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Diffstat (limited to 'include/linux/idr.h')
-rw-r--r--include/linux/idr.h34
1 files changed, 32 insertions, 2 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h
index a0dce14090a9..2267902d29a7 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -15,6 +15,7 @@
#include <linux/radix-tree.h>
#include <linux/gfp.h>
#include <linux/percpu.h>
+#include <linux/cleanup.h>
struct idr {
struct radix_tree_root idr_rt;
@@ -124,6 +125,22 @@ void *idr_get_next_ul(struct idr *, unsigned long *nextid);
void *idr_replace(struct idr *, void *, unsigned long id);
void idr_destroy(struct idr *);
+struct __class_idr {
+ struct idr *idr;
+ int id;
+};
+
+#define idr_null ((struct __class_idr){ NULL, -1 })
+#define take_idr_id(id) __get_and_null(id, idr_null)
+
+DEFINE_CLASS(idr_alloc, struct __class_idr,
+ if (_T.id >= 0) idr_remove(_T.idr, _T.id),
+ ((struct __class_idr){
+ .idr = idr,
+ .id = idr_alloc(idr, ptr, start, end, gfp),
+ }),
+ struct idr *idr, void *ptr, int start, int end, gfp_t gfp);
+
/**
* idr_init_base() - Initialise an IDR.
* @idr: IDR handle.
@@ -200,7 +217,7 @@ static inline void idr_preload_end(void)
*/
#define idr_for_each_entry_ul(idr, entry, tmp, id) \
for (tmp = 0, id = 0; \
- tmp <= id && ((entry) = idr_get_next_ul(idr, &(id))) != NULL; \
+ ((entry) = tmp <= id ? idr_get_next_ul(idr, &(id)) : NULL) != NULL; \
tmp = id, ++id)
/**
@@ -224,10 +241,12 @@ static inline void idr_preload_end(void)
* @id: Entry ID.
*
* Continue to iterate over entries, continuing after the current position.
+ * After normal termination @entry is left with the value NULL. This
+ * is convenient for a "not found" value.
*/
#define idr_for_each_entry_continue_ul(idr, entry, tmp, id) \
for (tmp = id; \
- tmp <= id && ((entry) = idr_get_next_ul(idr, &(id))) != NULL; \
+ ((entry) = tmp <= id ? idr_get_next_ul(idr, &(id)) : NULL) != NULL; \
tmp = id, ++id)
/*
@@ -255,6 +274,7 @@ struct ida {
int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t);
void ida_free(struct ida *, unsigned int id);
void ida_destroy(struct ida *ida);
+int ida_find_first_range(struct ida *ida, unsigned int min, unsigned int max);
/**
* ida_alloc() - Allocate an unused ID.
@@ -326,4 +346,14 @@ static inline bool ida_is_empty(const struct ida *ida)
{
return xa_empty(&ida->xa);
}
+
+static inline bool ida_exists(struct ida *ida, unsigned int id)
+{
+ return ida_find_first_range(ida, id, id) == id;
+}
+
+static inline int ida_find_first(struct ida *ida)
+{
+ return ida_find_first_range(ida, 0, ~0);
+}
#endif /* __IDR_H__ */