XArray: Add support for 1s-based allocation

[linux-block.git] / include / linux / xarray.h

diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index 57cf35c4d0945da9df294d2772653ff6156db981..99dd0838b4ba827dd64a88f17b952bb32a611df1 100644 (file)
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -220,10 +220,13 @@ enum xa_lock_type {
 #define XA_FLAGS_LOCK_IRQ      ((__force gfp_t)XA_LOCK_IRQ)
 #define XA_FLAGS_LOCK_BH       ((__force gfp_t)XA_LOCK_BH)
 #define XA_FLAGS_TRACK_FREE    ((__force gfp_t)4U)
+#define XA_FLAGS_ZERO_BUSY     ((__force gfp_t)8U)
 #define XA_FLAGS_MARK(mark)    ((__force gfp_t)((1U << __GFP_BITS_SHIFT) << \
                                                (__force unsigned)(mark)))
 
+/* ALLOC is for a normal 0-based alloc.  ALLOC1 is for an 1-based alloc */
 #define XA_FLAGS_ALLOC (XA_FLAGS_TRACK_FREE | XA_FLAGS_MARK(XA_FREE_MARK))
+#define XA_FLAGS_ALLOC1        (XA_FLAGS_TRACK_FREE | XA_FLAGS_ZERO_BUSY)
 
 /**
  * struct xarray - The anchor of the XArray.
@@ -279,7 +282,7 @@ struct xarray {
 #define DEFINE_XARRAY(name) DEFINE_XARRAY_FLAGS(name, 0)
 
 /**
- * DEFINE_XARRAY_ALLOC() - Define an XArray which can allocate IDs.
+ * DEFINE_XARRAY_ALLOC() - Define an XArray which allocates IDs starting at 0.
  * @name: A string that names your XArray.
  *
  * This is intended for file scope definitions of allocating XArrays.
@@ -287,6 +290,15 @@ struct xarray {
  */
 #define DEFINE_XARRAY_ALLOC(name) DEFINE_XARRAY_FLAGS(name, XA_FLAGS_ALLOC)
 
+/**
+ * DEFINE_XARRAY_ALLOC1() - Define an XArray which allocates IDs starting at 1.
+ * @name: A string that names your XArray.
+ *
+ * This is intended for file scope definitions of allocating XArrays.
+ * See also DEFINE_XARRAY().
+ */
+#define DEFINE_XARRAY_ALLOC1(name) DEFINE_XARRAY_FLAGS(name, XA_FLAGS_ALLOC1)
+
 void *xa_load(struct xarray *, unsigned long index);
 void *xa_store(struct xarray *, unsigned long index, void *entry, gfp_t);
 void *xa_erase(struct xarray *, unsigned long index);