Merge git://git.infradead.org/mtd-2.6

* git://git.infradead.org/mtd-2.6: (46 commits)
  [MTD] [MAPS] drivers/mtd/maps/ck804xrom.c: convert pci_module_init()
  [MTD] [NAND] CM-x270 MTD driver
  [MTD] [NAND] Wrong calculation of page number in nand_block_bad()
  [MTD] [MAPS] fix plat-ram printk format
  [JFFS2] Fix compr_rubin.c build after include file elimination.
  [JFFS2] Handle inodes with only a single metadata node with non-zero isize
  [JFFS2] Tidy up licensing/copyright boilerplate.
  [MTD] [OneNAND] Exit loop only when column start with 0
  [MTD] [OneNAND] Fix access the past of the real oobfree array
  [MTD] [OneNAND] Update Samsung OneNAND official URL
  [JFFS2] Better fix for all-zero node headers
  [JFFS2] Improve read_inode memory usage, v2.
  [JFFS2] Improve failure mode if inode checking leaves unchecked space.
  [JFFS2] Fix cross-endian build.
  [MTD] Finish conversion mtd_blkdevs to use the kthread API
  [JFFS2] Obsolete dirent nodes immediately on unlink, where possible.
  Use menuconfig objects: MTD
  [MTD] mtd_blkdevs: Convert to use the kthread API
  [MTD] Fix fwh_lock locking
  [JFFS2] Speed up mount for directly-mapped NOR flash
  ...

4 files changed, 509 insertions, 70 deletions

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 440f6851da69..690c94236d7f 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -6,7 +6,7 @@ menu "Self-contained MTD device drivers"
 
 config MTD_PMC551
         tristate "Ramix PMC551 PCI Mezzanine RAM card support"
-        depends on MTD && PCI
+        depends on PCI
         ---help---
           This provides a MTD device driver for the Ramix PMC551 RAM PCI card
           from Ramix Inc. <http://www.ramix.com/products/memory/pmc551.html>.
@@ -40,7 +40,7 @@ config MTD_PMC551_DEBUG
 
 config MTD_MS02NV
         tristate "DEC MS02-NV NVRAM module support"
-        depends on MTD && MACH_DECSTATION
+        depends on MACH_DECSTATION
         help
           This is an MTD driver for the DEC's MS02-NV (54-20948-01) battery
           backed-up NVRAM module.  The module was originally meant as an NFS
@@ -54,15 +54,23 @@ config MTD_MS02NV
 
 config MTD_DATAFLASH
         tristate "Support for AT45xxx DataFlash"
-        depends on MTD && SPI_MASTER && EXPERIMENTAL
+        depends on SPI_MASTER && EXPERIMENTAL
         help
           This enables access to AT45xxx DataFlash chips, using SPI.
           Sometimes DataFlash chips are packaged inside MMC-format
           cards; at this writing, the MMC stack won't handle those.
 
+config MTD_DATAFLASH26
+        tristate "AT91RM9200 DataFlash AT26xxx"
+        depends on MTD && ARCH_AT91RM9200 && AT91_SPI
+        help
+          This enables access to the DataFlash chip (AT26xxx) on an
+          AT91RM9200-based board.
+          If you have such a board and such a DataFlash, say 'Y'.
+
 config MTD_M25P80
         tristate "Support for M25 SPI Flash"
-        depends on MTD && SPI_MASTER && EXPERIMENTAL
+        depends on SPI_MASTER && EXPERIMENTAL
         help
           This enables access to ST M25P80 and similar SPI flash chips,
           used for program and data storage.  Set up your spi devices
@@ -70,7 +78,6 @@ config MTD_M25P80
 
 config MTD_SLRAM
         tristate "Uncached system RAM"
-        depends on MTD
         help
           If your CPU cannot cache all of the physical memory in your machine,
           you can still use it for storage or swap by using this driver to
@@ -78,7 +85,6 @@ config MTD_SLRAM
 
 config MTD_PHRAM
         tristate "Physical system RAM"
-        depends on MTD
         help
           This is a re-implementation of the slram driver above.
 
