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!
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
new file mode 100644
index 0000000..cfe6ccf
--- /dev/null
+++ b/drivers/mtd/devices/block2mtd.c
@@ -0,0 +1,495 @@
+/*
+ * $Id: block2mtd.c,v 1.23 2005/01/05 17:05:46 dwmw2 Exp $
+ *
+ * block2mtd.c - create an mtd from a block device
+ *
+ * Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
+ * Copyright (C) 2004 Gareth Bult <Gareth@Encryptec.net>
+ * Copyright (C) 2004,2005 Jörn Engel <joern@wh.fh-wedel.de>
+ *
+ * Licence: GPL
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/list.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+#include <linux/buffer_head.h>
+
+#define VERSION "$Revision: 1.23 $"
+
+
+#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
+#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
+
+
+/* Info for the block device */
+struct block2mtd_dev {
+ struct list_head list;
+ struct block_device *blkdev;
+ struct mtd_info mtd;
+ struct semaphore write_mutex;
+};
+
+
+/* Static info about the MTD, used in cleanup_module */
+static LIST_HEAD(blkmtd_device_list);
+
+
+#define PAGE_READAHEAD 64
+void cache_readahead(struct address_space *mapping, int index)
+{
+ filler_t *filler = (filler_t*)mapping->a_ops->readpage;
+ int i, pagei;
+ unsigned ret = 0;
+ unsigned long end_index;
+ struct page *page;
+ LIST_HEAD(page_pool);
+ struct inode *inode = mapping->host;
+ loff_t isize = i_size_read(inode);
+
+ if (!isize) {
+ INFO("iSize=0 in cache_readahead\n");
+ return;
+ }
+
+ end_index = ((isize - 1) >> PAGE_CACHE_SHIFT);
+
+ read_lock_irq(&mapping->tree_lock);
+ for (i = 0; i < PAGE_READAHEAD; i++) {
+ pagei = index + i;
+ if (pagei > end_index) {
+ INFO("Overrun end of disk in cache readahead\n");
+ break;
+ }
+ page = radix_tree_lookup(&mapping->page_tree, pagei);
+ if (page && (!i))
+ break;
+ if (page)
+ continue;
+ read_unlock_irq(&mapping->tree_lock);
+ page = page_cache_alloc_cold(mapping);
+ read_lock_irq(&mapping->tree_lock);
+ if (!page)
+ break;
+ page->index = pagei;
+ list_add(&page->lru, &page_pool);
+ ret++;
+ }
+ read_unlock_irq(&mapping->tree_lock);
+ if (ret)
+ read_cache_pages(mapping, &page_pool, filler, NULL);
+}
+
+
+static struct page* page_readahead(struct address_space *mapping, int index)
+{
+ filler_t *filler = (filler_t*)mapping->a_ops->readpage;
+ //do_page_cache_readahead(mapping, index, XXX, 64);
+ cache_readahead(mapping, index);
+ return read_cache_page(mapping, index, filler, NULL);
+}
+
+
+/* erase a specified part of the device */
+static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
+{
+ struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
+ struct page *page;
+ int index = to >> PAGE_SHIFT; // page index
+ int pages = len >> PAGE_SHIFT;
+ u_long *p;
+ u_long *max;
+
+ while (pages) {
+ page = page_readahead(mapping, index);
+ if (!page)
+ return -ENOMEM;
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ max = (u_long*)page_address(page) + PAGE_SIZE;
+ for (p=(u_long*)page_address(page); p<max; p++)
+ if (*p != -1UL) {
+ lock_page(page);
+ memset(page_address(page), 0xff, PAGE_SIZE);
+ set_page_dirty(page);
+ unlock_page(page);
+ break;
+ }
+
+ page_cache_release(page);
+ pages--;
+ index++;
+ }
+ return 0;
+}
+static int block2mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+ struct block2mtd_dev *dev = mtd->priv;
+ size_t from = instr->addr;
+ size_t len = instr->len;
+ int err;
+
+ instr->state = MTD_ERASING;
+ down(&dev->write_mutex);
+ err = _block2mtd_erase(dev, from, len);
+ up(&dev->write_mutex);
+ if (err) {
+ ERROR("erase failed err = %d", err);
+ instr->state = MTD_ERASE_FAILED;
+ } else
+ instr->state = MTD_ERASE_DONE;
