1 files changed, 692 insertions, 0 deletions

diff --git a/linux-2.4.x/drivers/mtd/mtd_blkdevs-24.c b/linux-2.4.x/drivers/mtd/mtd_blkdevs-24.c
new file mode 100644
index 0000000..688028b
--- /dev/null
+++ b/linux-2.4.x/drivers/mtd/mtd_blkdevs-24.c
@@ -0,0 +1,692 @@
+/*
+ * $Id: mtd_blkdevs-24.c,v 1.18 2005/11/07 11:14:20 gleixner Exp $
+ *
+ * (C) 2003 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Interface to Linux 2.4 block layer for MTD 'translation layers'.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/mtd/blktrans.h>
+#include <linux/mtd/mtd.h>
+#include <linux/blkdev.h>
+#include <linux/blk.h>
+#include <linux/blkpg.h>
+#include <linux/spinlock.h>
+#include <linux/hdreg.h>
+#include <linux/init.h>
+#include <asm/semaphore.h>
+#include <asm/uaccess.h>
+
+static LIST_HEAD(blktrans_majors);
+
+extern struct semaphore mtd_table_mutex;
+extern struct mtd_info *mtd_table[];
+
+struct mtd_blkcore_priv {
+	devfs_handle_t devfs_dir_handle;
+	int blksizes[256];
+	int sizes[256];
+	struct hd_struct part_table[256];
+	struct gendisk gd;
+	spinlock_t devs_lock; /* See comment in _request function */
+	struct completion thread_dead;
+	int exiting;
+	wait_queue_head_t thread_wq;
+};
+
+static inline struct mtd_blktrans_dev *tr_get_dev(struct mtd_blktrans_ops *tr,
+					   int devnum)
+{
+	struct list_head *this;
+	struct mtd_blktrans_dev *d;
+
+	list_for_each(this, &tr->devs) {
+		d = list_entry(this, struct mtd_blktrans_dev, list);
+
+		if (d->devnum == devnum)
+			return d;
+	}
+	return NULL;
+}
+
+static inline struct mtd_blktrans_ops *get_tr(int major)
+{
+	struct list_head *this;
+	struct mtd_blktrans_ops *t;
+
+	list_for_each(this, &blktrans_majors) {
+		t = list_entry(this, struct mtd_blktrans_ops, list);
+
+		if (t->major == major)
+			return t;
+	}
+	return NULL;
+}
+
+static int do_blktrans_request(struct mtd_blktrans_ops *tr,
+			       struct mtd_blktrans_dev *dev,
+			       struct request *req)
+{
+	unsigned long block, nsect;
+	char *buf;
+	int minor;
+
+	minor = MINOR(req->rq_dev);
+	block = req->sector;
+	nsect = req->current_nr_sectors;
+	buf = req->buffer;
+
+	if (block + nsect > tr->blkcore_priv->part_table[minor].nr_sects) {
+		printk(KERN_WARNING "Access beyond end of device.\n");
+		return 0;
+	}
+	block += tr->blkcore_priv->part_table[minor].start_sect;
+
+	switch(req->cmd) {
+	case READ:
+		for (; nsect > 0; nsect--, block++, buf += 512)
+			if (tr->readsect(dev, block, buf))
+				return 0;
+		return 1;
+
+	case WRITE:
+		if (!tr->writesect)
+			return 0;
+
+		for (; nsect > 0; nsect--, block++, buf += 512)
+			if (tr->writesect(dev, block, buf))
+				return 0;
+		return 1;
+
+	default:
+		printk(KERN_NOTICE "Unknown request cmd %d\n", req->cmd);
+		return 0;
+	}
+}
+
+static int mtd_blktrans_thread(void *arg)
+{
+	struct mtd_blktrans_ops *tr = arg;
+	struct request_queue *rq = BLK_DEFAULT_QUEUE(tr->major);