@@ -88,7 +94,7 @@ config MTD_PHRAM
 
 config MTD_LART
         tristate "28F160xx flash driver for LART"
-        depends on SA1100_LART && MTD
+        depends on SA1100_LART
         help
           This enables the flash driver for LART. Please note that you do
           not need any mapping/chip driver for LART. This one does it all
@@ -96,7 +102,6 @@ config MTD_LART
 
 config MTD_MTDRAM
         tristate "Test driver using RAM"
-        depends on MTD
         help
           This enables a test MTD device driver which uses vmalloc() to
           provide storage.  You probably want to say 'N' unless you're
@@ -136,7 +141,7 @@ config MTDRAM_ABS_POS
 
 config MTD_BLOCK2MTD
         tristate "MTD using block device"
-        depends on MTD && BLOCK
+        depends on BLOCK
         help
           This driver allows a block device to appear as an MTD. It would
           generally be used in the following cases:
@@ -150,7 +155,6 @@ comment "Disk-On-Chip Device Drivers"
 
 config MTD_DOC2000
         tristate "M-Systems Disk-On-Chip 2000 and Millennium (DEPRECATED)"
-        depends on MTD
         select MTD_DOCPROBE
         select MTD_NAND_IDS
         ---help---
@@ -173,7 +177,6 @@ config MTD_DOC2000
 
 config MTD_DOC2001
         tristate "M-Systems Disk-On-Chip Millennium-only alternative driver (DEPRECATED)"
-        depends on MTD
         select MTD_DOCPROBE
         select MTD_NAND_IDS
         ---help---
@@ -195,7 +198,6 @@ config MTD_DOC2001
 
