIN))
+ if (unlikely(ret == -EAGAIN)) {
+ if (!ida_pre_get(ida, gfp))
+ return -ENOMEM;
goto again;
+ }
return ret;
}
-EXPORT_SYMBOL(ida_simple_get);
+EXPORT_SYMBOL(ida_alloc_range);
/**
- * ida_simple_remove - remove an allocated id.
- * @ida: the (initialized) ida.
- * @id: the id returned by ida_simple_get.
- *
- * Use to release an id allocated with ida_simple_get().
+ * ida_free() - Release an allocated ID.
+ * @ida: IDA handle.
+ * @id: Previously allocated ID.
*
- * Compared to ida_remove() this function does its own locking, and should be
- * used unless there are special requirements.
+ * Context: Any context.
*/
-void ida_simple_remove(struct ida *ida, unsigned int id)
+void ida_free(struct ida *ida, unsigned int id)
{
unsigned long flags;
@@ -624,4 +616,4 @@ void ida_simple_remove(struct ida *ida, unsigned int id)
ida_remove(ida, id);
xa_unlock_irqrestore(&ida->ida_rt, flags);
}
-EXPORT_SYMBOL(ida_simple_remove);
+EXPORT_SYMBOL(ida_free);