+
+ instr->state = MTD_ERASE_DONE;
+ mtd_erase_callback(instr);
+ return err;
+}
+
+
+static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ struct block2mtd_dev *dev = mtd->priv;
+ struct page *page;
+ int index = from >> PAGE_SHIFT;
+ int offset = from & (PAGE_SHIFT-1);
+ int cpylen;
+
+ if (from > mtd->size)
+ return -EINVAL;
+ if (from + len > mtd->size)
+ len = mtd->size - from;
+
+ if (retlen)
+ *retlen = 0;
+
+ while (len) {
+ if ((offset + len) > PAGE_SIZE)
+ cpylen = PAGE_SIZE - offset; // multiple pages
+ else
+ cpylen = len; // this page
+ len = len - cpylen;
+
+ // Get page
+ page = page_readahead(dev->blkdev->bd_inode->i_mapping, index);
+ if (!page)
+ return -ENOMEM;
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ memcpy(buf, page_address(page) + offset, cpylen);
+ page_cache_release(page);
+
+ if (retlen)
+ *retlen += cpylen;
+ buf += cpylen;
+ offset = 0;
+ index++;
+ }
+ return 0;
+}
+
+
+/* write data to the underlying device */
+static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
+ loff_t to, size_t len, size_t *retlen)
+{
+ struct page *page;
+ struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
+ int index = to >> PAGE_SHIFT; // page index
+ int offset = to & ~PAGE_MASK; // page offset
+ int cpylen;
+
+ if (retlen)
+ *retlen = 0;
+ while (len) {
+ if ((offset+len) > PAGE_SIZE)
+ cpylen = PAGE_SIZE - offset; // multiple pages
+ else
+ cpylen = len; // this page
+ len = len - cpylen;
+
+ // Get page
+ page = page_readahead(mapping, index);
+ if (!page)
+ return -ENOMEM;
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ if (memcmp(page_address(page)+offset, buf, cpylen)) {
+ lock_page(page);
+ memcpy(page_address(page) + offset, buf, cpylen);
+ set_page_dirty(page);
+ unlock_page(page);
+ }
+ page_cache_release(page);
+
+ if (retlen)
+ *retlen += cpylen;
+
+ buf += cpylen;
+ offset = 0;
+ index++;
+ }
+ return 0;
+}
+static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ struct block2mtd_dev *dev = mtd->priv;
+ int err;
+
+ if (!len)
+ return 0;
+ if (to >= mtd->size)
+ return -ENOSPC;
+ if (to + len > mtd->size)
+ len = mtd->size - to;
+
+ down(&dev->write_mutex);
+ err = _block2mtd_write(dev, buf, to, len, retlen);
+ up(&dev->write_mutex);
+ if (err > 0)
+ err = 0;
+ return err;
+}
+
+
+/* sync the device - wait until the write queue is empty */
+static void block2mtd_sync(struct mtd_info *mtd)
+{
+ struct block2mtd_dev *dev = mtd->priv;
+ sync_blockdev(dev->blkdev);
+ return;
+}
+
+
+static void block2mtd_free_device(struct block2mtd_dev *dev)
+{
+ if (!dev)
+ return;
+
+ kfree(dev->mtd.name);
+
+ if (dev->blkdev) {
+ invalidate_inode_pages(dev->blkdev->bd_inode->i_mapping);
+ close_bdev_excl(dev->blkdev);
+ }
+
+ kfree(dev);
+}
+
+
+/* FIXME: ensure that mtd->size % erase_size == 0 */
+static struct block2mtd_dev *add_device(char *devname, int erase_size)
+{
+ struct block_device *bdev;
+ struct block2mtd_dev *dev;
+
+ if (!devname)
+ return NULL;
+
+ dev = kmalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
+ if (!dev)
+ return NULL;
+ memset(dev, 0, sizeof(*dev));
+
+ /* Get a handle on the device */
+ bdev = open_bdev_excl(devname, O_RDWR, NULL);
+ if (IS_ERR(bdev)) {
+ ERROR("error: cannot open device %s", devname);
+ goto devinit_err;
+ }
+ dev->blkdev = bdev;
+
+ if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
+ ERROR("attempting to use an MTD device as a block device");
+ goto devinit_err;
+ }
+
+ init_MUTEX(&dev->write_mutex);
+
+ /* Setup the MTD structure */
+ /* make the name contain the block device in */
+ dev->mtd.name = kmalloc(sizeof("block2mtd: ") + strlen(devname),
+ GFP_KERNEL);
+ if (!dev->mtd.name)
+ goto devinit_err;
+