+
+	/* we might get involved when memory gets low, so use PF_MEMALLOC */
+	current->flags |= PF_MEMALLOC;
+
+	snprintf(current->comm, sizeof(current->comm), "%sd", tr->name);
+
+	/* daemonize() doesn't do this for us since some kernel threads
+	   actually want to deal with signals. We can't just call
+	   exit_sighand() since that'll cause an oops when we finally
+	   do exit. */
+	spin_lock_irq(&current->sigmask_lock);
+	sigfillset(&current->blocked);
+	recalc_sigpending();
+	spin_unlock_irq(&current->sigmask_lock);
+
+	daemonize("%sd", tr->name);
+
+	while (!tr->blkcore_priv->exiting) {
+		struct request *req;
+		struct mtd_blktrans_dev *dev;
+		int devnum;
+		int res = 0;
+		DECLARE_WAITQUEUE(wait, current);
+
+		spin_lock_irq(&io_request_lock);
+
+		if (list_empty(&rq->queue_head)) {
+
+			add_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
+			set_current_state(TASK_INTERRUPTIBLE);
+
+			spin_unlock_irq(&io_request_lock);
+
+			schedule();
+			remove_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
+
+			continue;
+		}
+
+		req = blkdev_entry_next_request(&rq->queue_head);
+
+		devnum = MINOR(req->rq_dev) >> tr->part_bits;
+
+		/* The ll_rw_blk code knows not to touch the request
+		   at the head of the queue */
+		spin_unlock_irq(&io_request_lock);
+
+		/* FIXME: Where can we store the dev, on which
+		   we already have a refcount anyway? We need to
+		   lock against concurrent addition/removal of devices,
+		   but if we use the mtd_table_mutex we deadlock when
+		   grok_partitions is called from the registration
+		   callbacks. */
+		spin_lock(&tr->blkcore_priv->devs_lock);
+		dev = tr_get_dev(tr, devnum);
+		spin_unlock(&tr->blkcore_priv->devs_lock);
+
+		BUG_ON(!dev);
+
+		/* Ensure serialisation of requests */
+		down(&dev->sem);
+
+		res = do_blktrans_request(tr, dev, req);
+		up(&dev->sem);
+
+		if (!end_that_request_first(req, res, tr->name)) {
+			spin_lock_irq(&io_request_lock);
+			blkdev_dequeue_request(req);
+			end_that_request_last(req);
+			spin_unlock_irq(&io_request_lock);
+		}
+	}
+	complete_and_exit(&tr->blkcore_priv->thread_dead, 0);
+}
+
+static void mtd_blktrans_request(struct request_queue *rq)
+{
+	struct mtd_blktrans_ops *tr = rq->queuedata;
+	wake_up(&tr->blkcore_priv->thread_wq);
+}
+
+int blktrans_open(struct inode *i, struct file *f)
+{
+	struct mtd_blktrans_ops *tr = NULL;
+	struct mtd_blktrans_dev *dev = NULL;
+	int major_nr = MAJOR(i->i_rdev);
+	int minor_nr = MINOR(i->i_rdev);
+	int devnum;
+	int ret = -ENODEV;
+
+	if (is_read_only(i->i_rdev) && (f->f_mode & FMODE_WRITE))
+		return -EROFS;
+
+	down(&mtd_table_mutex);
+
+	tr = get_tr(major_nr);
+
+	if (!tr)
+		goto out;
+
+	devnum = minor_nr >> tr->part_bits;
+
+	dev = tr_get_dev(tr, devnum);
+
+	if (!dev)
+		goto out;
+
+	if (!tr->blkcore_priv->part_table[minor_nr].nr_sects) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (!try_inc_mod_count(dev->mtd->owner))
