dca: Convert dca_idr to IDA

The DCA code never looks up the pointer it stores in the IDR, so it
can use the IDA which is more efficient and easier to use.

Signed-off-by: Matthew Wilcox <willy@infradead.org>

diff --git a/drivers/dca/dca-sysfs.c b/drivers/dca/dca-sysfs.c
index eb25627b059dc3dbcbdf48ddedbdc50614bf1228..e8979e61d255c0ab7c7be110cf5558aeb001435e 100644 (file)
--- a/drivers/dca/dca-sysfs.c
+++ b/drivers/dca/dca-sysfs.c
@@ -14,8 +14,7 @@
 #include <linux/export.h>
 
 static struct class *dca_class;
-static struct idr dca_idr;
-static spinlock_t dca_idr_lock;
+static DEFINE_IDA(providers);
 
 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
 {
@@ -39,23 +38,14 @@ int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
        struct device *cd;
        int ret;
 
-       idr_preload(GFP_KERNEL);
-       spin_lock(&dca_idr_lock);
-
-       ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
-       if (ret >= 0)
-               dca->id = ret;
-
-       spin_unlock(&dca_idr_lock);
-       idr_preload_end();
+       ret = ida_alloc(&providers, GFP_KERNEL);
        if (ret < 0)
                return ret;
+       dca->id = ret;
 
        cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
        if (IS_ERR(cd)) {
-               spin_lock(&dca_idr_lock);
-               idr_remove(&dca_idr, dca->id);
-               spin_unlock(&dca_idr_lock);
+               ida_free(&providers, dca->id);
                return PTR_ERR(cd);
        }
        dca->cd = cd;
@@ -66,27 +56,16 @@ void dca_sysfs_remove_provider(struct dca_provider *dca)
 {
        device_unregister(dca->cd);
        dca->cd = NULL;
-       spin_lock(&dca_idr_lock);
-       idr_remove(&dca_idr, dca->id);
-       spin_unlock(&dca_idr_lock);
+       ida_free(&providers, dca->id);
 }
 
 int __init dca_sysfs_init(void)
 {
-       idr_init(&dca_idr);
-       spin_lock_init(&dca_idr_lock);
-
        dca_class = class_create(THIS_MODULE, "dca");
-       if (IS_ERR(dca_class)) {
-               idr_destroy(&dca_idr);
-               return PTR_ERR(dca_class);
-       }
-       return 0;
+       return PTR_ERR_OR_ZERO(dca_class);
 }
 
 void __exit dca_sysfs_exit(void)
 {
        class_destroy(dca_class);
-       idr_destroy(&dca_idr);
 }
-