[PATCH v3 memstick: support for legacy sony memsticks

[PATCH v3 memstick: support for legacy sony memsticks

[Maxim Levitsky]

Hi,
I am sending an updated version of the driver, this time
addressing comments by Tejun Heo


Changes since V2:

* Removed the mutex kludge - ordered worqueue indeed works well
* Removed manul major/minor handling
* Gave more specific names to two sg helpers.

Changes from V1:

* Replaced explicit state numbers with enum items.
  I agree that code is cleaner this way.

* Swithced to using a workqueue.
  Unfortunelly, I still see that workqueue items are executed in parallel
  I suspect that this happens if one work item sleeps. In this case I
  don't want other work items to run too. I fixed this with a mutex, and anyway
  it nice to have it to guaranteee this.

* moved sg_nents into scatterlist.c/h and put that in separate patch as
  requested

* Made functions static, fixed most whitespace issues (I hope all),
  and I hope addressed all other comments by Andrew Morton.

[PATCH 1/2] scatterlist: add sg_nents

[Maxim Levitsky]

Useful helper to know the number of entries in scatterlist.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
 include/linux/scatterlist.h |    1 +
 lib/scatterlist.c           |   22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 7b600da..4bd6c06 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -201,6 +201,7 @@ static inline void *sg_virt(struct scatterlist *sg)
 	return page_address(sg_page(sg)) + sg->offset;
 }
 
+int sg_nents(struct scatterlist *sg);
 struct scatterlist *sg_next(struct scatterlist *);
 struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
 void sg_init_table(struct scatterlist *, unsigned int);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index e76d85c..5cd9cdc 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -39,6 +39,28 @@ struct scatterlist *sg_next(struct scatterlist *sg)
 EXPORT_SYMBOL(sg_next);
 
 /**
+ * sg_nents - return total count of entries in scatterlist
+ * @sg:		The scatterlist
+ *
+ * Description:
+ * Allows to know how many entries are in sg, taking into acount
+ * chaining as well
+ *
+ **/
+int sg_nents(struct scatterlist *sg)
+{
+	int nents = 0;
+	while (sg) {
+		nents++;
+		sg = sg_next(sg);
+	}
+
+	return nents;
+}
+EXPORT_SYMBOL(sg_nents);
+
+
+/**
  * sg_last - return the last scatterlist entry in a list
  * @sgl:	First entry in the scatterlist
  * @nents:	Number of entries in the scatterlist
-- 
1.7.9.5

[PATCH 2/2] memstick: add support for legacy memorysticks

[Maxim Levitsky]

Based partially on MS standard spec quotes from Alex Dubov.

As any code that works with user data this driver isn't
recommended to use to write cards that contain valuable data.

It tries its best though to avoid data corruption
and possible damage to the card.

Tested on MS DUO 64 MB card on Ricoh R592 card reader.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
 MAINTAINERS                      |    5 +
 drivers/memstick/core/Kconfig    |   12 +
 drivers/memstick/core/Makefile   |    2 +-
 drivers/memstick/core/ms_block.c | 2395 ++++++++++++++++++++++++++++++++++++++
 drivers/memstick/core/ms_block.h |  293 +++++
 5 files changed, 2706 insertions(+), 1 deletion(-)
 create mode 100644 drivers/memstick/core/ms_block.c
 create mode 100644 drivers/memstick/core/ms_block.h

diff --git a/MAINTAINERS b/MAINTAINERS
index fdc0119..8fb6bf0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6393,6 +6393,11 @@ W:	http://tifmxx.berlios.de/
 S:	Maintained
 F:	drivers/memstick/host/tifm_ms.c
 
+SONY MEMORYSTICK STANDARD SUPPORT
+M:	Maxim Levitsky <maximlevitsky@gmail.com>
+S:	Maintained
+F:	drivers/memstick/core/ms_block.*
+
 SOUND
 M:	Jaroslav Kysela <perex@perex.cz>
 M:	Takashi Iwai <tiwai@suse.de>
diff --git a/drivers/memstick/core/Kconfig b/drivers/memstick/core/Kconfig
index 95f1814..f79f2a8 100644
--- a/drivers/memstick/core/Kconfig
+++ b/drivers/memstick/core/Kconfig
@@ -24,3 +24,15 @@ config MSPRO_BLOCK
 	  support. This provides a block device driver, which you can use
 	  to mount the filesystem. Almost everyone wishing MemoryStick
 	  support should say Y or M here.
+
+config MS_BLOCK
+	tristate "MemoryStick Standard device driver"
+	depends on BLOCK && EXPERIMENTAL
+	help
+	  Say Y here to enable the MemoryStick Standard device driver
+	  support. This provides a block device driver, which you can use
+	  to mount the filesystem.
+	  This driver works with old (bulky) MemoryStick and MemoryStick Duo
+	  but not PRO. Say Y if you have such card.
+	  Driver is new and not yet well tested, thus it can damage your card
+	  (even permanently)
diff --git a/drivers/memstick/core/Makefile b/drivers/memstick/core/Makefile
index ecd0299..0d7f90c 100644
--- a/drivers/memstick/core/Makefile
+++ b/drivers/memstick/core/Makefile
@@ -3,5 +3,5 @@
 #
 