+		goto out;
+
+	if (!try_inc_mod_count(tr->owner))
+		goto out_tr;
+
+	dev->mtd->usecount++;
+
+	ret = 0;
+	if (tr->open && (ret = tr->open(dev))) {
+		dev->mtd->usecount--;
+		if (dev->mtd->owner)
+			__MOD_DEC_USE_COUNT(dev->mtd->owner);
+	out_tr:
+		if (tr->owner)
+			__MOD_DEC_USE_COUNT(tr->owner);
+	}
+ out:
+	up(&mtd_table_mutex);
+
+	return ret;
+}
+
+int blktrans_release(struct inode *i, struct file *f)
+{
+	struct mtd_blktrans_dev *dev;
+	struct mtd_blktrans_ops *tr;
+	int ret = 0;
+	int devnum;
+
+	down(&mtd_table_mutex);
+
+	tr = get_tr(MAJOR(i->i_rdev));
+	if (!tr) {
+		up(&mtd_table_mutex);
+		return -ENODEV;
+	}
+
+	devnum = MINOR(i->i_rdev) >> tr->part_bits;
+	dev = tr_get_dev(tr, devnum);
+
+	if (!dev) {
+		up(&mtd_table_mutex);
+		return -ENODEV;
+	}
+
+	if (tr->release)
+		ret = tr->release(dev);
+
+	if (!ret) {
+		dev->mtd->usecount--;
+		if (dev->mtd->owner)
+			__MOD_DEC_USE_COUNT(dev->mtd->owner);
+		if (tr->owner)
+			__MOD_DEC_USE_COUNT(tr->owner);
+	}
+
+	up(&mtd_table_mutex);
+
+	return ret;
+}
+
+static int mtd_blktrans_rrpart(kdev_t rdev, struct mtd_blktrans_ops *tr,
+			       struct mtd_blktrans_dev *dev)
+{
+	struct gendisk *gd = &(tr->blkcore_priv->gd);
+	int i;
+	int minor = MINOR(rdev);
+
+	if (minor & ((1<<tr->part_bits)-1) || !tr->part_bits) {
+		/* BLKRRPART on a partition. Go away. */
+		return -ENOTTY;
+	}
+
+	if (!capable(CAP_SYS_ADMIN))
+	    return -EACCES;
+
+	/* We are required to prevent simultaneous open() ourselves.
+	   The core doesn't do that for us. Did I ever mention how
+	   much the Linux block layer sucks? Sledgehammer approach... */
+	down(&mtd_table_mutex);
+
+	for (i=0; i < (1<<tr->part_bits); i++) {
+		invalidate_device(MKDEV(tr->major, minor+i), 1);
+		gd->part[minor + i].start_sect = 0;
+		gd->part[minor + i].nr_sects = 0;
+	}
+
+	grok_partitions(gd, minor, 1 << tr->part_bits,
+                        dev->size);
+	up(&mtd_table_mutex);
+
+	return 0;
+}
+
+static int blktrans_ioctl(struct inode *inode, struct file *file,
+			      unsigned int cmd, unsigned long arg)
+{
+	struct mtd_blktrans_dev *dev;
+	struct mtd_blktrans_ops *tr;
+	int devnum;
+
+	switch(cmd) {
+	case BLKGETSIZE:
+        case BLKGETSIZE64:
+        case BLKBSZSET:
+        case BLKBSZGET:
+        case BLKROSET:
+        case BLKROGET:
+        case BLKRASET:
+        case BLKRAGET:
+        case BLKPG:
+        case BLKELVGET:
+        case BLKELVSET:
+		return blk_ioctl(inode->i_rdev, cmd, arg);
+	}
+
+	down(&mtd_table_mutex);
+
+	tr = get_tr(MAJOR(inode->i_rdev));
+	if (!tr) {
+		up(&mtd_table_mutex);
+		return -ENODEV;
+	}
+
+	devnum = MINOR(inode->i_rdev) >> tr->part_bits;
+	dev = tr_get_dev(tr, devnum);
+
+	up(&mtd_table_mutex);
+
+	if (!dev)
+		return -ENODEV;
+
+	switch(cmd) {
+	case BLKRRPART:
+		return mtd_blktrans_rrpart(inode->i_rdev, tr, dev);
