Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 478 insertions, 0 deletions

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
new file mode 100644
index 000000000000..f8d2185819e7
--- /dev/null
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -0,0 +1,478 @@
+/*
+ * $Id: mtd_blkdevs.c,v 1.24 2004/11/16 18:28:59 dwmw2 Exp $
+ *
+ * (C) 2003 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Interface to Linux 2.5 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/blkpg.h>
+#include <linux/spinlock.h>
+#include <linux/hdreg.h>
+#include <linux/init.h>
+#include <asm/semaphore.h>
+#include <asm/uaccess.h>
+#include <linux/devfs_fs_kernel.h>
+
+static LIST_HEAD(blktrans_majors);
+
+extern struct semaphore mtd_table_mutex;
+extern struct mtd_info *mtd_table[];
+
+struct mtd_blkcore_priv {
+        struct completion thread_dead;
+        int exiting;
+        wait_queue_head_t thread_wq;
+        struct request_queue *rq;
+        spinlock_t queue_lock;
+};
+
+static int do_blktrans_request(struct mtd_blktrans_ops *tr,
+                               struct mtd_blktrans_dev *dev,
+                               struct request *req)
+{
+        unsigned long block, nsect;
+        char *buf;
+
+        block = req->sector;
+        nsect = req->current_nr_sectors;
+        buf = req->buffer;
+
+        if (!(req->flags & REQ_CMD))
+                return 0;
+
+        if (block + nsect > get_capacity(req->rq_disk))
+                return 0;
+
+        switch(rq_data_dir(req)) {
+        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 %ld\n", rq_data_dir(req));
+                return 0;
+        }
+}
+
+static int mtd_blktrans_thread(void *arg)
+{
+        struct mtd_blktrans_ops *tr = arg;
+        struct request_queue *rq = tr->blkcore_priv->rq;
+
+        /* we might get involved when memory gets low, so use PF_MEMALLOC */
+        current->flags |= PF_MEMALLOC | PF_NOFREEZE;
+
+        daemonize("%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->sighand->siglock);
+        sigfillset(&current->blocked);
+        recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
+
+        spin_lock_irq(rq->queue_lock);
+                
+        while (!tr->blkcore_priv->exiting) {
+                struct request *req;
+                struct mtd_blktrans_dev *dev;
+                int res = 0;
+                DECLARE_WAITQUEUE(wait, current);
+
+                req = elv_next_request(rq);
+
+                if (!req) {
+                        add_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
+                        set_current_state(TASK_INTERRUPTIBLE);
+
+                        spin_unlock_irq(rq->queue_lock);
+
+                        schedule();
+                        remove_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
+
+                        spin_lock_irq(rq->queue_lock);
+
+                        continue;
+                }
+
+                dev = req->rq_disk->private_data;
+                tr = dev->tr;
+
+                spin_unlock_irq(rq->queue_lock);
+
+                down(&dev->sem);
+                res = do_blktrans_request(tr, dev, req);
+                up(&dev->sem);
+
+                spin_lock_irq(rq->queue_lock);
+
+                end_request(req, res);
+        }
+        spin_unlock_irq(rq->queue_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);
+}
+
+
+static int blktrans_open(struct inode *i, struct file *f)
+{
+        struct mtd_blktrans_dev *dev;
+        struct mtd_blktrans_ops *tr;
+        int ret = -ENODEV;
+
+        dev = i->i_bdev->bd_disk->private_data;
+        tr = dev->tr;
+
+        if (!try_module_get(dev->mtd->owner))
+                goto out;
+
+        if (!try_module_get(tr->owner))
+                goto out_tr;
+
+        /* FIXME: Locking. A hot pluggable device can go away 
+           (del_mtd_device can be called for it) without its module
+           being unloaded. */
+        dev->mtd->usecount++;
+
+        ret = 0;
+        if (tr->open && (ret = tr->open(dev))) {
+                dev->mtd->usecount--;
+                module_put(dev->mtd->owner);
+        out_tr:
+                module_put(tr->owner);
+        }
+ out:
+        return ret;
+}
+
+static int blktrans_release(struct inode *i, struct file *f)
+{
+        struct mtd_blktrans_dev *dev;
+        struct mtd_blktrans_ops *tr;
+        int ret = 0;
+
+        dev = i->i_bdev->bd_disk->private_data;
