i2o_scsi.c

linux-2.6.15.6

/*
 * 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, 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 avoidance of doubt the "preferred form" of this code is one which
 * is in an open non patent encumbered format. Where cryptographic key signing
 * forms part of the process of creating an executable the information
 * including keys needed to generate an equivalently functional executable
 * are deemed to be part of the source code.
 *
 *  Complications for I2O scsi
 *
 *	o	Each (bus,lun) is a logical device in I2O. We keep a map
 *		table. We spoof failed selection for unmapped units
 *	o	Request sense buffers can come back for free.
 *	o	Scatter gather is a bit dynamic. We have to investigate at
 *		setup time.
 *	o	Some of our resources are dynamically shared. The i2o core
 *		needs a message reservation protocol to avoid swap v net
 *		deadlocking. We need to back off queue requests.
 *
 *	In general the firmware wants to help. Where its help isn't performance
 *	useful we just ignore the aid. Its not worth the code in truth.
 *
 * Fixes/additions:
 *	Steve Ralston:
 *		Scatter gather now works
 *	Markus Lidel <[e-mail]>:
 *		Minor fixes for 2.6.
 *
 * To Do:
 *	64bit cleanups
 *	Fix the resource management problems.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/prefetch.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/i2o.h>
#include <linux/scatterlist.h>

#include <asm/dma.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/atomic.h>

#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_request.h>
#include <scsi/sg.h>
#include <scsi/sg_request.h>

#define OSM_NAME	"scsi-osm"
#define OSM_VERSION	"1.282"
#define OSM_DESCRIPTION	"I2O SCSI Peripheral OSM"

static struct i2o_driver i2o_scsi_driver;

static unsigned int i2o_scsi_max_id = 16;
static unsigned int i2o_scsi_max_lun = 255;

struct i2o_scsi_host {
	struct Scsi_Host *scsi_host;	/* pointer to the SCSI host */
	struct i2o_controller *iop;	/* pointer to the I2O controller */
	unsigned int lun;	/* lun's used for block devices */
	struct i2o_device *channel[0];	/* channel->i2o_dev mapping table */
};

static struct scsi_host_template i2o_scsi_host_template;

#define I2O_SCSI_CAN_QUEUE	4

/* SCSI OSM class handling definition */
static struct i2o_class_id i2o_scsi_class_id[] = {
	{I2O_CLASS_SCSI_PERIPHERAL},
	{I2O_CLASS_END}
};

static struct i2o_scsi_host *i2o_scsi_host_alloc(struct i2o_controller *c)
{
	struct i2o_scsi_host *i2o_shost;
	struct i2o_device *i2o_dev;
	struct Scsi_Host *scsi_host;
	int max_channel = 0;
	u8 type;
	int i;
	size_t size;
	u16 body_size = 6;

#ifdef CONFIG_I2O_EXT_ADAPTEC
	if (c->adaptec)
		body_size = 8;
#endif

	list_for_each_entry(i2o_dev, &c->devices, list)
	    if (i2o_dev->lct_data.class_id == I2O_CLASS_BUS_ADAPTER) {
		if (i2o_parm_field_get(i2o_dev, 0x0000, 0, &type, 1)
		    && (type == 0x01))	/* SCSI bus */
			max_channel++;
	}

	if (!max_channel) {
		osm_warn("no channels found on %s\n", c->name);
		return ERR_PTR(-EFAULT);
	}

	size = max_channel * sizeof(struct i2o_device *)
	    + sizeof(struct i2o_scsi_host);

	scsi_host = scsi_host_alloc(&i2o_scsi_host_template, size);
	if (!scsi_host) {
		osm_warn("Could not allocate SCSI host\n");
		return ERR_PTR(-ENOMEM);
	}

	scsi_host->max_channel = max_channel - 1;
	scsi_host->max_id = i2o_scsi_max_id;
	scsi_host->max_lun = i2o_scsi_max_lun;
	scsi_host->this_id = c->unit;
	scsi_host->sg_tablesize = i2o_sg_tablesize(c, body_size);

	i2o_shost = (struct i2o_scsi_host *)scsi_host->hostdata;
	i2o_shost->scsi_host = scsi_host;
	i2o_shost->iop = c;
	i2o_shost->lun = 1;

	i = 0;
	list_for_each_entry(i2o_dev, &c->devices, list)
	    if (i2o_dev->lct_data.class_id == I2O_CLASS_BUS_ADAPTER) {
		if (i2o_parm_field_get(i2o_dev, 0x0000, 0, &type, 1)
		    && (type == 0x01))	/* only SCSI bus */
			i2o_shost->channel[i++] = i2o_dev;

		if (i >= max_channel)
			break;
	}

	return i2o_shost;
};

