|
@@ -29,6 +29,7 @@
|
|
|
#include <linux/init.h>
|
|
|
#include <linux/module.h>
|
|
|
#endif
|
|
|
+#include <linux/err.h>
|
|
|
#include <linux/string.h>
|
|
|
#include <linux/idr.h>
|
|
|
|
|
@@ -398,6 +399,48 @@ void *idr_find(struct idr *idp, int id)
|
|
|
}
|
|
|
EXPORT_SYMBOL(idr_find);
|
|
|
|
|
|
+/**
|
|
|
+ * idr_replace - replace pointer for given id
|
|
|
+ * @idp: idr handle
|
|
|
+ * @ptr: pointer you want associated with the id
|
|
|
+ * @id: lookup key
|
|
|
+ *
|
|
|
+ * Replace the pointer registered with an id and return the old value.
|
|
|
+ * A -ENOENT return indicates that @id was not found.
|
|
|
+ * A -EINVAL return indicates that @id was not within valid constraints.
|
|
|
+ *
|
|
|
+ * The caller must serialize vs idr_find(), idr_get_new(), and idr_remove().
|
|
|
+ */
|
|
|
+void *idr_replace(struct idr *idp, void *ptr, int id)
|
|
|
+{
|
|
|
+ int n;
|
|
|
+ struct idr_layer *p, *old_p;
|
|
|
+
|
|
|
+ n = idp->layers * IDR_BITS;
|
|
|
+ p = idp->top;
|
|
|
+
|
|
|
+ id &= MAX_ID_MASK;
|
|
|
+
|
|
|
+ if (id >= (1 << n))
|
|
|
+ return ERR_PTR(-EINVAL);
|
|
|
+
|
|
|
+ n -= IDR_BITS;
|
|
|
+ while ((n > 0) && p) {
|
|
|
+ p = p->ary[(id >> n) & IDR_MASK];
|
|
|
+ n -= IDR_BITS;
|
|
|
+ }
|
|
|
+
|
|
|
+ n = id & IDR_MASK;
|
|
|
+ if (unlikely(p == NULL || !test_bit(n, &p->bitmap)))
|
|
|
+ return ERR_PTR(-ENOENT);
|
|
|
+
|
|
|
+ old_p = p->ary[n];
|
|
|
+ p->ary[n] = ptr;
|
|
|
+
|
|
|
+ return old_p;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(idr_replace);
|
|
|
+
|
|
|
static void idr_cache_ctor(void * idr_layer, kmem_cache_t *idr_layer_cache,
|
|
|
unsigned long flags)
|
|
|
{
|