1 files changed, 156 insertions, 129 deletions

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index b177e750efc3..a1b8b70d2d0a 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -19,7 +19,9 @@
 #include <linux/init.h>
 #include <linux/mtd/compatmac.h>
 #include <linux/proc_fs.h>
+#include <linux/idr.h>
 #include <linux/backing-dev.h>
+#include <linux/gfp.h>
 
 #include <linux/mtd/mtd.h>
 
@@ -63,13 +65,18 @@ static struct class mtd_class = {
 	.resume = mtd_cls_resume,
 };
 
+static DEFINE_IDR(mtd_idr);
+
 /* These are exported solely for the purpose of mtd_blkdevs.c. You
    should not use them for _anything_ else */
 DEFINE_MUTEX(mtd_table_mutex);
-struct mtd_info *mtd_table[MAX_MTD_DEVICES];
-
 EXPORT_SYMBOL_GPL(mtd_table_mutex);
-EXPORT_SYMBOL_GPL(mtd_table);
+
+struct mtd_info *__mtd_next_device(int i)
+{
+	return idr_get_next(&mtd_idr, &i);
+}
+EXPORT_SYMBOL_GPL(__mtd_next_device);
 
 static LIST_HEAD(mtd_notifiers);
 
@@ -265,13 +272,13 @@ static struct device_type mtd_devtype = {
  *	Add a device to the list of MTD devices present in the system, and
  *	notify each currently active MTD 'user' of its arrival. Returns
  *	zero on success or 1 on failure, which currently will only happen
- *	if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
- *	or there's a sysfs error.
+ *	if there is insufficient memory or a sysfs error.
  */
 
 int add_mtd_device(struct mtd_info *mtd)
 {
-	int i;
+	struct mtd_notifier *not;
+	int i, error;
 
 	if (!mtd->backing_dev_info) {
 		switch (mtd->type) {
@@ -290,70 +297,73 @@ int add_mtd_device(struct mtd_info *mtd)
 	BUG_ON(mtd->writesize == 0);
 	mutex_lock(&mtd_table_mutex);
 
-	for (i=0; i < MAX_MTD_DEVICES; i++)
-		if (!mtd_table[i]) {
-			struct mtd_notifier *not;
-
-			mtd_table[i] = mtd;
-			mtd->index = i;
-			mtd->usecount = 0;
-
-			if (is_power_of_2(mtd->erasesize))
-				mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
-			else
-				mtd->erasesize_shift = 0;
-
-			if (is_power_of_2(mtd->writesize))
-				mtd->writesize_shift = ffs(mtd->writesize) - 1;
-			else
-				mtd->writesize_shift = 0;
-
-			mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
-			mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
-
-			/* Some chips always power up locked. Unlock them now */
-			if ((mtd->flags & MTD_WRITEABLE)
-			    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
-				if (mtd->unlock(mtd, 0, mtd->size))
-					printk(KERN_WARNING
-					       "%s: unlock failed, "
-					       "writes may not work\n",
-					       mtd->name);
-			}
+	do {
+		if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
+			goto fail_locked;
+		error = idr_get_new(&mtd_idr, mtd, &i);
+	} while (error == -EAGAIN);
 
-			/* Caller should have set dev.parent to match the
-			 * physical device.
-			 */
-			mtd->dev.type = &mtd_devtype;
-			mtd->dev.class = &mtd_class;
-			mtd->dev.devt = MTD_DEVT(i);
-			dev_set_name(&mtd->dev, "mtd%d", i);
-			dev_set_drvdata(&mtd->dev, mtd);
-			if (device_register(&mtd->dev) != 0) {
-				mtd_table[i] = NULL;
-				break;
-			}
+	if (error)
+		goto fail_locked;
 
