[PATCH v2 07/19] ioasid: Convert ioasid_idr to XArray

Jacob Pan
2019-04-23T23:31:07Z

IDR is to be replaced by XArray, keep up with the changes.
XArray has internal locking for normal APIs used here, also removed
radix tree related preload.

Suggested-by: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
drivers/base/ioasid.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/drivers/base/ioasid.c b/drivers/base/ioasid.c
index cf122b2..c4012aa 100644
--- a/drivers/base/ioasid.c
+++ b/drivers/base/ioasid.c
@@ -4,7 +4,7 @@
* subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and
* free IOASIDs with ioasid_alloc and ioasid_free.
*/
-#include <linux/idr.h>
+#include <linux/xarray.h>
#include <linux/ioasid.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
@@ -16,13 +16,12 @@ struct ioasid_data {
struct rcu_head rcu;
};

-static DEFINE_IDR(ioasid_idr);
-
+static DEFINE_XARRAY_ALLOC(ioasid_xa);
/**
* ioasid_alloc - Allocate an IOASID
* @set: the IOASID set
* @min: the minimum ID (inclusive)
- * @max: the maximum ID (exclusive)
+ * @max: the maximum ID (inclusive)
* @private: data private to the caller
*
* Allocate an ID between @min and @max (or %0 and %INT_MAX). Return the
@@ -41,13 +40,13 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,

data->set = set;
data->private = private;
+ if (xa_alloc(&ioasid_xa, &id, data, XA_LIMIT(min, max), GFP_KERNEL)) {
+ pr_err("Failed to alloc ioasid from %d to %d\n", min, max);
+ goto exit_free;
+ }

- idr_preload(GFP_KERNEL);
- idr_lock(&ioasid_idr);
- data->id = id = idr_alloc(&ioasid_idr, data, min, max, GFP_ATOMIC);
- idr_unlock(&ioasid_idr);
- idr_preload_end();
-
+ data->id = id;
+exit_free:
if (id < 0) {
kfree(data);
return INVALID_IOASID;
@@ -64,12 +63,8 @@ void ioasid_free(ioasid_t ioasid)
{
struct ioasid_data *ioasid_data;

- idr_lock(&ioasid_idr);
- ioasid_data = idr_remove(&ioasid_idr, ioasid);
- idr_unlock(&ioasid_idr);
-
- if (ioasid_data)
- kfree_rcu(ioasid_data, rcu);
+ ioasid_data = xa_erase(&ioasid_xa, ioasid);
+ kfree_rcu(ioasid_data, rcu);
}
EXPORT_SYMBOL_GPL(ioasid_free);

@@ -93,7 +88,7 @@ void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
struct ioasid_data *ioasid_data;

rcu_read_lock();
- ioasid_data = idr_find(&ioasid_idr, ioasid);
+ ioasid_data = xa_load(&ioasid_xa, ioasid);
if (ioasid_data && ioasid_data->set == set) {
priv = ioasid_data->private;
if (getter && !getter(priv))
--
2.7.4