 config MTD_DOC2001PLUS
         tristate "M-Systems Disk-On-Chip Millennium Plus"
-        depends on MTD
         select MTD_DOCPROBE
         select MTD_NAND_IDS
         ---help---
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index 0f788d5c4bf8..8ab568b3f533 100644
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -16,4 +16,5 @@ obj-$(CONFIG_MTD_MTDRAM)	+= mtdram.o
 obj-$(CONFIG_MTD_LART)          += lart.o
 obj-$(CONFIG_MTD_BLOCK2MTD)     += block2mtd.o
 obj-$(CONFIG_MTD_DATAFLASH)     += mtd_dataflash.o
+obj-$(CONFIG_MTD_DATAFLASH26)   += at91_dataflash26.o
 obj-$(CONFIG_MTD_M25P80)        += m25p80.o
diff --git a/drivers/mtd/devices/at91_dataflash26.c b/drivers/mtd/devices/at91_dataflash26.c
new file mode 100644
index 000000000000..64ce37f986fc
--- /dev/null
+++ b/drivers/mtd/devices/at91_dataflash26.c
@@ -0,0 +1,485 @@
+/*
+ * Atmel DataFlash driver for Atmel AT91RM9200 (Thunder)
+ * This is a largely modified version of at91_dataflash.c that
+ * supports AT26xxx dataflash chips. The original driver supports
+ * AT45xxx chips.
+ *
+ * Note: This driver was only tested with an AT26F004. It should be
+ * easy to make it work with other AT26xxx dataflash devices, though.
+ *
+ * Copyright (C) 2007 Hans J. Koch <hjk@linutronix.de>
+ * original Copyright (C) SAN People (Pty) Ltd
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+
+#include <asm/arch/at91_spi.h>
+
+#define DATAFLASH_MAX_DEVICES   4       /* max number of dataflash devices */
+
+#define MANUFACTURER_ID_ATMEL           0x1F
+
+/* command codes */
+
+#define AT26_OP_READ_STATUS             0x05
+#define AT26_OP_READ_DEV_ID             0x9F
+#define AT26_OP_ERASE_PAGE_4K           0x20
+#define AT26_OP_READ_ARRAY_FAST         0x0B
+#define AT26_OP_SEQUENTIAL_WRITE        0xAF
+#define AT26_OP_WRITE_ENABLE            0x06
+#define AT26_OP_WRITE_DISABLE           0x04
+#define AT26_OP_SECTOR_PROTECT          0x36
+#define AT26_OP_SECTOR_UNPROTECT        0x39
+
+/* status register bits */
+
+#define AT26_STATUS_BUSY                0x01
+#define AT26_STATUS_WRITE_ENABLE        0x02
+
+struct dataflash_local
+{
+        int spi;                        /* SPI chip-select number */
+        unsigned int page_size;         /* number of bytes per page */
+};
+
+
+/* Detected DataFlash devices */
+static struct mtd_info* mtd_devices[DATAFLASH_MAX_DEVICES];
+static int nr_devices = 0;
+
+/* Allocate a single SPI transfer descriptor.  We're assuming that if multiple
+   SPI transfers occur at the same time, spi_access_bus() will serialize them.
+   If this is not valid, then either (i) each dataflash 'priv' structure
+   needs it's own transfer descriptor, (ii) we lock this one, or (iii) use
+   another mechanism.   */
+static struct spi_transfer_list* spi_transfer_desc;
+
+/*
+ * Perform a SPI transfer to access the DataFlash device.
+ */
+static int do_spi_transfer(int nr, char* tx, int tx_len, char* rx, int rx_len,
+                char* txnext, int txnext_len, char* rxnext, int rxnext_len)
+{
+        struct spi_transfer_list* list = spi_transfer_desc;
+
+        list->tx[0] = tx;       list->txlen[0] = tx_len;
+        list->rx[0] = rx;       list->rxlen[0] = rx_len;
+
+        list->tx[1] = txnext;   list->txlen[1] = txnext_len;
+        list->rx[1] = rxnext;   list->rxlen[1] = rxnext_len;
+
+        list->nr_transfers = nr;
+        /* Note: spi_transfer() always returns 0, there are no error checks */
+        return spi_transfer(list);
+}
+
+/*
+ * Return the status of the DataFlash device.
+ */
+static unsigned char at91_dataflash26_status(void)
+{
+        unsigned char command[2];
+
+        command[0] = AT26_OP_READ_STATUS;
+        command[1] = 0;
+
+        do_spi_transfer(1, command, 2, command, 2, NULL, 0, NULL, 0);
+
+        return command[1];
+}
+
+/*
+ * Poll the DataFlash device until it is READY.
+ */
+static unsigned char at91_dataflash26_waitready(void)
+{
+        unsigned char status;
+
+        while (1) {
+                status = at91_dataflash26_status();
+                if (!(status & AT26_STATUS_BUSY))
+                        return status;
+        }
+}
+
+/*
+ * Enable/disable write access
+ */
+ static void at91_dataflash26_write_enable(int enable)
+{
+        unsigned char cmd[2];
+
+        DEBUG(MTD_DEBUG_LEVEL3, "write_enable: enable=%i\n", enable);
+
+        if (enable)
+                cmd[0] = AT26_OP_WRITE_ENABLE;
+        else
+                cmd[0] = AT26_OP_WRITE_DISABLE;
+        cmd[1] = 0;
+
+        do_spi_transfer(1, cmd, 2, cmd, 2, NULL, 0, NULL, 0);
+}
+
+/*
+ * Protect/unprotect sector
+ */
+ static void at91_dataflash26_sector_protect(loff_t addr, int protect)
+{
+        unsigned char cmd[4];
+
+        DEBUG(MTD_DEBUG_LEVEL3, "sector_protect: addr=0x%06x prot=%d\n",
+               addr, protect);
+
+        if (protect)
+                cmd[0] = AT26_OP_SECTOR_PROTECT;
+        else
+                cmd[0] = AT26_OP_SECTOR_UNPROTECT;
+        cmd[1] = (addr & 0x00FF0000) >> 16;
+        cmd[2] = (addr & 0x0000FF00) >> 8;
+        cmd[3] = (addr & 0x000000FF);
+
+        do_spi_transfer(1, cmd, 4, cmd, 4, NULL, 0, NULL, 0);
+}
+
+/*
+ * Erase blocks of flash.
+ */
+static int at91_dataflash26_erase(struct mtd_info *mtd,
+                                  struct erase_info *instr)
+{
+        struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;
+        unsigned char cmd[4];
+
+        DEBUG(MTD_DEBUG_LEVEL1, "dataflash_erase: addr=0x%06x len=%i\n",
+               instr->addr, instr->len);
+
+        /* Sanity checks */
