i2o_block.c

linux-2.6.15.6

/*
 *	Block OSM
 *
 * 	Copyright (C) 1999-2002	Red Hat Software
 *
 *	Written by Alan Cox, Building Number Three Ltd
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License as published by the
 *	Free Software Foundation; either version 2 of the License, or (at your
 *	option) any later version.
 *
 *	This program is distributed in the hope that it will be useful, but
 *	WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *	General Public License for more details.
 *
 *	For the purpose of avoiding doubt the preferred form of the work
 *	for making modifications shall be a standards compliant form such
 *	gzipped tar and not one requiring a proprietary or patent encumbered
 *	tool to unpack.
 *
 *	Fixes/additions:
 *		Steve Ralston:
 *			Multiple device handling error fixes,
 *			Added a queue depth.
 *		Alan Cox:
 *			FC920 has an rmw bug. Dont or in the end marker.
 *			Removed queue walk, fixed for 64bitness.
 *			Rewrote much of the code over time
 *			Added indirect block lists
 *			Handle 64K limits on many controllers
 *			Don't use indirects on the Promise (breaks)
 *			Heavily chop down the queue depths
 *		Deepak Saxena:
 *			Independent queues per IOP
 *			Support for dynamic device creation/deletion
 *			Code cleanup
 *	    		Support for larger I/Os through merge* functions
 *			(taken from DAC960 driver)
 *		Boji T Kannanthanam:
 *			Set the I2O Block devices to be detected in increasing
 *			order of TIDs during boot.
 *			Search and set the I2O block device that we boot off
 *			from as the first device to be claimed (as /dev/i2o/hda)
 *			Properly attach/detach I2O gendisk structure from the
 *			system gendisk list. The I2O block devices now appear in
 *			/proc/partitions.
 *		Markus Lidel <[e-mail]>:
 *			Minor bugfixes for 2.6.
 */

#include <linux/module.h>
#include <linux/i2o.h>

#include <linux/mempool.h>

#include <linux/genhd.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>

#include "i2o_block.h"

#define OSM_NAME	"block-osm"
#define OSM_VERSION	"1.287"
#define OSM_DESCRIPTION	"I2O Block Device OSM"

static struct i2o_driver i2o_block_driver;

/* global Block OSM request mempool */
static struct i2o_block_mempool i2o_blk_req_pool;

/* Block OSM class handling definition */
static struct i2o_class_id i2o_block_class_id[] = {
	{I2O_CLASS_RANDOM_BLOCK_STORAGE},
	{I2O_CLASS_END}
};

/**
 *	i2o_block_device_free - free the memory of the I2O Block device
 *	@dev: I2O Block device, which should be cleaned up
 *
 *	Frees the request queue, gendisk and the i2o_block_device structure.
 */
static void i2o_block_device_free(struct i2o_block_device *dev)
{
	blk_cleanup_queue(dev->gd->queue);

	put_disk(dev->gd);

	kfree(dev);
};

/**
 *	i2o_block_remove - remove the I2O Block device from the system again
 *	@dev: I2O Block device which should be removed
 *
 *	Remove gendisk from system and free all allocated memory.
 *
 *	Always returns 0.
 */
static int i2o_block_remove(struct device *dev)
{
	struct i2o_device *i2o_dev = to_i2o_device(dev);
	struct i2o_block_device *i2o_blk_dev = dev_get_drvdata(dev);

	osm_info("device removed (TID: %03x): %s\n", i2o_dev->lct_data.tid,
		 i2o_blk_dev->gd->disk_name);

	i2o_event_register(i2o_dev, &i2o_block_driver, 0, 0);

	del_gendisk(i2o_blk_dev->gd);

	dev_set_drvdata(dev, NULL);

	i2o_device_claim_release(i2o_dev);

	i2o_block_device_free(i2o_blk_dev);

	return 0;
};