+
+        case BLKFLSBUF:
+		blk_ioctl(inode->i_rdev, cmd, arg);
+		if (tr->flush)
+			return tr->flush(dev);
+		/* The core code did the work, we had nothing to do. */
+		return 0;
+
+	case HDIO_GETGEO:
+		if (tr->getgeo) {
+			struct hd_geometry g;
+			struct gendisk *gd = &(tr->blkcore_priv->gd);
+			int ret;
+
+			memset(&g, 0, sizeof(g));
+			ret = tr->getgeo(dev, &g);
+			if (ret)
+				return ret;
+
+			g.start = gd->part[MINOR(inode->i_rdev)].start_sect;
+			if (copy_to_user((void *)arg, &g, sizeof(g)))
+				return -EFAULT;
+			return 0;
+		} /* else */
+	default:
+		return -ENOTTY;
+	}
+}
+
+struct block_device_operations mtd_blktrans_ops = {
+	.owner		= THIS_MODULE,
+	.open		= blktrans_open,
+	.release	= blktrans_release,
+	.ioctl		= blktrans_ioctl,
+};
+
+int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
+{
+	struct mtd_blktrans_ops *tr = new->tr;
+	struct list_head *this;
+	int last_devnum = -1;
+	int i;
+
+	if (!down_trylock(&mtd_table_mutex)) {
+		up(&mtd_table_mutex);
+		BUG();
+	}
+
+	spin_lock(&tr->blkcore_priv->devs_lock);
+
+	list_for_each(this, &tr->devs) {
+		struct mtd_blktrans_dev *d = list_entry(this, struct mtd_blktrans_dev, list);
+		if (new->devnum == -1) {
+			/* Use first free number */
+			if (d->devnum != last_devnum+1) {
+				/* Found a free devnum. Plug it in here */
+				new->devnum = last_devnum+1;
+				list_add_tail(&new->list, &d->list);
+				goto added;
+			}
+		} else if (d->devnum == new->devnum) {
+			/* Required number taken */
+			spin_unlock(&tr->blkcore_priv->devs_lock);
+			return -EBUSY;
+		} else if (d->devnum > new->devnum) {
+			/* Required number was free */
+			list_add_tail(&new->list, &d->list);
+			goto added;
+		}
+		last_devnum = d->devnum;
+	}
+	if (new->devnum == -1)
+		new->devnum = last_devnum+1;
+
+	if ((new->devnum << tr->part_bits) > 256) {
+		spin_unlock(&tr->blkcore_priv->devs_lock);
+		return -EBUSY;
+	}
+
+	init_MUTEX(&new->sem);
+	list_add_tail(&new->list, &tr->devs);
+ added:
+	spin_unlock(&tr->blkcore_priv->devs_lock);
+
+	if (!tr->writesect)
+		new->readonly = 1;
+
+	for (i = new->devnum << tr->part_bits;
+	     i < (new->devnum+1) << tr->part_bits;
+	     i++) {
+		set_device_ro(MKDEV(tr->major, i), new->readonly);
+		tr->blkcore_priv->blksizes[i] = new->blksize;
+		tr->blkcore_priv->sizes[i] = 0;
+		tr->blkcore_priv->part_table[i].nr_sects = 0;
+		tr->blkcore_priv->part_table[i].start_sect = 0;
+	}
+
+	/*
+	  <viro_zzz> dwmw2: BLOCK_SIZE_BITS has nothing to do with block devices
+	  <viro> dwmw2: any code which sets blk_size[][] should be
+			size >> 10 /+ 2.4 and its dumb units */
+
+	tr->blkcore_priv->sizes[new->devnum << tr->part_bits] =
+		(new->size * new->blksize) >> 10; /* 2.4 and its dumb units */
+
+	/* But this is still in device's sectors? $DEITY knows */
+	tr->blkcore_priv->part_table[new->devnum << tr->part_bits].nr_sects = new->size;