+        if (priv->page_size != 4096)
+                return -EINVAL; /* Can't handle other sizes at the moment */
+
+        if (   ((instr->len % mtd->erasesize) != 0)
+            || ((instr->len % priv->page_size) != 0)
+            || ((instr->addr % priv->page_size) != 0)
+            || ((instr->addr + instr->len) > mtd->size))
+                return -EINVAL;
+
+        spi_access_bus(priv->spi);
+
+        while (instr->len > 0) {
+                at91_dataflash26_write_enable(1);
+                at91_dataflash26_sector_protect(instr->addr, 0);
+                at91_dataflash26_write_enable(1);
+                cmd[0] = AT26_OP_ERASE_PAGE_4K;
+                cmd[1] = (instr->addr & 0x00FF0000) >> 16;
+                cmd[2] = (instr->addr & 0x0000FF00) >> 8;
+                cmd[3] = (instr->addr & 0x000000FF);
+
+                DEBUG(MTD_DEBUG_LEVEL3, "ERASE: (0x%02x) 0x%02x 0x%02x"
+                                        "0x%02x\n",
+                        cmd[0], cmd[1], cmd[2], cmd[3]);
+
+                do_spi_transfer(1, cmd, 4, cmd, 4, NULL, 0, NULL, 0);
+                at91_dataflash26_waitready();
+
+                instr->addr += priv->page_size;  /* next page */
+                instr->len -= priv->page_size;
+        }
+
+        at91_dataflash26_write_enable(0);
+        spi_release_bus(priv->spi);
+
+        /* Inform MTD subsystem that erase is complete */
+        instr->state = MTD_ERASE_DONE;
+        if (instr->callback)
+                instr->callback(instr);
+
+        return 0;
+}
+
+/*
+ * Read from the DataFlash device.
+ *   from   : Start offset in flash device
+ *   len    : Number of bytes to read
+ *   retlen : Number of bytes actually read
+ *   buf    : Buffer that will receive data
+ */
+static int at91_dataflash26_read(struct mtd_info *mtd, loff_t from, size_t len,
+                                 size_t *retlen, u_char *buf)
+{
+        struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;
+        unsigned char cmd[5];
+
+        DEBUG(MTD_DEBUG_LEVEL1, "dataflash_read: %lli .. %lli\n",
+              from, from+len);
+
+        *retlen = 0;
+
+        /* Sanity checks */
+        if (!len)
+                return 0;
+        if (from + len > mtd->size)
+                return -EINVAL;
+
+        cmd[0] = AT26_OP_READ_ARRAY_FAST;
+        cmd[1] = (from & 0x00FF0000) >> 16;
+        cmd[2] = (from & 0x0000FF00) >> 8;
+        cmd[3] = (from & 0x000000FF);
+        /* cmd[4] is a "Don't care" byte  */
+
+        DEBUG(MTD_DEBUG_LEVEL3, "READ: (0x%02x) 0x%02x 0x%02x 0x%02x\n",
+               cmd[0], cmd[1], cmd[2], cmd[3]);
+
+        spi_access_bus(priv->spi);
+        do_spi_transfer(2, cmd, 5, cmd, 5, buf, len, buf, len);
+        spi_release_bus(priv->spi);
+
+        *retlen = len;
+        return 0;
+}
+
+/*
+ * Write to the DataFlash device.
+ *   to     : Start offset in flash device
+ *   len    : Number of bytes to write
+ *   retlen : Number of bytes actually written
+ *   buf    : Buffer containing the data
+ */
+static int at91_dataflash26_write(struct mtd_info *mtd, loff_t to, size_t len,
+                                  size_t *retlen, const u_char *buf)
+{
+        struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;
+        unsigned int addr, buf_index = 0;
+        int ret = -EIO, sector, last_sector;
+        unsigned char status, cmd[5];
+
+        DEBUG(MTD_DEBUG_LEVEL1, "dataflash_write: %lli .. %lli\n", to, to+len);
+
+        *retlen = 0;
+
+        /* Sanity checks */
+        if (!len)
+                return 0;
+        if (to + len > mtd->size)
+                return -EINVAL;
+
+        spi_access_bus(priv->spi);
+
+        addr = to;
+        last_sector = -1;
+
+        while (buf_index < len) {
+                sector = addr / priv->page_size;
+                /* Write first byte if a new sector begins */
+                if (sector != last_sector) {
+                        at91_dataflash26_write_enable(1);
+                        at91_dataflash26_sector_protect(addr, 0);
+                        at91_dataflash26_write_enable(1);
+
+                        /* Program first byte of a new sector */
+                        cmd[0] = AT26_OP_SEQUENTIAL_WRITE;
+                        cmd[1] = (addr & 0x00FF0000) >> 16;
+                        cmd[2] = (addr & 0x0000FF00) >> 8;
+                        cmd[3] = (addr & 0x000000FF);
+                        cmd[4] = buf[buf_index++];
+                        do_spi_transfer(1, cmd, 5, cmd, 5, NULL, 0, NULL, 0);
+                        status = at91_dataflash26_waitready();
+                        addr++;
+                        /* On write errors, the chip resets the write enable
+                           flag. This also happens after the last byte of a
+                           sector is successfully programmed. */
+                        if (   ( !(status & AT26_STATUS_WRITE_ENABLE))
+                            && ((addr % priv->page_size) != 0) ) {
+                                DEBUG(MTD_DEBUG_LEVEL1,
+                                        "write error1: addr=0x%06x, "
+                                        "status=0x%02x\n", addr, status);
+                                goto write_err;
+                        }
+                        (*retlen)++;
+                        last_sector = sector;
+                }
+
+                /* Write subsequent bytes in the same sector */
+                cmd[0] = AT26_OP_SEQUENTIAL_WRITE;
+                cmd[1] = buf[buf_index++];
+                do_spi_transfer(1, cmd, 2, cmd, 2, NULL, 0, NULL, 0);