 obj-$(CONFIG_MEMSTICK)		+= memstick.o
-
+obj-$(CONFIG_MS_BLOCK)		+= ms_block.o
 obj-$(CONFIG_MSPRO_BLOCK)	+= mspro_block.o
diff --git a/drivers/memstick/core/ms_block.c b/drivers/memstick/core/ms_block.c
new file mode 100644
index 0000000..c815fe5
--- /dev/null
+++ b/drivers/memstick/core/ms_block.c
@@ -0,0 +1,2395 @@
+/*
+ *  ms_block.c - Sony MemoryStick (legacy) storage support
+
+ *  Copyright (C) 2012 Maxim Levitsky <maximlevitsky@gmail.com>
+ *
+ * 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.
+ *
+ * Minor portions of the driver were copied from mspro_block.c which is
+ * Copyright (C) 2007 Alex Dubov <oakad@yahoo.com>
+ *
+ */
+
+#define pr_fmt(fmt) DRIVER_NAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/memstick.h>
+#include <linux/idr.h>
+#include <linux/hdreg.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/bitmap.h>
+#include <linux/scatterlist.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.h>
+#include "ms_block.h"
+
+static int debug;
+static int cache_flush_timeout = 1000;
+static bool verify_writes;
+
+/*
+ * Copies section of 'sg_from' starting from offset 'offset' and with length
+ * 'len' To another scatterlist of to_nents enties
+ */
+static size_t msb_sg_copy(struct scatterlist *sg_from, struct scatterlist *sg_to,
+					int to_nents, size_t offset, size_t len)
+{
+	size_t copied = 0;
+
+	while (offset > 0) {
+		if (offset >= sg_from->length) {
+			if (sg_is_last(sg_from))
+				return 0;
+
+			offset -= sg_from->length;
+			sg_from = sg_next(sg_from);
+			continue;
+		}
+
+		copied = min(len, sg_from->length - offset);
+		sg_set_page(sg_to, sg_page(sg_from),
+			copied, sg_from->offset + offset);
+
+		len -= copied;
+		offset = 0;
+
+		if (sg_is_last(sg_from) || !len)
+			goto out;
+
+		sg_to = sg_next(sg_to);
+		to_nents--;
+		sg_from = sg_next(sg_from);
+	}
+
+	while (len > sg_from->length && to_nents--) {
+		len -= sg_from->length;
+		copied += sg_from->length;
+
+		sg_set_page(sg_to, sg_page(sg_from),
+				sg_from->length, sg_from->offset);
+
+		if (sg_is_last(sg_from) || !len)
+			goto out;
+
+		sg_from = sg_next(sg_from);
+		sg_to = sg_next(sg_to);
+	}
+
+	if (len && to_nents) {
+		sg_set_page(sg_to, sg_page(sg_from), len, sg_from->offset);
+		copied += len;
+	}
+out:
+	sg_mark_end(sg_to);
+	return copied;
+}
+
+/*
+ * Compares section of 'sg' starting from offset 'offset' and with length 'len'
+ * to linear buffer of length 'len' at address 'buffer'
+ * Returns 0 if equal and  -1 otherwice
+ */
+static int msb_sg_compare_to_buffer(struct scatterlist *sg,
+					size_t offset, u8 *buffer, size_t len)
+{
+	int retval = 0, cmplen;
+	struct sg_mapping_iter miter;
+
+	sg_miter_start(&miter, sg, sg_nents(sg),
+					SG_MITER_ATOMIC | SG_MITER_FROM_SG);
+
+	while (sg_miter_next(&miter) && len > 0) {
+		if (offset >= miter.length) {
+			offset -= miter.length;
+			continue;
+		}
+
+		cmplen = min(miter.length - offset, len);
+		retval = memcmp(miter.addr + offset, buffer, cmplen) ? -1 : 0;
+		if (retval)
+			break;
+
+		buffer += cmplen;
+		len -= cmplen;
+		offset = 0;
+	}
+
+	if (!retval && len)
+		retval = -1;
+
+	sg_miter_stop(&miter);
+	return retval;
+}
+
+
+/* Get zone at which block with logical address 'lba' lives
+ * Flash is broken into zones.
+ * Each zone consists of 512 eraseblocks, out of which in first
+ * zone 494 are used and 496 are for all following zones.
+ * Therefore zone #0 hosts blocks 0-493, zone #1 blocks 494-988, etc...
+*/
+static int msb_get_zone_from_lba(int lba)
+{
+	if (lba < 494)
+		return 0;
+	return ((lba - 494) / 496) + 1;
+}
+
+/* Get zone of physical block. Trivial */
+static int msb_get_zone_from_pba(int pba)
+{
+	return pba / MS_BLOCKS_IN_ZONE;
+}
+
+/* Debug test to validate free block counts */
+#ifdef DEBUG
+static int msb_validate_used_block_bitmap(struct msb_data *msb)
+{
+	int total_free_blocks = 0;
+	int i;
+
+	for (i = 0 ; i < msb->zone_count ; i++)
+		total_free_blocks += msb->free_block_count[i];
+
+	if (msb->block_count - bitmap_weight(msb->used_blocks_bitmap,
+					msb->block_count) == total_free_blocks)
+		return 0;
+
+	pr_err("BUG: free block counts don't match the bitmap");
+	msb->read_only = true;
+	return -EINVAL;
+}
+#endif
+
+/* Mark physical block as used */
+static void msb_mark_block_used(struct msb_data *msb, int pba)
+{
+	int zone = msb_get_zone_from_pba(pba);
+
+	if (test_bit(pba, msb->used_blocks_bitmap)) {
+		pr_err(
+		"BUG: attempt to mark already used pba %d as used", pba);
+		msb->read_only = true;
+		return;
+	}
+
+#ifdef DEBUG
+	if (msb_validate_used_block_bitmap(msb))
+		return;
+#endif
+	/* No races because all IO is single threaded */
+	__set_bit(pba, msb->used_blocks_bitmap);
+	msb->free_block_count[zone]--;
+}
+
+/* Mark physical block as free */
+static void msb_mark_block_unused(struct msb_data *msb, int pba)
+{
+	int zone = msb_get_zone_from_pba(pba);
+
+	if (!test_bit(pba, msb->used_blocks_bitmap)) {
+		pr_err("BUG: attempt to mark "
+				"already unused pba %d as unused" , pba);
+		msb->read_only = true;
+		return;
+	}
+
+#ifdef DEBUG
+	if (msb_validate_used_block_bitmap(msb))
+		return;
+#endif
+	/* No races because all IO is single threaded */
+	__clear_bit(pba, msb->used_blocks_bitmap);
+	msb->free_block_count[zone]++;
+}
+
+/* Invalidate current register window */
+static void msb_invalidate_reg_window(struct msb_data *msb)
+{
+	msb->reg_addr.w_offset = offsetof(struct ms_register, id);
+	msb->reg_addr.w_length = sizeof(struct ms_id_register);
+	msb->reg_addr.r_offset = offsetof(struct ms_register, id);
+	msb->reg_addr.r_length = sizeof(struct ms_id_register);
+	msb->addr_valid = false;
+}
+
+/* Start a state machine */
+static int msb_run_state_machine(struct msb_data *msb, int   (*state_func)
+		(struct memstick_dev *card, struct memstick_request **req))
+{
+	struct memstick_dev *card = msb->card;
+
+	WARN_ON(msb->state != -1);
+	msb->int_polling = false;
+	msb->state = 0;
+	msb->exit_error = 0;
+
+	memset(&card->current_mrq, 0, sizeof(card->current_mrq));
+
+	card->next_request = state_func;
+	memstick_new_req(card->host);
+	wait_for_completion(&card->mrq_complete);
+
+	WARN_ON(msb->state != -1);
+	return msb->exit_error;
+}
+
+/* State machines call that to exit */
+static int msb_exit_state_machine(struct msb_data *msb, int error)
+{
+	WARN_ON(msb->state == -1);
+
+	msb->state = -1;
+	msb->exit_error = error;
+	msb->card->next_request = h_msb_default_bad;
+
+	/* Invalidate reg window on errors */
+	if (error)
+		msb_invalidate_reg_window(msb);
+
+	complete(&msb->card->mrq_complete);
+	return -ENXIO;
+}
+
+/* read INT register */
+static int msb_read_int_reg(struct msb_data *msb, long timeout)
+{
+	struct memstick_request *mrq = &msb->card->current_mrq;
+
+	WARN_ON(msb->state == -1);
+
+	if (!msb->int_polling) {
+		msb->int_timeout = jiffies +
+			msecs_to_jiffies(timeout == -1 ? 500 : timeout);
+		msb->int_polling = true;
+	} else if (time_after(jiffies, msb->int_timeout)) {
+		mrq->data[0] = MEMSTICK_INT_CMDNAK;
+		return 0;
+	}
+
+	if ((msb->caps & MEMSTICK_CAP_AUTO_GET_INT) &&
+				mrq->need_card_int && !mrq->error) {
+		mrq->data[0] = mrq->int_reg;
+		mrq->need_card_int = false;
+		return 0;
+	} else {
+		memstick_init_req(mrq, MS_TPC_GET_INT, NULL, 1);
+		return 1;
+	}
+}
+
+/* Read a register */
+static int msb_read_regs(struct msb_data *msb, int offset, int len)
+{
+	struct memstick_request *req = &msb->card->current_mrq;
+
+	if (msb->reg_addr.r_offset != offset ||
+	    msb->reg_addr.r_length != len || !msb->addr_valid) {
+
+		msb->reg_addr.r_offset = offset;
+		msb->reg_addr.r_length = len;
+		msb->addr_valid = true;
+
+		memstick_init_req(req, MS_TPC_SET_RW_REG_ADRS,
+			&msb->reg_addr, sizeof(msb->reg_addr));
+		return 0;
+	}
+
+	memstick_init_req(req, MS_TPC_READ_REG, NULL, len);
+	return 1;
+}
+
+/* Write a card register */
+static int msb_write_regs(struct msb_data *msb, int offset, int len, void *buf)
+{
+	struct memstick_request *req = &msb->card->current_mrq;
+
+	if (msb->reg_addr.w_offset != offset ||
+		msb->reg_addr.w_length != len  || !msb->addr_valid) {
+
+		msb->reg_addr.w_offset = offset;
+		msb->reg_addr.w_length = len;
+		msb->addr_valid = true;
+
+		memstick_init_req(req, MS_TPC_SET_RW_REG_ADRS,
+			&msb->reg_addr, sizeof(msb->reg_addr));
+		return 0;
+	}
+
+	memstick_init_req(req, MS_TPC_WRITE_REG, buf, len);
+	return 1;
+}
+
+/* Handler for absence of IO */
+static int h_msb_default_bad(struct memstick_dev *card,
+						struct memstick_request **mrq)
+{
+	return -ENXIO;
+}
+
+/*
+ * This function is a handler for reads of one page from device.
+ * Writes output to msb->current_sg, takes sector address from msb->reg.param
+ * Can also be used to read extra data only. Set params accordintly.
+ */
+static int h_msb_read_page(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	struct scatterlist sg[2];
+	u8 command, intreg;
+
+	if (mrq->error) {
+		dbg("read_page, unknown error");
+		return msb_exit_state_machine(msb, mrq->error);
+	}
+again:
+	switch (msb->state) {
+	case MSB_RP_SEND_BLOCK_ADDRESS:
+		/* msb_write_regs sometimes "fails" because it needs to update
+			the reg window, and thus it returns request for that.
+			Then we stay in this state and retry */
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			sizeof(struct ms_param_register),
+			(unsigned char *)&msb->regs.param))
+			return 0;
+
+		msb->state = MSB_RP_SEND_READ_COMMAND;
+		return 0;
+
+	case MSB_RP_SEND_READ_COMMAND:
+		command = MS_CMD_BLOCK_READ;
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &command, 1);
+		msb->state = MSB_RP_SEND_INT_REQ;
+		return 0;
+
+	case MSB_RP_SEND_INT_REQ:
+		msb->state = MSB_RP_RECEIVE_INT_REQ_RESULT;
+		/* If dont actually need to send the int read request (only in
+			serial mode), then just fall through */
+		if (msb_read_int_reg(msb, -1))
+			return 0;
+		/* fallthrough */
+
+	case MSB_RP_RECEIVE_INT_REQ_RESULT:
+		intreg = mrq->data[0];
+		msb->regs.status.interrupt = intreg;
+
+		if (intreg & MEMSTICK_INT_CMDNAK)
+			return msb_exit_state_machine(msb, -EIO);
+
+		if (!(intreg & MEMSTICK_INT_CED)) {
+			msb->state = MSB_RP_SEND_INT_REQ;
+			goto again;
+		}
+
+		msb->int_polling = false;
+		msb->state = (intreg & MEMSTICK_INT_ERR) ?
+			MSB_RP_SEND_READ_STATUS_REG : MSB_RP_SEND_OOB_READ;
+		goto again;
+
+	case MSB_RP_SEND_READ_STATUS_REG:
+		 /* read the status register to understand source of the INT_ERR */
+		if (!msb_read_regs(msb,
+			offsetof(struct ms_register, status),
+			sizeof(struct ms_status_register)))
+			return 0;
+
+		msb->state = MSB_RP_RECEIVE_OOB_READ;
+		return 0;
+
+	case MSB_RP_RECIVE_STATUS_REG:
+		msb->regs.status = *(struct ms_status_register *)mrq->data;
+		msb->state = MSB_RP_SEND_OOB_READ;
+		/* fallthrough */
+
+	case MSB_RP_SEND_OOB_READ:
+		if (!msb_read_regs(msb,
+			offsetof(struct ms_register, extra_data),
+			sizeof(struct ms_extra_data_register)))
+			return 0;
+
+		msb->state = MSB_RP_RECEIVE_OOB_READ;
+		return 0;
+
+	case MSB_RP_RECEIVE_OOB_READ:
+		msb->regs.extra_data =
+			*(struct ms_extra_data_register *) mrq->data;
+		msb->state = MSB_RP_SEND_READ_DATA;
+		/* fallthrough */
+
+	case MSB_RP_SEND_READ_DATA:
+		/* Skip that state if we only read the oob */
+		if (msb->regs.param.cp == MEMSTICK_CP_EXTRA) {
+			msb->state = MSB_RP_RECEIVE_READ_DATA;
+			goto again;
+		}
+
+		sg_init_table(sg, ARRAY_SIZE(sg));
+		msb_sg_copy(msb->current_sg, sg, ARRAY_SIZE(sg),
+			msb->current_sg_offset,
+			msb->page_size);
+
+		memstick_init_req_sg(mrq, MS_TPC_READ_LONG_DATA, sg);
+		msb->state = MSB_RP_RECEIVE_READ_DATA;
+		return 0;
+
+	case MSB_RP_RECEIVE_READ_DATA:
+		if (!(msb->regs.status.interrupt & MEMSTICK_INT_ERR)) {
+			msb->current_sg_offset += msb->page_size;
+			return msb_exit_state_machine(msb, 0);
+		}
+
+		if (msb->regs.status.status1 & MEMSTICK_UNCORR_ERROR) {
+			dbg("read_page: uncorrectable error");
+			return msb_exit_state_machine(msb, -EBADMSG);
+		}
+
+		if (msb->regs.status.status1 & MEMSTICK_CORR_ERROR) {
+			dbg("read_page: correctable error");
+			msb->current_sg_offset += msb->page_size;
+			return msb_exit_state_machine(msb, -EUCLEAN);
+		} else {
+			dbg("read_page: INT error, but no status error bits");
+			return msb_exit_state_machine(msb, -EIO);
+		}
+	}
+
+	BUG();
+}
+
+/*
+ * Handler of writes of exactly one block.
+ * Takes address from msb->regs.param.
+ * Writes same extra data to blocks, also taken
+ * from msb->regs.extra
+ * Returns -EBADMSG if write fails due to uncorrectable error, or -EIO if
+ * device refuses to take the command or something else
+ */
+static int h_msb_write_block(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	struct scatterlist sg[2];
+	u8 intreg, command;
+
+	if (mrq->error)
+		return msb_exit_state_machine(msb, mrq->error);
+
+again:
+	switch (msb->state) {
+
+	/* HACK: Jmicon handling of TPCs between 8 and
+	 *	sizeof(memstick_request.data) is broken due to hardware
+	 *	bug in PIO mode that is used for these TPCs
+	 *	Therefore split the write
+	 */
+
+	case MSB_WB_SEND_WRITE_PARAMS:
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			sizeof(struct ms_param_register),
+			&msb->regs.param))
+			return 0;
+
+		msb->state = MSB_WB_SEND_WRITE_OOB;
+		return 0;
+
+	case MSB_WB_SEND_WRITE_OOB:
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, extra_data),
+			sizeof(struct ms_extra_data_register),
+			&msb->regs.extra_data))
+			return 0;
+		msb->state = MSB_WB_SEND_WRITE_COMMAND;
+		return 0;
+
+
+	case MSB_WB_SEND_WRITE_COMMAND:
+		command = MS_CMD_BLOCK_WRITE;
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &command, 1);
+		msb->state = MSB_WB_SEND_INT_REQ;
+		return 0;
+
+	case MSB_WB_SEND_INT_REQ:
+		msb->state = MSB_WB_RECEIVE_INT_REQ;
+		if (msb_read_int_reg(msb, -1))
+			return 0;
+		/* fallthrough */
+
+	case MSB_WB_RECEIVE_INT_REQ:
+		intreg = mrq->data[0];
+		msb->regs.status.interrupt = intreg;
+
+		/* errors mean out of here, and fast... */
+		if (intreg & (MEMSTICK_INT_CMDNAK))
+			return msb_exit_state_machine(msb, -EIO);
+
+		if (intreg & MEMSTICK_INT_ERR)
+			return msb_exit_state_machine(msb, -EBADMSG);
+
+
+		/* for last page we need to poll CED */
+		if (msb->current_page == msb->pages_in_block) {
+			if (intreg & MEMSTICK_INT_CED)
+				return msb_exit_state_machine(msb, 0);
+			msb->state = MSB_WB_SEND_INT_REQ;
+			goto again;
+
+		}
+
+		/* for non-last page we need BREQ before writing next chunk */
+		if (!(intreg & MEMSTICK_INT_BREQ)) {
+			msb->state = MSB_WB_SEND_INT_REQ;
+			goto again;
+		}
+
+		msb->int_polling = false;
+		msb->state = MSB_WB_SEND_WRITE_DATA;
+		/* fallthrough */
+
+	case MSB_WB_SEND_WRITE_DATA:
+		sg_init_table(sg, ARRAY_SIZE(sg));
+
+		if (msb_sg_copy(msb->current_sg, sg, ARRAY_SIZE(sg),
+			msb->current_sg_offset,
+			msb->page_size) < msb->page_size)
+			return msb_exit_state_machine(msb, -EIO);
+
+		memstick_init_req_sg(mrq, MS_TPC_WRITE_LONG_DATA, sg);
+		mrq->need_card_int = 1;
+		msb->state = MSB_WB_RECEIVE_WRITE_CONFIRMATION;
+		return 0;
+
+	case MSB_WB_RECEIVE_WRITE_CONFIRMATION:
+		msb->current_page++;
+		msb->current_sg_offset += msb->page_size;
+		msb->state = MSB_WB_SEND_INT_REQ;
+		goto again;
+	default:
+		BUG();
+	}
+
+	return 0;
+}
+
+/*
+ * This function is used to send simple IO requests to device that consist
+ * of register write + command
+ */
+static int h_msb_send_command(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	u8 intreg;
+
+	if (mrq->error) {
+		dbg("send_command: unknown error");
+		return msb_exit_state_machine(msb, mrq->error);
+	}
+again:
+	switch (msb->state) {
+
+	/* HACK: see h_msb_write_block */
+	case MSB_SC_SEND_WRITE_PARAMS: /* write param register*/
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			sizeof(struct ms_param_register),
+			&msb->regs.param))
+			return 0;
+		msb->state = MSB_SC_SEND_WRITE_OOB;
+		return 0;
+
+	case MSB_SC_SEND_WRITE_OOB:
+		if (!msb->command_need_oob) {
+			msb->state = MSB_SC_SEND_COMMAND;
+			goto again;
+		}
+
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, extra_data),
+			sizeof(struct ms_extra_data_register),
+			&msb->regs.extra_data))
+			return 0;
+
+		msb->state = MSB_SC_SEND_COMMAND;
+		return 0;
+
+	case MSB_SC_SEND_COMMAND:
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &msb->command_value, 1);
+		msb->state = MSB_SC_SEND_INT_REQ;
+		return 0;
+
+	case MSB_SC_SEND_INT_REQ:
+		msb->state = MSB_SC_RECEIVE_INT_REQ;
+		if (msb_read_int_reg(msb, -1))
+			return 0;
+		/* fallthrough */
+
+	case MSB_SC_RECEIVE_INT_REQ:
+		intreg = mrq->data[0];
+
+		if (intreg & MEMSTICK_INT_CMDNAK)
+			return msb_exit_state_machine(msb, -EIO);
+		if (intreg & MEMSTICK_INT_ERR)
+			return msb_exit_state_machine(msb, -EBADMSG);
+
+		if (!(intreg & MEMSTICK_INT_CED)) {
+			msb->state = MSB_SC_SEND_INT_REQ;
+			goto again;
+		}
+
+		return msb_exit_state_machine(msb, 0);
+	}
+
+	BUG();
+}
+
+/* Small handler for card reset */
+static int h_msb_reset(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	u8 command = MS_CMD_RESET;
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+
+	if (mrq->error)
+		return msb_exit_state_machine(msb, mrq->error);
+
+	switch (msb->state) {
+	case MSB_RS_SEND:
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &command, 1);
+		mrq->need_card_int = 0;
+		msb->state = MSB_RS_CONFIRM;
+		return 0;
+	case MSB_RS_CONFIRM:
+		return msb_exit_state_machine(msb, 0);
+	}
+	BUG();
+}
+
+/* This handler is used to do serial->parallel switch */
+static int h_msb_parallel_switch(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	struct memstick_host *host = card->host;
+
+	if (mrq->error) {
+		dbg("parallel_switch: error");
+		msb->regs.param.system &= ~MEMSTICK_SYS_PAM;
+		return msb_exit_state_machine(msb, mrq->error);
+	}
+
+	switch (msb->state) {
+	case MSB_PS_SEND_SWITCH_COMMAND:
+		/* Set the parallel interface on memstick side */
+		msb->regs.param.system |= MEMSTICK_SYS_PAM;
+
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			1,
+			(unsigned char *)&msb->regs.param))
+			return 0;
+
+		msb->state = MSB_PS_SWICH_HOST;
+		return 0;
+
+	case MSB_PS_SWICH_HOST:
+		 /* Set parallel interface on our side + send a dummy request
+			to see if card responds */
+		host->set_param(host, MEMSTICK_INTERFACE, MEMSTICK_PAR4);
+		memstick_init_req(mrq, MS_TPC_GET_INT, NULL, 1);
+		msb->state = MSB_PS_CONFIRM;
+		return 0;
+
+	case MSB_PS_CONFIRM:
+		return msb_exit_state_machine(msb, 0);
+	}
+
+	BUG();
+}
+
+static int msb_switch_to_parallel(struct msb_data *msb);
+
+/* Reset the card, to guard against hw errors beeing treated as bad blocks */
+static int msb_reset(struct msb_data *msb, bool full)
+{
+
+	bool was_parallel = msb->regs.param.system & MEMSTICK_SYS_PAM;
+	struct memstick_dev *card = msb->card;
+	struct memstick_host *host = card->host;
+	int error;
+
+	/* Reset the card */
+	msb->regs.param.system = MEMSTICK_SYS_BAMD;
+
+	if (full) {
+		error =  host->set_param(host,
+					MEMSTICK_POWER, MEMSTICK_POWER_OFF);
+		if (error)
+			goto out_error;
+
+		msb_invalidate_reg_window(msb);
+
+		error = host->set_param(host,
+					MEMSTICK_POWER, MEMSTICK_POWER_ON);
+		if (error)
+			goto out_error;
+
+		error = host->set_param(host,
+					MEMSTICK_INTERFACE, MEMSTICK_SERIAL);
+		if (error) {
+out_error:
+			dbg("Failed to reset the host controller");
+			msb->read_only = true;
+			return -EFAULT;
+		}
+	}
+
+	error = msb_run_state_machine(msb, h_msb_reset);
+	if (error) {
+		dbg("Failed to reset the card");
+		msb->read_only = true;
+		return -ENODEV;
+	}
+
+	/* Set parallel mode */
+	if (was_parallel)
+		msb_switch_to_parallel(msb);
+	return 0;
+}
+
+/* Attempts to switch interface to parallel mode */
+static int msb_switch_to_parallel(struct msb_data *msb)
+{
+	int error;
+
+	error = msb_run_state_machine(msb, h_msb_parallel_switch);
+	if (error) {
+		pr_err("Switch to parallel failed");
+		msb->regs.param.system &= ~MEMSTICK_SYS_PAM;
+		msb_reset(msb, true);
+		return -EFAULT;
+	}
+
+	msb->caps |= MEMSTICK_CAP_AUTO_GET_INT;
+	return 0;
+}
+
+/* Changes overwrite flag on a page */
+static int msb_set_overwrite_flag(struct msb_data *msb,
+						u16 pba, u8 page, u8 flag)
+{
+	if (msb->read_only)
+		return -EROFS;
+
+	msb->regs.param.block_address = cpu_to_be16(pba);
+	msb->regs.param.page_address = page;
+	msb->regs.param.cp = MEMSTICK_CP_OVERWRITE;
+	msb->regs.extra_data.overwrite_flag = flag;
+	msb->command_value = MS_CMD_BLOCK_WRITE;
+	msb->command_need_oob = true;
+
+	dbg_verbose("changing overwrite flag to %02x for sector %d, page %d",
+							flag, pba, page);
+	return msb_run_state_machine(msb, h_msb_send_command);
+}
+
+static int msb_mark_bad(struct msb_data *msb, int pba)
+{
+	pr_notice("marking pba %d as bad", pba);
+	msb_reset(msb, true);
+	return msb_set_overwrite_flag(
+			msb, pba, 0, 0xFF & ~MEMSTICK_OVERWRITE_BKST);
+}
+
+static int msb_mark_page_bad(struct msb_data *msb, int pba, int page)
+{
+	dbg("marking page %d of pba %d as bad", page, pba);
+	msb_reset(msb, true);
+	return msb_set_overwrite_flag(msb,
+		pba, page, ~MEMSTICK_OVERWRITE_PGST0);
+}
+
+/* Erases one physical block */
+static int msb_erase_block(struct msb_data *msb, u16 pba)
+{
+	int error, try;
+	if (msb->read_only)
+		return -EROFS;
+
+	dbg_verbose("erasing pba %d", pba);
+
+	for (try = 1 ; try < 3 ; try++) {
+		msb->regs.param.block_address = cpu_to_be16(pba);
+		msb->regs.param.page_address = 0;
+		msb->regs.param.cp = MEMSTICK_CP_BLOCK;
+		msb->command_value = MS_CMD_BLOCK_ERASE;
+		msb->command_need_oob = false;
+
+
+		error = msb_run_state_machine(msb, h_msb_send_command);
+		if (!error || msb_reset(msb, true))
+			break;
+	}
+
+	if (error) {
+		pr_err("erase failed, marking pba %d as bad", pba);
+		msb_mark_bad(msb, pba);
+	}
+
+	dbg_verbose("erase success, marking pba %d as unused", pba);
+	msb_mark_block_unused(msb, pba);
+	__set_bit(pba, msb->erased_blocks_bitmap);
+	return error;
+}
+
+/* Reads one page from device */
+static int msb_read_page(struct msb_data *msb,
+	u16 pba, u8 page, struct ms_extra_data_register *extra,
+					struct scatterlist *sg,  int offset)
+{
+	int try, error;
+
+	if (pba == MS_BLOCK_INVALID) {
+		unsigned long flags;
+		struct sg_mapping_iter miter;
+		size_t len = msb->page_size;
+
+		dbg_verbose("read unmapped sector. returning 0xFF");
+
+		local_irq_save(flags);
+		sg_miter_start(&miter, sg, sg_nents(sg),
+				SG_MITER_ATOMIC | SG_MITER_TO_SG);
+
+		while (sg_miter_next(&miter) && len > 0) {
+
+			int chunklen;
+
+			if (offset && offset >= miter.length) {
+				offset -= miter.length;
+				continue;
+			}
+
+			chunklen = min(miter.length - offset, len);
+			memset(miter.addr + offset, 0xFF, chunklen);
+			len -= chunklen;
+			offset = 0;
+		}
+
+		sg_miter_stop(&miter);
+		local_irq_restore(flags);
+
+		if (offset)
+			return -EFAULT;
+
+		if (extra)
+			memset(extra, 0xFF, sizeof(*extra));
+		return 0;
+	}
+
+	if (pba >= msb->block_count) {
+		pr_err("BUG: attempt to read beyond"
+					" the end of the card at pba %d", pba);
+		return -EINVAL;
+	}
+
+	for (try = 1 ; try < 3 ; try++) {
+		msb->regs.param.block_address = cpu_to_be16(pba);
+		msb->regs.param.page_address = page;
+		msb->regs.param.cp = MEMSTICK_CP_PAGE;
+
+		msb->current_sg = sg;
+		msb->current_sg_offset = offset;
+		error = msb_run_state_machine(msb, h_msb_read_page);
+
+
+		if (error == -EUCLEAN) {
+			pr_notice("correctable error on pba %d, page %d",
+				pba, page);
+			error = 0;
+		}
+
+		if (!error && extra)
+			*extra = msb->regs.extra_data;
+
+		if (!error || msb_reset(msb, true))
+			break;
+
+	}
+
+	/* Mark bad pages */
+	if (error == -EBADMSG) {
+		pr_err("uncorrectable error on read of pba %d, page %d",
+			pba, page);
+
+		if (msb->regs.extra_data.overwrite_flag &
+					MEMSTICK_OVERWRITE_PGST0)
+			msb_mark_page_bad(msb, pba, page);
+		return -EBADMSG;
+	}
+
+	if (error)
+		pr_err("read of pba %d, page %d failed with error %d",
+			pba, page, error);
+	return error;
+}
+
+/* Reads oob of page only */
+static int msb_read_oob(struct msb_data *msb, u16 pba, u16 page,
+	struct ms_extra_data_register *extra)
+{
+	int error;
+
+	BUG_ON(!extra);
+	msb->regs.param.block_address = cpu_to_be16(pba);
+	msb->regs.param.page_address = page;
+	msb->regs.param.cp = MEMSTICK_CP_EXTRA;
+
+	if (pba > msb->block_count) {
+		pr_err("BUG: attempt to read beyond"
+					" the end of card at pba %d", pba);
+		return -EINVAL;
+	}
+
+	error = msb_run_state_machine(msb, h_msb_read_page);
+	*extra = msb->regs.extra_data;
+
+	if (error == -EUCLEAN) {
+		pr_notice("correctable error on pba %d, page %d",
+			pba, page);
+		return 0;
+	}
+
+	return error;
+}
+
+
+/* Reads a block and compares it with data contained in scatterlist orig_sg */
+static int msb_verify_block(struct msb_data *msb, u16 pba,
+				struct scatterlist *orig_sg,  int offset)
+{
+	struct scatterlist sg;
+	int page = 0, error;
+
+	sg_init_one(&sg, msb->block_buffer, msb->block_size);
+
+	while (page < msb->pages_in_block) {
+
+		error = msb_read_page(msb, pba, page,
+				NULL, &sg, page * msb->page_size);
+		if (error)
+			return error;
+		page++;
+	}
+
+	if (msb_sg_compare_to_buffer(orig_sg, offset,
+				msb->block_buffer, msb->block_size))
+		return -EIO;
+	return 0;
+}
+
+/* Writes exectly one block + oob */
+static int msb_write_block(struct msb_data *msb,
+			u16 pba, u32 lba, struct scatterlist *sg, int offset)
+{
+	int error, current_try = 1;
+	BUG_ON(sg->length < msb->page_size);
+
+	if (msb->read_only)
+		return -EROFS;
+
+	if (pba == MS_BLOCK_INVALID) {
+		pr_err(
+			"BUG: write: attempt to write MS_BLOCK_INVALID block");
+		return -EINVAL;
+	}
+
+	if (pba >= msb->block_count || lba >= msb->logical_block_count) {
+		pr_err(
+		"BUG: write: attempt to write beyond the end of device");
+		return -EINVAL;
+	}
+
+	if (msb_get_zone_from_lba(lba) != msb_get_zone_from_pba(pba)) {
+		pr_err("BUG: write: lba zone mismatch");
+		return -EINVAL;
+	}
+
+	if (pba == msb->boot_block_locations[0] ||
+		pba == msb->boot_block_locations[1]) {
+		pr_err("BUG: write: attempt to write to boot blocks!");
+		return -EINVAL;
+	}
+
+	while (1) {
+
+		if (msb->read_only)
+			return -EROFS;
+
+		msb->regs.param.cp = MEMSTICK_CP_BLOCK;
+		msb->regs.param.page_address = 0;
+		msb->regs.param.block_address = cpu_to_be16(pba);
+
+		msb->regs.extra_data.management_flag = 0xFF;
+		msb->regs.extra_data.overwrite_flag = 0xF8;
+		msb->regs.extra_data.logical_address = cpu_to_be16(lba);
+
+		msb->current_sg = sg;
+		msb->current_sg_offset = offset;
+		msb->current_page = 0;
+
+		error = msb_run_state_machine(msb, h_msb_write_block);
+
+		/* Sector we just wrote to is assumed erased since its pba
+			was erased. If it wasn't erased, write will succeed
+			and will just clear the bits that were set in the block
+			thus test that what we have written,
+			matches what we expect.
+			We do trust the blocks that we erased */
+		if (!error && (verify_writes ||
+				!test_bit(pba, msb->erased_blocks_bitmap)))
+			error = msb_verify_block(msb, pba, sg, offset);
+
+		if (!error)
+			break;
+
+		if (current_try > 1 || msb_reset(msb, true))
+			break;
+
+		pr_err("write failed, trying to erase the pba %d", pba);
+		error = msb_erase_block(msb, pba);
+		if (error)
+			break;
+
+		current_try++;
+	}
+	return error;
+}
+
+/* Finds a free block for write replacement */
+static u16 msb_get_free_block(struct msb_data *msb, int zone)
+{
+	u16 pos;
+	int pba = zone * MS_BLOCKS_IN_ZONE;
+	int i;
+
+	get_random_bytes(&pos, sizeof(pos));
+
+	if (!msb->free_block_count[zone]) {
+		pr_err("NO free blocks in the zone %d, to use for a write, "
+			"(media is WORN out) switching to RO mode", zone);
+		msb->read_only = true;
+		return MS_BLOCK_INVALID;
+	}
+
+	pos %= msb->free_block_count[zone];
+
+	dbg_verbose("have %d choices for a free block, selected randomally: %d",
+		msb->free_block_count[zone], pos);
+
+	pba = find_next_zero_bit(msb->used_blocks_bitmap,
+							msb->block_count, pba);
+	for (i = 0 ; i < pos ; ++i)
+		pba = find_next_zero_bit(msb->used_blocks_bitmap,
+						msb->block_count, pba + 1);
+
+	dbg_verbose("result of the free blocks scan: pba %d", pba);
+
+	if (pba == msb->block_count || (msb_get_zone_from_pba(pba)) != zone) {
+		pr_err("BUG: cant get a free block");
+		msb->read_only = true;
+		return MS_BLOCK_INVALID;
+	}
+
+	msb_mark_block_used(msb, pba);
+	return pba;
+}
+
+static int msb_update_block(struct msb_data *msb, u16 lba,
+	struct scatterlist *sg, int offset)
+{
+	u16 pba, new_pba;
+	int error, try;
+
+	pba = msb->lba_to_pba_table[lba];
+	dbg_verbose("start of a block update at lba  %d, pba %d", lba, pba);
+
+	if (pba != MS_BLOCK_INVALID) {
+		dbg_verbose("setting the update flag on the block");
+		msb_set_overwrite_flag(msb, pba, 0,
+				0xFF & ~MEMSTICK_OVERWRITE_UDST);
+	}
+
+	for (try = 0 ; try < 3 ; try++) {
+		new_pba = msb_get_free_block(msb,
+			msb_get_zone_from_lba(lba));
+
+		if (new_pba == MS_BLOCK_INVALID) {
+			error = -EIO;
+			goto out;
+		}
+
+		dbg_verbose("block update: writing updated block to the pba %d",
+								new_pba);
+		error = msb_write_block(msb, new_pba, lba, sg, offset);
+		if (error == -EBADMSG) {
+			msb_mark_bad(msb, new_pba);
+			continue;
+		}
+
+		if (error)
+			goto out;
+
+		dbg_verbose("block update: erasing the old block");
+		msb_erase_block(msb, pba);
+		msb->lba_to_pba_table[lba] = new_pba;
+		return 0;
+	}
+out:
+	if (error) {
+		pr_err("block update error after %d tries, "
+						"switching to r/o mode", try);
+		msb->read_only = true;
+	}
+	return error;
+}
+
+/* Converts endiannes in the boot block for easy use */
+static void msb_fix_boot_page_endianness(struct ms_boot_page *p)
+{
+	p->header.block_id = be16_to_cpu(p->header.block_id);
+	p->header.format_reserved = be16_to_cpu(p->header.format_reserved);
+	p->entry.disabled_block.start_addr
+		= be32_to_cpu(p->entry.disabled_block.start_addr);
+	p->entry.disabled_block.data_size
+		= be32_to_cpu(p->entry.disabled_block.data_size);
+	p->entry.cis_idi.start_addr
+		= be32_to_cpu(p->entry.cis_idi.start_addr);
+	p->entry.cis_idi.data_size
+		= be32_to_cpu(p->entry.cis_idi.data_size);
+	p->attr.block_size = be16_to_cpu(p->attr.block_size);
+	p->attr.number_of_blocks = be16_to_cpu(p->attr.number_of_blocks);
+	p->attr.number_of_effective_blocks
+		= be16_to_cpu(p->attr.number_of_effective_blocks);
+	p->attr.page_size = be16_to_cpu(p->attr.page_size);
+	p->attr.memory_manufacturer_code
+		= be16_to_cpu(p->attr.memory_manufacturer_code);
+	p->attr.memory_device_code = be16_to_cpu(p->attr.memory_device_code);
+	p->attr.implemented_capacity
+		= be16_to_cpu(p->attr.implemented_capacity);
+	p->attr.controller_number = be16_to_cpu(p->attr.controller_number);
+	p->attr.controller_function = be16_to_cpu(p->attr.controller_function);
+}
+
+static int msb_read_boot_blocks(struct msb_data *msb)
+{
+	int pba = 0;
+	struct scatterlist sg;
+	struct ms_extra_data_register extra;
+	struct ms_boot_page *page;
+
+	msb->boot_block_locations[0] = MS_BLOCK_INVALID;
+	msb->boot_block_locations[1] = MS_BLOCK_INVALID;
+	msb->boot_block_count = 0;
+
+	dbg_verbose("Start of a scan for the boot blocks");
+
+	if (!msb->boot_page) {
+		page = kmalloc(sizeof(struct ms_boot_page)*2, GFP_KERNEL);
+		if (!page)
+			return -ENOMEM;
+
+		msb->boot_page = page;
+	} else
+		page = msb->boot_page;
+
+	msb->block_count = MS_BLOCK_MAX_BOOT_ADDR;
+
+	for (pba = 0 ; pba < MS_BLOCK_MAX_BOOT_ADDR ; pba++) {
+
+		sg_init_one(&sg, page, sizeof(*page));
+		if (msb_read_page(msb, pba, 0, &extra, &sg, 0)) {
+			dbg("boot scan: can't read pba %d", pba);
+			continue;
+		}
+
+		if (extra.management_flag & MEMSTICK_MANAGEMENT_SYSFLG) {
+			dbg("managment flag doesn't indicate boot block %d",
+									pba);
+			continue;
+		}
+
+		if (be16_to_cpu(page->header.block_id) != MS_BLOCK_BOOT_ID) {
+			dbg("the pba at %d doesn' contain boot block ID", pba);
+			continue;
+		}
+
+		msb_fix_boot_page_endianness(page);
+		msb->boot_block_locations[msb->boot_block_count] = pba;
+
+		page++;
+		msb->boot_block_count++;
+
+		if (msb->boot_block_count == 2)
+			break;
+	}
+
+	if (!msb->boot_block_count) {
+		pr_err("media doesn't contain master page, aborting");
+		return -EIO;
+	}
+
+	dbg_verbose("End of scan for boot blocks");
+	return 0;
+}
+
+static int msb_read_bad_block_table(struct msb_data *msb, int block_nr)
+{
+	struct ms_boot_page *boot_block;
+	struct scatterlist sg;
+	u16 *buffer = NULL;
+	int offset = 0;
+	int i, error = 0;
+	int data_size, data_offset, page, page_offset, size_to_read;
+	u16 pba;
+
+	BUG_ON(block_nr > 1);
+	boot_block = &msb->boot_page[block_nr];
+	pba = msb->boot_block_locations[block_nr];
+
+	if (msb->boot_block_locations[block_nr] == MS_BLOCK_INVALID)
+		return -EINVAL;
+
+	data_size = boot_block->entry.disabled_block.data_size;
+	data_offset = sizeof(struct ms_boot_page) +
+			boot_block->entry.disabled_block.start_addr;
+	if (!data_size)
+		return 0;
+
+	page = data_offset / msb->page_size;
+	page_offset = data_offset % msb->page_size;
+	size_to_read =
+		DIV_ROUND_UP(data_size + page_offset, msb->page_size) *
+			msb->page_size;
+
+	dbg("reading bad block of boot block at pba %d, offset %d len %d",
+		pba, data_offset, data_size);
+
+	buffer = kzalloc(size_to_read, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	/* Read the buffer */
+	sg_init_one(&sg, buffer, size_to_read);
+
+	while (offset < size_to_read) {
+		error = msb_read_page(msb, pba, page, NULL, &sg, offset);
+		if (error)
+			goto out;
+
+		page++;
+		offset += msb->page_size;
+
+		if (page == msb->pages_in_block) {
+			pr_err(
+			"bad block table extends beyond the boot block");
+			break;
+		}
+	}
+
+	/* Process the bad block table */
+	for (i = page_offset ; i < data_size / sizeof(u16) ; i++) {
+
+		u16 bad_block = be16_to_cpu(buffer[i]);
+
+		if (bad_block >= msb->block_count) {
+			dbg("bad block table contains invalid block %d",
+								bad_block);
+			continue;
+		}
+