-			if (MTD_DEVT(i))
-				device_create(&mtd_class, mtd->dev.parent,
-						MTD_DEVT(i) + 1,
-						NULL, "mtd%dro", i);
-
-			DEBUG(0, "mtd: Giving out device %d to %s\n",i, 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)
-				not->add(mtd);
-
-			mutex_unlock(&mtd_table_mutex);
-			/* We _know_ we aren't being removed, because
-			   our caller is still holding us here. So none
-			   of this try_ nonsense, and no bitching about it
-			   either. :) */
-			__module_get(THIS_MODULE);
-			return 0;
-		}
+	mtd->index = i;
+	mtd->usecount = 0;
+
+	if (is_power_of_2(mtd->erasesize))
+		mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
+	else
+		mtd->erasesize_shift = 0;
+
+	if (is_power_of_2(mtd->writesize))
+		mtd->writesize_shift = ffs(mtd->writesize) - 1;
+	else
+		mtd->writesize_shift = 0;
+
+	mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
+	mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
+
+	/* Some chips always power up locked. Unlock them now */
+	if ((mtd->flags & MTD_WRITEABLE)
+	    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
+		if (mtd->unlock(mtd, 0, mtd->size))
+			printk(KERN_WARNING
+			       "%s: unlock failed, writes may not work\n",
+			       mtd->name);
+	}
+
+	/* Caller should have set dev.parent to match the
+	 * physical device.
+	 */
+	mtd->dev.type = &mtd_devtype;
+	mtd->dev.class = &mtd_class;
+	mtd->dev.devt = MTD_DEVT(i);
+	dev_set_name(&mtd->dev, "mtd%d", i);
+	dev_set_drvdata(&mtd->dev, mtd);
+	if (device_register(&mtd->dev) != 0)
+		goto fail_added;
+
+	if (MTD_DEVT(i))
+		device_create(&mtd_class, mtd->dev.parent,
+			      MTD_DEVT(i) + 1,
+			      NULL, "mtd%dro", i);
+
+	DEBUG(0, "mtd: Giving out device %d to %s\n", i, 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)
+		not->add(mtd);
+
+	mutex_unlock(&mtd_table_mutex);
+	/* We _know_ we aren't being removed, because
+	   our caller is still holding us here. So none
+	   of this try_ nonsense, and no bitching about it
+	   either. :) */
+	__module_get(THIS_MODULE);
+	return 0;
 
+fail_added:
+	idr_remove(&mtd_idr, i);
+fail_locked:
 	mutex_unlock(&mtd_table_mutex);
 	return 1;
 }
@@ -371,31 +381,34 @@ int add_mtd_device(struct mtd_info *mtd)
 int del_mtd_device (struct mtd_info *mtd)
 {
 	int ret;
+	struct mtd_notifier *not;
 
 	mutex_lock(&mtd_table_mutex);
 
-	if (mtd_table[mtd->index] != mtd) {
+	if (idr_find(&mtd_idr, mtd->index) != mtd) {
 		ret = -ENODEV;
-	} else if (mtd->usecount) {
+		goto out_error;
+	}
+
+	/* 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)
+		not->remove(mtd);
+
+	if (mtd->usecount) {
 		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
 		       mtd->index, mtd->name, mtd->usecount);
 		ret = -EBUSY;
 	} else {
-		struct mtd_notifier *not;
-
 		device_unregister(&mtd->dev);
 
-		/* 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)
-			not->remove(mtd);
-
-		mtd_table[mtd->index] = NULL;
+		idr_remove(&mtd_idr, mtd->index);
 
 		module_put(THIS_MODULE);
 		ret = 0;
 	}
 
+out_error:
 	mutex_unlock(&mtd_table_mutex);
 	return ret;
 }
@@ -411,7 +424,7 @@ int del_mtd_device (struct mtd_info *mtd)
 
 void register_mtd_user (struct mtd_notifier *new)
 {
-	int i;
+	struct mtd_info *mtd;
 
 	mutex_lock(&mtd_table_mutex);
 
@@ -419,9 +432,8 @@ void register_mtd_user (struct mtd_notifier *new)
 
  	__module_get(THIS_MODULE);
 
-	for (i=0; i< MAX_MTD_DEVICES; i++)
-		if (mtd_table[i])
-			new->add(mtd_table[i]);
+	mtd_for_each_device(mtd)
+		new->add(mtd);
 
 	mutex_unlock(&mtd_table_mutex);
 }
@@ -438,15 +450,14 @@ void register_mtd_user (struct mtd_notifier *new)
 
 int unregister_mtd_user (struct mtd_notifier *old)
 {
-	int i;
+	struct mtd_info *mtd;
 
 	mutex_lock(&mtd_table_mutex);
 
 	module_put(THIS_MODULE);
 
-	for (i=0; i< MAX_MTD_DEVICES; i++)
-		if (mtd_table[i])
-			old->remove(mtd_table[i]);
+	mtd_for_each_device(mtd)
+		old->remove(mtd);
 
 	list_del(&old->list);
 	mutex_unlock(&mtd_table_mutex);
@@ -468,42 +479,56 @@ int unregister_mtd_user (struct mtd_notifier *old)
 
 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
 {
-	struct mtd_info *ret = NULL;
-	int i, err = -ENODEV;
+	struct mtd_info *ret = NULL, *other;
+	int err = -ENODEV;
 
 	mutex_lock(&mtd_table_mutex);
 
 	if (num == -1) {
-		for (i=0; i< MAX_MTD_DEVICES; i++)
-			if (mtd_table[i] == mtd)
-				ret = mtd_table[i];
-	} else if (num >= 0 && num < MAX_MTD_DEVICES) {
-		ret = mtd_table[num];
+		mtd_for_each_device(other) {
+			if (other == mtd) {
+				ret = mtd;
+				break;
+			}
+		}
+	} else if (num >= 0) {
+		ret = idr_find(&mtd_idr, num);
 		if (mtd && mtd != ret)
 			ret = NULL;
 	}
 