+                status = at91_dataflash26_waitready();
+                addr++;
+
+                if (   ( !(status & AT26_STATUS_WRITE_ENABLE))
+                    && ((addr % priv->page_size) != 0) ) {
+                        DEBUG(MTD_DEBUG_LEVEL1, "write error2: addr=0x%06x, "
+                                "status=0x%02x\n", addr, status);
+                        goto write_err;
+                }
+
+                (*retlen)++;
+        }
+
+        ret = 0;
+        at91_dataflash26_write_enable(0);
+write_err:
+        spi_release_bus(priv->spi);
+        return ret;
+}
+
+/*
+ * Initialize and register DataFlash device with MTD subsystem.
+ */
+static int __init add_dataflash(int channel, char *name, int nr_pages,
+                                int pagesize)
+{
+        struct mtd_info *device;
+        struct dataflash_local *priv;
+
+        if (nr_devices >= DATAFLASH_MAX_DEVICES) {
+                printk(KERN_ERR "at91_dataflash26: Too many devices "
+                                "detected\n");
+                return 0;
+        }
+
+        device = kzalloc(sizeof(struct mtd_info) + strlen(name) + 8,
+                         GFP_KERNEL);
+        if (!device)
+                return -ENOMEM;
+
+        device->name = (char *)&device[1];
+        sprintf(device->name, "%s.spi%d", name, channel);
+        device->size = nr_pages * pagesize;
+        device->erasesize = pagesize;
+        device->owner = THIS_MODULE;
+        device->type = MTD_DATAFLASH;
+        device->flags = MTD_CAP_NORFLASH;
+        device->erase = at91_dataflash26_erase;
+        device->read = at91_dataflash26_read;
+        device->write = at91_dataflash26_write;
+
+        priv = (struct dataflash_local *)kzalloc(sizeof(struct dataflash_local),
+                GFP_KERNEL);
+        if (!priv) {
+                kfree(device);
+                return -ENOMEM;
+        }
+
+        priv->spi = channel;
+        priv->page_size = pagesize;
+        device->priv = priv;
+
+        mtd_devices[nr_devices] = device;
+        nr_devices++;
+        printk(KERN_INFO "at91_dataflash26: %s detected [spi%i] (%i bytes)\n",
+               name, channel, device->size);
+
+        return add_mtd_device(device);
+}
+
+/*
+ * Detect and initialize DataFlash device connected to specified SPI channel.
+ *
+ */
+
+struct dataflash26_types {
+        unsigned char id0;
+        unsigned char id1;
+        char *name;
+        int pagesize;
+        int nr_pages;
+};
+
+struct dataflash26_types df26_types[] = {
+        {
+                .id0 = 0x04,
+                .id1 = 0x00,
+                .name = "AT26F004",
+                .pagesize = 4096,
+                .nr_pages = 128,
+        },
+        {
+                .id0 = 0x45,
+                .id1 = 0x01,
+                .name = "AT26DF081A", /* Not tested ! */
+                .pagesize = 4096,
+                .nr_pages = 256,
+        },
+};
+
+static int __init at91_dataflash26_detect(int channel)
+{
+        unsigned char status, cmd[5];
+        int i;
+
+        spi_access_bus(channel);
+        status = at91_dataflash26_status();
+
+        if (status == 0 || status == 0xff) {
+                printk(KERN_ERR "at91_dataflash26_detect: status error %d\n",
+                        status);
+                spi_release_bus(channel);
+                return -ENODEV;
+        }
+
+        cmd[0] = AT26_OP_READ_DEV_ID;
+        do_spi_transfer(1, cmd, 5, cmd, 5, NULL, 0, NULL, 0);
+        spi_release_bus(channel);
+
+        if (cmd[1] != MANUFACTURER_ID_ATMEL)
+                return -ENODEV;
+
+        for (i = 0; i < ARRAY_SIZE(df26_types); i++) {
+                if (   cmd[2] == df26_types[i].id0
+                    && cmd[3] == df26_types[i].id1)
+                        return add_dataflash(channel,
+                                                df26_types[i].name,
+                                                df26_types[i].nr_pages,
+                                                df26_types[i].pagesize);
+        }
+
+        printk(KERN_ERR "at91_dataflash26_detect: Unsupported device "
+                        "(0x%02x/0x%02x)\n", cmd[2], cmd[3]);
+        return -ENODEV;
+}
+
+static int __init at91_dataflash26_init(void)
+{
+        spi_transfer_desc = kmalloc(sizeof(struct spi_transfer_list),
+                                    GFP_KERNEL);
+        if (!spi_transfer_desc)
+                return -ENOMEM;
+
+        /* DataFlash (SPI chip select 0) */
+        at91_dataflash26_detect(0);
+
+#ifdef CONFIG_MTD_AT91_DATAFLASH_CARD
+        /* DataFlash card (SPI chip select 3) */
+        at91_dataflash26_detect(3);
+#endif
+        return 0;
+}
+
+static void __exit at91_dataflash26_exit(void)
+{
+        int i;
+
+        for (i = 0; i < DATAFLASH_MAX_DEVICES; i++) {
+                if (mtd_devices[i]) {
+                        del_mtd_device(mtd_devices[i]);
+                        kfree(mtd_devices[i]->priv);
+                        kfree(mtd_devices[i]);
+                }
+        }
+        nr_devices = 0;
+        kfree(spi_transfer_desc);
+}
+
+module_init(at91_dataflash26_init);
+module_exit(at91_dataflash26_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Hans J. Koch");
+MODULE_DESCRIPTION("DataFlash AT26xxx driver for Atmel AT91RM9200");
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index f9f2ce7806b0..ce47544dc120 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -40,56 +40,9 @@ struct block2mtd_dev {
 static LIST_HEAD(blkmtd_device_list);
 