+ sprintf(dev->mtd.name, "block2mtd: %s", devname);
+
+ dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
+ dev->mtd.erasesize = erase_size;
+ dev->mtd.type = MTD_RAM;
+ dev->mtd.flags = MTD_CAP_RAM;
+ dev->mtd.erase = block2mtd_erase;
+ dev->mtd.write = block2mtd_write;
+ dev->mtd.writev = default_mtd_writev;
+ dev->mtd.sync = block2mtd_sync;
+ dev->mtd.read = block2mtd_read;
+ dev->mtd.readv = default_mtd_readv;
+ dev->mtd.priv = dev;
+ dev->mtd.owner = THIS_MODULE;
+
+ if (add_mtd_device(&dev->mtd)) {
+ /* Device didnt get added, so free the entry */
+ goto devinit_err;
+ }
+ list_add(&dev->list, &blkmtd_device_list);
+ INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
+ dev->mtd.name + strlen("blkmtd: "),
+ dev->mtd.erasesize >> 10, dev->mtd.erasesize);
+ return dev;
+
+devinit_err:
+ block2mtd_free_device(dev);
+ return NULL;
+}
+
+
+static int ustrtoul(const char *cp, char **endp, unsigned int base)
+{
+ unsigned long result = simple_strtoul(cp, endp, base);
+ switch (**endp) {
+ case 'G' :
+ result *= 1024;
+ case 'M':
+ result *= 1024;
+ case 'k':
+ result *= 1024;
+ /* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
+ if ((*endp)[1] == 'i')
+ (*endp) += 2;
+ }
+ return result;
+}
+
+
+static int parse_num32(u32 *num32, const char *token)
+{
+ char *endp;
+ unsigned long n;
+
+ n = ustrtoul(token, &endp, 0);
+ if (*endp)
+ return -EINVAL;
+
+ *num32 = n;
+ return 0;
+}
+
+
+static int parse_name(char **pname, const char *token, size_t limit)
+{
+ size_t len;
+ char *name;
+
+ len = strlen(token) + 1;
+ if (len > limit)
+ return -ENOSPC;
+
+ name = kmalloc(len, GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+
+ strcpy(name, token);
+
+ *pname = name;
+ return 0;
+}
+
+
+static inline void kill_final_newline(char *str)
+{
+ char *newline = strrchr(str, '\n');
+ if (newline && !newline[1])
+ *newline = 0;
+}
+
+
+#define parse_err(fmt, args...) do { \
+ ERROR("block2mtd: " fmt "\n", ## args); \
+ return 0; \
+} while (0)
+
+static int block2mtd_setup(const char *val, struct kernel_param *kp)
+{
+ char buf[80+12], *str=buf; /* 80 for device, 12 for erase size */
+ char *token[2];
+ char *name;
+ u32 erase_size = PAGE_SIZE;
+ int i, ret;
+
+ if (strnlen(val, sizeof(buf)) >= sizeof(buf))
+ parse_err("parameter too long");
+
+ strcpy(str, val);
+ kill_final_newline(str);
+
+ for (i=0; i<2; i++)
+ token[i] = strsep(&str, ",");
+
+ if (str)
+ parse_err("too many arguments");
+
+ if (!token[0])
+ parse_err("no argument");
+
+ ret = parse_name(&name, token[0], 80);
+ if (ret == -ENOMEM)
+ parse_err("out of memory");
+ if (ret == -ENOSPC)
+ parse_err("name too long");
+ if (ret)
+ return 0;
+
+ if (token[1]) {
+ ret = parse_num32(&erase_size, token[1]);
+ if (ret)
+ parse_err("illegal erase size");
+ }
+
+ add_device(name, erase_size);
+
+ return 0;
+}
+
+
+module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
+MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
+
+static int __init block2mtd_init(void)
+{
+ INFO("version " VERSION);
+ return 0;
+}
+
+
+static void __devexit block2mtd_exit(void)
+{
+ struct list_head *pos, *next;
+
+ /* Remove the MTD devices */
+ list_for_each_safe(pos, next, &blkmtd_device_list) {
+ struct block2mtd_dev *dev = list_entry(pos, typeof(*dev), list);
+ block2mtd_sync(&dev->mtd);
+ del_mtd_device(&dev->mtd);
+ INFO("mtd%d: [%s] removed", dev->mtd.index,
+ dev->mtd.name + strlen("blkmtd: "));
+ list_del(&dev->list);
+ block2mtd_free_device(dev);
+ }
+}
+
+
+module_init(block2mtd_init);
+module_exit(block2mtd_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Simon Evans <spse@secret.org.uk> and others");
+MODULE_DESCRIPTION("Emulate an MTD using a block device");