+        tr = dev->tr;
+
+        if (tr->release)
+                ret = tr->release(dev);
+
+        if (!ret) {
+                dev->mtd->usecount--;
+                module_put(dev->mtd->owner);
+                module_put(tr->owner);
+        }
+
+        return ret;
+}
+
+
+static int blktrans_ioctl(struct inode *inode, struct file *file, 
+                              unsigned int cmd, unsigned long arg)
+{
+        struct mtd_blktrans_dev *dev = inode->i_bdev->bd_disk->private_data;
+        struct mtd_blktrans_ops *tr = dev->tr;
+
+        switch (cmd) {
+        case BLKFLSBUF:
+                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;
+                        int ret;
+
+                        memset(&g, 0, sizeof(g));
+                        ret = tr->getgeo(dev, &g);
+                        if (ret)
+                                return ret;
+
+                        g.start = get_start_sect(inode->i_bdev);
+                        if (copy_to_user((void __user *)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;
+        struct gendisk *gd;
+
+        if (!down_trylock(&mtd_table_mutex)) {
+                up(&mtd_table_mutex);
+                BUG();
+        }
+
+        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 */
+                        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) {
+                return -EBUSY;
+        }
+
+        init_MUTEX(&new->sem);
+        list_add_tail(&new->list, &tr->devs);
+ added:
+        if (!tr->writesect)
+                new->readonly = 1;
+
+        gd = alloc_disk(1 << tr->part_bits);
+        if (!gd) {
+                list_del(&new->list);
+                return -ENOMEM;
+        }
+        gd->major = tr->major;
+        gd->first_minor = (new->devnum) << tr->part_bits;
+        gd->fops = &mtd_blktrans_ops;
+        
+        snprintf(gd->disk_name, sizeof(gd->disk_name),
+                 "%s%c", tr->name, (tr->part_bits?'a':'0') + new->devnum);
+        snprintf(gd->devfs_name, sizeof(gd->devfs_name),
+                 "%s/%c", tr->name, (tr->part_bits?'a':'0') + new->devnum);
+
+        /* 2.5 has capacity in units of 512 bytes while still
+           having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */
+        set_capacity(gd, (new->size * new->blksize) >> 9);
+
+        gd->private_data = new;
+        new->blkcore_priv = gd;
+        gd->queue = tr->blkcore_priv->rq;
+
+        if (new->readonly)
+                set_disk_ro(gd, 1);
+
+        add_disk(gd);
+        
+        return 0;
+}
+
+int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
+{
+        if (!down_trylock(&mtd_table_mutex)) {
+                up(&mtd_table_mutex);
+                BUG();
+        }
+
+        list_del(&old->list);
+
+        del_gendisk(old->blkcore_priv);
+        put_disk(old->blkcore_priv);
+                
+        return 0;
+}
+
+static 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);
+                }
+        }
+}
+
+static 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 = register_blkdev(tr->major, tr->name);
+        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;
+        }
+        spin_lock_init(&tr->blkcore_priv->queue_lock);
+        init_completion(&tr->blkcore_priv->thread_dead);
+        init_waitqueue_head(&tr->blkcore_priv->thread_wq);
+
+        tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock);
+        if (!tr->blkcore_priv->rq) {
+                unregister_blkdev(tr->major, tr->name);
+                kfree(tr->blkcore_priv);
+                up(&mtd_table_mutex);
+                return -ENOMEM;
+        }
+
+        tr->blkcore_priv->rq->queuedata = tr;
+
+        ret = kernel_thread(mtd_blktrans_thread, tr, CLONE_KERNEL);
+        if (ret < 0) {
+                blk_cleanup_queue(tr->blkcore_priv->rq);
+                unregister_blkdev(tr->major, tr->name);
+                kfree(tr->blkcore_priv);
+                up(&mtd_table_mutex);
+                return ret;
+        } 
+
+        devfs_mk_dir(tr->name);
+
+        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);
+
+        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);
+        }
+
+        devfs_remove(tr->name);
+        blk_cleanup_queue(tr->blkcore_priv->rq);
+        unregister_blkdev(tr->major, tr->name);
+
+        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'");