+		if (test_bit(bad_block, msb->used_blocks_bitmap))  {
+			dbg("duplicate bad block %d in the table",
+				bad_block);
+			continue;
+		}
+
+		dbg("block %d is marked as factory bad", bad_block);
+		msb_mark_block_used(msb, bad_block);
+	}
+out:
+	kfree(buffer);
+	return error;
+}
+
+static int msb_ftl_initialize(struct msb_data *msb)
+{
+	int i;
+
+	if (msb->ftl_initialized)
+		return 0;
+
+	msb->zone_count = msb->block_count / MS_BLOCKS_IN_ZONE;
+	msb->logical_block_count = msb->zone_count * 496 - 2;
+
+	msb->used_blocks_bitmap = kzalloc(msb->block_count / 8, GFP_KERNEL);
+	msb->erased_blocks_bitmap = kzalloc(msb->block_count / 8, GFP_KERNEL);
+	msb->lba_to_pba_table =
+		kmalloc(msb->logical_block_count * sizeof(u16), GFP_KERNEL);
+
+	if (!msb->used_blocks_bitmap || !msb->lba_to_pba_table ||
+						!msb->erased_blocks_bitmap) {
+		kfree(msb->used_blocks_bitmap);
+		kfree(msb->lba_to_pba_table);
+		kfree(msb->erased_blocks_bitmap);
+		return -ENOMEM;
+	}
+
+	for (i = 0 ; i < msb->zone_count ; i++)
+		msb->free_block_count[i] = MS_BLOCKS_IN_ZONE;
+
+	memset(msb->lba_to_pba_table, MS_BLOCK_INVALID,
+			msb->logical_block_count * sizeof(u16));
+
+	dbg("initial FTL tables created. Zone count = %d, "
+					"Logical block count = %d",
+		msb->zone_count, msb->logical_block_count);
+
+	msb->ftl_initialized = true;
+	return 0;
+}
+
+static int msb_ftl_scan(struct msb_data *msb)
+{
+	u16 pba, lba, other_block;
+	u8 overwrite_flag, managment_flag, other_overwrite_flag;
+	int error;
+	struct ms_extra_data_register extra;
+	u8 *overwrite_flags = kzalloc(msb->block_count, GFP_KERNEL);
+
+	if (!overwrite_flags)
+		return -ENOMEM;
+
+	dbg("Start of media scanning");
+	for (pba = 0 ; pba < msb->block_count ; pba++) {
+
+		if (pba == msb->boot_block_locations[0] ||
+			pba == msb->boot_block_locations[1]) {
+			dbg_verbose("pba %05d -> [boot block]", pba);
+			msb_mark_block_used(msb, pba);
+			continue;
+		}
+
+		if (test_bit(pba, msb->used_blocks_bitmap)) {
+			dbg_verbose("pba %05d -> [factory bad]", pba);
+			continue;
+		}
+
+		memset(&extra, 0, sizeof(extra));
+		error = msb_read_oob(msb, pba, 0, &extra);
+
+		/* can't trust the page if we can't read the oob */
+		if (error == -EBADMSG) {
+			pr_notice(
+			"oob of pba %d damaged, will try to erase it", pba);
+			msb_mark_block_used(msb, pba);
+			msb_erase_block(msb, pba);
+			continue;
+		} else if (error)
+			return error;
+
+		lba = be16_to_cpu(extra.logical_address);
+		managment_flag = extra.management_flag;
+		overwrite_flag = extra.overwrite_flag;
+		overwrite_flags[pba] = overwrite_flag;
+
+		/* Skip bad blocks */
+		if (!(overwrite_flag & MEMSTICK_OVERWRITE_BKST)) {
+			dbg("pba %05d -> [BAD]", pba);
+			msb_mark_block_used(msb, pba);
+			continue;
+		}
+
+		/* Skip system/drm blocks */
+		if ((managment_flag & MEMSTICK_MANAGMENT_FLAG_NORMAL) !=
+			MEMSTICK_MANAGMENT_FLAG_NORMAL) {
+			dbg("pba %05d -> [reserved managment flag %02x]",
+							pba, managment_flag);
+			msb_mark_block_used(msb, pba);
+			continue;
+		}
+
+		/* Erase temporary tables */
+		if (!(managment_flag & MEMSTICK_MANAGEMENT_ATFLG)) {
+			dbg("pba %05d -> [temp table] - will erase", pba);
+
+			msb_mark_block_used(msb, pba);
+			msb_erase_block(msb, pba);
+			continue;
+		}
+
+		if (lba == MS_BLOCK_INVALID) {
+			dbg_verbose("pba %05d -> [free]", pba);
+			continue;
+		}
+
+		msb_mark_block_used(msb, pba);
+
+		/* Block has LBA not according to zoning*/
+		if (msb_get_zone_from_lba(lba) != msb_get_zone_from_pba(pba)) {
+			pr_notice("pba %05d -> [bad lba %05d] - will erase",
+								pba, lba);
+			msb_erase_block(msb, pba);
+			continue;
+		}
+
+		/* No collisions - great */
+		if (msb->lba_to_pba_table[lba] == MS_BLOCK_INVALID) {
+			dbg_verbose("pba %05d -> [lba %05d]", pba, lba);
+			msb->lba_to_pba_table[lba] = pba;
+			continue;
+		}
+
+		other_block = msb->lba_to_pba_table[lba];
+		other_overwrite_flag = overwrite_flags[other_block];
+
+		pr_notice("Collision between pba %d and pba %d",
+			pba, other_block);
+
+		if (!(overwrite_flag & MEMSTICK_OVERWRITE_UDST)) {
+			pr_notice("pba %d is marked as stable, use it", pba);
+			msb_erase_block(msb, other_block);
+			msb->lba_to_pba_table[lba] = pba;
+			continue;
+		}
+
+		if (!(other_overwrite_flag & MEMSTICK_OVERWRITE_UDST)) {
+			pr_notice("pba %d is marked as stable, use it",
+								other_block);
+			msb_erase_block(msb, pba);
+			continue;
+		}
+
+		pr_notice("collision between blocks %d and %d,"
+		" without stable flag set on both, erasing pba %d",
+				pba, other_block, other_block);
+
+		msb_erase_block(msb, other_block);
+		msb->lba_to_pba_table[lba] = pba;
+	}
+
+	dbg("End of media scanning");
+	kfree(overwrite_flags);
+	return 0;
+}
+
+static void msb_cache_flush_timer(unsigned long data)
+{
+	struct msb_data *msb = (struct msb_data *)data;
+	msb->need_flush_cache = true;
+	queue_work(msb->io_queue, &msb->io_work);
+}
+
+
+static void msb_cache_discard(struct msb_data *msb)
+{
+	if (msb->cache_block_lba == MS_BLOCK_INVALID)
+		return;
+
+	del_timer_sync(&msb->cache_flush_timer);
+
+	dbg_verbose("Discarding the write cache");
+	msb->cache_block_lba = MS_BLOCK_INVALID;
+	bitmap_zero(&msb->valid_cache_bitmap, msb->pages_in_block);
+}
+
+static int msb_cache_init(struct msb_data *msb)
+{
+	setup_timer(&msb->cache_flush_timer, msb_cache_flush_timer,
+		(unsigned long)msb);
+
+	if (!msb->cache)
+		msb->cache = kzalloc(msb->block_size, GFP_KERNEL);
+	if (!msb->cache)
+		return -ENOMEM;
+
+	msb_cache_discard(msb);
+	return 0;
+}
+
+static int msb_cache_flush(struct msb_data *msb)
+{
+	struct scatterlist sg;
+	struct ms_extra_data_register extra;
+	int page, offset, error;
+	u16 pba, lba;
+
+	if (msb->read_only)
+		return -EROFS;
+
+	if (msb->cache_block_lba == MS_BLOCK_INVALID)
+		return 0;
+
+	lba = msb->cache_block_lba;
+	pba = msb->lba_to_pba_table[lba];
+
+	dbg_verbose("Flushing the write cache of pba %d (LBA %d)",
+						pba, msb->cache_block_lba);
+
+	sg_init_one(&sg, msb->cache , msb->block_size);
+
+	/* Read all missing pages in cache */
+	for (page = 0 ; page < msb->pages_in_block ; page++) {
+
+		if (test_bit(page, &msb->valid_cache_bitmap))
+			continue;
+
+		offset = page * msb->page_size;
+
+		dbg_verbose("reading non-present sector %d of cache block %d",
+			page, lba);
+		error = msb_read_page(msb, pba, page, &extra, &sg, offset);
+
+		/* Bad pages are copied with 00 page status */
+		if (error == -EBADMSG) {
+			pr_err("read error on sector %d, contents probably"
+				" damaged", page);
+			continue;
+		}
+
+		if (error)
+			return error;
+
+		if ((extra.overwrite_flag & MEMSTICK_OV_PG_NORMAL) !=
+							MEMSTICK_OV_PG_NORMAL) {
+			dbg("page %d is marked as bad", page);
+			continue;
+		}
+
+		set_bit(page, &msb->valid_cache_bitmap);
+	}
+
+	/* Write the cache now */
+	error = msb_update_block(msb, msb->cache_block_lba, &sg, 0);
+	pba = msb->lba_to_pba_table[msb->cache_block_lba];
+
+	/* Mark invalid pages */
+	if (!error) {
+		for (page = 0 ; page < msb->pages_in_block ; page++) {
+
+			if (test_bit(page, &msb->valid_cache_bitmap))
+				continue;
+
+			dbg("marking page %d as containing damaged data",
+				page);
+			msb_set_overwrite_flag(msb,
+				pba , page, 0xFF & ~MEMSTICK_OV_PG_NORMAL);
+		}
+	}
+
+	msb_cache_discard(msb);
+	return error;
+}
+
+static int msb_cache_write(struct msb_data *msb, int lba,
+	int page, bool add_to_cache_only, struct scatterlist *sg, int offset)
+{
+	int error;
+	struct scatterlist sg_tmp[10];
+
+	if (msb->read_only)
+		return -EROFS;
+
+	if (msb->cache_block_lba == MS_BLOCK_INVALID ||
+						lba != msb->cache_block_lba)
+		if (add_to_cache_only)
+			return 0;
+
+	/* If we need to write different block */
+	if (msb->cache_block_lba != MS_BLOCK_INVALID &&
+						lba != msb->cache_block_lba) {
+		dbg_verbose("first flush the cache");
+		error = msb_cache_flush(msb);
+		if (error)
+			return error;
+	}
+
+	if (msb->cache_block_lba  == MS_BLOCK_INVALID) {
+		msb->cache_block_lba  = lba;
+		mod_timer(&msb->cache_flush_timer,
+			jiffies + msecs_to_jiffies(cache_flush_timeout));
+	}
+
+	dbg_verbose("Write of LBA %d page %d to cache ", lba, page);
+
+	sg_init_table(sg_tmp, ARRAY_SIZE(sg_tmp));
+	msb_sg_copy(sg, sg_tmp, ARRAY_SIZE(sg_tmp), offset, msb->page_size);
+
+	sg_copy_to_buffer(sg_tmp, sg_nents(sg_tmp),
+		msb->cache + page * msb->page_size, msb->page_size);
+
+	set_bit(page, &msb->valid_cache_bitmap);
+	return 0;
+}
+
+static int msb_cache_read(struct msb_data *msb, int lba,
+				int page, struct scatterlist *sg, int offset)
+{
+	int pba = msb->lba_to_pba_table[lba];
+	struct scatterlist sg_tmp[10];
+	int error = 0;
+
+	if (lba == msb->cache_block_lba &&
+			test_bit(page, &msb->valid_cache_bitmap)) {
+
+		dbg_verbose("Read of LBA %d (pba %d) sector %d from cache",
+							lba, pba, page);
+
+		sg_init_table(sg_tmp, ARRAY_SIZE(sg_tmp));
+		msb_sg_copy(sg, sg_tmp, ARRAY_SIZE(sg_tmp), offset, msb->page_size);
+		sg_copy_from_buffer(sg_tmp, sg_nents(sg_tmp),
+			msb->cache + msb->page_size * page,
+							msb->page_size);
+	} else {
+		dbg_verbose("Read of LBA %d (pba %d) sector %d from device",
+							lba, pba, page);
+
+		error = msb_read_page(msb, pba, page, NULL, sg, offset);
+		if (error)
+			return error;
+
+		msb_cache_write(msb, lba, page, true, sg, offset);
+	}
+	return error;
+}
+
+/* Emulated geometry table
+ * This table content isn't that importaint,
+ * One could put here different values, providing that they still
+ * cover whole disk.
+ * 64 MB entry is what windows reports for my 64M memstick */
+
+static const struct chs_entry chs_table[] = {
+/*        size sectors cylynders  heads */
+	{ 4,    16,    247,       2  },
+	{ 8,    16,    495,       2  },
+	{ 16,   16,    495,       4  },
+	{ 32,   16,    991,       4  },
+	{ 64,   16,    991,       8  },
+	{128,   16,    991,       16 },
+	{ 0 }
+};
+
+/* Load information about the card */
+static int msb_init_card(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_host *host = card->host;
+	struct ms_boot_page *boot_block;
+	int error = 0, i, raw_size_in_megs;
+
+	msb->caps = 0;
+
+	if (card->id.class >= MEMSTICK_CLASS_ROM &&
+				card->id.class <= MEMSTICK_CLASS_ROM)
+		msb->read_only = true;
+
+	msb->state = -1;
+	error = msb_reset(msb, false);
+	if (error)
+		return error;
+
+	/* Due to a bug in Jmicron driver written by Alex Dubov,
+	 its serial mode barely works,
+	 so we switch to parallel mode right away */
+	if (host->caps & MEMSTICK_CAP_PAR4)
+		msb_switch_to_parallel(msb);
+
+	msb->page_size = sizeof(struct ms_boot_page);
+
+	/* Read the boot page */
+	error = msb_read_boot_blocks(msb);
+	if (error)
+		return -EIO;
+
+	boot_block = &msb->boot_page[0];
+
+	/* Save intersting attributes from boot page */
+	msb->block_count = boot_block->attr.number_of_blocks;
+	msb->page_size = boot_block->attr.page_size;
+
+	msb->pages_in_block = boot_block->attr.block_size * 2;
+	msb->block_size = msb->page_size * msb->pages_in_block;
+
+	if (msb->page_size > PAGE_SIZE) {
+		/* this isn't supported by linux at all, anyway*/
+		dbg("device page %d size isn't supported", msb->page_size);
+		return -EINVAL;
+	}
+
+	msb->block_buffer = kzalloc(msb->block_size, GFP_KERNEL);
+	if (!msb->block_buffer)
+		return -ENOMEM;
+
+	raw_size_in_megs = (msb->block_size * msb->block_count) >> 20;
+
+	for (i = 0 ; chs_table[i].size ; i++) {
+
+		if (chs_table[i].size != raw_size_in_megs)
+			continue;
+
+		msb->geometry.cylinders = chs_table[i].cyl;
+		msb->geometry.heads = chs_table[i].head;
+		msb->geometry.sectors = chs_table[i].sec;
+		break;
+	}
+
+	if (boot_block->attr.transfer_supporting == 1)
+		msb->caps |= MEMSTICK_CAP_PAR4;
+
+	if (boot_block->attr.device_type & 0x03)
+		msb->read_only = true;
+
+	dbg("Total block count = %d", msb->block_count);
+	dbg("Each block consists of %d pages", msb->pages_in_block);
+	dbg("Page size = %d bytes", msb->page_size);
+	dbg("Parallel mode supported: %d", !!(msb->caps & MEMSTICK_CAP_PAR4));
+	dbg("Read only: %d", msb->read_only);
+
+#if 0
+	/* Now we can switch the interface */
+	if (host->caps & msb->caps & MEMSTICK_CAP_PAR4)
+		msb_switch_to_parallel(msb);
+#endif
+
+	error = msb_cache_init(msb);
+	if (error)
+		return error;
+
+	error = msb_ftl_initialize(msb);
+	if (error)
+		return error;
+
+
+	/* Read the bad block table */
+	error = msb_read_bad_block_table(msb, 0);
+
+	if (error && error != -ENOMEM) {
+		dbg("failed to read bad block table from primary boot block,"
+							" trying from backup");
+		error = msb_read_bad_block_table(msb, 1);
+	}
+
+	if (error)
+		return error;
+
+	/* *drum roll* Scan the media */
+	error = msb_ftl_scan(msb);
+	if (error) {
+		pr_err("Scan of media failed");
+		return error;
+	}
+
+	return 0;
+
+}
+
+static int msb_do_write_request(struct msb_data *msb, int lba,
+	int page, struct scatterlist *sg, size_t len, int *sucessfuly_written)
+{
+	int error = 0;
+	off_t offset = 0;
+	*sucessfuly_written = 0;
+
+	while (offset < len) {
+		if (page == 0 && len - offset >= msb->block_size) {
+
+			if (msb->cache_block_lba == lba)
+				msb_cache_discard(msb);
+
+			dbg_verbose("Writing whole lba %d", lba);
+			error = msb_update_block(msb, lba, sg, offset);
+			if (error)
+				return error;
+
+			offset += msb->block_size;
+			*sucessfuly_written += msb->block_size;
+			lba++;
+			continue;
+		}
+
+		error = msb_cache_write(msb, lba, page, false, sg, offset);
+		if (error)
+			return error;
+
+		offset += msb->page_size;
+		*sucessfuly_written += msb->page_size;
+
+		page++;
+		if (page == msb->pages_in_block) {
+			page = 0;
+			lba++;
+		}
+	}
+	return 0;
+}
+
+static int msb_do_read_request(struct msb_data *msb, int lba,
+		int page, struct scatterlist *sg, int len, int *sucessfuly_read)
+{
+	int error = 0;
+	int offset = 0;
+	*sucessfuly_read = 0;
+
+	while (offset < len) {
+
+		error = msb_cache_read(msb, lba, page, sg, offset);
+		if (error)
+			return error;
+
+		offset += msb->page_size;
+		*sucessfuly_read += msb->page_size;
+
+		page++;
+		if (page == msb->pages_in_block) {
+			page = 0;
+			lba++;
+		}
+	}
+	return 0;
+}
+
+static void msb_io_work(struct work_struct *work)
+{
+	struct msb_data *msb = container_of(work, struct msb_data, io_work);
+	int page, error, len;
+	sector_t lba;
+	unsigned long flags;
+	struct scatterlist *sg = msb->prealloc_sg;
+
+	dbg_verbose("IO: work started");
+
+	while (1) {
+		spin_lock_irqsave(&msb->q_lock, flags);
+
+		if (msb->need_flush_cache) {
+			msb->need_flush_cache = false;
+			spin_unlock_irqrestore(&msb->q_lock, flags);
+			msb_cache_flush(msb);
+			continue;
+		}
+
+		if (!msb->req) {
+			msb->req = blk_fetch_request(msb->queue);
+			if (!msb->req) {
+				dbg_verbose("IO: no more requests exiting");
+				spin_unlock_irqrestore(&msb->q_lock, flags);
+				return;
+			}
+		}
+
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+
+		/* If card was removed meanwhile */
+		if (!msb->req)
+			return;
+
+		/* process the request */
+		dbg_verbose("IO: processing new request");
+		blk_rq_map_sg(msb->queue, msb->req, sg);
+
+		lba = blk_rq_pos(msb->req);
+
+		sector_div(lba, msb->page_size / 512);
+		page = do_div(lba, msb->pages_in_block);
+
+		if (rq_data_dir(msb->req) == READ)
+			error = msb_do_read_request(msb, lba, page, sg,
+				blk_rq_bytes(msb->req), &len);
+		else
+			error = msb_do_write_request(msb, lba, page, sg,
+				blk_rq_bytes(msb->req), &len);
+
+		spin_lock_irqsave(&msb->q_lock, flags);
+
+		if (len)
+			if (!__blk_end_request(msb->req, 0, len))
+				msb->req = NULL;
+
+		if (error && msb->req) {
+			dbg_verbose("IO: ending one sector "
+					"of the request with error");
+			if (!__blk_end_request(msb->req, error, msb->page_size))
+				msb->req = NULL;
+		}
+
+		if (msb->req)
+			dbg_verbose("IO: request still pending");
+
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+	}
+}
+
+static DEFINE_IDR(msb_disk_idr); /*set of used disk numbers */
+static DEFINE_MUTEX(msb_disk_lock); /* protects against races in open/release */
+
+static int msb_bd_open(struct block_device *bdev, fmode_t mode)
+{
+	struct gendisk *disk = bdev->bd_disk;
+	struct msb_data *msb = disk->private_data;
+
+	dbg_verbose("block device open");
+
+	mutex_lock(&msb_disk_lock);
+
+	if (msb && msb->card)
+		msb->usage_count++;
+
+	mutex_unlock(&msb_disk_lock);
+	return 0;
+}
+
+static void msb_data_clear(struct msb_data *msb)
+{
+	kfree(msb->boot_page);
+	kfree(msb->used_blocks_bitmap);
+	kfree(msb->lba_to_pba_table);
+	kfree(msb->cache);
+	msb->card = NULL;
+}
+
+static int msb_disk_release(struct gendisk *disk)
+{
+	struct msb_data *msb = disk->private_data;
+
+	dbg_verbose("block device release");
+	mutex_lock(&msb_disk_lock);
+
+	if (msb) {
+		if (msb->usage_count)
+			msb->usage_count--;
+
+		if (!msb->usage_count) {
+			kfree(msb);
+			disk->private_data = NULL;
+			idr_remove(&msb_disk_idr, msb->disk_id);
+			put_disk(disk);
+		}
+	}
+	mutex_unlock(&msb_disk_lock);
+	return 0;
+}
+
+static int msb_bd_release(struct gendisk *disk, fmode_t mode)
+{
+	return msb_disk_release(disk);
+}
+
+static int msb_bd_getgeo(struct block_device *bdev,
+				 struct hd_geometry *geo)
+{
+	struct msb_data *msb = bdev->bd_disk->private_data;
+	*geo = msb->geometry;
+	return 0;
+}
+
+static int msb_prepare_req(struct request_queue *q, struct request *req)
+{
+	if (req->cmd_type != REQ_TYPE_FS &&
+				req->cmd_type != REQ_TYPE_BLOCK_PC) {
+		blk_dump_rq_flags(req, "MS unsupported request");
+		return BLKPREP_KILL;
+	}
+	req->cmd_flags |= REQ_DONTPREP;
+	return BLKPREP_OK;
+}
+
+static void msb_submit_req(struct request_queue *q)
+{
+	struct memstick_dev *card = q->queuedata;
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct request *req = NULL;
+
+	dbg_verbose("Submit request");
+
+	if (msb->card_dead) {
+		dbg("Refusing requests on removed card");
+
+		WARN_ON(!msb->io_queue_stopped);
+
+		while ((req = blk_fetch_request(q)) != NULL)
+			__blk_end_request_all(req, -ENODEV);
+		return;
+	}
+
+	if (msb->req)
+		return;
+
+	if (!msb->io_queue_stopped)
+		queue_work(msb->io_queue, &msb->io_work);
+}
+
+static int msb_check_card(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	return (msb->card_dead == 0);
+}
+
+static void msb_stop(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	unsigned long flags;
+
+	dbg("Stopping all msblock IO");
+
+	spin_lock_irqsave(&msb->q_lock, flags);
+	blk_stop_queue(msb->queue);
+	msb->io_queue_stopped = true;
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	del_timer_sync(&msb->cache_flush_timer);
+	flush_workqueue(msb->io_queue);
+
+	if (msb->req) {
+		spin_lock_irqsave(&msb->q_lock, flags);
+		blk_requeue_request(msb->queue, msb->req);
+		msb->req = NULL;
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+	}
+
+}
+
+static void msb_start(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	unsigned long flags;
+
+	dbg("Resuming IO from msblock");
+
+	msb_invalidate_reg_window(msb);
+
+	spin_lock_irqsave(&msb->q_lock, flags);
+	if (!msb->io_queue_stopped || msb->card_dead) {
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	/* Kick cache flush anyway, its harmless */
+	msb->need_flush_cache = true;
+	msb->io_queue_stopped = false;
+
+	spin_lock_irqsave(&msb->q_lock, flags);
+	blk_start_queue(msb->queue);
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	queue_work(msb->io_queue, &msb->io_work);
+
+}
+
+static const struct block_device_operations msb_bdops = {
+	.open    = msb_bd_open,
+	.release = msb_bd_release,
+	.getgeo  = msb_bd_getgeo,
+	.owner   = THIS_MODULE
+};
+
+/* Registers the block device */
+static int msb_init_disk(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_host *host = card->host;
+	int rc;
+	u64 limit = BLK_BOUNCE_HIGH;
+	unsigned long capacity;
+
+	if (host->dev.dma_mask && *(host->dev.dma_mask))
+		limit = *(host->dev.dma_mask);
+
+	mutex_lock(&msb_disk_lock);
+	if (!idr_pre_get(&msb_disk_idr, GFP_KERNEL)) {
+		mutex_unlock(&msb_disk_lock);
+		return -ENOMEM;
+	}
+	rc = idr_get_new(&msb_disk_idr, card, &msb->disk_id);
+	mutex_unlock(&msb_disk_lock);
+
+	if (rc)
+		return rc;
+
+	msb->disk = alloc_disk(0);
+	if (!msb->disk) {
+		rc = -ENOMEM;
+		goto out_release_id;
+	}
+
+	msb->queue = blk_init_queue(msb_submit_req, &msb->q_lock);
+	if (!msb->queue) {
+		rc = -ENOMEM;
+		goto out_put_disk;
+	}
+
+	msb->queue->queuedata = card;
+	blk_queue_prep_rq(msb->queue, msb_prepare_req);
+
+	blk_queue_bounce_limit(msb->queue, limit);
+	blk_queue_max_hw_sectors(msb->queue, MS_BLOCK_MAX_PAGES);
+	blk_queue_max_segments(msb->queue, MS_BLOCK_MAX_SEGS);
+	blk_queue_max_segment_size(msb->queue,
+				   MS_BLOCK_MAX_PAGES * msb->page_size);
+	blk_queue_logical_block_size(msb->queue, msb->page_size);
+
+	sprintf(msb->disk->disk_name, "msblk%d", msb->disk_id);
+	msb->disk->fops = &msb_bdops;
+	msb->disk->private_data = msb;
+	msb->disk->queue = msb->queue;
+	msb->disk->driverfs_dev = &card->dev;
+	msb->disk->flags |= GENHD_FL_EXT_DEVT;
+
+	capacity = msb->pages_in_block * msb->logical_block_count;
+	capacity *= (msb->page_size / 512);
+	set_capacity(msb->disk, capacity);
+	dbg("Set total disk size to %lu sectors", capacity);
+
+	msb->usage_count = 1;
+	msb->io_queue = alloc_ordered_workqueue("ms_block", WQ_MEM_RECLAIM);
+	INIT_WORK(&msb->io_work, msb_io_work);
+	sg_init_table(msb->prealloc_sg, MS_BLOCK_MAX_SEGS+1);
+
+	if (msb->read_only)
+		set_disk_ro(msb->disk, 1);
+
+	msb_start(card);
+	add_disk(msb->disk);
+	dbg("Disk added");
+	return 0;
+
+out_put_disk:
+	put_disk(msb->disk);
+out_release_id:
+	mutex_lock(&msb_disk_lock);
+	idr_remove(&msb_disk_idr, msb->disk_id);
+	mutex_unlock(&msb_disk_lock);
+	return rc;
+}
+
+static int msb_probe(struct memstick_dev *card)
+{
+	struct msb_data *msb;
+	int rc = 0;
+
+	msb = kzalloc(sizeof(struct msb_data), GFP_KERNEL);
+	if (!msb)
+		return -ENOMEM;
+	memstick_set_drvdata(card, msb);
+	msb->card = card;
+	spin_lock_init(&msb->q_lock);
+
+	rc = msb_init_card(card);
+	if (rc)
+		goto out_free;
+
+	rc = msb_init_disk(card);
+	if (!rc) {
+		card->check = msb_check_card;
+		card->stop = msb_stop;
+		card->start = msb_start;
+		return 0;
+	}
+out_free:
+	memstick_set_drvdata(card, NULL);
+	msb_data_clear(msb);
+	kfree(msb);
+	return rc;
+}
+
+static void msb_remove(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	unsigned long flags;
+
+	if (!msb->io_queue_stopped)
+		msb_stop(card);
+
+	dbg("Removing the disk device");
+
+	/* Take care of unhandled + new requests from now on */
+	spin_lock_irqsave(&msb->q_lock, flags);
+	msb->card_dead = true;
+	blk_start_queue(msb->queue);
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	/* Remove the disk */
+	del_gendisk(msb->disk);
+	blk_cleanup_queue(msb->queue);
+	msb->queue = NULL;
+
+	mutex_lock(&msb_disk_lock);
+	msb_data_clear(msb);
+	mutex_unlock(&msb_disk_lock);
+
+	msb_disk_release(msb->disk);
+	memstick_set_drvdata(card, NULL);
+}
+
+#ifdef CONFIG_PM
+
+static int msb_suspend(struct memstick_dev *card, pm_message_t state)
+{
+	msb_stop(card);
+	return 0;
+}
+
+static int msb_resume(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct msb_data *new_msb = NULL;
+	bool card_dead = true;
+
+#ifndef CONFIG_MEMSTICK_UNSAFE_RESUME
+	msb->card_dead = true;
+	return 0;
+#endif
+	mutex_lock(&card->host->lock);
+
+	new_msb = kzalloc(sizeof(struct msb_data), GFP_KERNEL);
+	if (!new_msb)
+		goto out;
+
+	new_msb->card = card;
+	memstick_set_drvdata(card, new_msb);
+	spin_lock_init(&new_msb->q_lock);
+	sg_init_table(msb->prealloc_sg, MS_BLOCK_MAX_SEGS+1);
+
+	if (msb_init_card(card))
+		goto out;
+
+	if (msb->block_size != new_msb->block_size)
+		goto out;
+
+	if (memcmp(msb->boot_page, new_msb->boot_page,
+					sizeof(struct ms_boot_page)))
+		goto out;
+
+	if (msb->logical_block_count != new_msb->logical_block_count ||
+		memcmp(msb->lba_to_pba_table, new_msb->lba_to_pba_table,
+						msb->logical_block_count))
+		goto out;
+
+	if (msb->block_count != new_msb->block_count ||
+		memcmp(msb->used_blocks_bitmap, new_msb->used_blocks_bitmap,
+							msb->block_count / 8))
+		goto out;
+
+	card_dead = false;
+out:
+	if (card_dead)
+		dbg("Card was removed/replaced during suspend");
+
+	msb->card_dead = card_dead;
+	memstick_set_drvdata(card, msb);
+
+	if (new_msb) {
+		msb_data_clear(new_msb);
+		kfree(new_msb);
+	}
+
+	msb_start(card);
+	mutex_unlock(&card->host->lock);
+	return 0;
+}
+#else
+
+#define msb_suspend NULL
+#define msb_resume NULL
+
+#endif /* CONFIG_PM */
+
+static struct memstick_device_id msb_id_tbl[] = {
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_FLASH},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_ROM},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_RO},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_WP},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_DUO, MEMSTICK_CATEGORY_STORAGE_DUO,
+	 MEMSTICK_CLASS_DUO},
+	{}
+};
+MODULE_DEVICE_TABLE(memstick, msb_id_tbl);
+
+
+static struct memstick_driver msb_driver = {
+	.driver = {
+		.name  = DRIVER_NAME,
+		.owner = THIS_MODULE
+	},
+	.id_table = msb_id_tbl,
+	.probe    = msb_probe,
+	.remove   = msb_remove,
+	.suspend  = msb_suspend,
+	.resume   = msb_resume
+};
+
+static int major;
+
+static int __init msb_init(void)
+{
+	int rc = register_blkdev(0, DRIVER_NAME);
+
+	if (rc < 0) {
+		pr_err("failed to register major (error %d)\n", rc);
+		return rc;
+	}
+
+	major = rc;
+	rc = memstick_register_driver(&msb_driver);
+	if (rc) {
+		unregister_blkdev(major, DRIVER_NAME);
+		pr_err("failed to register memstick driver (error %d)\n", rc);
+	}
+
+	return rc;
+}
+
+static void __exit msb_exit(void)
+{
+	memstick_unregister_driver(&msb_driver);
+	unregister_blkdev(major, DRIVER_NAME);
+	idr_destroy(&msb_disk_idr);
+}
+
+module_init(msb_init);
+module_exit(msb_exit);
+
+module_param(cache_flush_timeout, int, S_IRUGO);
+MODULE_PARM_DESC(cache_flush_timeout,
+				"Cache flush timeout in msec (1000 default)");
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug level (0-2)");
+
+module_param(verify_writes, bool, S_IRUGO);
+MODULE_PARM_DESC(verify_writes, "Read back and check all data that is written");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Maxim Levitsky");
+MODULE_DESCRIPTION("Sony MemoryStick block device driver");
diff --git a/drivers/memstick/core/ms_block.h b/drivers/memstick/core/ms_block.h
new file mode 100644
index 0000000..6b5b83e
--- /dev/null
+++ b/drivers/memstick/core/ms_block.h
@@ -0,0 +1,293 @@
+/*
+ *  ms_block.c - Sony MemoryStick (legacy) storage support
+
+ *  Copyright (C) 2010 Maxim Levitsky <maximlevitsky@gmail.com>
+ *
+ * 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.
+ *
+ * Minor portions of the driver are copied from mspro_block.c which is
+ * Copyright (C) 2007 Alex Dubov <oakad@yahoo.com>
+ *
+ * Also ms structures were copied from old broken driver by same author
+ * These probably come from MS spec
+ *
+ */
+
+#ifndef MS_BLOCK_NEW_H
+#define MS_BLOCK_NEW_H
+
+#define MS_BLOCK_MAX_SEGS      32
+#define MS_BLOCK_MAX_PAGES     ((2 << 16) - 1)
+
+#define MS_BLOCK_MAX_BOOT_ADDR 0x000c
+#define MS_BLOCK_BOOT_ID       0x0001
+#define MS_BLOCK_INVALID       0xffff
+#define MS_MAX_ZONES           16
+#define MS_BLOCKS_IN_ZONE      512
+
+#define MS_BLOCK_MAP_LINE_SZ   16
+#define MS_BLOCK_PART_SHIFT    3
+
+
+#define MEMSTICK_UNCORR_ERROR (MEMSTICK_STATUS1_UCFG | \
+		MEMSTICK_STATUS1_UCEX | MEMSTICK_STATUS1_UCDT)
+
+#define MEMSTICK_CORR_ERROR (MEMSTICK_STATUS1_FGER | MEMSTICK_STATUS1_EXER | \
+	MEMSTICK_STATUS1_DTER)
+
+#define MEMSTICK_INT_ERROR (MEMSTICK_INT_CMDNAK | MEMSTICK_INT_ERR)
+
+#define MEMSTICK_OVERWRITE_FLAG_NORMAL \
+	(MEMSTICK_OVERWRITE_PGST1 | \
+	MEMSTICK_OVERWRITE_PGST0  | \
+	MEMSTICK_OVERWRITE_BKST)
+
+#define MEMSTICK_OV_PG_NORMAL \
+	(MEMSTICK_OVERWRITE_PGST1 | MEMSTICK_OVERWRITE_PGST0)
+
+#define MEMSTICK_MANAGMENT_FLAG_NORMAL \
+	(MEMSTICK_MANAGEMENT_SYSFLG |  \
+	MEMSTICK_MANAGEMENT_SCMS1   |  \
+	MEMSTICK_MANAGEMENT_SCMS0)     \
+
+struct ms_boot_header {
+	unsigned short block_id;
+	unsigned short format_reserved;
+	unsigned char  reserved0[184];
+	unsigned char  data_entry;
+	unsigned char  reserved1[179];
+} __packed;
+
+
+struct ms_system_item {
+	unsigned int  start_addr;
+	unsigned int  data_size;
+	unsigned char data_type_id;
+	unsigned char reserved[3];
+} __packed;
+
+struct ms_system_entry {
+	struct ms_system_item disabled_block;
+	struct ms_system_item cis_idi;
+	unsigned char         reserved[24];
+} __packed;
+
+struct ms_boot_attr_info {
+	unsigned char      memorystick_class;
+	unsigned char      format_unique_value1;
+	unsigned short     block_size;
+	unsigned short     number_of_blocks;
+	unsigned short     number_of_effective_blocks;
+	unsigned short     page_size;
+	unsigned char      extra_data_size;
+	unsigned char      format_unique_value2;
+	unsigned char      assembly_time[8];
+	unsigned char      format_unique_value3;
+	unsigned char      serial_number[3];
+	unsigned char      assembly_manufacturer_code;
+	unsigned char      assembly_model_code[3];
+	unsigned short     memory_manufacturer_code;
+	unsigned short     memory_device_code;
+	unsigned short     implemented_capacity;
+	unsigned char      format_unique_value4[2];
+	unsigned char      vcc;
+	unsigned char      vpp;
+	unsigned short     controller_number;
+	unsigned short     controller_function;
+	unsigned char      reserved0[9];
+	unsigned char      transfer_supporting;
+	unsigned short     format_unique_value5;
+	unsigned char      format_type;
+	unsigned char      memorystick_application;
+	unsigned char      device_type;
+	unsigned char      reserved1[22];
+	unsigned char      format_uniqure_value6[2];
+	unsigned char      reserved2[15];
+} __packed;
+
+struct ms_cis_idi {
+	unsigned short general_config;
+	unsigned short logical_cylinders;
+	unsigned short reserved0;
+	unsigned short logical_heads;
+	unsigned short track_size;
+	unsigned short page_size;
+	unsigned short pages_per_track;
+	unsigned short msw;
+	unsigned short lsw;
+	unsigned short reserved1;
+	unsigned char  serial_number[20];
+	unsigned short buffer_type;
+	unsigned short buffer_size_increments;
+	unsigned short long_command_ecc;
+	unsigned char  firmware_version[28];
+	unsigned char  model_name[18];
+	unsigned short reserved2[5];
+	unsigned short pio_mode_number;
+	unsigned short dma_mode_number;
+	unsigned short field_validity;
+	unsigned short current_logical_cylinders;
+	unsigned short current_logical_heads;
+	unsigned short current_pages_per_track;
+	unsigned int   current_page_capacity;
+	unsigned short mutiple_page_setting;
+	unsigned int   addressable_pages;
+	unsigned short single_word_dma;
+	unsigned short multi_word_dma;
+	unsigned char  reserved3[128];
+} __packed;
+
+
+struct ms_boot_page {
+	struct ms_boot_header    header;
+	struct ms_system_entry   entry;
+	struct ms_boot_attr_info attr;
+} __packed;
+
+struct msb_data {
+	unsigned int			usage_count;
+	struct memstick_dev		*card;
+	struct gendisk			*disk;
+	struct request_queue		*queue;
+	spinlock_t			q_lock;
+	struct hd_geometry		geometry;
+	struct attribute_group		attr_group;
+	struct request			*req;
+	int				caps;
+	int				disk_id;
+
+	/* IO */
+	struct workqueue_struct		*io_queue;
+	bool				io_queue_stopped;
+	struct work_struct		io_work;
+	struct scatterlist		prealloc_sg[MS_BLOCK_MAX_SEGS+1];
+	bool				card_dead;
+
+	/* Media properties */
+	struct ms_boot_page		*boot_page;
+	u16				boot_block_locations[2];
+	int				boot_block_count;
+
+	bool				read_only;
+	unsigned short			page_size;
+	int				block_size;
+	int				pages_in_block;
+	int				zone_count;
+	int				block_count;
+	int				logical_block_count;
+
+	/* FTL tables */
+	unsigned long			*used_blocks_bitmap;
+	unsigned long			*erased_blocks_bitmap;
+	u16				*lba_to_pba_table;
+	int				free_block_count[MS_MAX_ZONES];
+	bool				ftl_initialized;
+
+	/* Cache */
+	unsigned char			*cache;
+	unsigned long			valid_cache_bitmap;
+	int				cache_block_lba;
+	bool				need_flush_cache;
+	struct timer_list		cache_flush_timer;
+
+	/* Preallocated buffers */
+	unsigned char			*block_buffer;
+	struct scatterlist		sg[MS_BLOCK_MAX_SEGS+1];
+
+
+	/* handler's local data */
+	struct ms_register_addr		reg_addr;
+	bool				addr_valid;
+
+	u8				command_value;
+	bool				command_need_oob;
+	struct scatterlist		*current_sg;
+	int				current_sg_offset;
+
+	struct ms_register		regs;
+	int				current_page;
+
+	int				state;
+	int				exit_error;
+	bool				int_polling;
+	unsigned long			int_timeout;
+
+};
+
+enum msb_readpage_states {
+	MSB_RP_SEND_BLOCK_ADDRESS = 0,
+	MSB_RP_SEND_READ_COMMAND,
+
+	MSB_RP_SEND_INT_REQ,
+	MSB_RP_RECEIVE_INT_REQ_RESULT,
+
+	MSB_RP_SEND_READ_STATUS_REG,
+	MSB_RP_RECIVE_STATUS_REG,
+
+	MSB_RP_SEND_OOB_READ,
+	MSB_RP_RECEIVE_OOB_READ,
+
+	MSB_RP_SEND_READ_DATA,
+	MSB_RP_RECEIVE_READ_DATA,
+};
+
+enum msb_write_block_states {
+	MSB_WB_SEND_WRITE_PARAMS = 0,
+	MSB_WB_SEND_WRITE_OOB,
+	MSB_WB_SEND_WRITE_COMMAND,
+
+	MSB_WB_SEND_INT_REQ,
+	MSB_WB_RECEIVE_INT_REQ,
+
+	MSB_WB_SEND_WRITE_DATA,
+	MSB_WB_RECEIVE_WRITE_CONFIRMATION,
+};
+
+enum msb_send_command_states {
+	MSB_SC_SEND_WRITE_PARAMS,
+	MSB_SC_SEND_WRITE_OOB,
+	MSB_SC_SEND_COMMAND,
+
+	MSB_SC_SEND_INT_REQ,
+	MSB_SC_RECEIVE_INT_REQ,
+
+};
+
+enum msb_reset_states {
+	MSB_RS_SEND,
+	MSB_RS_CONFIRM,
+};
+
+enum msb_par_switch_states {
+	MSB_PS_SEND_SWITCH_COMMAND,
+	MSB_PS_SWICH_HOST,
+	MSB_PS_CONFIRM,
+};
+
+struct chs_entry {
+	unsigned long size;
+	unsigned char sec;
+	unsigned short cyl;
+	unsigned char head;
+};
+
+static int msb_reset(struct msb_data *msb, bool full);
+
+static int h_msb_default_bad(struct memstick_dev *card,
+						struct memstick_request **mrq);
+
+#define DRIVER_NAME "ms_block"
+
+#define __dbg(level, format, ...) \
+	do { \
+		if (debug >= level) \
+			pr_err(format "\n", ## __VA_ARGS__); \
+	} while (0)
+
+
+#define dbg(format, ...)		__dbg(1, format, ## __VA_ARGS__)
+#define dbg_verbose(format, ...)	__dbg(2, format, ## __VA_ARGS__)
+
+#endif
-- 
1.7.9.5