/**
 *	i2o_scsi_get_host - Get an I2O SCSI host
 *	@c: I2O controller to for which to get the SCSI host
 *
 *	If the I2O controller already exists as SCSI host, the SCSI host
 *	is returned, otherwise the I2O controller is added to the SCSI
 *	core.
 *
 *	Returns pointer to the I2O SCSI host on success or NULL on failure.
 */
static struct i2o_scsi_host *i2o_scsi_get_host(struct i2o_controller *c)
{
	return c->driver_data[i2o_scsi_driver.context];
};

/**
 *	i2o_scsi_remove - Remove I2O device from SCSI core
 *	@dev: device which should be removed
 *
 *	Removes the I2O device from the SCSI core again.
 *
 *	Returns 0 on success.
 */
static int i2o_scsi_remove(struct device *dev)
{
	struct i2o_device *i2o_dev = to_i2o_device(dev);
	struct i2o_controller *c = i2o_dev->iop;
	struct i2o_scsi_host *i2o_shost;
	struct scsi_device *scsi_dev;

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

	i2o_shost = i2o_scsi_get_host(c);

	shost_for_each_device(scsi_dev, i2o_shost->scsi_host)
	    if (scsi_dev->hostdata == i2o_dev) {
		sysfs_remove_link(&i2o_dev->device.kobj, "scsi");
		scsi_remove_device(scsi_dev);
		scsi_device_put(scsi_dev);
		break;
	}

	return 0;
};

/**
 *	i2o_scsi_probe - verify if dev is a I2O SCSI device and install it
 *	@dev: device to verify if it is a I2O SCSI device
 *
 *	Retrieve channel, id and lun for I2O device. If everthing goes well
 *	register the I2O device as SCSI device on the I2O SCSI controller.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_scsi_probe(struct device *dev)
{
	struct i2o_device *i2o_dev = to_i2o_device(dev);
	struct i2o_controller *c = i2o_dev->iop;
	struct i2o_scsi_host *i2o_shost;
	struct Scsi_Host *scsi_host;
	struct i2o_device *parent;
	struct scsi_device *scsi_dev;
	u32 id = -1;
	u64 lun = -1;
	int channel = -1;
	int i;

	i2o_shost = i2o_scsi_get_host(c);
	if (!i2o_shost)
		return -EFAULT;

	scsi_host = i2o_shost->scsi_host;

	switch (i2o_dev->lct_data.class_id) {
	case I2O_CLASS_RANDOM_BLOCK_STORAGE:
	case I2O_CLASS_EXECUTIVE:
#ifdef CONFIG_I2O_EXT_ADAPTEC
		if (c->adaptec) {
			u8 type;
			struct i2o_device *d = i2o_shost->channel[0];

			if (i2o_parm_field_get(d, 0x0000, 0, &type, 1)
			    && (type == 0x01))	/* SCSI bus */
				if (i2o_parm_field_get(d, 0x0200, 4, &id, 4)) {
					channel = 0;
					if (i2o_dev->lct_data.class_id ==
					    I2O_CLASS_RANDOM_BLOCK_STORAGE)
						lun = i2o_shost->lun++;
					else
						lun = 0;
				}
		}
#endif
		break;

	case I2O_CLASS_SCSI_PERIPHERAL:
		if (i2o_parm_field_get(i2o_dev, 0x0000, 3, &id, 4) < 0)
			return -EFAULT;

		if (i2o_parm_field_get(i2o_dev, 0x0000, 4, &lun, 8) < 0)
			return -EFAULT;

		parent = i2o_iop_find_device(c, i2o_dev->lct_data.parent_tid);
		if (!parent) {
			osm_warn("can not find parent of device %03x\n",
				 i2o_dev->lct_data.tid);
			return -EFAULT;
		}

		for (i = 0; i <= i2o_shost->scsi_host->max_channel; i++)
			if (i2o_shost->channel[i] == parent)
				channel = i;
		break;

	default:
		return -EFAULT;
	}

	if (channel == -1) {
		osm_warn("can not find channel of device %03x\n",
			 i2o_dev->lct_data.tid);
		return -EFAULT;
	}

