rtc: s3c: initialize driver data before using it
[safe/jmp/linux-2.6] / drivers / mtd / mtdcore.c
index 541d556..a1b8b70 100644 (file)
@@ -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) {
@@ -290,71 +297,74 @@ 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;
@@ -659,20 +686,55 @@ done:
 /*====================================================================*/
 /* Init code */
 
+static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
+{
+       int ret;
+
+       ret = bdi_init(bdi);
+       if (!ret)
+               ret = bdi_register(bdi, NULL, name);
+
+       if (ret)
+               bdi_destroy(bdi);
+
+       return ret;
+}
+
 static int __init init_mtd(void)
 {
        int ret;
+
        ret = class_register(&mtd_class);
+       if (ret)
+               goto err_reg;
+
+       ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
+       if (ret)
+               goto err_bdi1;
+
+       ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
+       if (ret)
+               goto err_bdi2;
+
+       ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
+       if (ret)
+               goto err_bdi3;
 
-       if (ret) {
-               pr_err("Error registering mtd class: %d\n", ret);
-               return ret;
-       }
 #ifdef CONFIG_PROC_FS
        if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
                proc_mtd->read_proc = mtd_read_proc;
 #endif /* CONFIG_PROC_FS */
        return 0;
+
+err_bdi3:
+       bdi_destroy(&mtd_bdi_ro_mappable);
+err_bdi2:
+       bdi_destroy(&mtd_bdi_unmappable);
+err_bdi1:
+       class_unregister(&mtd_class);
+err_reg:
+       pr_err("Error registering mtd class or bdi: %d\n", ret);
+       return ret;
 }
 
 static void __exit cleanup_mtd(void)
@@ -682,6 +744,9 @@ static void __exit cleanup_mtd(void)
                remove_proc_entry( "mtd", NULL);
 #endif /* CONFIG_PROC_FS */
        class_unregister(&mtd_class);
+       bdi_destroy(&mtd_bdi_unmappable);
+       bdi_destroy(&mtd_bdi_ro_mappable);
+       bdi_destroy(&mtd_bdi_rw_mappable);
 }
 
 module_init(init_mtd);