Re: [PATCH 1/2] scatterlist: add sg_nents

[Tejun Heo]

(cc'ing Jens)

On Wed, Sep 26, 2012 at 11:49:00AM +0200, Maxim Levitsky wrote:
> Useful helper to know the number of entries in scatterlist.
> 
> Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
> ---
>  include/linux/scatterlist.h |    1 +
>  lib/scatterlist.c           |   22 ++++++++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
> index 7b600da..4bd6c06 100644
> --- a/include/linux/scatterlist.h
> +++ b/include/linux/scatterlist.h
> @@ -201,6 +201,7 @@ static inline void *sg_virt(struct scatterlist *sg)
>  	return page_address(sg_page(sg)) + sg->offset;
>  }
>  
> +int sg_nents(struct scatterlist *sg);
>  struct scatterlist *sg_next(struct scatterlist *);
>  struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
>  void sg_init_table(struct scatterlist *, unsigned int);
> diff --git a/lib/scatterlist.c b/lib/scatterlist.c
> index e76d85c..5cd9cdc 100644
> --- a/lib/scatterlist.c
> +++ b/lib/scatterlist.c
> @@ -39,6 +39,28 @@ struct scatterlist *sg_next(struct scatterlist *sg)
>  EXPORT_SYMBOL(sg_next);
>  
>  /**
> + * sg_nents - return total count of entries in scatterlist
> + * @sg:		The scatterlist
> + *
> + * Description:
> + * Allows to know how many entries are in sg, taking into acount
> + * chaining as well
> + *
> + **/
> +int sg_nents(struct scatterlist *sg)
> +{
> +	int nents = 0;
> +	while (sg) {
> +		nents++;
> +		sg = sg_next(sg);
> +	}
> +
> +	return nents;
> +}
> +EXPORT_SYMBOL(sg_nents);

How about the following instead?

	for (nents = 0; sg; sg = sg_next(sg))
		nents++;
	return nents;

Other than that,

 Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun

Re: [PATCH 2/2] memstick: add support for legacy memorysticks

[Tejun Heo]

On Wed, Sep 26, 2012 at 11:49:01AM +0200, Maxim Levitsky wrote:
> Based partially on MS standard spec quotes from Alex Dubov.
> 
> As any code that works with user data this driver isn't
> recommended to use to write cards that contain valuable data.
> 
> It tries its best though to avoid data corruption
> and possible damage to the card.
> 
> Tested on MS DUO 64 MB card on Ricoh R592 card reader.
> 
> Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>

Workqueue related part looks good to me.  Don't have much clue about
other stuff.

Thanks.

-- 
tejun

Re: [PATCH 1/2] scatterlist: add sg_nents

[Jens Axboe]

On 09/26/2012 06:38 PM, Tejun Heo wrote:
> (cc'ing Jens)
> 
> On Wed, Sep 26, 2012 at 11:49:00AM +0200, Maxim Levitsky wrote:
>> Useful helper to know the number of entries in scatterlist.
>>
>> Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
>> ---
>>  include/linux/scatterlist.h |    1 +
>>  lib/scatterlist.c           |   22 ++++++++++++++++++++++
>>  2 files changed, 23 insertions(+)
>>
>> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
>> index 7b600da..4bd6c06 100644
>> --- a/include/linux/scatterlist.h
>> +++ b/include/linux/scatterlist.h
>> @@ -201,6 +201,7 @@ static inline void *sg_virt(struct scatterlist *sg)
>>  	return page_address(sg_page(sg)) + sg->offset;
>>  }
>>  
>> +int sg_nents(struct scatterlist *sg);
>>  struct scatterlist *sg_next(struct scatterlist *);
>>  struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
>>  void sg_init_table(struct scatterlist *, unsigned int);
>> diff --git a/lib/scatterlist.c b/lib/scatterlist.c
>> index e76d85c..5cd9cdc 100644
>> --- a/lib/scatterlist.c
>> +++ b/lib/scatterlist.c
>> @@ -39,6 +39,28 @@ struct scatterlist *sg_next(struct scatterlist *sg)
>>  EXPORT_SYMBOL(sg_next);
>>  
>>  /**
>> + * sg_nents - return total count of entries in scatterlist
>> + * @sg:		The scatterlist
>> + *
>> + * Description:
>> + * Allows to know how many entries are in sg, taking into acount
>> + * chaining as well
>> + *
>> + **/
>> +int sg_nents(struct scatterlist *sg)
>> +{
>> +	int nents = 0;
>> +	while (sg) {
>> +		nents++;
>> +		sg = sg_next(sg);
>> +	}
>> +
>> +	return nents;
>> +}
>> +EXPORT_SYMBOL(sg_nents);
> 
> How about the following instead?
> 
> 	for (nents = 0; sg; sg = sg_next(sg))
> 		nents++;
> 	return nents;
> 
> Other than that,
> 
>  Acked-by: Tejun Heo <tj@kernel.org>

Agree, that'd be cleaner. I've just applied it as-is. Maxim, feel free
to send an update to it. I pulled the driver bit into the
for-3.7/drivers branch as well.

-- 
Jens Axboe

[PATCH] scatterlist: refactor the sg_nents

[Maxim Levitsky]

Replace 'while' with 'for' as suggested by Tejun Heo

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
 lib/scatterlist.c |    7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 5cd9cdc..3675452b 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -49,12 +49,9 @@ EXPORT_SYMBOL(sg_next);
  **/
 int sg_nents(struct scatterlist *sg)
 {
-	int nents = 0;
-	while (sg) {
+	int nents;
+	for (nents = 0; sg; sg = sg_next(sg))
 		nents++;
-		sg = sg_next(sg);
-	}
-
 	return nents;
 }
 EXPORT_SYMBOL(sg_nents);
-- 
1.7.9.5

Re: [PATCH] scatterlist: refactor the sg_nents

[Jens Axboe]

On 2012-09-27 16:28, Maxim Levitsky wrote:
> Replace 'while' with 'for' as suggested by Tejun Heo

Thanks, purtier :-)

-- 
Jens Axboe

Re: [PATCH 2/2] memstick: add support for legacy memorysticks

[Geert Uytterhoeven]

On Wed, Sep 26, 2012 at 11:49 AM, Maxim Levitsky
<maximlevitsky@gmail.com> wrote:
> --- /dev/null
> +++ b/drivers/memstick/core/ms_block.c

> +#define pr_fmt(fmt) DRIVER_NAME ": " fmt
> +
> +#include <linux/module.h>
> +#include <linux/blkdev.h>
> +#include <linux/memstick.h>
> +#include <linux/idr.h>
> +#include <linux/hdreg.h>
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/random.h>
> +#include <linux/bitmap.h>
> +#include <linux/scatterlist.h>
> +#include <linux/jiffies.h>
> +#include <linux/workqueue.h>
> +#include <linux/mutex.h>
> +#include "ms_block.h"

http://kisskb.ellerman.id.au/kisskb/buildresult/7280352/
arch/m68k/include/asm/hardirq.h:23:20: error: expected ')' before 'DRIVER_NAME'
make[4]: *** [drivers/memstick/core/ms_block.o] Error 1

The reason for this is that pr_fmt() references DRIVER_NAME and is defined
before the first include, while DRIVER_NAME is only defined in ms_block.h,
which is the last included file. If any subsequent include file uses pr_fmt()
(e.g. the call to pr_crit() in arch/m68k/include/asm/hardirq.h), this
causes a build
failure.

I suggest moving the DRIVER_NAME define to ms_block.c.
Cfr. memstick.c and mspro_block.c, who already have their own definition.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 2/2] memstick: add support for legacy memorysticks

[Maxim Levitsky]

On Sat, 2012-09-29 at 19:20 +0200, Geert Uytterhoeven wrote: 
> On Wed, Sep 26, 2012 at 11:49 AM, Maxim Levitsky
> <maximlevitsky@gmail.com> wrote:
> > --- /dev/null
> > +++ b/drivers/memstick/core/ms_block.c
> 
> > +#define pr_fmt(fmt) DRIVER_NAME ": " fmt
> > +
> > +#include <linux/module.h>
> > +#include <linux/blkdev.h>
> > +#include <linux/memstick.h>
> > +#include <linux/idr.h>
> > +#include <linux/hdreg.h>
> > +#include <linux/delay.h>
> > +#include <linux/slab.h>
> > +#include <linux/random.h>
> > +#include <linux/bitmap.h>
> > +#include <linux/scatterlist.h>
> > +#include <linux/jiffies.h>
> > +#include <linux/workqueue.h>
> > +#include <linux/mutex.h>
> > +#include "ms_block.h"
> 
> http://kisskb.ellerman.id.au/kisskb/buildresult/7280352/
> arch/m68k/include/asm/hardirq.h:23:20: error: expected ')' before 'DRIVER_NAME'
> make[4]: *** [drivers/memstick/core/ms_block.o] Error 1
> 
> The reason for this is that pr_fmt() references DRIVER_NAME and is defined
> before the first include, while DRIVER_NAME is only defined in ms_block.h,
> which is the last included file. If any subsequent include file uses pr_fmt()
> (e.g. the call to pr_crit() in arch/m68k/include/asm/hardirq.h), this
> causes a build
> failure.
> 
> I suggest moving the DRIVER_NAME define to ms_block.c.
> Cfr. memstick.c and mspro_block.c, who already have their own definition.
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
Completely agree!
I was somewhat busy lately, so I didn't address this yet.
I'll send a patch tomorrow.

Best regards,
Maxim Levitsky

Fixes for ms_block

[Maxim Levitsky]

Hi,

I finally found time to send the fix for the compile issue on m68k
Among with small cosmetic fix to remove unused field that slipped thorough.

Do you know if my driver will be merged in 3.7 or later?
I hope that the compile issue which I should have handled earlier is not to blame.

[PATCH 1/2] memstick: remove unused field from state struct.

[Maxim Levitsky]

Oops, I forgot that I have thet field there already.
Just save memory by not allocating it.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
 drivers/memstick/core/ms_block.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/memstick/core/ms_block.h b/drivers/memstick/core/ms_block.h
index 6b5b83e..a2b2765 100644
--- a/drivers/memstick/core/ms_block.h
+++ b/drivers/memstick/core/ms_block.h
@@ -162,7 +162,6 @@ struct msb_data {
 	struct workqueue_struct		*io_queue;
 	bool				io_queue_stopped;
 	struct work_struct		io_work;
-	struct scatterlist		prealloc_sg[MS_BLOCK_MAX_SEGS+1];
 	bool				card_dead;
 
 	/* Media properties */
@@ -194,7 +193,7 @@ struct msb_data {
 
 	/* Preallocated buffers */
 	unsigned char			*block_buffer;
-	struct scatterlist		sg[MS_BLOCK_MAX_SEGS+1];
+	struct scatterlist		prealloc_sg[MS_BLOCK_MAX_SEGS+1];
 
 
 	/* handler's local data */
-- 
1.7.9.5

[PATCH 2/2] memstick: ms_block: fix complile issue.

[Maxim Levitsky]

As suggested by Geert Uytterhoeven

http://kisskb.ellerman.id.au/kisskb/buildresult/7280352/
arch/m68k/include/asm/hardirq.h:23:20: error: expected ')' before 'DRIVER_NAME'
make[4]: *** [drivers/memstick/core/ms_block.o] Error 1

The reason for this is that pr_fmt() references DRIVER_NAME and is defined
before the first include, while DRIVER_NAME is only defined in ms_block.h,
which is the last included file. If any subsequent include file uses pr_fmt()
(e.g. the call to pr_crit() in arch/m68k/include/asm/hardirq.h), this
causes a build
failure.

I suggest moving the DRIVER_NAME define to ms_block.c.
Cfr. memstick.c and mspro_block.c, who already have their own definition.


CC: Geert Uytterhoeven <geert@linux-m68k.org>

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
 drivers/memstick/core/ms_block.c |    2 +-
 drivers/memstick/core/ms_block.h |    2 --
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/memstick/core/ms_block.c b/drivers/memstick/core/ms_block.c
index c815fe5..71e5937 100644
--- a/drivers/memstick/core/ms_block.c
+++ b/drivers/memstick/core/ms_block.c
@@ -11,7 +11,7 @@
  * Copyright (C) 2007 Alex Dubov <oakad@yahoo.com>
  *
  */
-
+#define DRIVER_NAME "ms_block"
 #define pr_fmt(fmt) DRIVER_NAME ": " fmt
 
 #include <linux/module.h>
diff --git a/drivers/memstick/core/ms_block.h b/drivers/memstick/core/ms_block.h
index a2b2765..546b55e 100644
--- a/drivers/memstick/core/ms_block.h
+++ b/drivers/memstick/core/ms_block.h
@@ -277,8 +277,6 @@ static int msb_reset(struct msb_data *msb, bool full);
 static int h_msb_default_bad(struct memstick_dev *card,
 						struct memstick_request **mrq);
 
-#define DRIVER_NAME "ms_block"
-
 #define __dbg(level, format, ...) \
 	do { \
 		if (debug >= level) \
-- 
1.7.9.5

Re: [PATCH 1/2] scatterlist: add sg_nents

[Geert Uytterhoeven]

On Wed, Sep 26, 2012 at 11:49 AM, Maxim Levitsky
<maximlevitsky@gmail.com> wrote:
> +int sg_nents(struct scatterlist *sg)

unsigned int?

> +{
> +       int nents = 0;
> +       while (sg) {
> +               nents++;
> +               sg = sg_next(sg);
> +       }
> +
> +       return nents;
> +}

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] scatterlist: add sg_nents

[Geert Uytterhoeven]

On Thu, Oct 11, 2012 at 12:27 PM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> On Wed, Sep 26, 2012 at 11:49 AM, Maxim Levitsky
> <maximlevitsky@gmail.com> wrote:
>> +int sg_nents(struct scatterlist *sg)
>
> unsigned int?

and "const struct scatterlist *sg"? Ah no, that won't work as
sg_next() treats non-const pointers :-(

>> +{
>> +       int nents = 0;
>> +       while (sg) {
>> +               nents++;
>> +               sg = sg_next(sg);
>> +       }
>> +
>> +       return nents;
>> +}

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 2/2] memstick: add support for legacy memorysticks

[Maxim Levitsky]

On Tue, 2012-09-25 at 12:38 -0700, Tejun Heo wrote: 
> Hello, Maxim.
> 
> On Tue, Sep 25, 2012 at 09:26:13PM +0200, Maxim Levitsky wrote:
> > > Probably not the best idea to use a name this generic in driver code.
> > > linux/scatterlist.h likely might wanna use the name.
> >
> > Lets not go this route again. I already once submitted these, and had
> > a share of problems with merging these poor functions into the scatter
> > list.
> > scatter list users mostly dont need these as they just translate it into
> > hardware specific representation.
> > In my case, I don't and yet its easier that working with BIOs. 
> 
> Hmmm... then please at least add a prefix to the names.
Will do! 
> 
> > > Also, from what it does, it seems sg_copy() is a bit of misnomer.
> > > Rename it to sg_remap_with_offset() or something and move it to
> > > lib/scatterlist.c?
> >
> > Don't think so. This copies part of a scatter list into another
> > scatterlist.
> > I have to use is as memstick underlying drivers expect a single
> > scatterlist for each 512 bytes sector I read. Yes, it contains just one
> > entry, but still. I haven't designed the interface. 
> 
> It doesn't really matter if it's a function only used in the driver,
> but please don't use sg_copy() as its name.
Sure! 
> 
> > > Maybe we can make sg_copy_buffer() more generic so that it takes a
> > > callback and implement this on top of it?  Having sglist manipulation
> > > scattered isn't too attractive.
> >
> > Again this is very specific to my driver. Usually nobody pokes the
> > scatterlists. 
> 
> The problem is that there are talks of improving sglist handling (make
> it more generic, unify it with bvec and so on) and this sort of one
> off direct manipulations often become headaches afterwards, so if at
> all possible it's best to keep stuff centralized.
If the sglist gets improved, I will be glad to update my driver to use
the new generic code.

Compared to my xD driver, which just works directly with pointers to 512
byte buffers (with the price of not utilizing highmem), the sglist (and
bios are even worse, I recall), gave me lot of headaches :-(

> 
> > > Is it really necessary to implement explicit state machine?  Can't you
> > > just throw a work item at it and process it synchronously?  Explicit
> > > state machines can save some resources at the cost of a lot more
> > > complexity and generally making things a lot more fragile.  Is it
> > > really worth it here?
> >
> > It would be awesome to not use these ugly state machines, but I have to,
> > because this is required by underlying driver interface.
> > Its callback driven, that is underlying driver calls into this driver,
> > when it wants, and I supply it new command to execute.
> > Unfortunately with legacy memsticks, to read or write a sector, one
> > needs to send it many different commands. Thats why these state
> > machines. I at least made them more or less consistent.
> > Just take a look at mspro_blk.c....
> 
> I see.  Eeeek...

I tried once to improve it, dunno if I did or made it even worse, its a
long story.... Anyway it wasn't liked my its author.