+
+	if (tr->part_bits) {
+		grok_partitions(&tr->blkcore_priv->gd, new->devnum,
+				1 << tr->part_bits, new->size);
+	}
+#ifdef CONFIG_DEVFS_FS
+	if (!tr->part_bits) {
+		char name[2];
+
+		name[0] = '0' + new->devnum;
+		name[1] = 0;
+
+		new->blkcore_priv =
+			devfs_register(tr->blkcore_priv->devfs_dir_handle,
+				       name, DEVFS_FL_DEFAULT, tr->major,
+				       new->devnum, S_IFBLK|S_IRUGO|S_IWUGO,
+				       &mtd_blktrans_ops, NULL);
+	}
+#endif
+	return 0;
+}
+
+int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
+{
+	struct mtd_blktrans_ops *tr = old->tr;
+	int i;
+
+	if (!down_trylock(&mtd_table_mutex)) {
+		up(&mtd_table_mutex);
+		BUG();
+	}
+
+#ifdef CONFIG_DEVFS_FS
+	if (!tr->part_bits) {
+		devfs_unregister(old->blkcore_priv);
+		old->blkcore_priv = NULL;
+	} else {
+		devfs_register_partitions(&tr->blkcore_priv->gd,
+					  old->devnum << tr->part_bits, 1);
+	}
+#endif
+	spin_lock(&tr->blkcore_priv->devs_lock);
+	list_del(&old->list);
+	spin_unlock(&tr->blkcore_priv->devs_lock);
+
+	for (i = (old->devnum << tr->part_bits);
+	     i < ((old->devnum+1) << tr->part_bits); i++) {
+		tr->blkcore_priv->sizes[i] = 0;
+		tr->blkcore_priv->part_table[i].nr_sects = 0;
+		tr->blkcore_priv->part_table[i].start_sect = 0;
+	}
+
+	return 0;
+}
+
+void blktrans_notify_remove(struct mtd_info *mtd)
+{
+	struct list_head *this, *this2, *next;
+
+	list_for_each(this, &blktrans_majors) {
+		struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
+
+		list_for_each_safe(this2, next, &tr->devs) {
+			struct mtd_blktrans_dev *dev = list_entry(this2, struct mtd_blktrans_dev, list);
+
+			if (dev->mtd == mtd)
+				tr->remove_dev(dev);
+		}
+	}
+}
+
+void blktrans_notify_add(struct mtd_info *mtd)
+{
+	struct list_head *this;
+
+	if (mtd->type == MTD_ABSENT)
+		return;
+
+	list_for_each(this, &blktrans_majors) {
+		struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
+
+		tr->add_mtd(tr, mtd);
+	}
+
+}
+
+static struct mtd_notifier blktrans_notifier = {
+	.add = blktrans_notify_add,
+	.remove = blktrans_notify_remove,
+};
+
+int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
+{
+	int ret, i;
+
+	/* Register the notifier if/when the first device type is
+	   registered, to prevent the link/init ordering from fucking
+	   us over. */
+	if (!blktrans_notifier.list.next)
+		register_mtd_user(&blktrans_notifier);
+
+	tr->blkcore_priv = kmalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL);
+	if (!tr->blkcore_priv)
+		return -ENOMEM;
+
+	memset(tr->blkcore_priv, 0, sizeof(*tr->blkcore_priv));
+
+	down(&mtd_table_mutex);
+
+	ret = devfs_register_blkdev(tr->major, tr->name, &mtd_blktrans_ops);
+	if (ret) {
+		printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
+		       tr->name, tr->major, ret);
+		kfree(tr->blkcore_priv);
+		up(&mtd_table_mutex);
+		return ret;
+	}
+
