From: Matthew Wilcox <willy@infradead.org>
Date: Mon, 18 Feb 2019 20:27:48 +0000 (-0500)
Subject: mtdcore: Convert mtd_idr to XArray
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=16f99b09225b6f6f681cf199d5a781b437f7eeb5;p=users%2Fwilly%2Fxarray.git

mtdcore: Convert mtd_idr to XArray

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

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 408615f29e57..4508c88926a7 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -66,16 +66,16 @@ static struct class mtd_class = {
 	.pm = MTD_CLS_PM_OPS,
 };
 
-static DEFINE_IDR(mtd_idr);
+static DEFINE_XARRAY_ALLOC(mtd_devs);
 
 /* These are exported solely for the purpose of mtd_blkdevs.c. You
    should not use them for _anything_ else */
 DEFINE_MUTEX(mtd_table_mutex);
 EXPORT_SYMBOL_GPL(mtd_table_mutex);
 
-struct mtd_info *__mtd_next_device(int i)
+struct mtd_info *__mtd_next_device(unsigned long i)
 {
-	return idr_get_next(&mtd_idr, &i);
+	return xa_find(&mtd_devs, &i, ULONG_MAX, XA_PRESENT);
 }
 EXPORT_SYMBOL_GPL(__mtd_next_device);
 
@@ -526,7 +526,7 @@ static struct dentry *dfs_dir_mtd;
 int add_mtd_device(struct mtd_info *mtd)
 {
 	struct mtd_notifier *not;
-	int i, error;
+	int error;
 
 	/*
 	 * May occur, for instance, on buggy drivers which call
@@ -552,13 +552,10 @@ int add_mtd_device(struct mtd_info *mtd)
 
 	mutex_lock(&mtd_table_mutex);
 
-	i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
-	if (i < 0) {
-		error = i;
+	error = xa_alloc(&mtd_devs, &mtd->index, mtd, xa_limit_31b, GFP_KERNEL);
+	if (error < 0)
 		goto fail_locked;
-	}
 
-	mtd->index = i;
 	mtd->usecount = 0;
 
 	/* default value if not set by driver */
@@ -594,8 +591,8 @@ int add_mtd_device(struct mtd_info *mtd)
 	 */
 	mtd->dev.type = &mtd_devtype;
 	mtd->dev.class = &mtd_class;
-	mtd->dev.devt = MTD_DEVT(i);
-	dev_set_name(&mtd->dev, "mtd%d", i);
+	mtd->dev.devt = MTD_DEVT(mtd->index);
+	dev_set_name(&mtd->dev, "mtd%d", mtd->index);
 	dev_set_drvdata(&mtd->dev, mtd);
 	of_node_get(mtd_get_of_node(mtd));
 	error = device_register(&mtd->dev);
@@ -615,10 +612,10 @@ int add_mtd_device(struct mtd_info *mtd)
 		}
 	}
 
-	device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
-		      "mtd%dro", i);
+	device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(mtd->index) + 1, NULL,
+		      "mtd%dro", mtd->index);
 
-	pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
+	pr_debug("mtd: Giving out device %d to %s\n", mtd->index, mtd->name);
 	/* No need to get a refcount on the module containing
 	   the notifier, since we hold the mtd_table_mutex */
 	list_for_each_entry(not, &mtd_notifiers, list)
@@ -636,7 +633,7 @@ fail_nvmem_add:
 	device_unregister(&mtd->dev);
 fail_added:
 	of_node_put(mtd_get_of_node(mtd));
-	idr_remove(&mtd_idr, i);
+	xa_erase(&mtd_devs, mtd->index);
 fail_locked:
 	mutex_unlock(&mtd_table_mutex);
 	return error;
@@ -661,7 +658,7 @@ int del_mtd_device(struct mtd_info *mtd)
 
 	debugfs_remove_recursive(mtd->dbg.dfs_dir);
 
-	if (idr_find(&mtd_idr, mtd->index) != mtd) {
+	if (xa_load(&mtd_devs, mtd->index) != mtd) {
 		ret = -ENODEV;
 		goto out_error;
 	}
@@ -682,7 +679,7 @@ int del_mtd_device(struct mtd_info *mtd)
 
 		device_unregister(&mtd->dev);
 
-		idr_remove(&mtd_idr, mtd->index);
+		xa_erase(&mtd_devs, mtd->index);
 		of_node_put(mtd_get_of_node(mtd));
 
 		module_put(THIS_MODULE);
@@ -893,7 +890,7 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
 			}
 		}
 	} else if (num >= 0) {
-		ret = idr_find(&mtd_idr, num);
+		ret = xa_load(&mtd_devs, num);
 		if (mtd && mtd != ret)
 			ret = NULL;
 	}
@@ -1933,7 +1930,6 @@ static void __exit cleanup_mtd(void)
 		remove_proc_entry("mtd", NULL);
 	class_unregister(&mtd_class);
 	bdi_put(mtd_bdi);
-	idr_destroy(&mtd_idr);
 }
 
 module_init(init_mtd);
diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index b31c868019ad..978f91daecb3 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -6,7 +6,7 @@
 
 extern struct mutex mtd_table_mutex;
 
-struct mtd_info *__mtd_next_device(int i);
+struct mtd_info *__mtd_next_device(unsigned long i);
 int __must_check add_mtd_device(struct mtd_info *mtd);
 int del_mtd_device(struct mtd_info *mtd);
 int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int);