Anyway, my goal now is to get this driver merged, as its the last piece
of the puzzle to make my card reader perfect. If can now read/write
everything, and its the only such reader supported by Linux.

To be honest the Jmicron reader I have doesn't have a driver for xD
part, and I need to stop beeing lazy and write a driver, I do have even
docs for it.

Thanks for review, I will address these comments soon,

Best regards,
        Maxim Levitsky

Re: [PATCH 2/2] memstick: add support for legacy memorysticks

[Tejun Heo]

Hello, Maxim.

On Tue, Sep 25, 2012 at 09:26:13PM +0200, Maxim Levitsky wrote:
> > Probably not the best idea to use a name this generic in driver code.
> > linux/scatterlist.h likely might wanna use the name.
>
> Lets not go this route again. I already once submitted these, and had
> a share of problems with merging these poor functions into the scatter
> list.
> scatter list users mostly dont need these as they just translate it into
> hardware specific representation.
> In my case, I don't and yet its easier that working with BIOs. 

Hmmm... then please at least add a prefix to the names.

> > Also, from what it does, it seems sg_copy() is a bit of misnomer.
> > Rename it to sg_remap_with_offset() or something and move it to
> > lib/scatterlist.c?
>
> Don't think so. This copies part of a scatter list into another
> scatterlist.
> I have to use is as memstick underlying drivers expect a single
> scatterlist for each 512 bytes sector I read. Yes, it contains just one
> entry, but still. I haven't designed the interface. 

It doesn't really matter if it's a function only used in the driver,
but please don't use sg_copy() as its name.

> > Maybe we can make sg_copy_buffer() more generic so that it takes a
> > callback and implement this on top of it?  Having sglist manipulation
> > scattered isn't too attractive.
>
> Again this is very specific to my driver. Usually nobody pokes the
> scatterlists. 

The problem is that there are talks of improving sglist handling (make
it more generic, unify it with bvec and so on) and this sort of one
off direct manipulations often become headaches afterwards, so if at
all possible it's best to keep stuff centralized.

> > Is it really necessary to implement explicit state machine?  Can't you
> > just throw a work item at it and process it synchronously?  Explicit
> > state machines can save some resources at the cost of a lot more
> > complexity and generally making things a lot more fragile.  Is it
> > really worth it here?
>
> It would be awesome to not use these ugly state machines, but I have to,
> because this is required by underlying driver interface.
> Its callback driven, that is underlying driver calls into this driver,
> when it wants, and I supply it new command to execute.
> Unfortunately with legacy memsticks, to read or write a sector, one
> needs to send it many different commands. Thats why these state
> machines. I at least made them more or less consistent.
> Just take a look at mspro_blk.c....

I see.  Eeeek...

Thanks.

-- 
tejun

Re: [PATCH 2/2] memstick: add support for legacy memorysticks

[Maxim Levitsky]

On Tue, 2012-09-25 at 11:25 -0700, Tejun Heo wrote: 
> Hello,
> 
> On Tue, Sep 25, 2012 at 10:38:46AM +0200, Maxim Levitsky wrote:
> > diff --git a/drivers/memstick/core/ms_block.c b/drivers/memstick/core/ms_block.c
> > new file mode 100644
> > index 0000000..318e40b
> > --- /dev/null
> > +++ b/drivers/memstick/core/ms_block.c
> > @@ -0,0 +1,2422 @@
> > +/*
> > + *  ms_block.c - Sony MemoryStick (legacy) storage support
> > +
> 
> Missing '*'?
> 
> > + *  Copyright (C) 2012 Maxim Levitsky <maximlevitsky@gmail.com>
> > + *
> > + * 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.
> > + *
> > + * Minor portions of the driver were copied from mspro_block.c which is
> > + * Copyright (C) 2007 Alex Dubov <oakad@yahoo.com>
> > + *
> > + */
> ...
> > +static size_t sg_copy(struct scatterlist *sg_from, struct scatterlist *sg_to,
> > +					int to_nents, size_t offset, size_t len)
> 
> Probably not the best idea to use a name this generic in driver code.
> linux/scatterlist.h likely might wanna use the name.
Lets not go this route again. I already once submitted these, and had
a share of problems with merging these poor functions into the scatter
list.
scatter list users mostly dont need these as they just translate it into
hardware specific representation.
In my case, I don't and yet its easier that working with BIOs. 
> 
> > +{
> > +	size_t copied = 0;
> > +
> > +	while (offset > 0) {
> > +
> > +		if (offset >= sg_from->length) {
> > +			if (sg_is_last(sg_from))
> > +				return 0;
> > +
> > +			offset -= sg_from->length;
> > +			sg_from = sg_next(sg_from);
> > +			continue;
> > +		}
> > +
> > +		copied = min(len, sg_from->length - offset);
> > +		sg_set_page(sg_to, sg_page(sg_from),
> > +			copied, sg_from->offset + offset);
> > +
> > +		len -= copied;
> > +		offset = 0;
> > +
> > +		if (sg_is_last(sg_from) || !len)
> > +			goto out;
> > +
> > +		sg_to = sg_next(sg_to);
> > +		to_nents--;
> > +		sg_from = sg_next(sg_from);
> > +	}
> > +
> > +	while (len > sg_from->length && to_nents--) {
> > +
> > +		len -= sg_from->length;
> > +		copied += sg_from->length;
> > +
> > +		sg_set_page(sg_to, sg_page(sg_from),
> > +				sg_from->length, sg_from->offset);
> > +
> > +		if (sg_is_last(sg_from) || !len)
> > +			goto out;
> > +
> > +		sg_from = sg_next(sg_from);
> > +		sg_to = sg_next(sg_to);
> > +	}
> > +
> > +	if (len && to_nents) {
> > +		sg_set_page(sg_to, sg_page(sg_from), len, sg_from->offset);
> > +		copied += len;
> > +	}
> > +
> > +out:
> > +	sg_mark_end(sg_to);
> > +	return copied;
> > +}
> 
> Also, from what it does, it seems sg_copy() is a bit of misnomer.
> Rename it to sg_remap_with_offset() or something and move it to
> lib/scatterlist.c?
Don't think so. This copies part of a scatter list into another
scatterlist.
I have to use is as memstick underlying drivers expect a single
scatterlist for each 512 bytes sector I read. Yes, it contains just one
entry, but still. I haven't designed the interface. 
> 
> > +/*
> > + * Compares section of 'sg' starting from offset 'offset' and with length 'len'
> > + * to linear buffer of length 'len' at address 'buffer'
> > + * Returns 0 if equal and  -1 otherwice
> > + */
> > +static int sg_compare_to_buffer(struct scatterlist *sg,
> > +					size_t offset, u8 *buffer, size_t len)
> > +{
> > +	int retval = 0;
> > +	struct sg_mapping_iter miter;
> > +
> > +	sg_miter_start(&miter, sg, sg_nents(sg),
> > +					SG_MITER_ATOMIC | SG_MITER_FROM_SG);
> > +
> > +	while (sg_miter_next(&miter) && len > 0) {
> > +
> > +		int cmplen;
> > +
> > +		if (offset >= miter.length) {
> > +			offset -= miter.length;
> > +			continue;
> > +		}
> > +
> > +		cmplen = min(miter.length - offset, len);
> > +		retval = memcmp(miter.addr + offset, buffer, cmplen) ? -1 : 0;
> > +		if (retval)
> > +			break;
> > +
> > +		buffer += cmplen;
> > +		len -= cmplen;
> > +		offset = 0;
> > +	}
> > +
> > +	if (!retval && len)
> > +		retval = -1;
> > +
> > +	sg_miter_stop(&miter);
> > +	return retval;
> > +}
> 
> Maybe we can make sg_copy_buffer() more generic so that it takes a
> callback and implement this on top of it?  Having sglist manipulation
> scattered isn't too attractive.
Again this is very specific to my driver. Usually nobody pokes the
scatterlists. 
> 
> ...
> > +/*
> > + * This function is a handler for reads of one page from device.
> > + * Writes output to msb->current_sg, takes sector address from msb->reg.param
> > + * Can also be used to read extra data only. Set params accordintly.
> > + */
> > +static int h_msb_read_page(struct memstick_dev *card,
> > +					struct memstick_request **out_mrq)
> > +{
> > +	struct msb_data *msb = memstick_get_drvdata(card);
> > +	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
> > +	struct scatterlist sg[2];
> > +	u8 command, intreg;
> > +
> > +	if (mrq->error) {
> > +		dbg("read_page, unknown error");
> > +		return msb_exit_state_machine(msb, mrq->error);
> > +	}
> > +again:
> > +	switch (msb->state) {
> > +	case MSB_RP_SEND_BLOCK_ADDRESS:
> ...
> > +	case MSB_RP_SEND_READ_COMMAND:
> ...
> > +	case MSB_RP_SEND_INT_REQ:
> ...
> > +	case MSB_RP_RECEIVE_INT_REQ_RESULT:
> ...
> 
> Is it really necessary to implement explicit state machine?  Can't you
> just throw a work item at it and process it synchronously?  Explicit
> state machines can save some resources at the cost of a lot more
> complexity and generally making things a lot more fragile.  Is it
> really worth it here?
It would be awesome to not use these ugly state machines, but I have to,
because this is required by underlying driver interface.
Its callback driven, that is underlying driver calls into this driver,
when it wants, and I supply it new command to execute.
Unfortunately with legacy memsticks, to read or write a sector, one
needs to send it many different commands. Thats why these state
machines. I at least made them more or less consistent.
Just take a look at mspro_blk.c....

> 
> > +/* Registers the block device */
> > +static int msb_init_disk(struct memstick_dev *card)
> > +{
> > +	struct msb_data *msb = memstick_get_drvdata(card);
> > +	struct memstick_host *host = card->host;
> > +	int rc, disk_id;
> > +	u64 limit = BLK_BOUNCE_HIGH;
> > +	unsigned long capacity;
> > +
> > +	if (host->dev.dma_mask && *(host->dev.dma_mask))
> > +		limit = *(host->dev.dma_mask);
> > +
> > +	mutex_lock(&msb_disk_lock);
> > +
> > +	if (!idr_pre_get(&msb_disk_idr, GFP_KERNEL)) {
> > +		mutex_unlock(&msb_disk_lock);
> > +		return -ENOMEM;
> > +	}
> > +
> > +	rc = idr_get_new(&msb_disk_idr, card, &disk_id);
> > +	mutex_unlock(&msb_disk_lock);
> > +
> > +	if (rc)
> > +		return rc;
> > +
> > +	if ((disk_id << MS_BLOCK_PART_SHIFT) > 255) {
> > +		rc = -ENOSPC;
> > +		goto out_release_id;
> > +	}
> > +
> > +	msb->disk = alloc_disk(1 << MS_BLOCK_PART_SHIFT);
> > +	if (!msb->disk) {
> > +		rc = -ENOMEM;
> > +		goto out_release_id;
> > +	}
> 
> Unless you need fixed major:minor mapping (and you don't), you can
> simply leave disk->major, first_minor and minors zero and set
> GENHD_FL_EXT_DEVT.  Block layer will automatically allocate device
> numbers dynamically as necessary.  No need to worry about MAJ:MIN.
Nice to know. This part I mostly copied from mspro driver. 
> 
> Thanks.
> 

-- 
Best regards,
        Maxim Levitsky

Re: [PATCH 2/2] memstick: add support for legacy memorysticks

[Tejun Heo]

Hello,

On Tue, Sep 25, 2012 at 10:38:46AM +0200, Maxim Levitsky wrote:
> diff --git a/drivers/memstick/core/ms_block.c b/drivers/memstick/core/ms_block.c
> new file mode 100644
> index 0000000..318e40b
> --- /dev/null
> +++ b/drivers/memstick/core/ms_block.c
> @@ -0,0 +1,2422 @@
> +/*
> + *  ms_block.c - Sony MemoryStick (legacy) storage support
> +

Missing '*'?

> + *  Copyright (C) 2012 Maxim Levitsky <maximlevitsky@gmail.com>
> + *
> + * 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.
> + *
> + * Minor portions of the driver were copied from mspro_block.c which is
> + * Copyright (C) 2007 Alex Dubov <oakad@yahoo.com>
> + *
> + */
...
> +static size_t sg_copy(struct scatterlist *sg_from, struct scatterlist *sg_to,
> +					int to_nents, size_t offset, size_t len)

Probably not the best idea to use a name this generic in driver code.
linux/scatterlist.h likely might wanna use the name.

> +{
> +	size_t copied = 0;
> +
> +	while (offset > 0) {
> +
> +		if (offset >= sg_from->length) {
> +			if (sg_is_last(sg_from))
> +				return 0;
> +
> +			offset -= sg_from->length;
> +			sg_from = sg_next(sg_from);
> +			continue;
> +		}
> +
> +		copied = min(len, sg_from->length - offset);
> +		sg_set_page(sg_to, sg_page(sg_from),
> +			copied, sg_from->offset + offset);
> +
> +		len -= copied;
> +		offset = 0;
> +
> +		if (sg_is_last(sg_from) || !len)
> +			goto out;
> +
> +		sg_to = sg_next(sg_to);
> +		to_nents--;
> +		sg_from = sg_next(sg_from);
> +	}
> +
> +	while (len > sg_from->length && to_nents--) {
> +
> +		len -= sg_from->length;
> +		copied += sg_from->length;
> +
> +		sg_set_page(sg_to, sg_page(sg_from),
> +				sg_from->length, sg_from->offset);
> +
> +		if (sg_is_last(sg_from) || !len)
> +			goto out;
> +
> +		sg_from = sg_next(sg_from);
> +		sg_to = sg_next(sg_to);
> +	}
> +
> +	if (len && to_nents) {
> +		sg_set_page(sg_to, sg_page(sg_from), len, sg_from->offset);
> +		copied += len;
> +	}
> +
> +out:
> +	sg_mark_end(sg_to);
> +	return copied;
> +}

Also, from what it does, it seems sg_copy() is a bit of misnomer.
Rename it to sg_remap_with_offset() or something and move it to
lib/scatterlist.c?

> +/*
> + * Compares section of 'sg' starting from offset 'offset' and with length 'len'
> + * to linear buffer of length 'len' at address 'buffer'
> + * Returns 0 if equal and  -1 otherwice
> + */
> +static int sg_compare_to_buffer(struct scatterlist *sg,
> +					size_t offset, u8 *buffer, size_t len)
> +{
> +	int retval = 0;
> +	struct sg_mapping_iter miter;
> +
> +	sg_miter_start(&miter, sg, sg_nents(sg),
> +					SG_MITER_ATOMIC | SG_MITER_FROM_SG);
> +
> +	while (sg_miter_next(&miter) && len > 0) {
> +
> +		int cmplen;
> +
> +		if (offset >= miter.length) {
> +			offset -= miter.length;
> +			continue;
> +		}
> +
> +		cmplen = min(miter.length - offset, len);
> +		retval = memcmp(miter.addr + offset, buffer, cmplen) ? -1 : 0;
> +		if (retval)
> +			break;
> +
> +		buffer += cmplen;
> +		len -= cmplen;
> +		offset = 0;
> +	}
> +
> +	if (!retval && len)
> +		retval = -1;
> +
> +	sg_miter_stop(&miter);
> +	return retval;
> +}

Maybe we can make sg_copy_buffer() more generic so that it takes a
callback and implement this on top of it?  Having sglist manipulation
scattered isn't too attractive.

...
> +/*
> + * This function is a handler for reads of one page from device.
> + * Writes output to msb->current_sg, takes sector address from msb->reg.param
> + * Can also be used to read extra data only. Set params accordintly.
> + */
> +static int h_msb_read_page(struct memstick_dev *card,
> +					struct memstick_request **out_mrq)
> +{
> +	struct msb_data *msb = memstick_get_drvdata(card);
> +	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
> +	struct scatterlist sg[2];
> +	u8 command, intreg;
> +
> +	if (mrq->error) {
> +		dbg("read_page, unknown error");
> +		return msb_exit_state_machine(msb, mrq->error);
> +	}
> +again:
> +	switch (msb->state) {
> +	case MSB_RP_SEND_BLOCK_ADDRESS:
...
> +	case MSB_RP_SEND_READ_COMMAND:
...
> +	case MSB_RP_SEND_INT_REQ:
...
> +	case MSB_RP_RECEIVE_INT_REQ_RESULT:
...

Is it really necessary to implement explicit state machine?  Can't you
just throw a work item at it and process it synchronously?  Explicit
state machines can save some resources at the cost of a lot more
complexity and generally making things a lot more fragile.  Is it
really worth it here?

> +/* Registers the block device */
> +static int msb_init_disk(struct memstick_dev *card)
> +{
> +	struct msb_data *msb = memstick_get_drvdata(card);
> +	struct memstick_host *host = card->host;
> +	int rc, disk_id;
> +	u64 limit = BLK_BOUNCE_HIGH;
> +	unsigned long capacity;
> +
> +	if (host->dev.dma_mask && *(host->dev.dma_mask))
> +		limit = *(host->dev.dma_mask);
> +
> +	mutex_lock(&msb_disk_lock);
> +
> +	if (!idr_pre_get(&msb_disk_idr, GFP_KERNEL)) {
> +		mutex_unlock(&msb_disk_lock);
> +		return -ENOMEM;
> +	}
> +
> +	rc = idr_get_new(&msb_disk_idr, card, &disk_id);
> +	mutex_unlock(&msb_disk_lock);
> +
> +	if (rc)
> +		return rc;
> +
> +	if ((disk_id << MS_BLOCK_PART_SHIFT) > 255) {
> +		rc = -ENOSPC;
> +		goto out_release_id;
> +	}
> +
> +	msb->disk = alloc_disk(1 << MS_BLOCK_PART_SHIFT);
> +	if (!msb->disk) {
> +		rc = -ENOMEM;
> +		goto out_release_id;
> +	}

Unless you need fixed major:minor mapping (and you don't), you can
simply leave disk->major, first_minor and minors zero and set
GENHD_FL_EXT_DEVT.  Block layer will automatically allocate device
numbers dynamically as necessary.  No need to worry about MAJ:MIN.

Thanks.

-- 
tejun

[PATCH 2/2] memstick: add support for legacy memorysticks

[Maxim Levitsky]

Based partially on MS standard spec quotes from Alex Dubov.

As any code that works with user data this driver isn't
recommended to use to write cards that contain valuable data.

It tries its best though to avoid data corruption
and possible damage to the card.

Tested on MS DUO 64 MB card on Ricoh R592 card reader.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
 MAINTAINERS                      |    5 +
 drivers/memstick/core/Kconfig    |   12 +
 drivers/memstick/core/Makefile   |    2 +-
 drivers/memstick/core/ms_block.c | 2422 ++++++++++++++++++++++++++++++++++++++
 drivers/memstick/core/ms_block.h |  293 +++++
 5 files changed, 2733 insertions(+), 1 deletion(-)
 create mode 100644 drivers/memstick/core/ms_block.c
 create mode 100644 drivers/memstick/core/ms_block.h

diff --git a/MAINTAINERS b/MAINTAINERS
index fdc0119..8fb6bf0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6393,6 +6393,11 @@ W:	http://tifmxx.berlios.de/
 S:	Maintained
 F:	drivers/memstick/host/tifm_ms.c
 
+SONY MEMORYSTICK STANDARD SUPPORT
+M:	Maxim Levitsky <maximlevitsky@gmail.com>
+S:	Maintained
+F:	drivers/memstick/core/ms_block.*
+
 SOUND
 M:	Jaroslav Kysela <perex@perex.cz>
 M:	Takashi Iwai <tiwai@suse.de>
diff --git a/drivers/memstick/core/Kconfig b/drivers/memstick/core/Kconfig
index 95f1814..f79f2a8 100644
--- a/drivers/memstick/core/Kconfig
+++ b/drivers/memstick/core/Kconfig
@@ -24,3 +24,15 @@ config MSPRO_BLOCK
 	  support. This provides a block device driver, which you can use
 	  to mount the filesystem. Almost everyone wishing MemoryStick
 	  support should say Y or M here.
+
+config MS_BLOCK
+	tristate "MemoryStick Standard device driver"
+	depends on BLOCK && EXPERIMENTAL
+	help
+	  Say Y here to enable the MemoryStick Standard device driver
+	  support. This provides a block device driver, which you can use
+	  to mount the filesystem.
+	  This driver works with old (bulky) MemoryStick and MemoryStick Duo
+	  but not PRO. Say Y if you have such card.
+	  Driver is new and not yet well tested, thus it can damage your card
+	  (even permanently)
diff --git a/drivers/memstick/core/Makefile b/drivers/memstick/core/Makefile
index ecd0299..0d7f90c 100644
--- a/drivers/memstick/core/Makefile
+++ b/drivers/memstick/core/Makefile
@@ -3,5 +3,5 @@
 #
 