+	blk_init_queue(BLK_DEFAULT_QUEUE(tr->major), &mtd_blktrans_request);
+	(BLK_DEFAULT_QUEUE(tr->major))->queuedata = tr;
+
+	init_completion(&tr->blkcore_priv->thread_dead);
+	init_waitqueue_head(&tr->blkcore_priv->thread_wq);
+
+	ret = kernel_thread(mtd_blktrans_thread, tr,
+			  CLONE_FS|CLONE_FILES|CLONE_SIGHAND);
+	if (ret < 0) {
+		blk_cleanup_queue(BLK_DEFAULT_QUEUE(tr->major));
+		devfs_unregister_blkdev(tr->major, tr->name);
+		kfree(tr->blkcore_priv);
+		up(&mtd_table_mutex);
+		return ret;
+	}
+
+	tr->blkcore_priv->devfs_dir_handle =
+			devfs_mk_dir(NULL, tr->name, NULL);
+
+	blksize_size[tr->major] = tr->blkcore_priv->blksizes;
+	blk_size[tr->major] = tr->blkcore_priv->sizes;
+
+	tr->blkcore_priv->gd.major = tr->major;
+	tr->blkcore_priv->gd.major_name = tr->name;
+	tr->blkcore_priv->gd.minor_shift = tr->part_bits;
+	tr->blkcore_priv->gd.max_p = (1<<tr->part_bits) - 1;
+	tr->blkcore_priv->gd.part = tr->blkcore_priv->part_table;
+	tr->blkcore_priv->gd.sizes = tr->blkcore_priv->sizes;
+	tr->blkcore_priv->gd.nr_real = 256 >> tr->part_bits;
+
+	spin_lock_init(&tr->blkcore_priv->devs_lock);
+
+	add_gendisk(&tr->blkcore_priv->gd);
+
+	INIT_LIST_HEAD(&tr->devs);
+	list_add(&tr->list, &blktrans_majors);
+
+	for (i=0; i<MAX_MTD_DEVICES; i++) {
+		if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT)
+			tr->add_mtd(tr, mtd_table[i]);
+	}
+	up(&mtd_table_mutex);
+
+	return 0;
+}
+
+int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
+{
+	struct list_head *this, *next;
+
+	down(&mtd_table_mutex);
+
+	/* Clean up the kernel thread */
+	tr->blkcore_priv->exiting = 1;
+	wake_up(&tr->blkcore_priv->thread_wq);
+	wait_for_completion(&tr->blkcore_priv->thread_dead);
+
+	/* Remove it from the list of active majors */
+	list_del(&tr->list);
+
+	/* Remove each of its devices */
+	list_for_each_safe(this, next, &tr->devs) {
+		struct mtd_blktrans_dev *dev = list_entry(this, struct mtd_blktrans_dev, list);
+		tr->remove_dev(dev);
+	}
+
+	blksize_size[tr->major] = NULL;
+	blk_size[tr->major] = NULL;
+
+	del_gendisk(&tr->blkcore_priv->gd);
+
+	blk_cleanup_queue(BLK_DEFAULT_QUEUE(tr->major));
+	devfs_unregister_blkdev(tr->major, tr->name);
+
+	devfs_unregister(tr->blkcore_priv->devfs_dir_handle);
+
+	up(&mtd_table_mutex);
+
+	kfree(tr->blkcore_priv);
+
+	if (!list_empty(&tr->devs))
+		BUG();
+	return 0;
+}
+
+static void __exit mtd_blktrans_exit(void)
+{
+	/* No race here -- if someone's currently in register_mtd_blktrans
+	   we're screwed anyway. */
+	if (blktrans_notifier.list.next)
+		unregister_mtd_user(&blktrans_notifier);
+}
+
+module_exit(mtd_blktrans_exit);
+
+EXPORT_SYMBOL_GPL(register_mtd_blktrans);
+EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
+EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
+EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
+
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");