 
-#define PAGE_READAHEAD 64
-static void cache_readahead(struct address_space *mapping, int index)
+static struct page* page_read(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;
-        cache_readahead(mapping, index);
         return read_cache_page(mapping, index, filler, NULL);
 }
 
@@ -105,14 +58,14 @@ static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
         u_long *max;
 
         while (pages) {
-                page = page_readahead(mapping, index);
+                page = page_read(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++)
+                max = page_address(page) + PAGE_SIZE;
+                for (p=page_address(page); p<max; p++)
                         if (*p != -1UL) {
                                 lock_page(page);
                                 memset(page_address(page), 0xff, PAGE_SIZE);
@@ -174,8 +127,7 @@ static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
                         cpylen = len;   // this page
                 len = len - cpylen;
 
-                //      Get page
-                page = page_readahead(dev->blkdev->bd_inode->i_mapping, index);
+                page = page_read(dev->blkdev->bd_inode->i_mapping, index);
                 if (!page)
                         return -ENOMEM;
                 if (IS_ERR(page))
@@ -213,8 +165,7 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
                         cpylen = len;                   // this page
                 len = len - cpylen;
 
-                //      Get page
-                page = page_readahead(mapping, index);
+                page = page_read(mapping, index);
                 if (!page)
                         return -ENOMEM;
                 if (IS_ERR(page))
@@ -308,9 +259,9 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
                 /* We might not have rootfs mounted at this point. Try
                    to resolve the device name by other means. */
 
-                dev_t dev = name_to_dev_t(devname);
-                if (dev != 0) {
-                        bdev = open_by_devnum(dev, FMODE_WRITE | FMODE_READ);
+                dev_t devt = name_to_dev_t(devname);
+                if (devt) {
+                        bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
                 }
         }
 #endif