 obj-$(CONFIG_MEMSTICK)		+= memstick.o
-
+obj-$(CONFIG_MS_BLOCK)		+= ms_block.o
 obj-$(CONFIG_MSPRO_BLOCK)	+= mspro_block.o
diff --git a/drivers/memstick/core/ms_block.c b/drivers/memstick/core/ms_block.c
new file mode 100644
index 0000000..318e40b
--- /dev/null
+++ b/drivers/memstick/core/ms_block.c
@@ -0,0 +1,2422 @@
+/*
+ *  ms_block.c - Sony MemoryStick (legacy) storage support
+
+ *  Copyright (C) 2012 Maxim Levitsky <maximlevitsky@gmail.com>
+ *
+ * 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.
+ *
+ * Minor portions of the driver were copied from mspro_block.c which is
+ * Copyright (C) 2007 Alex Dubov <oakad@yahoo.com>
+ *
+ */
+
+#define pr_fmt(fmt) DRIVER_NAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/memstick.h>
+#include <linux/idr.h>
+#include <linux/hdreg.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/bitmap.h>
+#include <linux/scatterlist.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.h>
+#include "ms_block.h"
+
+static int major;
+static int debug;
+static int cache_flush_timeout = 1000;
+static bool verify_writes;
+
+/*
+ * Copies section of 'sg_from' starting from offset 'offset' and with length
+ * 'len' To another scatterlist of to_nents enties
+ */
+static size_t sg_copy(struct scatterlist *sg_from, struct scatterlist *sg_to,
+					int to_nents, size_t offset, size_t len)
+{
+	size_t copied = 0;
+
+	while (offset > 0) {
+
+		if (offset >= sg_from->length) {
+			if (sg_is_last(sg_from))
+				return 0;
+
+			offset -= sg_from->length;
+			sg_from = sg_next(sg_from);
+			continue;
+		}
+
+		copied = min(len, sg_from->length - offset);
+		sg_set_page(sg_to, sg_page(sg_from),
+			copied, sg_from->offset + offset);
+
+		len -= copied;
+		offset = 0;
+
+		if (sg_is_last(sg_from) || !len)
+			goto out;
+
+		sg_to = sg_next(sg_to);
+		to_nents--;
+		sg_from = sg_next(sg_from);
+	}
+
+	while (len > sg_from->length && to_nents--) {
+
+		len -= sg_from->length;
+		copied += sg_from->length;
+
+		sg_set_page(sg_to, sg_page(sg_from),
+				sg_from->length, sg_from->offset);
+
+		if (sg_is_last(sg_from) || !len)
+			goto out;
+
+		sg_from = sg_next(sg_from);
+		sg_to = sg_next(sg_to);
+	}
+
+	if (len && to_nents) {
+		sg_set_page(sg_to, sg_page(sg_from), len, sg_from->offset);
+		copied += len;
+	}
+
+out:
+	sg_mark_end(sg_to);
+	return copied;
+}
+
+/*
+ * Compares section of 'sg' starting from offset 'offset' and with length 'len'
+ * to linear buffer of length 'len' at address 'buffer'
+ * Returns 0 if equal and  -1 otherwice
+ */
+static int sg_compare_to_buffer(struct scatterlist *sg,
+					size_t offset, u8 *buffer, size_t len)
+{
+	int retval = 0;
+	struct sg_mapping_iter miter;
+
+	sg_miter_start(&miter, sg, sg_nents(sg),
+					SG_MITER_ATOMIC | SG_MITER_FROM_SG);
+
+	while (sg_miter_next(&miter) && len > 0) {
+
+		int cmplen;
+
+		if (offset >= miter.length) {
+			offset -= miter.length;
+			continue;
+		}
+
+		cmplen = min(miter.length - offset, len);
+		retval = memcmp(miter.addr + offset, buffer, cmplen) ? -1 : 0;
+		if (retval)
+			break;
+
+		buffer += cmplen;
+		len -= cmplen;
+		offset = 0;
+	}
+
+	if (!retval && len)
+		retval = -1;
+
+	sg_miter_stop(&miter);
+	return retval;
+}
+
+
+/* Get zone at which block with logical address 'lba' lives
+ * Flash is broken into zones.
+ * Each zone consists of 512 eraseblocks, out of which in first
+ * zone 494 are used and 496 are for all following zones.
+ * Therefore zone #0 hosts blocks 0-493, zone #1 blocks 494-988, etc...
+*/
+static int msb_get_zone_from_lba(int lba)
+{
+	if (lba < 494)
+		return 0;
+	return ((lba - 494) / 496) + 1;
+}
+
+/* Get zone of physical block. Trivial */
+static int msb_get_zone_from_pba(int pba)
+{
+	return pba / MS_BLOCKS_IN_ZONE;
+}
+
+/* Debug test to validate free block counts */
+#ifdef DEBUG
+static int msb_validate_used_block_bitmap(struct msb_data *msb)
+{
+	int total_free_blocks = 0;
+	int i;
+
+	for (i = 0 ; i < msb->zone_count ; i++)
+		total_free_blocks += msb->free_block_count[i];
+
+	if (msb->block_count - bitmap_weight(msb->used_blocks_bitmap,
+					msb->block_count) == total_free_blocks)
+		return 0;
+
+	pr_err("BUG: free block counts don't match the bitmap");
+	msb->read_only = true;
+	return -EINVAL;
+}
+#endif
+
+/* Mark physical block as used */
+static void msb_mark_block_used(struct msb_data *msb, int pba)
+{
+	int zone = msb_get_zone_from_pba(pba);
+
+	if (test_bit(pba, msb->used_blocks_bitmap)) {
+		pr_err(
+		"BUG: attempt to mark already used pba %d as used", pba);
+		msb->read_only = true;
+		return;
+	}
+
+#ifdef DEBUG
+	if (msb_validate_used_block_bitmap(msb))
+		return;
+#endif
+	/* No races because all IO is single threaded */
+	__set_bit(pba, msb->used_blocks_bitmap);
+	msb->free_block_count[zone]--;
+}
+
+/* Mark physical block as free */
+static void msb_mark_block_unused(struct msb_data *msb, int pba)
+{
+	int zone = msb_get_zone_from_pba(pba);
+
+	if (!test_bit(pba, msb->used_blocks_bitmap)) {
+		pr_err("BUG: attempt to mark "
+				"already unused pba %d as unused" , pba);
+		msb->read_only = true;
+		return;
+	}
+
+#ifdef DEBUG
+	if (msb_validate_used_block_bitmap(msb))
+		return;
+#endif
+	/* No races because all IO is single threaded */
+	__clear_bit(pba, msb->used_blocks_bitmap);
+	msb->free_block_count[zone]++;
+}
+
+/* Invalidate current register window */
+static void msb_invalidate_reg_window(struct msb_data *msb)
+{
+	msb->reg_addr.w_offset = offsetof(struct ms_register, id);
+	msb->reg_addr.w_length = sizeof(struct ms_id_register);
+	msb->reg_addr.r_offset = offsetof(struct ms_register, id);
+	msb->reg_addr.r_length = sizeof(struct ms_id_register);
+	msb->addr_valid = false;
+}
+
+/* Start a state machine */
+static int msb_run_state_machine(struct msb_data *msb, int   (*state_func)
+		(struct memstick_dev *card, struct memstick_request **req))
+{
+	struct memstick_dev *card = msb->card;
+
+	WARN_ON(msb->state != -1);
+	msb->int_polling = false;
+	msb->state = 0;
+	msb->exit_error = 0;
+
+	memset(&card->current_mrq, 0, sizeof(card->current_mrq));
+
+	card->next_request = state_func;
+	memstick_new_req(card->host);
+	wait_for_completion(&card->mrq_complete);
+
+	WARN_ON(msb->state != -1);
+	return msb->exit_error;
+}
+
+/* State machines call that to exit */
+static int msb_exit_state_machine(struct msb_data *msb, int error)
+{
+	WARN_ON(msb->state == -1);
+
+	msb->state = -1;
+	msb->exit_error = error;
+	msb->card->next_request = h_msb_default_bad;
+
+	/* Invalidate reg window on errors */
+	if (error)
+		msb_invalidate_reg_window(msb);
+
+	complete(&msb->card->mrq_complete);
+	return -ENXIO;
+}
+
+/* read INT register */
+static int msb_read_int_reg(struct msb_data *msb, long timeout)
+{
+	struct memstick_request *mrq = &msb->card->current_mrq;
+
+	WARN_ON(msb->state == -1);
+
+	if (!msb->int_polling) {
+		msb->int_timeout = jiffies +
+			msecs_to_jiffies(timeout == -1 ? 500 : timeout);
+		msb->int_polling = true;
+	} else if (time_after(jiffies, msb->int_timeout)) {
+		mrq->data[0] = MEMSTICK_INT_CMDNAK;
+		return 0;
+	}
+
+	if ((msb->caps & MEMSTICK_CAP_AUTO_GET_INT) &&
+				mrq->need_card_int && !mrq->error) {
+		mrq->data[0] = mrq->int_reg;
+		mrq->need_card_int = false;
+		return 0;
+	} else {
+		memstick_init_req(mrq, MS_TPC_GET_INT, NULL, 1);
+		return 1;
+	}
+}
+
+/* Read a register */
+static int msb_read_regs(struct msb_data *msb, int offset, int len)
+{
+	struct memstick_request *req = &msb->card->current_mrq;
+
+	if (msb->reg_addr.r_offset != offset ||
+	    msb->reg_addr.r_length != len || !msb->addr_valid) {
+
+		msb->reg_addr.r_offset = offset;
+		msb->reg_addr.r_length = len;
+		msb->addr_valid = true;
+
+		memstick_init_req(req, MS_TPC_SET_RW_REG_ADRS,
+			&msb->reg_addr, sizeof(msb->reg_addr));
+		return 0;
+	}
+
+	memstick_init_req(req, MS_TPC_READ_REG, NULL, len);
+	return 1;
+}
+
+/* Write a card register */
+static int msb_write_regs(struct msb_data *msb, int offset, int len, void *buf)
+{
+	struct memstick_request *req = &msb->card->current_mrq;
+
+	if (msb->reg_addr.w_offset != offset ||
+		msb->reg_addr.w_length != len  || !msb->addr_valid) {
+
+		msb->reg_addr.w_offset = offset;
+		msb->reg_addr.w_length = len;
+		msb->addr_valid = true;
+
+		memstick_init_req(req, MS_TPC_SET_RW_REG_ADRS,
+			&msb->reg_addr, sizeof(msb->reg_addr));
+		return 0;
+	}
+
+	memstick_init_req(req, MS_TPC_WRITE_REG, buf, len);
+	return 1;
+}
+
+/* Handler for absence of IO */
+static int h_msb_default_bad(struct memstick_dev *card,
+						struct memstick_request **mrq)
+{
+	return -ENXIO;
+}
+
+/*
+ * This function is a handler for reads of one page from device.
+ * Writes output to msb->current_sg, takes sector address from msb->reg.param
+ * Can also be used to read extra data only. Set params accordintly.
+ */
+static int h_msb_read_page(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	struct scatterlist sg[2];
+	u8 command, intreg;
+
+	if (mrq->error) {
+		dbg("read_page, unknown error");
+		return msb_exit_state_machine(msb, mrq->error);
+	}
+again:
+	switch (msb->state) {
+	case MSB_RP_SEND_BLOCK_ADDRESS:
+		/* msb_write_regs sometimes "fails" because it needs to update
+			the reg window, and thus it returns request for that.
+			Then we stay in this state and retry */
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			sizeof(struct ms_param_register),
+			(unsigned char *)&msb->regs.param))
+			return 0;
+
+		msb->state = MSB_RP_SEND_READ_COMMAND;
+		return 0;
+
+	case MSB_RP_SEND_READ_COMMAND:
+		command = MS_CMD_BLOCK_READ;
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &command, 1);
+		msb->state = MSB_RP_SEND_INT_REQ;
+		return 0;
+
+	case MSB_RP_SEND_INT_REQ:
+		msb->state = MSB_RP_RECEIVE_INT_REQ_RESULT;
+		/* If dont actually need to send the int read request (only in
+			serial mode), then just fall through */
+		if (msb_read_int_reg(msb, -1))
+			return 0;
+		/* fallthrough */
+
+	case MSB_RP_RECEIVE_INT_REQ_RESULT:
+		intreg = mrq->data[0];
+		msb->regs.status.interrupt = intreg;
+
+		if (intreg & MEMSTICK_INT_CMDNAK)
+			return msb_exit_state_machine(msb, -EIO);
+
+		if (!(intreg & MEMSTICK_INT_CED)) {
+			msb->state = MSB_RP_SEND_INT_REQ;
+			goto again;
+		}
+
+		msb->int_polling = false;
+		msb->state = (intreg & MEMSTICK_INT_ERR) ?
+			MSB_RP_SEND_READ_STATUS_REG : MSB_RP_SEND_OOB_READ;
+		goto again;
+
+	case MSB_RP_SEND_READ_STATUS_REG:
+		 /* read the status register to understand source of the INT_ERR */
+		if (!msb_read_regs(msb,
+			offsetof(struct ms_register, status),
+			sizeof(struct ms_status_register)))
+			return 0;
+
+		msb->state = MSB_RP_RECEIVE_OOB_READ;
+		return 0;
+
+	case MSB_RP_RECIVE_STATUS_REG:
+		msb->regs.status = *(struct ms_status_register *)mrq->data;
+		msb->state = MSB_RP_SEND_OOB_READ;
+		/* fallthrough */
+
+	case MSB_RP_SEND_OOB_READ:
+		if (!msb_read_regs(msb,
+			offsetof(struct ms_register, extra_data),
+			sizeof(struct ms_extra_data_register)))
+			return 0;
+
+		msb->state = MSB_RP_RECEIVE_OOB_READ;
+		return 0;
+
+	case MSB_RP_RECEIVE_OOB_READ:
+		msb->regs.extra_data =
+			*(struct ms_extra_data_register *) mrq->data;
+		msb->state = MSB_RP_SEND_READ_DATA;
+		/* fallthrough */
+
+	case MSB_RP_SEND_READ_DATA:
+		/* Skip that state if we only read the oob */
+		if (msb->regs.param.cp == MEMSTICK_CP_EXTRA) {
+			msb->state = MSB_RP_RECEIVE_READ_DATA;
+			goto again;
+		}
+
+		sg_init_table(sg, ARRAY_SIZE(sg));
+		sg_copy(msb->current_sg, sg, ARRAY_SIZE(sg),
+			msb->current_sg_offset,
+			msb->page_size);
+
+		memstick_init_req_sg(mrq, MS_TPC_READ_LONG_DATA, sg);
+		msb->state = MSB_RP_RECEIVE_READ_DATA;
+		return 0;
+
+	case MSB_RP_RECEIVE_READ_DATA:
+		if (!(msb->regs.status.interrupt & MEMSTICK_INT_ERR)) {
+			msb->current_sg_offset += msb->page_size;
+			return msb_exit_state_machine(msb, 0);
+		}
+
+		if (msb->regs.status.status1 & MEMSTICK_UNCORR_ERROR) {
+			dbg("read_page: uncorrectable error");
+			return msb_exit_state_machine(msb, -EBADMSG);
+		}
+
+		if (msb->regs.status.status1 & MEMSTICK_CORR_ERROR) {
+			dbg("read_page: correctable error");
+			msb->current_sg_offset += msb->page_size;
+			return msb_exit_state_machine(msb, -EUCLEAN);
+		} else {
+			dbg("read_page: INT error, but no status error bits");
+			return msb_exit_state_machine(msb, -EIO);
+		}
+	}
+
+	BUG();
+}
+
+/*
+ * Handler of writes of exactly one block.
+ * Takes address from msb->regs.param.
+ * Writes same extra data to blocks, also taken
+ * from msb->regs.extra
+ * Returns -EBADMSG if write fails due to uncorrectable error, or -EIO if
+ * device refuses to take the command or something else
+ */
+static int h_msb_write_block(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	struct scatterlist sg[2];
+	u8 intreg, command;
+
+	if (mrq->error)
+		return msb_exit_state_machine(msb, mrq->error);
+
+again:
+	switch (msb->state) {
+
+	/* HACK: Jmicon handling of TPCs between 8 and
+	 *	sizeof(memstick_request.data) is broken due to hardware
+	 *	bug in PIO mode that is used for these TPCs
+	 *	Therefore split the write
+	 */
+
+	case MSB_WB_SEND_WRITE_PARAMS:
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			sizeof(struct ms_param_register),
+			&msb->regs.param))
+			return 0;
+
+		msb->state = MSB_WB_SEND_WRITE_OOB;
+		return 0;
+
+	case MSB_WB_SEND_WRITE_OOB:
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, extra_data),
+			sizeof(struct ms_extra_data_register),
+			&msb->regs.extra_data))
+			return 0;
+		msb->state = MSB_WB_SEND_WRITE_COMMAND;
+		return 0;
+
+
+	case MSB_WB_SEND_WRITE_COMMAND:
+		command = MS_CMD_BLOCK_WRITE;
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &command, 1);
+		msb->state = MSB_WB_SEND_INT_REQ;
+		return 0;
+
+	case MSB_WB_SEND_INT_REQ:
+		msb->state = MSB_WB_RECEIVE_INT_REQ;
+		if (msb_read_int_reg(msb, -1))
+			return 0;
+		/* fallthrough */
+
+	case MSB_WB_RECEIVE_INT_REQ:
+		intreg = mrq->data[0];
+		msb->regs.status.interrupt = intreg;
+
+		/* errors mean out of here, and fast... */
+		if (intreg & (MEMSTICK_INT_CMDNAK))
+			return msb_exit_state_machine(msb, -EIO);
+
+		if (intreg & MEMSTICK_INT_ERR)
+			return msb_exit_state_machine(msb, -EBADMSG);
+
+
+		/* for last page we need to poll CED */
+		if (msb->current_page == msb->pages_in_block) {
+			if (intreg & MEMSTICK_INT_CED)
+				return msb_exit_state_machine(msb, 0);
+			msb->state = MSB_WB_SEND_INT_REQ;
+			goto again;
+
+		}
+
+		/* for non-last page we need BREQ before writing next chunk */
+		if (!(intreg & MEMSTICK_INT_BREQ)) {
+			msb->state = MSB_WB_SEND_INT_REQ;
+			goto again;
+		}
+
+		msb->int_polling = false;
+		msb->state = MSB_WB_SEND_WRITE_DATA;
+		/* fallthrough */
+
+	case MSB_WB_SEND_WRITE_DATA:
+		sg_init_table(sg, ARRAY_SIZE(sg));
+
+		if (sg_copy(msb->current_sg, sg, ARRAY_SIZE(sg),
+			msb->current_sg_offset,
+			msb->page_size) < msb->page_size)
+			return msb_exit_state_machine(msb, -EIO);
+
+		memstick_init_req_sg(mrq, MS_TPC_WRITE_LONG_DATA, sg);
+		mrq->need_card_int = 1;
+		msb->state = MSB_WB_RECEIVE_WRITE_CONFIRMATION;
+		return 0;
+
+	case MSB_WB_RECEIVE_WRITE_CONFIRMATION:
+		msb->current_page++;
+		msb->current_sg_offset += msb->page_size;
+		msb->state = MSB_WB_SEND_INT_REQ;
+		goto again;
+	default:
+		BUG();
+	}
+
+	return 0;
+}
+
+/*
+ * This function is used to send simple IO requests to device that consist
+ * of register write + command
+ */
+static int h_msb_send_command(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	u8 intreg;
+
+	if (mrq->error) {
+		dbg("send_command: unknown error");
+		return msb_exit_state_machine(msb, mrq->error);
+	}
+again:
+	switch (msb->state) {
+
+	/* HACK: see h_msb_write_block */
+	case MSB_SC_SEND_WRITE_PARAMS: /* write param register*/
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			sizeof(struct ms_param_register),
+			&msb->regs.param))
+			return 0;
+		msb->state = MSB_SC_SEND_WRITE_OOB;
+		return 0;
+
+	case MSB_SC_SEND_WRITE_OOB:
+		if (!msb->command_need_oob) {
+			msb->state = MSB_SC_SEND_COMMAND;
+			goto again;
+		}
+
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, extra_data),
+			sizeof(struct ms_extra_data_register),
+			&msb->regs.extra_data))
+			return 0;
+
+		msb->state = MSB_SC_SEND_COMMAND;
+		return 0;
+
+	case MSB_SC_SEND_COMMAND:
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &msb->command_value, 1);
+		msb->state = MSB_SC_SEND_INT_REQ;
+		return 0;
+
+	case MSB_SC_SEND_INT_REQ:
+		msb->state = MSB_SC_RECEIVE_INT_REQ;
+		if (msb_read_int_reg(msb, -1))
+			return 0;
+		/* fallthrough */
+
+	case MSB_SC_RECEIVE_INT_REQ:
+		intreg = mrq->data[0];
+
+		if (intreg & MEMSTICK_INT_CMDNAK)
+			return msb_exit_state_machine(msb, -EIO);
+		if (intreg & MEMSTICK_INT_ERR)
+			return msb_exit_state_machine(msb, -EBADMSG);
+
+		if (!(intreg & MEMSTICK_INT_CED)) {
+			msb->state = MSB_SC_SEND_INT_REQ;
+			goto again;
+		}
+
+		return msb_exit_state_machine(msb, 0);
+	}
+
+	BUG();
+}
+
+/* Small handler for card reset */
+static int h_msb_reset(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	u8 command = MS_CMD_RESET;
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+
+	if (mrq->error)
+		return msb_exit_state_machine(msb, mrq->error);
+
+	switch (msb->state) {
+	case MSB_RS_SEND:
+		memstick_init_req(mrq, MS_TPC_SET_CMD, &command, 1);
+		mrq->need_card_int = 0;
+		msb->state = MSB_RS_CONFIRM;
+		return 0;
+	case MSB_RS_CONFIRM:
+		return msb_exit_state_machine(msb, 0);
+	}
+	BUG();
+}
+
+/* This handler is used to do serial->parallel switch */
+static int h_msb_parallel_switch(struct memstick_dev *card,
+					struct memstick_request **out_mrq)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_request *mrq = *out_mrq = &card->current_mrq;
+	struct memstick_host *host = card->host;
+
+	if (mrq->error) {
+		dbg("parallel_switch: error");
+		msb->regs.param.system &= ~MEMSTICK_SYS_PAM;
+		return msb_exit_state_machine(msb, mrq->error);
+	}
+
+	switch (msb->state) {
+	case MSB_PS_SEND_SWITCH_COMMAND:
+		/* Set the parallel interface on memstick side */
+		msb->regs.param.system |= MEMSTICK_SYS_PAM;
+
+		if (!msb_write_regs(msb,
+			offsetof(struct ms_register, param),
+			1,
+			(unsigned char *)&msb->regs.param))
+			return 0;
+
+		msb->state = MSB_PS_SWICH_HOST;
+		return 0;
+
+	case MSB_PS_SWICH_HOST:
+		 /* Set parallel interface on our side + send a dummy request
+			to see if card responds */
+		host->set_param(host, MEMSTICK_INTERFACE, MEMSTICK_PAR4);
+		memstick_init_req(mrq, MS_TPC_GET_INT, NULL, 1);
+		msb->state = MSB_PS_CONFIRM;
+		return 0;
+
+	case MSB_PS_CONFIRM:
+		return msb_exit_state_machine(msb, 0);
+	}
+
+	BUG();
+}
+
+static int msb_switch_to_parallel(struct msb_data *msb);
+
+/* Reset the card, to guard against hw errors beeing treated as bad blocks */
+static int msb_reset(struct msb_data *msb, bool full)
+{
+
+	bool was_parallel = msb->regs.param.system & MEMSTICK_SYS_PAM;
+	struct memstick_dev *card = msb->card;
+	struct memstick_host *host = card->host;
+	int error;
+
+	/* Reset the card */
+	msb->regs.param.system = MEMSTICK_SYS_BAMD;
+
+	if (full) {
+		error =  host->set_param(host,
+					MEMSTICK_POWER, MEMSTICK_POWER_OFF);
+		if (error)
+			goto out_error;
+
+		msb_invalidate_reg_window(msb);
+
+		error = host->set_param(host,
+					MEMSTICK_POWER, MEMSTICK_POWER_ON);
+		if (error)
+			goto out_error;
+
+		error = host->set_param(host,
+					MEMSTICK_INTERFACE, MEMSTICK_SERIAL);
+		if (error) {
+out_error:
+			dbg("Failed to reset the host controller");
+			msb->read_only = true;
+			return -EFAULT;
+		}
+	}
+
+	error = msb_run_state_machine(msb, h_msb_reset);
+	if (error) {
+		dbg("Failed to reset the card");
+		msb->read_only = true;
+		return -ENODEV;
+	}
+
+	/* Set parallel mode */
+	if (was_parallel)
+		msb_switch_to_parallel(msb);
+	return 0;
+}
+
+/* Attempts to switch interface to parallel mode */
+static int msb_switch_to_parallel(struct msb_data *msb)
+{
+	int error;
+
+	error = msb_run_state_machine(msb, h_msb_parallel_switch);
+	if (error) {
+		pr_err("Switch to parallel failed");
+		msb->regs.param.system &= ~MEMSTICK_SYS_PAM;
+		msb_reset(msb, true);
+		return -EFAULT;
+	}
+
+	msb->caps |= MEMSTICK_CAP_AUTO_GET_INT;
+	return 0;
+}
+
+/* Changes overwrite flag on a page */
+static int msb_set_overwrite_flag(struct msb_data *msb,
+						u16 pba, u8 page, u8 flag)
+{
+	if (msb->read_only)
+		return -EROFS;
+
+	msb->regs.param.block_address = cpu_to_be16(pba);
+	msb->regs.param.page_address = page;
+	msb->regs.param.cp = MEMSTICK_CP_OVERWRITE;
+	msb->regs.extra_data.overwrite_flag = flag;
+	msb->command_value = MS_CMD_BLOCK_WRITE;
+	msb->command_need_oob = true;
+
+	dbg_verbose("changing overwrite flag to %02x for sector %d, page %d",
+							flag, pba, page);
+	return msb_run_state_machine(msb, h_msb_send_command);
+}
+
+static int msb_mark_bad(struct msb_data *msb, int pba)
+{
+	pr_notice("marking pba %d as bad", pba);
+	msb_reset(msb, true);
+	return msb_set_overwrite_flag(
+			msb, pba, 0, 0xFF & ~MEMSTICK_OVERWRITE_BKST);
+}
+
+static int msb_mark_page_bad(struct msb_data *msb, int pba, int page)
+{
+	dbg("marking page %d of pba %d as bad", page, pba);
+	msb_reset(msb, true);
+	return msb_set_overwrite_flag(msb,
+		pba, page, ~MEMSTICK_OVERWRITE_PGST0);
+}
+
+/* Erases one physical block */
+static int msb_erase_block(struct msb_data *msb, u16 pba)
+{
+	int error, try;
+	if (msb->read_only)
+		return -EROFS;
+
+	dbg_verbose("erasing pba %d", pba);
+
+	for (try = 1 ; try < 3 ; try++) {
+		msb->regs.param.block_address = cpu_to_be16(pba);
+		msb->regs.param.page_address = 0;
+		msb->regs.param.cp = MEMSTICK_CP_BLOCK;
+		msb->command_value = MS_CMD_BLOCK_ERASE;
+		msb->command_need_oob = false;
+
+
+		error = msb_run_state_machine(msb, h_msb_send_command);
+		if (!error || msb_reset(msb, true))
+			break;
+	}
+
+	if (error) {
+		pr_err("erase failed, marking pba %d as bad", pba);
+		msb_mark_bad(msb, pba);
+	}
+
+	dbg_verbose("erase success, marking pba %d as unused", pba);
+	msb_mark_block_unused(msb, pba);
+	__set_bit(pba, msb->erased_blocks_bitmap);
+	return error;
+}
+
+/* Reads one page from device */
+static int msb_read_page(struct msb_data *msb,
+	u16 pba, u8 page, struct ms_extra_data_register *extra,
+					struct scatterlist *sg,  int offset)
+{
+	int try, error;
+
+	if (pba == MS_BLOCK_INVALID) {
+		unsigned long flags;
+		struct sg_mapping_iter miter;
+		size_t len = msb->page_size;
+
+		dbg_verbose("read unmapped sector. returning 0xFF");
+
+		local_irq_save(flags);
+		sg_miter_start(&miter, sg, sg_nents(sg),
+				SG_MITER_ATOMIC | SG_MITER_TO_SG);
+
+		while (sg_miter_next(&miter) && len > 0) {
+
+			int chunklen;
+
+			if (offset && offset >= miter.length) {
+				offset -= miter.length;
+				continue;
+			}
+
+			chunklen = min(miter.length - offset, len);
+			memset(miter.addr + offset, 0xFF, chunklen);
+			len -= chunklen;