/**
 *	i2o_block_device flush - Flush all dirty data of I2O device dev
 *	@dev: I2O device which should be flushed
 *
 *	Flushes all dirty data on device dev.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_block_device_flush(struct i2o_device *dev)
{
	struct i2o_message __iomem *msg;
	u32 m;

	m = i2o_msg_get_wait(dev->iop, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	writel(FIVE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_BLOCK_CFLUSH << 24 | HOST_TID << 12 | dev->lct_data.tid,
	       &msg->u.head[1]);
	writel(60 << 16, &msg->body[0]);
	osm_debug("Flushing...\n");

	return i2o_msg_post_wait(dev->iop, m, 60);
};

/**
 *	i2o_block_issue_flush - device-flush interface for block-layer
 *	@queue: the request queue of the device which should be flushed
 *	@disk: gendisk
 *	@error_sector: error offset
 *
 *	Helper function to provide flush functionality to block-layer.
 *
 *	Returns 0 on success or negative error code on failure.
 */

static int i2o_block_issue_flush(request_queue_t * queue, struct gendisk *disk,
				 sector_t * error_sector)
{
	struct i2o_block_device *i2o_blk_dev = queue->queuedata;
	int rc = -ENODEV;

	if (likely(i2o_blk_dev))
		rc = i2o_block_device_flush(i2o_blk_dev->i2o_dev);

	return rc;
}

/**
 *	i2o_block_device_mount - Mount (load) the media of device dev
 *	@dev: I2O device which should receive the mount request
 *	@media_id: Media Identifier
 *
 *	Load a media into drive. Identifier should be set to -1, because the
 *	spec does not support any other value.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_block_device_mount(struct i2o_device *dev, u32 media_id)
{
	struct i2o_message __iomem *msg;
	u32 m;

	m = i2o_msg_get_wait(dev->iop, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	writel(FIVE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_BLOCK_MMOUNT << 24 | HOST_TID << 12 | dev->lct_data.tid,
	       &msg->u.head[1]);
	writel(-1, &msg->body[0]);
	writel(0, &msg->body[1]);
	osm_debug("Mounting...\n");

	return i2o_msg_post_wait(dev->iop, m, 2);
};

/**
 *	i2o_block_device_lock - Locks the media of device dev
 *	@dev: I2O device which should receive the lock request
 *	@media_id: Media Identifier
 *
 *	Lock media of device dev to prevent removal. The media identifier
 *	should be set to -1, because the spec does not support any other value.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_block_device_lock(struct i2o_device *dev, u32 media_id)
{
	struct i2o_message __iomem *msg;
	u32 m;

	m = i2o_msg_get_wait(dev->iop, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	writel(FIVE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_BLOCK_MLOCK << 24 | HOST_TID << 12 | dev->lct_data.tid,
	       &msg->u.head[1]);
	writel(-1, &msg->body[0]);
	osm_debug("Locking...\n");

	return i2o_msg_post_wait(dev->iop, m, 2);
};

/**
 *	i2o_block_device_unlock - Unlocks the media of device dev
 *	@dev: I2O device which should receive the unlocked request
 *	@media_id: Media Identifier
 *
 *	Unlocks the media in device dev. The media identifier should be set to
 *	-1, because the spec does not support any other value.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_block_device_unlock(struct i2o_device *dev, u32 media_id)
{
	struct i2o_message __iomem *msg;
	u32 m;

	m = i2o_msg_get_wait(dev->iop, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	writel(FIVE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_BLOCK_MUNLOCK << 24 | HOST_TID << 12 | dev->lct_data.tid,
	       &msg->u.head[1]);
	writel(media_id, &msg->body[0]);
	osm_debug("Unlocking...\n");

	return i2o_msg_post_wait(dev->iop, m, 2);
};

/**
 *	i2o_block_device_power - Power management for device dev
 *	@dev: I2O device which should receive the power management request
 *	@operation: Operation which should be send
 *
 *	Send a power management request to the device dev.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_block_device_power(struct i2o_block_device *dev, u8 op)
{
	struct i2o_device *i2o_dev = dev->i2o_dev;
	struct i2o_controller *c = i2o_dev->iop;
	struct i2o_message __iomem *msg;
	u32 m;
	int rc;

	m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	writel(FOUR_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_BLOCK_POWER << 24 | HOST_TID << 12 | i2o_dev->lct_data.
	       tid, &msg->u.head[1]);
	writel(op << 24, &msg->body[0]);
	osm_debug("Power...\n");

	rc = i2o_msg_post_wait(c, m, 60);
	if (!rc)
		dev->power = op;

	return rc;
};