-	if (!ret)
-		goto out_unlock;
-
-	if (!try_module_get(ret->owner))
-		goto out_unlock;
-
-	if (ret->get_device) {
-		err = ret->get_device(ret);
-		if (err)
-			goto out_put;
+	if (!ret) {
+		ret = ERR_PTR(err);
+		goto out;
 	}
 
-	ret->usecount++;
+	err = __get_mtd_device(ret);
+	if (err)
+		ret = ERR_PTR(err);
+out:
 	mutex_unlock(&mtd_table_mutex);
 	return ret;
+}
 
-out_put:
-	module_put(ret->owner);
-out_unlock:
-	mutex_unlock(&mtd_table_mutex);
-	return ERR_PTR(err);
+
+int __get_mtd_device(struct mtd_info *mtd)
+{
+	int err;
+
+	if (!try_module_get(mtd->owner))
+		return -ENODEV;
+
+	if (mtd->get_device) {
+
+		err = mtd->get_device(mtd);
+
+		if (err) {
+			module_put(mtd->owner);
+			return err;
+		}
+	}
+	mtd->usecount++;
+	return 0;
 }
 
 /**
@@ -517,14 +542,14 @@ out_unlock:
 
 struct mtd_info *get_mtd_device_nm(const char *name)
 {
-	int i, err = -ENODEV;
-	struct mtd_info *mtd = NULL;
+	int err = -ENODEV;
+	struct mtd_info *mtd = NULL, *other;
 
 	mutex_lock(&mtd_table_mutex);
 
-	for (i = 0; i < MAX_MTD_DEVICES; i++) {
-		if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
-			mtd = mtd_table[i];
+	mtd_for_each_device(other) {
+		if (!strcmp(name, other->name)) {
+			mtd = other;
 			break;
 		}
 	}
@@ -554,14 +579,19 @@ out_unlock:
 
 void put_mtd_device(struct mtd_info *mtd)
 {
-	int c;
-
 	mutex_lock(&mtd_table_mutex);
-	c = --mtd->usecount;
+	__put_mtd_device(mtd);
+	mutex_unlock(&mtd_table_mutex);
+
+}
+
+void __put_mtd_device(struct mtd_info *mtd)
+{
+	--mtd->usecount;
+	BUG_ON(mtd->usecount < 0);
+
 	if (mtd->put_device)
 		mtd->put_device(mtd);
-	mutex_unlock(&mtd_table_mutex);
-	BUG_ON(c < 0);
 
 	module_put(mtd->owner);
 }
@@ -599,7 +629,9 @@ EXPORT_SYMBOL_GPL(add_mtd_device);
 EXPORT_SYMBOL_GPL(del_mtd_device);
 EXPORT_SYMBOL_GPL(get_mtd_device);
 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
+EXPORT_SYMBOL_GPL(__get_mtd_device);
 EXPORT_SYMBOL_GPL(put_mtd_device);
+EXPORT_SYMBOL_GPL(__put_mtd_device);
 EXPORT_SYMBOL_GPL(register_mtd_user);
 EXPORT_SYMBOL_GPL(unregister_mtd_user);
 EXPORT_SYMBOL_GPL(default_mtd_writev);
@@ -611,14 +643,9 @@ EXPORT_SYMBOL_GPL(default_mtd_writev);
 
 static struct proc_dir_entry *proc_mtd;
 
-static inline int mtd_proc_info (char *buf, int i)
+static inline int mtd_proc_info(char *buf, struct mtd_info *this)
 {
-	struct mtd_info *this = mtd_table[i];
-
-	if (!this)
-		return 0;
-
-	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", i,
+	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", this->index,
 		       (unsigned long long)this->size,
 		       this->erasesize, this->name);
 }
@@ -626,15 +653,15 @@ static inline int mtd_proc_info (char *buf, int i)
 static int mtd_read_proc (char *page, char **start, off_t off, int count,
 			  int *eof, void *data_unused)
 {
-	int len, l, i;
+	struct mtd_info *mtd;
+	int len, l;
         off_t   begin = 0;
 
 	mutex_lock(&mtd_table_mutex);
 
 	len = sprintf(page, "dev:    size   erasesize  name\n");
-        for (i=0; i< MAX_MTD_DEVICES; i++) {
-
-                l = mtd_proc_info(page + len, i);
+	mtd_for_each_device(mtd) {
+		l = mtd_proc_info(page + len, mtd);
                 len += l;
                 if (len+begin > off+count)
                         goto done;