+			offset = 0;
+		}
+
+		sg_miter_stop(&miter);
+		local_irq_restore(flags);
+
+		if (offset)
+			return -EFAULT;
+
+		if (extra)
+			memset(extra, 0xFF, sizeof(*extra));
+		return 0;
+	}
+
+	if (pba >= msb->block_count) {
+		pr_err("BUG: attempt to read beyond"
+					" the end of the card at pba %d", pba);
+		return -EINVAL;
+	}
+
+	for (try = 1 ; try < 3 ; try++) {
+		msb->regs.param.block_address = cpu_to_be16(pba);
+		msb->regs.param.page_address = page;
+		msb->regs.param.cp = MEMSTICK_CP_PAGE;
+
+		msb->current_sg = sg;
+		msb->current_sg_offset = offset;
+		error = msb_run_state_machine(msb, h_msb_read_page);
+
+
+		if (error == -EUCLEAN) {
+			pr_notice("correctable error on pba %d, page %d",
+				pba, page);
+			error = 0;
+		}
+
+		if (!error && extra)
+			*extra = msb->regs.extra_data;
+
+		if (!error || msb_reset(msb, true))
+			break;
+
+	}
+
+	/* Mark bad pages */
+	if (error == -EBADMSG) {
+		pr_err("uncorrectable error on read of pba %d, page %d",
+			pba, page);
+
+		if (msb->regs.extra_data.overwrite_flag &
+					MEMSTICK_OVERWRITE_PGST0)
+			msb_mark_page_bad(msb, pba, page);
+		return -EBADMSG;
+	}
+
+	if (error)
+		pr_err("read of pba %d, page %d failed with error %d",
+			pba, page, error);
+	return error;
+}
+
+/* Reads oob of page only */
+static int msb_read_oob(struct msb_data *msb, u16 pba, u16 page,
+	struct ms_extra_data_register *extra)
+{
+	int error;
+
+	BUG_ON(!extra);
+	msb->regs.param.block_address = cpu_to_be16(pba);
+	msb->regs.param.page_address = page;
+	msb->regs.param.cp = MEMSTICK_CP_EXTRA;
+
+	if (pba > msb->block_count) {
+		pr_err("BUG: attempt to read beyond"
+					" the end of card at pba %d", pba);
+		return -EINVAL;
+	}
+
+	error = msb_run_state_machine(msb, h_msb_read_page);
+	*extra = msb->regs.extra_data;
+
+	if (error == -EUCLEAN) {
+		pr_notice("correctable error on pba %d, page %d",
+			pba, page);
+		return 0;
+	}
+
+	return error;
+}
+
+
+/* Reads a block and compares it with data contained in scatterlist orig_sg */
+static int msb_verify_block(struct msb_data *msb, u16 pba,
+				struct scatterlist *orig_sg,  int offset)
+{
+	struct scatterlist sg;
+	int page = 0, error;
+
+	sg_init_one(&sg, msb->block_buffer, msb->block_size);
+
+	while (page < msb->pages_in_block) {
+
+		error = msb_read_page(msb, pba, page,
+				NULL, &sg, page * msb->page_size);
+		if (error)
+			return error;
+		page++;
+	}
+
+	if (sg_compare_to_buffer(orig_sg, offset,
+				msb->block_buffer, msb->block_size))
+		return -EIO;
+	return 0;
+}
+
+/* Writes exectly one block + oob */
+static int msb_write_block(struct msb_data *msb,
+			u16 pba, u32 lba, struct scatterlist *sg, int offset)
+{
+	int error, current_try = 1;
+	BUG_ON(sg->length < msb->page_size);
+
+	if (msb->read_only)
+		return -EROFS;
+
+	if (pba == MS_BLOCK_INVALID) {
+		pr_err(
+			"BUG: write: attempt to write MS_BLOCK_INVALID block");
+		return -EINVAL;
+	}
+
+	if (pba >= msb->block_count || lba >= msb->logical_block_count) {
+		pr_err(
+		"BUG: write: attempt to write beyond the end of device");
+		return -EINVAL;
+	}
+
+	if (msb_get_zone_from_lba(lba) != msb_get_zone_from_pba(pba)) {
+		pr_err("BUG: write: lba zone mismatch");
+		return -EINVAL;
+	}
+
+	if (pba == msb->boot_block_locations[0] ||
+		pba == msb->boot_block_locations[1]) {
+		pr_err("BUG: write: attempt to write to boot blocks!");
+		return -EINVAL;
+	}
+
+	while (1) {
+
+		if (msb->read_only)
+			return -EROFS;
+
+		msb->regs.param.cp = MEMSTICK_CP_BLOCK;
+		msb->regs.param.page_address = 0;
+		msb->regs.param.block_address = cpu_to_be16(pba);
+
+		msb->regs.extra_data.management_flag = 0xFF;
+		msb->regs.extra_data.overwrite_flag = 0xF8;
+		msb->regs.extra_data.logical_address = cpu_to_be16(lba);
+
+		msb->current_sg = sg;
+		msb->current_sg_offset = offset;
+		msb->current_page = 0;
+
+		error = msb_run_state_machine(msb, h_msb_write_block);
+
+		/* Sector we just wrote to is assumed erased since its pba
+			was erased. If it wasn't erased, write will succeed
+			and will just clear the bits that were set in the block
+			thus test that what we have written,
+			matches what we expect.
+			We do trust the blocks that we erased */
+		if (!error && (verify_writes ||
+				!test_bit(pba, msb->erased_blocks_bitmap)))
+			error = msb_verify_block(msb, pba, sg, offset);
+
+		if (!error)
+			break;
+
+		if (current_try > 1 || msb_reset(msb, true))
+			break;
+
+		pr_err("write failed, trying to erase the pba %d", pba);
+		error = msb_erase_block(msb, pba);
+		if (error)
+			break;
+
+		current_try++;
+	}
+	return error;
+}
+
+/* Finds a free block for write replacement */
+static u16 msb_get_free_block(struct msb_data *msb, int zone)
+{
+	u16 pos;
+	int pba = zone * MS_BLOCKS_IN_ZONE;
+	int i;
+
+	get_random_bytes(&pos, sizeof(pos));
+
+	if (!msb->free_block_count[zone]) {
+		pr_err("NO free blocks in the zone %d, to use for a write, "
+			"(media is WORN out) switching to RO mode", zone);
+		msb->read_only = true;
+		return MS_BLOCK_INVALID;
+	}
+
+	pos %= msb->free_block_count[zone];
+
+	dbg_verbose("have %d choices for a free block, selected randomally: %d",
+		msb->free_block_count[zone], pos);
+
+	pba = find_next_zero_bit(msb->used_blocks_bitmap,
+							msb->block_count, pba);
+	for (i = 0 ; i < pos ; ++i)
+		pba = find_next_zero_bit(msb->used_blocks_bitmap,
+						msb->block_count, pba + 1);
+
+	dbg_verbose("result of the free blocks scan: pba %d", pba);
+
+	if (pba == msb->block_count || (msb_get_zone_from_pba(pba)) != zone) {
+		pr_err("BUG: cant get a free block");
+		msb->read_only = true;
+		return MS_BLOCK_INVALID;
+	}
+
+	msb_mark_block_used(msb, pba);
+	return pba;
+}
+
+static int msb_update_block(struct msb_data *msb, u16 lba,
+	struct scatterlist *sg, int offset)
+{
+	u16 pba, new_pba;
+	int error, try;
+
+	pba = msb->lba_to_pba_table[lba];
+	dbg_verbose("start of a block update at lba  %d, pba %d", lba, pba);
+
+	if (pba != MS_BLOCK_INVALID) {
+		dbg_verbose("setting the update flag on the block");
+		msb_set_overwrite_flag(msb, pba, 0,
+				0xFF & ~MEMSTICK_OVERWRITE_UDST);
+	}
+
+	for (try = 0 ; try < 3 ; try++) {
+		new_pba = msb_get_free_block(msb,
+			msb_get_zone_from_lba(lba));
+
+		if (new_pba == MS_BLOCK_INVALID) {
+			error = -EIO;
+			goto out;
+		}
+
+		dbg_verbose("block update: writing updated block to the pba %d",
+								new_pba);
+		error = msb_write_block(msb, new_pba, lba, sg, offset);
+		if (error == -EBADMSG) {
+			msb_mark_bad(msb, new_pba);
+			continue;
+		}
+
+		if (error)
+			goto out;
+
+		dbg_verbose("block update: erasing the old block");
+		msb_erase_block(msb, pba);
+		msb->lba_to_pba_table[lba] = new_pba;
+		return 0;
+	}
+out:
+	if (error) {
+		pr_err("block update error after %d tries, "
+						"switching to r/o mode", try);
+		msb->read_only = true;
+	}
+	return error;
+}
+
+/* Converts endiannes in the boot block for easy use */
+static void msb_fix_boot_page_endianness(struct ms_boot_page *p)
+{
+	p->header.block_id = be16_to_cpu(p->header.block_id);
+	p->header.format_reserved = be16_to_cpu(p->header.format_reserved);
+	p->entry.disabled_block.start_addr
+		= be32_to_cpu(p->entry.disabled_block.start_addr);
+	p->entry.disabled_block.data_size
+		= be32_to_cpu(p->entry.disabled_block.data_size);
+	p->entry.cis_idi.start_addr
+		= be32_to_cpu(p->entry.cis_idi.start_addr);
+	p->entry.cis_idi.data_size
+		= be32_to_cpu(p->entry.cis_idi.data_size);
+	p->attr.block_size = be16_to_cpu(p->attr.block_size);
+	p->attr.number_of_blocks = be16_to_cpu(p->attr.number_of_blocks);
+	p->attr.number_of_effective_blocks
+		= be16_to_cpu(p->attr.number_of_effective_blocks);
+	p->attr.page_size = be16_to_cpu(p->attr.page_size);
+	p->attr.memory_manufacturer_code
+		= be16_to_cpu(p->attr.memory_manufacturer_code);
+	p->attr.memory_device_code = be16_to_cpu(p->attr.memory_device_code);
+	p->attr.implemented_capacity
+		= be16_to_cpu(p->attr.implemented_capacity);
+	p->attr.controller_number = be16_to_cpu(p->attr.controller_number);
+	p->attr.controller_function = be16_to_cpu(p->attr.controller_function);
+}
+
+static int msb_read_boot_blocks(struct msb_data *msb)
+{
+	int pba = 0;
+	struct scatterlist sg;
+	struct ms_extra_data_register extra;
+	struct ms_boot_page *page;
+
+	msb->boot_block_locations[0] = MS_BLOCK_INVALID;
+	msb->boot_block_locations[1] = MS_BLOCK_INVALID;
+	msb->boot_block_count = 0;
+
+	dbg_verbose("Start of a scan for the boot blocks");
+
+	if (!msb->boot_page) {
+		page = kmalloc(sizeof(struct ms_boot_page)*2, GFP_KERNEL);
+		if (!page)
+			return -ENOMEM;
+
+		msb->boot_page = page;
+	} else
+		page = msb->boot_page;
+
+	msb->block_count = MS_BLOCK_MAX_BOOT_ADDR;
+
+	for (pba = 0 ; pba < MS_BLOCK_MAX_BOOT_ADDR ; pba++) {
+
+		sg_init_one(&sg, page, sizeof(*page));
+		if (msb_read_page(msb, pba, 0, &extra, &sg, 0)) {
+			dbg("boot scan: can't read pba %d", pba);
+			continue;
+		}
+
+		if (extra.management_flag & MEMSTICK_MANAGEMENT_SYSFLG) {
+			dbg("managment flag doesn't indicate boot block %d",
+									pba);
+			continue;
+		}
+
+		if (be16_to_cpu(page->header.block_id) != MS_BLOCK_BOOT_ID) {
+			dbg("the pba at %d doesn' contain boot block ID", pba);
+			continue;
+		}
+
+		msb_fix_boot_page_endianness(page);
+		msb->boot_block_locations[msb->boot_block_count] = pba;
+
+		page++;
+		msb->boot_block_count++;
+
+		if (msb->boot_block_count == 2)
+			break;
+	}
+
+	if (!msb->boot_block_count) {
+		pr_err("media doesn't contain master page, aborting");
+		return -EIO;
+	}
+
+	dbg_verbose("End of scan for boot blocks");
+	return 0;
+}
+
+static int msb_read_bad_block_table(struct msb_data *msb, int block_nr)
+{
+	struct ms_boot_page *boot_block;
+	struct scatterlist sg;
+	u16 *buffer = NULL;
+	int offset = 0;
+	int i, error = 0;
+	int data_size, data_offset, page, page_offset, size_to_read;
+	u16 pba;
+
+	BUG_ON(block_nr > 1);
+	boot_block = &msb->boot_page[block_nr];
+	pba = msb->boot_block_locations[block_nr];
+
+	if (msb->boot_block_locations[block_nr] == MS_BLOCK_INVALID)
+		return -EINVAL;
+
+	data_size = boot_block->entry.disabled_block.data_size;
+	data_offset = sizeof(struct ms_boot_page) +
+			boot_block->entry.disabled_block.start_addr;
+	if (!data_size)
+		return 0;
+
+	page = data_offset / msb->page_size;
+	page_offset = data_offset % msb->page_size;
+	size_to_read =
+		DIV_ROUND_UP(data_size + page_offset, msb->page_size) *
+			msb->page_size;
+
+	dbg("reading bad block of boot block at pba %d, offset %d len %d",
+		pba, data_offset, data_size);
+
+	buffer = kzalloc(size_to_read, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	/* Read the buffer */
+	sg_init_one(&sg, buffer, size_to_read);
+
+	while (offset < size_to_read) {
+		error = msb_read_page(msb, pba, page, NULL, &sg, offset);
+		if (error)
+			goto out;
+
+		page++;
+		offset += msb->page_size;
+
+		if (page == msb->pages_in_block) {
+			pr_err(
+			"bad block table extends beyond the boot block");
+			break;
+		}
+	}
+
+	/* Process the bad block table */
+	for (i = page_offset ; i < data_size / sizeof(u16) ; i++) {
+
+		u16 bad_block = be16_to_cpu(buffer[i]);
+
+		if (bad_block >= msb->block_count) {
+			dbg("bad block table contains invalid block %d",
+								bad_block);
+			continue;
+		}
+
+		if (test_bit(bad_block, msb->used_blocks_bitmap))  {
+			dbg("duplicate bad block %d in the table",
+				bad_block);
+			continue;
+		}
+
+		dbg("block %d is marked as factory bad", bad_block);
+		msb_mark_block_used(msb, bad_block);
+	}
+out:
+	kfree(buffer);
+	return error;
+}
+
+static int msb_ftl_initialize(struct msb_data *msb)
+{
+	int i;
+
+	if (msb->ftl_initialized)
+		return 0;
+
+	msb->zone_count = msb->block_count / MS_BLOCKS_IN_ZONE;
+	msb->logical_block_count = msb->zone_count * 496 - 2;
+
+	msb->used_blocks_bitmap = kzalloc(msb->block_count / 8, GFP_KERNEL);
+	msb->erased_blocks_bitmap = kzalloc(msb->block_count / 8, GFP_KERNEL);
+	msb->lba_to_pba_table =
+		kmalloc(msb->logical_block_count * sizeof(u16), GFP_KERNEL);
+
+	if (!msb->used_blocks_bitmap || !msb->lba_to_pba_table ||
+						!msb->erased_blocks_bitmap) {
+		kfree(msb->used_blocks_bitmap);
+		kfree(msb->lba_to_pba_table);
+		kfree(msb->erased_blocks_bitmap);
+		return -ENOMEM;
+	}
+
+	for (i = 0 ; i < msb->zone_count ; i++)
+		msb->free_block_count[i] = MS_BLOCKS_IN_ZONE;
+
+	memset(msb->lba_to_pba_table, MS_BLOCK_INVALID,
+			msb->logical_block_count * sizeof(u16));
+
+	dbg("initial FTL tables created. Zone count = %d, "
+					"Logical block count = %d",
+		msb->zone_count, msb->logical_block_count);
+
+	msb->ftl_initialized = true;
+	return 0;
+}
+
+static int msb_ftl_scan(struct msb_data *msb)
+{
+	u16 pba, lba, other_block;
+	u8 overwrite_flag, managment_flag, other_overwrite_flag;
+	int error;
+	struct ms_extra_data_register extra;
+	u8 *overwrite_flags = kzalloc(msb->block_count, GFP_KERNEL);
+
+	if (!overwrite_flags)
+		return -ENOMEM;
+
+	dbg("Start of media scanning");
+	for (pba = 0 ; pba < msb->block_count ; pba++) {
+
+		if (pba == msb->boot_block_locations[0] ||
+			pba == msb->boot_block_locations[1]) {
+			dbg_verbose("pba %05d -> [boot block]", pba);
+			msb_mark_block_used(msb, pba);
+			continue;
+		}
+
+		if (test_bit(pba, msb->used_blocks_bitmap)) {
+			dbg_verbose("pba %05d -> [factory bad]", pba);
+			continue;
+		}
+
+		memset(&extra, 0, sizeof(extra));
+		error = msb_read_oob(msb, pba, 0, &extra);
+
+		/* can't trust the page if we can't read the oob */
+		if (error == -EBADMSG) {
+			pr_notice(
+			"oob of pba %d damaged, will try to erase it", pba);
+			msb_mark_block_used(msb, pba);
+			msb_erase_block(msb, pba);
+			continue;
+		} else if (error)
+			return error;
+
+		lba = be16_to_cpu(extra.logical_address);
+		managment_flag = extra.management_flag;
+		overwrite_flag = extra.overwrite_flag;
+		overwrite_flags[pba] = overwrite_flag;
+
+		/* Skip bad blocks */
+		if (!(overwrite_flag & MEMSTICK_OVERWRITE_BKST)) {
+			dbg("pba %05d -> [BAD]", pba);
+			msb_mark_block_used(msb, pba);
+			continue;
+		}
+
+		/* Skip system/drm blocks */
+		if ((managment_flag & MEMSTICK_MANAGMENT_FLAG_NORMAL) !=
+			MEMSTICK_MANAGMENT_FLAG_NORMAL) {
+			dbg("pba %05d -> [reserved managment flag %02x]",
+							pba, managment_flag);
+			msb_mark_block_used(msb, pba);
+			continue;
+		}
+
+		/* Erase temporary tables */
+		if (!(managment_flag & MEMSTICK_MANAGEMENT_ATFLG)) {
+			dbg("pba %05d -> [temp table] - will erase", pba);
+
+			msb_mark_block_used(msb, pba);
+			msb_erase_block(msb, pba);
+			continue;
+		}
+
+		if (lba == MS_BLOCK_INVALID) {
+			dbg_verbose("pba %05d -> [free]", pba);
+			continue;
+		}
+
+		msb_mark_block_used(msb, pba);
+
+		/* Block has LBA not according to zoning*/
+		if (msb_get_zone_from_lba(lba) != msb_get_zone_from_pba(pba)) {
+			pr_notice("pba %05d -> [bad lba %05d] - will erase",
+								pba, lba);
+			msb_erase_block(msb, pba);
+			continue;
+		}
+
+		/* No collisions - great */
+		if (msb->lba_to_pba_table[lba] == MS_BLOCK_INVALID) {
+			dbg_verbose("pba %05d -> [lba %05d]", pba, lba);
+			msb->lba_to_pba_table[lba] = pba;
+			continue;
+		}
+
+		other_block = msb->lba_to_pba_table[lba];
+		other_overwrite_flag = overwrite_flags[other_block];
+
+		pr_notice("Collision between pba %d and pba %d",
+			pba, other_block);
+
+		if (!(overwrite_flag & MEMSTICK_OVERWRITE_UDST)) {
+			pr_notice("pba %d is marked as stable, use it", pba);
+			msb_erase_block(msb, other_block);
+			msb->lba_to_pba_table[lba] = pba;
+			continue;
+		}
+
+		if (!(other_overwrite_flag & MEMSTICK_OVERWRITE_UDST)) {
+			pr_notice("pba %d is marked as stable, use it",
+								other_block);
+			msb_erase_block(msb, pba);
+			continue;
+		}
+
+		pr_notice("collision between blocks %d and %d,"
+		" without stable flag set on both, erasing pba %d",
+				pba, other_block, other_block);
+
+		msb_erase_block(msb, other_block);
+		msb->lba_to_pba_table[lba] = pba;
+	}
+
+	dbg("End of media scanning");
+	kfree(overwrite_flags);
+	return 0;
+}
+
+static void msb_cache_flush_timer(unsigned long data)
+{
+	struct msb_data *msb = (struct msb_data *)data;
+	msb->need_flush_cache = true;
+	queue_work(msb->io_queue, &msb->io_work);
+}
+
+
+static void msb_cache_discard(struct msb_data *msb)
+{
+	if (msb->cache_block_lba == MS_BLOCK_INVALID)
+		return;
+
+	del_timer_sync(&msb->cache_flush_timer);
+
+	dbg_verbose("Discarding the write cache");
+	msb->cache_block_lba = MS_BLOCK_INVALID;
+	bitmap_zero(&msb->valid_cache_bitmap, msb->pages_in_block);
+}
+
+static int msb_cache_init(struct msb_data *msb)
+{
+	setup_timer(&msb->cache_flush_timer, msb_cache_flush_timer,
+		(unsigned long)msb);
+
+	if (!msb->cache)
+		msb->cache = kzalloc(msb->block_size, GFP_KERNEL);
+	if (!msb->cache)
+		return -ENOMEM;
+
+	msb_cache_discard(msb);
+	return 0;
+}
+
+static int msb_cache_flush(struct msb_data *msb)
+{
+	struct scatterlist sg;
+	struct ms_extra_data_register extra;
+	int page, offset, error;
+	u16 pba, lba;
+
+	if (msb->read_only)
+		return -EROFS;
+
+	if (msb->cache_block_lba == MS_BLOCK_INVALID)
+		return 0;
+
+	lba = msb->cache_block_lba;
+	pba = msb->lba_to_pba_table[lba];
+
+	dbg_verbose("Flushing the write cache of pba %d (LBA %d)",
+						pba, msb->cache_block_lba);
+
+	sg_init_one(&sg, msb->cache , msb->block_size);
+
+	/* Read all missing pages in cache */
+	for (page = 0 ; page < msb->pages_in_block ; page++) {
+
+		if (test_bit(page, &msb->valid_cache_bitmap))
+			continue;
+
+		offset = page * msb->page_size;
+
+		dbg_verbose("reading non-present sector %d of cache block %d",
+			page, lba);
+		error = msb_read_page(msb, pba, page, &extra, &sg, offset);
+
+		/* Bad pages are copied with 00 page status */
+		if (error == -EBADMSG) {
+			pr_err("read error on sector %d, contents probably"
+				" damaged", page);
+			continue;
+		}
+
+		if (error)
+			return error;
+
+		if ((extra.overwrite_flag & MEMSTICK_OV_PG_NORMAL) !=
+							MEMSTICK_OV_PG_NORMAL) {
+			dbg("page %d is marked as bad", page);
+			continue;
+		}
+
+		set_bit(page, &msb->valid_cache_bitmap);
+	}
+
+	/* Write the cache now */
+	error = msb_update_block(msb, msb->cache_block_lba, &sg, 0);
+	pba = msb->lba_to_pba_table[msb->cache_block_lba];
+
+	/* Mark invalid pages */
+	if (!error) {
+		for (page = 0 ; page < msb->pages_in_block ; page++) {
+
+			if (test_bit(page, &msb->valid_cache_bitmap))
+				continue;
+
+			dbg("marking page %d as containing damaged data",
+				page);
+			msb_set_overwrite_flag(msb,
+				pba , page, 0xFF & ~MEMSTICK_OV_PG_NORMAL);
+		}
+	}
+
+	msb_cache_discard(msb);
+	return error;
+}
+
+static int msb_cache_write(struct msb_data *msb, int lba,
+	int page, bool add_to_cache_only, struct scatterlist *sg, int offset)
+{
+	int error;
+	struct scatterlist sg_tmp[10];
+
+	if (msb->read_only)
+		return -EROFS;
+
+	if (msb->cache_block_lba == MS_BLOCK_INVALID ||
+						lba != msb->cache_block_lba)
+		if (add_to_cache_only)
+			return 0;
+
+	/* If we need to write different block */
+	if (msb->cache_block_lba != MS_BLOCK_INVALID &&
+						lba != msb->cache_block_lba) {
+		dbg_verbose("first flush the cache");
+		error = msb_cache_flush(msb);
+		if (error)
+			return error;
+	}
+
+	if (msb->cache_block_lba  == MS_BLOCK_INVALID) {
+		msb->cache_block_lba  = lba;
+		mod_timer(&msb->cache_flush_timer,
+			jiffies + msecs_to_jiffies(cache_flush_timeout));
+	}
+
+	dbg_verbose("Write of LBA %d page %d to cache ", lba, page);
+
+	sg_init_table(sg_tmp, ARRAY_SIZE(sg_tmp));
+	sg_copy(sg, sg_tmp, ARRAY_SIZE(sg_tmp), offset, msb->page_size);
+
+	sg_copy_to_buffer(sg_tmp, sg_nents(sg_tmp),
+		msb->cache + page * msb->page_size, msb->page_size);
+
+	set_bit(page, &msb->valid_cache_bitmap);
+	return 0;
+}
+
+static int msb_cache_read(struct msb_data *msb, int lba,
+				int page, struct scatterlist *sg, int offset)
+{
+	int pba = msb->lba_to_pba_table[lba];
+	struct scatterlist sg_tmp[10];
+	int error = 0;
+
+	if (lba == msb->cache_block_lba &&
+			test_bit(page, &msb->valid_cache_bitmap)) {
+
+		dbg_verbose("Read of LBA %d (pba %d) sector %d from cache",
+							lba, pba, page);
+
+		sg_init_table(sg_tmp, ARRAY_SIZE(sg_tmp));
+		sg_copy(sg, sg_tmp, ARRAY_SIZE(sg_tmp), offset, msb->page_size);
+		sg_copy_from_buffer(sg_tmp, sg_nents(sg_tmp),
+			msb->cache + msb->page_size * page,
+							msb->page_size);
+	} else {
+		dbg_verbose("Read of LBA %d (pba %d) sector %d from device",
+							lba, pba, page);
+
+		error = msb_read_page(msb, pba, page, NULL, sg, offset);
+		if (error)
+			return error;
+
+		msb_cache_write(msb, lba, page, true, sg, offset);
+	}
+	return error;
+}
+
+/* Emulated geometry table
+ * This table content isn't that importaint,
+ * One could put here different values, providing that they still
+ * cover whole disk.
+ * 64 MB entry is what windows reports for my 64M memstick */
+
+static const struct chs_entry chs_table[] = {
+/*        size sectors cylynders  heads */
+	{ 4,    16,    247,       2  },
+	{ 8,    16,    495,       2  },
+	{ 16,   16,    495,       4  },
+	{ 32,   16,    991,       4  },
+	{ 64,   16,    991,       8  },
+	{128,   16,    991,       16 },
+	{ 0 }
+};
+
+/* Load information about the card */
+static int msb_init_card(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_host *host = card->host;
+	struct ms_boot_page *boot_block;
+	int error = 0, i, raw_size_in_megs;
+
+	msb->caps = 0;
+
+	if (card->id.class >= MEMSTICK_CLASS_ROM &&
+				card->id.class <= MEMSTICK_CLASS_ROM)
+		msb->read_only = true;
+
+	msb->state = -1;
+	error = msb_reset(msb, false);
+	if (error)
+		return error;
+
+	/* Due to a bug in Jmicron driver written by Alex Dubov,
+	 its serial mode barely works,
+	 so we switch to parallel mode right away */
+	if (host->caps & MEMSTICK_CAP_PAR4)
+		msb_switch_to_parallel(msb);
+
+	msb->page_size = sizeof(struct ms_boot_page);
+
+	/* Read the boot page */
+	error = msb_read_boot_blocks(msb);
+	if (error)
+		return -EIO;
+
+	boot_block = &msb->boot_page[0];
+
+	/* Save intersting attributes from boot page */
+	msb->block_count = boot_block->attr.number_of_blocks;
+	msb->page_size = boot_block->attr.page_size;
+
+	msb->pages_in_block = boot_block->attr.block_size * 2;
+	msb->block_size = msb->page_size * msb->pages_in_block;
+
+	if (msb->page_size > PAGE_SIZE) {
+		/* this isn't supported by linux at all, anyway*/
+		dbg("device page %d size isn't supported", msb->page_size);
+		return -EINVAL;
+	}
+
+	msb->block_buffer = kzalloc(msb->block_size, GFP_KERNEL);
+	if (!msb->block_buffer)
+		return -ENOMEM;
+
+	raw_size_in_megs = (msb->block_size * msb->block_count) >> 20;
+
+	for (i = 0 ; chs_table[i].size ; i++) {
+
+		if (chs_table[i].size != raw_size_in_megs)
+			continue;
+
+		msb->geometry.cylinders = chs_table[i].cyl;
+		msb->geometry.heads = chs_table[i].head;
+		msb->geometry.sectors = chs_table[i].sec;
+		break;
+	}
+
+	if (boot_block->attr.transfer_supporting == 1)