/**
 *	i2o_block_request_alloc - Allocate an I2O block request struct
 *
 *	Allocates an I2O block request struct and initialize the list.
 *
 *	Returns a i2o_block_request pointer on success or negative error code
 *	on failure.
 */
static inline struct i2o_block_request *i2o_block_request_alloc(void)
{
	struct i2o_block_request *ireq;

	ireq = mempool_alloc(i2o_blk_req_pool.pool, GFP_ATOMIC);
	if (!ireq)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&ireq->queue);

	return ireq;
};

/**
 *	i2o_block_request_free - Frees a I2O block request
 *	@ireq: I2O block request which should be freed
 *
 *	Fres the allocated memory (give it back to the request mempool).
 */
static inline void i2o_block_request_free(struct i2o_block_request *ireq)
{
	mempool_free(ireq, i2o_blk_req_pool.pool);
};

/**
 *	i2o_block_sglist_alloc - Allocate the SG list and map it
 *	@c: I2O controller to which the request belongs
 *	@ireq: I2O block request
 *
 *	Builds the SG list and map it to be accessable by the controller.
 *
 *	Returns 0 on failure or 1 on success.
 */
static inline int i2o_block_sglist_alloc(struct i2o_controller *c,
					 struct i2o_block_request *ireq,
					 u32 __iomem ** mptr)
{
	int nents;
	enum dma_data_direction direction;

	ireq->dev = &c->pdev->dev;
	nents = blk_rq_map_sg(ireq->req->q, ireq->req, ireq->sg_table);

	if (rq_data_dir(ireq->req) == READ)
		direction = PCI_DMA_FROMDEVICE;
	else
		direction = PCI_DMA_TODEVICE;

	ireq->sg_nents = nents;

	return i2o_dma_map_sg(c, ireq->sg_table, nents, direction, mptr);
};

/**
 *	i2o_block_sglist_free - Frees the SG list
 *	@ireq: I2O block request from which the SG should be freed
 *
 *	Frees the SG list from the I2O block request.
 */
static inline void i2o_block_sglist_free(struct i2o_block_request *ireq)
{
	enum dma_data_direction direction;

	if (rq_data_dir(ireq->req) == READ)
		direction = PCI_DMA_FROMDEVICE;
	else
		direction = PCI_DMA_TODEVICE;

	dma_unmap_sg(ireq->dev, ireq->sg_table, ireq->sg_nents, direction);
};

/**
 *	i2o_block_prep_req_fn - Allocates I2O block device specific struct
 *	@q: request queue for the request
 *	@req: the request to prepare
 *
 *	Allocate the necessary i2o_block_request struct and connect it to
 *	the request. This is needed that we not loose the SG list later on.
 *
 *	Returns BLKPREP_OK on success or BLKPREP_DEFER on failure.
 */
static int i2o_block_prep_req_fn(struct request_queue *q, struct request *req)
{
	struct i2o_block_device *i2o_blk_dev = q->queuedata;
	struct i2o_block_request *ireq;

	if (unlikely(!i2o_blk_dev)) {
		osm_err("block device already removed\n");
		return BLKPREP_KILL;
	}

	/* request is already processed by us, so return */
	if (req->flags & REQ_SPECIAL) {
		osm_debug("REQ_SPECIAL already set!\n");
		req->flags |= REQ_DONTPREP;
		return BLKPREP_OK;
	}

	/* connect the i2o_block_request to the request */
	if (!req->special) {
		ireq = i2o_block_request_alloc();
		if (unlikely(IS_ERR(ireq))) {
			osm_debug("unable to allocate i2o_block_request!\n");
			return BLKPREP_DEFER;
		}

		ireq->i2o_blk_dev = i2o_blk_dev;
		req->special = ireq;
		ireq->req = req;
	} else
		ireq = req->special;

	/* do not come back here */
	req->flags |= REQ_DONTPREP | REQ_SPECIAL;

	return BLKPREP_OK;
};

/**
 *	i2o_block_delayed_request_fn - delayed request queue function