	if (id >= scsi_host->max_id) {
		osm_warn("SCSI device id (%d) >= max_id of I2O host (%d)", id,
			 scsi_host->max_id);
		return -EFAULT;
	}

	if (lun >= scsi_host->max_lun) {
		osm_warn("SCSI device id (%d) >= max_lun of I2O host (%d)",
			 (unsigned int)lun, scsi_host->max_lun);
		return -EFAULT;
	}

	scsi_dev =
	    __scsi_add_device(i2o_shost->scsi_host, channel, id, lun, i2o_dev);

	if (IS_ERR(scsi_dev)) {
		osm_warn("can not add SCSI device %03x\n",
			 i2o_dev->lct_data.tid);
		return PTR_ERR(scsi_dev);
	}

	sysfs_create_link(&i2o_dev->device.kobj, &scsi_dev->sdev_gendev.kobj,
			  "scsi");

	osm_info("device added (TID: %03x) channel: %d, id: %d, lun: %d\n",
		 i2o_dev->lct_data.tid, channel, id, (unsigned int)lun);

	return 0;
};

static const char *i2o_scsi_info(struct Scsi_Host *SChost)
{
	struct i2o_scsi_host *hostdata;
	hostdata = (struct i2o_scsi_host *)SChost->hostdata;
	return hostdata->iop->name;
}

/**
 *	i2o_scsi_reply - SCSI OSM message reply handler
 *	@c: controller issuing the reply
 *	@m: message id for flushing
 *	@msg: the message from the controller
 *
 *	Process reply messages (interrupts in normal scsi controller think).
 *	We can get a variety of messages to process. The normal path is
 *	scsi command completions. We must also deal with IOP failures,
 *	the reply to a bus reset and the reply to a LUN query.
 *
 *	Returns 0 on success and if the reply should not be flushed or > 0
 *	on success and if the reply should be flushed. Returns negative error
 *	code on failure and if the reply should be flushed.
 */
static int i2o_scsi_reply(struct i2o_controller *c, u32 m,
			  struct i2o_message *msg)
{
	struct scsi_cmnd *cmd;
	u32 error;
	struct device *dev;

	cmd = i2o_cntxt_list_get(c, le32_to_cpu(msg->u.s.tcntxt));
	if (unlikely(!cmd)) {
		osm_err("NULL reply received!\n");
		return -1;
	}

	/*
	 *      Low byte is device status, next is adapter status,
	 *      (then one byte reserved), then request status.
	 */
	error = le32_to_cpu(msg->body[0]);

	osm_debug("Completed %ld\n", cmd->serial_number);

	cmd->result = error & 0xff;
	/*
	 * if DeviceStatus is not SCSI_SUCCESS copy over the sense data and let
	 * the SCSI layer handle the error
	 */
	if (cmd->result)
		memcpy(cmd->sense_buffer, &msg->body[3],
		       min(sizeof(cmd->sense_buffer), (size_t) 40));

	/* only output error code if AdapterStatus is not HBA_SUCCESS */
	if ((error >> 8) & 0xff)
		osm_err("SCSI error %08x\n", error);

	dev = &c->pdev->dev;
	if (cmd->use_sg)
		dma_unmap_sg(dev, cmd->request_buffer, cmd->use_sg,
			     cmd->sc_data_direction);
	else if (cmd->SCp.dma_handle)
		dma_unmap_single(dev, cmd->SCp.dma_handle, cmd->request_bufflen,
				 cmd->sc_data_direction);

	cmd->scsi_done(cmd);

	return 1;
};

/**
 *	i2o_scsi_notify_device_add - Retrieve notifications of added devices
 *	@i2o_dev: the I2O device which was added
 *
 *	If a I2O device is added we catch the notification, because I2O classes
 *	other then SCSI peripheral will not be received through
 *	i2o_scsi_probe().
 */
static void i2o_scsi_notify_device_add(struct i2o_device *i2o_dev)
{
	switch (i2o_dev->lct_data.class_id) {
	case I2O_CLASS_EXECUTIVE:
	case I2O_CLASS_RANDOM_BLOCK_STORAGE:
		i2o_scsi_probe(&i2o_dev->device);
		break;

	default:
		break;
	}
};

/**
 *	i2o_scsi_notify_device_remove - Retrieve notifications of removed
 *				        devices
 *	@i2o_dev: the I2O device which was removed
 *
 *	If a I2O device is removed, we catch the notification to remove the
 *	corresponding SCSI device.