+		msb->caps |= MEMSTICK_CAP_PAR4;
+
+	if (boot_block->attr.device_type & 0x03)
+		msb->read_only = true;
+
+	dbg("Total block count = %d", msb->block_count);
+	dbg("Each block consists of %d pages", msb->pages_in_block);
+	dbg("Page size = %d bytes", msb->page_size);
+	dbg("Parallel mode supported: %d", !!(msb->caps & MEMSTICK_CAP_PAR4));
+	dbg("Read only: %d", msb->read_only);
+
+#if 0
+	/* Now we can switch the interface */
+	if (host->caps & msb->caps & MEMSTICK_CAP_PAR4)
+		msb_switch_to_parallel(msb);
+#endif
+
+	error = msb_cache_init(msb);
+	if (error)
+		return error;
+
+	error = msb_ftl_initialize(msb);
+	if (error)
+		return error;
+
+
+	/* Read the bad block table */
+	error = msb_read_bad_block_table(msb, 0);
+
+	if (error && error != -ENOMEM) {
+		dbg("failed to read bad block table from primary boot block,"
+							" trying from backup");
+		error = msb_read_bad_block_table(msb, 1);
+	}
+
+	if (error)
+		return error;
+
+	/* *drum roll* Scan the media */
+	error = msb_ftl_scan(msb);
+	if (error) {
+		pr_err("Scan of media failed");
+		return error;
+	}
+
+	return 0;
+
+}
+
+static int msb_do_write_request(struct msb_data *msb, int lba,
+	int page, struct scatterlist *sg, size_t len, int *sucessfuly_written)
+{
+	int error = 0;
+	off_t offset = 0;
+	*sucessfuly_written = 0;
+
+	while (offset < len) {
+		if (page == 0 && len - offset >= msb->block_size) {
+
+			if (msb->cache_block_lba == lba)
+				msb_cache_discard(msb);
+
+			dbg_verbose("Writing whole lba %d", lba);
+			error = msb_update_block(msb, lba, sg, offset);
+			if (error)
+				return error;
+
+			offset += msb->block_size;
+			*sucessfuly_written += msb->block_size;
+			lba++;
+			continue;
+		}
+
+		error = msb_cache_write(msb, lba, page, false, sg, offset);
+		if (error)
+			return error;
+
+		offset += msb->page_size;
+		*sucessfuly_written += msb->page_size;
+
+		page++;
+		if (page == msb->pages_in_block) {
+			page = 0;
+			lba++;
+		}
+	}
+	return 0;
+}
+
+static int msb_do_read_request(struct msb_data *msb, int lba,
+		int page, struct scatterlist *sg, int len, int *sucessfuly_read)
+{
+	int error = 0;
+	int offset = 0;
+	*sucessfuly_read = 0;
+
+	while (offset < len) {
+
+		error = msb_cache_read(msb, lba, page, sg, offset);
+		if (error)
+			return error;
+
+		offset += msb->page_size;
+		*sucessfuly_read += msb->page_size;
+
+		page++;
+		if (page == msb->pages_in_block) {
+			page = 0;
+			lba++;
+		}
+	}
+	return 0;
+}
+
+static void msb_io_work(struct work_struct *work)
+{
+	struct msb_data *msb = container_of(work, struct msb_data, io_work);
+	int page, error, len;
+	sector_t lba;
+	unsigned long flags;
+	struct scatterlist *sg = msb->prealloc_sg;
+
+	dbg("IO: work started");
+
+	mutex_lock(&msb->io_mutex);
+
+	while (1) {
+		spin_lock_irqsave(&msb->q_lock, flags);
+
+		if (msb->need_flush_cache) {
+			msb->need_flush_cache = false;
+			spin_unlock_irqrestore(&msb->q_lock, flags);
+			msb_cache_flush(msb);
+			continue;
+		}
+
+		if (!msb->req) {
+			msb->req = blk_fetch_request(msb->queue);
+			if (!msb->req) {
+				dbg("IO: no more requests exiting");
+				spin_unlock_irqrestore(&msb->q_lock, flags);
+				mutex_unlock(&msb->io_mutex);
+				return;
+			}
+		}
+
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+
+		/* If card was removed meanwhile */
+		if (!msb->req) {
+			mutex_unlock(&msb->io_mutex);
+			return;
+		}
+
+		/* process the request */
+		dbg_verbose("IO: processing new request");
+		blk_rq_map_sg(msb->queue, msb->req, sg);
+
+		lba = blk_rq_pos(msb->req);
+
+		sector_div(lba, msb->page_size / 512);
+		page = do_div(lba, msb->pages_in_block);
+
+		if (rq_data_dir(msb->req) == READ)
+			error = msb_do_read_request(
+				msb, lba, page, sg,
+					blk_rq_bytes(msb->req), &len);
+		else
+			error = msb_do_write_request(
+					msb, lba, page, sg,
+					blk_rq_bytes(msb->req), &len);
+
+		spin_lock_irqsave(&msb->q_lock, flags);
+
+		if (len)
+			if (!__blk_end_request(msb->req, 0, len))
+				msb->req = NULL;
+
+		if (error && msb->req) {
+			dbg_verbose("IO: ending one sector "
+					"of the request with error");
+			if (!__blk_end_request(msb->req, error, msb->page_size))
+				msb->req = NULL;
+		}
+
+		if (msb->req)
+			dbg_verbose("IO: request still pending");
+
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+	}
+}
+
+static DEFINE_IDR(msb_disk_idr); /*set of used disk numbers */
+static DEFINE_MUTEX(msb_disk_lock); /* protects against races in open/release */
+
+static int msb_bd_open(struct block_device *bdev, fmode_t mode)
+{
+	struct gendisk *disk = bdev->bd_disk;
+	struct msb_data *msb = disk->private_data;
+
+	dbg_verbose("block device open");
+
+	mutex_lock(&msb_disk_lock);
+
+	if (msb && msb->card)
+		msb->usage_count++;
+
+	mutex_unlock(&msb_disk_lock);
+	return 0;
+}
+
+static void msb_data_clear(struct msb_data *msb)
+{
+	kfree(msb->boot_page);
+	kfree(msb->used_blocks_bitmap);
+	kfree(msb->lba_to_pba_table);
+	kfree(msb->cache);
+	msb->card = NULL;
+}
+
+static int msb_disk_release(struct gendisk *disk)
+{
+	struct msb_data *msb = disk->private_data;
+	int disk_id = MINOR(disk_devt(disk)) >> MS_BLOCK_PART_SHIFT;
+
+	dbg_verbose("block device release");
+
+	mutex_lock(&msb_disk_lock);
+
+	if (msb) {
+		if (msb->usage_count)
+			msb->usage_count--;
+
+		if (!msb->usage_count) {
+			kfree(msb);
+			disk->private_data = NULL;
+			idr_remove(&msb_disk_idr, disk_id);
+			put_disk(disk);
+		}
+	}
+	mutex_unlock(&msb_disk_lock);
+	return 0;
+}
+
+static int msb_bd_release(struct gendisk *disk, fmode_t mode)
+{
+	return msb_disk_release(disk);
+}
+
+static int msb_bd_getgeo(struct block_device *bdev,
+				 struct hd_geometry *geo)
+{
+	struct msb_data *msb = bdev->bd_disk->private_data;
+	*geo = msb->geometry;
+	return 0;
+}
+
+static int msb_prepare_req(struct request_queue *q, struct request *req)
+{
+	if (req->cmd_type != REQ_TYPE_FS &&
+				req->cmd_type != REQ_TYPE_BLOCK_PC) {
+		blk_dump_rq_flags(req, "MS unsupported request");
+		return BLKPREP_KILL;
+	}
+	req->cmd_flags |= REQ_DONTPREP;
+	return BLKPREP_OK;
+}
+
+static void msb_submit_req(struct request_queue *q)
+{
+	struct memstick_dev *card = q->queuedata;
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct request *req = NULL;
+
+	dbg_verbose("Submit request");
+
+	if (msb->card_dead) {
+		dbg("Refusing requests on removed card");
+
+		WARN_ON(!msb->io_queue_stopped);
+
+		while ((req = blk_fetch_request(q)) != NULL)
+			__blk_end_request_all(req, -ENODEV);
+		return;
+	}
+
+	if (msb->req)
+		return;
+
+	if (!msb->io_queue_stopped)
+		queue_work(msb->io_queue, &msb->io_work);
+}
+
+static int msb_check_card(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	return (msb->card_dead == 0);
+}
+
+static void msb_stop(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	unsigned long flags;
+
+	dbg("Stopping all msblock IO");
+
+	spin_lock_irqsave(&msb->q_lock, flags);
+	blk_stop_queue(msb->queue);
+	msb->io_queue_stopped = true;
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	del_timer_sync(&msb->cache_flush_timer);
+	flush_workqueue(msb->io_queue);
+
+	if (msb->req) {
+		spin_lock_irqsave(&msb->q_lock, flags);
+		blk_requeue_request(msb->queue, msb->req);
+		msb->req = NULL;
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+	}
+
+}
+
+static void msb_start(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	unsigned long flags;
+
+	dbg("Resuming IO from msblock");
+
+	msb_invalidate_reg_window(msb);
+
+	spin_lock_irqsave(&msb->q_lock, flags);
+	if (!msb->io_queue_stopped || msb->card_dead) {
+		spin_unlock_irqrestore(&msb->q_lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	/* Kick cache flush anyway, its harmless */
+	msb->need_flush_cache = true;
+	msb->io_queue_stopped = false;
+
+	spin_lock_irqsave(&msb->q_lock, flags);
+	blk_start_queue(msb->queue);
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	queue_work(msb->io_queue, &msb->io_work);
+
+}
+
+static const struct block_device_operations msb_bdops = {
+	.open    = msb_bd_open,
+	.release = msb_bd_release,
+	.getgeo  = msb_bd_getgeo,
+	.owner   = THIS_MODULE
+};
+
+/* Registers the block device */
+static int msb_init_disk(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct memstick_host *host = card->host;
+	int rc, disk_id;
+	u64 limit = BLK_BOUNCE_HIGH;
+	unsigned long capacity;
+
+	if (host->dev.dma_mask && *(host->dev.dma_mask))
+		limit = *(host->dev.dma_mask);
+
+	mutex_lock(&msb_disk_lock);
+
+	if (!idr_pre_get(&msb_disk_idr, GFP_KERNEL)) {
+		mutex_unlock(&msb_disk_lock);
+		return -ENOMEM;
+	}
+
+	rc = idr_get_new(&msb_disk_idr, card, &disk_id);
+	mutex_unlock(&msb_disk_lock);
+
+	if (rc)
+		return rc;
+
+	if ((disk_id << MS_BLOCK_PART_SHIFT) > 255) {
+		rc = -ENOSPC;
+		goto out_release_id;
+	}
+
+	msb->disk = alloc_disk(1 << MS_BLOCK_PART_SHIFT);
+	if (!msb->disk) {
+		rc = -ENOMEM;
+		goto out_release_id;
+	}
+
+	msb->queue = blk_init_queue(msb_submit_req, &msb->q_lock);
+	if (!msb->queue) {
+		rc = -ENOMEM;
+		goto out_put_disk;
+	}
+
+	msb->queue->queuedata = card;
+	blk_queue_prep_rq(msb->queue, msb_prepare_req);
+
+	blk_queue_bounce_limit(msb->queue, limit);
+	blk_queue_max_hw_sectors(msb->queue, MS_BLOCK_MAX_PAGES);
+	blk_queue_max_segments(msb->queue, MS_BLOCK_MAX_SEGS);
+	blk_queue_max_segment_size(msb->queue,
+				   MS_BLOCK_MAX_PAGES * msb->page_size);
+	msb->disk->major = major;
+	msb->disk->first_minor = disk_id << MS_BLOCK_PART_SHIFT;
+	msb->disk->fops = &msb_bdops;
+	msb->usage_count = 1;
+	msb->disk->private_data = msb;
+	msb->disk->queue = msb->queue;
+	msb->disk->driverfs_dev = &card->dev;
+
+	msb->io_queue = alloc_workqueue("ms_block", WQ_MEM_RECLAIM, 1);
+	INIT_WORK(&msb->io_work, msb_io_work);
+	sg_init_table(msb->prealloc_sg, MS_BLOCK_MAX_SEGS+1);
+	mutex_init(&msb->io_mutex);
+
+	sprintf(msb->disk->disk_name, "msblk%d", disk_id);
+
+	blk_queue_logical_block_size(msb->queue, msb->page_size);
+
+	capacity = msb->pages_in_block * msb->logical_block_count;
+	capacity *= (msb->page_size / 512);
+
+	set_capacity(msb->disk, capacity);
+	dbg("Set total disk size to %lu sectors", capacity);
+
+	if (msb->read_only)
+		set_disk_ro(msb->disk, 1);
+
+	msb_start(card);
+	add_disk(msb->disk);
+	dbg("Disk added");
+	return 0;
+
+out_put_disk:
+	put_disk(msb->disk);
+out_release_id:
+	mutex_lock(&msb_disk_lock);
+	idr_remove(&msb_disk_idr, disk_id);
+	mutex_unlock(&msb_disk_lock);
+	return rc;
+}
+
+static int msb_probe(struct memstick_dev *card)
+{
+	struct msb_data *msb;
+	int rc = 0;
+
+	msb = kzalloc(sizeof(struct msb_data), GFP_KERNEL);
+	if (!msb)
+		return -ENOMEM;
+	memstick_set_drvdata(card, msb);
+	msb->card = card;
+	spin_lock_init(&msb->q_lock);
+
+	rc = msb_init_card(card);
+	if (rc)
+		goto out_free;
+
+	rc = msb_init_disk(card);
+	if (!rc) {
+		card->check = msb_check_card;
+		card->stop = msb_stop;
+		card->start = msb_start;
+		return 0;
+	}
+out_free:
+	memstick_set_drvdata(card, NULL);
+	msb_data_clear(msb);
+	kfree(msb);
+	return rc;
+}
+
+static void msb_remove(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	unsigned long flags;
+
+	if (!msb->io_queue_stopped)
+		msb_stop(card);
+
+	dbg("Removing the disk device");
+
+	/* Take care of unhandled + new requests from now on */
+	spin_lock_irqsave(&msb->q_lock, flags);
+	msb->card_dead = true;
+	blk_start_queue(msb->queue);
+	spin_unlock_irqrestore(&msb->q_lock, flags);
+
+	/* Remove the disk */
+	del_gendisk(msb->disk);
+	blk_cleanup_queue(msb->queue);
+	msb->queue = NULL;
+
+	mutex_lock(&msb_disk_lock);
+	msb_data_clear(msb);
+	mutex_unlock(&msb_disk_lock);
+
+	msb_disk_release(msb->disk);
+	memstick_set_drvdata(card, NULL);
+}
+
+#ifdef CONFIG_PM
+
+static int msb_suspend(struct memstick_dev *card, pm_message_t state)
+{
+	msb_stop(card);
+	return 0;
+}
+
+static int msb_resume(struct memstick_dev *card)
+{
+	struct msb_data *msb = memstick_get_drvdata(card);
+	struct msb_data *new_msb = NULL;
+	bool card_dead = true;
+
+#ifndef CONFIG_MEMSTICK_UNSAFE_RESUME
+	msb->card_dead = true;
+	return 0;
+#endif
+	mutex_lock(&card->host->lock);
+
+	new_msb = kzalloc(sizeof(struct msb_data), GFP_KERNEL);
+	if (!new_msb)
+		goto out;
+
+	new_msb->card = card;
+	memstick_set_drvdata(card, new_msb);
+	spin_lock_init(&new_msb->q_lock);
+	sg_init_table(msb->prealloc_sg, MS_BLOCK_MAX_SEGS+1);
+
+	if (msb_init_card(card))
+		goto out;
+
+	if (msb->block_size != new_msb->block_size)
+		goto out;
+
+	if (memcmp(msb->boot_page, new_msb->boot_page,
+					sizeof(struct ms_boot_page)))
+		goto out;
+
+	if (msb->logical_block_count != new_msb->logical_block_count ||
+		memcmp(msb->lba_to_pba_table, new_msb->lba_to_pba_table,
+						msb->logical_block_count))
+		goto out;
+
+	if (msb->block_count != new_msb->block_count ||
+		memcmp(msb->used_blocks_bitmap, new_msb->used_blocks_bitmap,
+							msb->block_count / 8))
+		goto out;
+
+	card_dead = false;
+out:
+	if (card_dead)
+		dbg("Card was removed/replaced during suspend");
+
+	msb->card_dead = card_dead;
+	memstick_set_drvdata(card, msb);
+
+	if (new_msb) {
+		msb_data_clear(new_msb);
+		kfree(new_msb);
+	}
+
+	msb_start(card);
+	mutex_unlock(&card->host->lock);
+	return 0;
+}
+#else
+
+#define msb_suspend NULL
+#define msb_resume NULL
+
+#endif /* CONFIG_PM */
+
+static struct memstick_device_id msb_id_tbl[] = {
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_FLASH},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_ROM},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_RO},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_LEGACY, MEMSTICK_CATEGORY_STORAGE,
+	 MEMSTICK_CLASS_WP},
+
+	{MEMSTICK_MATCH_ALL, MEMSTICK_TYPE_DUO, MEMSTICK_CATEGORY_STORAGE_DUO,
+	 MEMSTICK_CLASS_DUO},
+	{}
+};
+MODULE_DEVICE_TABLE(memstick, msb_id_tbl);
+
+
+static struct memstick_driver msb_driver = {
+	.driver = {
+		.name  = DRIVER_NAME,
+		.owner = THIS_MODULE
+	},
+	.id_table = msb_id_tbl,
+	.probe    = msb_probe,
+	.remove   = msb_remove,
+	.suspend  = msb_suspend,
+	.resume   = msb_resume
+};
+
+static int __init msb_init(void)
+{
+	int rc = -ENOMEM;
+
+	rc = register_blkdev(major, DRIVER_NAME);
+	if (rc < 0) {
+		pr_err("failed to register major %d, error %d\n", major, rc);
+		return rc;
+	}
+	if (!major)
+		major = rc;
+
+	rc = memstick_register_driver(&msb_driver);
+	if (rc)
+		unregister_blkdev(major, DRIVER_NAME);
+	return rc;
+}
+
+static void __exit msb_exit(void)
+{
+	memstick_unregister_driver(&msb_driver);
+	unregister_blkdev(major, DRIVER_NAME);
+	idr_destroy(&msb_disk_idr);
+}
+
+module_init(msb_init);
+module_exit(msb_exit);
+
+module_param(major, int, S_IRUGO);
+MODULE_PARM_DESC(major, "Major to use for block device (default auto)");
+
+module_param(cache_flush_timeout, int, S_IRUGO);
+MODULE_PARM_DESC(cache_flush_timeout,
+				"Cache flush timeout in msec (1000 default)");
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug level (0-3)");
+
+module_param(verify_writes, bool, S_IRUGO);
+MODULE_PARM_DESC(verify_writes, "Read back and check all data that is written");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Maxim Levitsky");
+MODULE_DESCRIPTION("Sony MemoryStick block device driver");
diff --git a/drivers/memstick/core/ms_block.h b/drivers/memstick/core/ms_block.h
new file mode 100644
index 0000000..cb689d7
--- /dev/null
+++ b/drivers/memstick/core/ms_block.h
@@ -0,0 +1,293 @@
+/*
+ *  ms_block.c - Sony MemoryStick (legacy) storage support
+
+ *  Copyright (C) 2010 Maxim Levitsky <maximlevitsky@gmail.com>
+ *
+ * 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.
+ *
+ * Minor portions of the driver are copied from mspro_block.c which is
+ * Copyright (C) 2007 Alex Dubov <oakad@yahoo.com>
+ *
+ * Also ms structures were copied from old broken driver by same author
+ * These probably come from MS spec
+ *
+ */
+
+#ifndef MS_BLOCK_NEW_H
+#define MS_BLOCK_NEW_H
+
+#define MS_BLOCK_MAX_SEGS      32
+#define MS_BLOCK_MAX_PAGES     ((2 << 16) - 1)
+
+#define MS_BLOCK_MAX_BOOT_ADDR 0x000c
+#define MS_BLOCK_BOOT_ID       0x0001
+#define MS_BLOCK_INVALID       0xffff
+#define MS_MAX_ZONES           16
+#define MS_BLOCKS_IN_ZONE      512
+
+#define MS_BLOCK_MAP_LINE_SZ   16
+#define MS_BLOCK_PART_SHIFT    3
+
+
+#define MEMSTICK_UNCORR_ERROR (MEMSTICK_STATUS1_UCFG | \
+		MEMSTICK_STATUS1_UCEX | MEMSTICK_STATUS1_UCDT)
+
+#define MEMSTICK_CORR_ERROR (MEMSTICK_STATUS1_FGER | MEMSTICK_STATUS1_EXER | \
+	MEMSTICK_STATUS1_DTER)
+
+#define MEMSTICK_INT_ERROR (MEMSTICK_INT_CMDNAK | MEMSTICK_INT_ERR)
+
+#define MEMSTICK_OVERWRITE_FLAG_NORMAL \
+	(MEMSTICK_OVERWRITE_PGST1 | \
+	MEMSTICK_OVERWRITE_PGST0  | \
+	MEMSTICK_OVERWRITE_BKST)
+
+#define MEMSTICK_OV_PG_NORMAL \
+	(MEMSTICK_OVERWRITE_PGST1 | MEMSTICK_OVERWRITE_PGST0)
+
+#define MEMSTICK_MANAGMENT_FLAG_NORMAL \
+	(MEMSTICK_MANAGEMENT_SYSFLG |  \
+	MEMSTICK_MANAGEMENT_SCMS1   |  \
+	MEMSTICK_MANAGEMENT_SCMS0)     \
+
+struct ms_boot_header {
+	unsigned short block_id;
+	unsigned short format_reserved;
+	unsigned char  reserved0[184];
+	unsigned char  data_entry;
+	unsigned char  reserved1[179];
+} __packed;
+
+
+struct ms_system_item {
+	unsigned int  start_addr;
+	unsigned int  data_size;
+	unsigned char data_type_id;
+	unsigned char reserved[3];
+} __packed;
+
+struct ms_system_entry {
+	struct ms_system_item disabled_block;
+	struct ms_system_item cis_idi;
+	unsigned char         reserved[24];
+} __packed;
+
+struct ms_boot_attr_info {
+	unsigned char      memorystick_class;
+	unsigned char      format_unique_value1;
+	unsigned short     block_size;
+	unsigned short     number_of_blocks;
+	unsigned short     number_of_effective_blocks;
+	unsigned short     page_size;
+	unsigned char      extra_data_size;
+	unsigned char      format_unique_value2;
+	unsigned char      assembly_time[8];
+	unsigned char      format_unique_value3;
+	unsigned char      serial_number[3];
+	unsigned char      assembly_manufacturer_code;
+	unsigned char      assembly_model_code[3];
+	unsigned short     memory_manufacturer_code;
+	unsigned short     memory_device_code;
+	unsigned short     implemented_capacity;
+	unsigned char      format_unique_value4[2];
+	unsigned char      vcc;
+	unsigned char      vpp;
+	unsigned short     controller_number;
+	unsigned short     controller_function;
+	unsigned char      reserved0[9];
+	unsigned char      transfer_supporting;
+	unsigned short     format_unique_value5;
+	unsigned char      format_type;
+	unsigned char      memorystick_application;
+	unsigned char      device_type;
+	unsigned char      reserved1[22];
+	unsigned char      format_uniqure_value6[2];
+	unsigned char      reserved2[15];
+} __packed;
+
+struct ms_cis_idi {
+	unsigned short general_config;
+	unsigned short logical_cylinders;
+	unsigned short reserved0;
+	unsigned short logical_heads;
+	unsigned short track_size;
+	unsigned short page_size;
+	unsigned short pages_per_track;
+	unsigned short msw;
+	unsigned short lsw;
+	unsigned short reserved1;
+	unsigned char  serial_number[20];
+	unsigned short buffer_type;
+	unsigned short buffer_size_increments;
+	unsigned short long_command_ecc;
+	unsigned char  firmware_version[28];
+	unsigned char  model_name[18];
+	unsigned short reserved2[5];
+	unsigned short pio_mode_number;
+	unsigned short dma_mode_number;
+	unsigned short field_validity;
+	unsigned short current_logical_cylinders;
+	unsigned short current_logical_heads;
+	unsigned short current_pages_per_track;
+	unsigned int   current_page_capacity;
+	unsigned short mutiple_page_setting;
+	unsigned int   addressable_pages;
+	unsigned short single_word_dma;
+	unsigned short multi_word_dma;
+	unsigned char  reserved3[128];
+} __packed;
+
+
+struct ms_boot_page {
+	struct ms_boot_header    header;
+	struct ms_system_entry   entry;
+	struct ms_boot_attr_info attr;
+} __packed;
+
+struct msb_data {
+	unsigned int			usage_count;
+	struct memstick_dev		*card;
+	struct gendisk			*disk;
+	struct request_queue		*queue;
+	spinlock_t			q_lock;
+	struct hd_geometry		geometry;
+	struct attribute_group		attr_group;
+	struct request			*req;
+	int				caps;
+
+	/* IO */
+	struct workqueue_struct		*io_queue;
+	bool				io_queue_stopped;
+	struct work_struct		io_work;
+	struct scatterlist		prealloc_sg[MS_BLOCK_MAX_SEGS+1];
+	bool				card_dead;
+	struct mutex			io_mutex;
+
+	/* Media properties */
+	struct ms_boot_page		*boot_page;
+	u16				boot_block_locations[2];
+	int				boot_block_count;
+
+	bool				read_only;
+	unsigned short			page_size;
+	int				block_size;
+	int				pages_in_block;
+	int				zone_count;
+	int				block_count;
+	int				logical_block_count;
+
+	/* FTL tables */
+	unsigned long			*used_blocks_bitmap;
+	unsigned long			*erased_blocks_bitmap;
+	u16				*lba_to_pba_table;
+	int				free_block_count[MS_MAX_ZONES];
+	bool				ftl_initialized;
+
+	/* Cache */
+	unsigned char			*cache;
+	unsigned long			valid_cache_bitmap;
+	int				cache_block_lba;
+	bool				need_flush_cache;
+	struct timer_list		cache_flush_timer;
+
+	/* Preallocated buffers */
+	unsigned char			*block_buffer;
+	struct scatterlist		sg[MS_BLOCK_MAX_SEGS+1];
+
+
+	/* handler's local data */
+	struct ms_register_addr		reg_addr;
+	bool				addr_valid;
+
+	u8				command_value;
+	bool				command_need_oob;
+	struct scatterlist		*current_sg;
+	int				current_sg_offset;
+
+	struct ms_register		regs;
+	int				current_page;
+
+	int				state;
+	int				exit_error;
+	bool				int_polling;
+	unsigned long			int_timeout;
+
+};
+
+enum msb_readpage_states {
+	MSB_RP_SEND_BLOCK_ADDRESS = 0,
+	MSB_RP_SEND_READ_COMMAND,
+
+	MSB_RP_SEND_INT_REQ,
+	MSB_RP_RECEIVE_INT_REQ_RESULT,
+
+	MSB_RP_SEND_READ_STATUS_REG,
+	MSB_RP_RECIVE_STATUS_REG,
+
+	MSB_RP_SEND_OOB_READ,
+	MSB_RP_RECEIVE_OOB_READ,
+
+	MSB_RP_SEND_READ_DATA,
+	MSB_RP_RECEIVE_READ_DATA,
+};
+
+enum msb_write_block_states {
+	MSB_WB_SEND_WRITE_PARAMS = 0,
+	MSB_WB_SEND_WRITE_OOB,
+	MSB_WB_SEND_WRITE_COMMAND,
+
+	MSB_WB_SEND_INT_REQ,
+	MSB_WB_RECEIVE_INT_REQ,
+
+	MSB_WB_SEND_WRITE_DATA,
+	MSB_WB_RECEIVE_WRITE_CONFIRMATION,
+};
+
+enum msb_send_command_states {
+	MSB_SC_SEND_WRITE_PARAMS,
+	MSB_SC_SEND_WRITE_OOB,
+	MSB_SC_SEND_COMMAND,
+
+	MSB_SC_SEND_INT_REQ,
+	MSB_SC_RECEIVE_INT_REQ,
+
+};
+
+enum msb_reset_states {
+	MSB_RS_SEND,
+	MSB_RS_CONFIRM,
+};
+
+enum msb_par_switch_states {
+	MSB_PS_SEND_SWITCH_COMMAND,
+	MSB_PS_SWICH_HOST,
+	MSB_PS_CONFIRM,
+};
+
+struct chs_entry {
+	unsigned long size;
+	unsigned char sec;
+	unsigned short cyl;
+	unsigned char head;
+};
+
+static int msb_reset(struct msb_data *msb, bool full);
+
+static int h_msb_default_bad(struct memstick_dev *card,
+						struct memstick_request **mrq);
+
+#define DRIVER_NAME "ms_block"
+
+#define __dbg(level, format, ...) \
+	do { \
+		if (debug >= level) \
+			pr_err(format "\n", ## __VA_ARGS__); \
+	} while (0)
+
+
+#define dbg(format, ...)		__dbg(1, format, ## __VA_ARGS__)
+#define dbg_verbose(format, ...)	__dbg(2, format, ## __VA_ARGS__)
+
+#endif
-- 
1.7.9.5