i2o_scsi.c

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/*
 * 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 <[email protected]>:
 *      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/io.h>
#include <linux/atomic.h>

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

#define OSM_NAME    "scsi-osm"
#define OSM_VERSION "1.316"
#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;
};

static struct i2o_scsi_host *i2o_scsi_get_host(struct i2o_controller *c)
{
    return c->driver_data[i2o_scsi_driver.context];
};

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;
};

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, rc;

    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 =
                            cpu_to_le64(i2o_shost->
                                lun++);
                    else
                        lun = 0;
                }
        }
#endif
        break;

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

        if (i2o_parm_field_get(i2o_dev, 0x0000, 4, &lun, 8))
            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 (le32_to_cpu(id) >= scsi_host->max_id) {
        osm_warn("SCSI device id (%d) >= max_id of I2O host (%d)",
             le32_to_cpu(id), scsi_host->max_id);
        return -EFAULT;
    }

    if (le64_to_cpu(lun) >= scsi_host->max_lun) {
        osm_warn("SCSI device lun (%lu) >= max_lun of I2O host (%d)",
             (long unsigned int)le64_to_cpu(lun),
             scsi_host->max_lun);
        return -EFAULT;
    }

    scsi_dev =
        __scsi_add_device(i2o_shost->scsi_host, channel, le32_to_cpu(id),
                  le64_to_cpu(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);
    }

    rc = sysfs_create_link(&i2o_dev->device.kobj,
                   &scsi_dev->sdev_gendev.kobj, "scsi");
    if (rc)
        goto err;

    osm_info("device added (TID: %03x) channel: %d, id: %d, lun: %ld\n",
         i2o_dev->lct_data.tid, channel, le32_to_cpu(id),
         (long unsigned int)le64_to_cpu(lun));

    return 0;

err:
    scsi_remove_device(scsi_dev);
    return rc;
};

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;
}

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 %0x%p\n", cmd);

    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(SCSI_SENSE_BUFFERSIZE, 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;

    scsi_dma_unmap(cmd);

    cmd->scsi_done(cmd);

    return 1;
};

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;
    }
};

static void i2o_scsi_notify_device_remove(struct i2o_device *i2o_dev)
{
    switch (i2o_dev->lct_data.class_id) {
    case I2O_CLASS_EXECUTIVE:
    case I2O_CLASS_RANDOM_BLOCK_STORAGE:
        i2o_scsi_remove(&i2o_dev->device);
        break;

    default:
        break;
    }
};

static void i2o_scsi_notify_controller_add(struct i2o_controller *c)
{
    struct i2o_scsi_host *i2o_shost;
    int rc;

    i2o_shost = i2o_scsi_host_alloc(c);
    if (IS_ERR(i2o_shost)) {
        osm_err("Could not initialize SCSI host\n");
        return;
    }

    rc = scsi_add_host(i2o_shost->scsi_host, &c->device);
    if (rc) {
        osm_err("Could not add SCSI host\n");
        scsi_host_put(i2o_shost->scsi_host);
        return;
    }

    c->driver_data[i2o_scsi_driver.context] = i2o_shost;

    osm_debug("new I2O SCSI host added\n");
};

static void i2o_scsi_notify_controller_remove(struct i2o_controller *c)
{
    struct i2o_scsi_host *i2o_shost;
    i2o_shost = i2o_scsi_get_host(c);
    if (!i2o_shost)
        return;

    c->driver_data[i2o_scsi_driver.context] = NULL;

    scsi_remove_host(i2o_shost->scsi_host);
    scsi_host_put(i2o_shost->scsi_host);
    osm_debug("I2O SCSI host removed\n");
};

/* SCSI OSM driver struct */
static struct i2o_driver i2o_scsi_driver = {
    .name = OSM_NAME,
    .reply = i2o_scsi_reply,
    .classes = i2o_scsi_class_id,
    .notify_device_add = i2o_scsi_notify_device_add,
    .notify_device_remove = i2o_scsi_notify_device_remove,
    .notify_controller_add = i2o_scsi_notify_controller_add,
    .notify_controller_remove = i2o_scsi_notify_controller_remove,
    .driver = {
           .probe = i2o_scsi_probe,
           .remove = i2o_scsi_remove,
           },
};

static int i2o_scsi_queuecommand_lck(struct scsi_cmnd *SCpnt,
                 void (*done) (struct scsi_cmnd *))
{
    struct i2o_controller *c;
    struct i2o_device *i2o_dev;
    int tid;
    struct i2o_message *msg;
    /*
     * ENABLE_DISCONNECT
     * SIMPLE_TAG
     * RETURN_SENSE_DATA_IN_REPLY_MESSAGE_FRAME
     */
    u32 scsi_flags = 0x20a00000;
    u32 sgl_offset;
    u32 *mptr;
    u32 cmd = I2O_CMD_SCSI_EXEC << 24;
    int rc = 0;

    /*
     *      Do the incoming paperwork
     */
    i2o_dev = SCpnt->device->hostdata;

    SCpnt->scsi_done = done;

    if (unlikely(!i2o_dev)) {
        osm_warn("no I2O device in request\n");
        SCpnt->result = DID_NO_CONNECT << 16;
        done(SCpnt);
        goto exit;
    }
    c = i2o_dev->iop;
    tid = i2o_dev->lct_data.tid;

    osm_debug("qcmd: Tid = %03x\n", tid);
    osm_debug("Real scsi messages.\n");

    /*
     *      Put together a scsi execscb message
     */
    switch (SCpnt->sc_data_direction) {
    case PCI_DMA_NONE:
        /* DATA NO XFER */
        sgl_offset = SGL_OFFSET_0;
        break;

    case PCI_DMA_TODEVICE:
        /* DATA OUT (iop-->dev) */
        scsi_flags |= 0x80000000;
        sgl_offset = SGL_OFFSET_10;
        break;

    case PCI_DMA_FROMDEVICE:
        /* DATA IN  (iop<--dev) */
        scsi_flags |= 0x40000000;
        sgl_offset = SGL_OFFSET_10;
        break;

    default:
        /* Unknown - kill the command */
        SCpnt->result = DID_NO_CONNECT << 16;
        done(SCpnt);
        goto exit;
    }

    /*
     *      Obtain an I2O message. If there are none free then
     *      throw it back to the scsi layer
     */

    msg = i2o_msg_get(c);
    if (IS_ERR(msg)) {
        rc = SCSI_MLQUEUE_HOST_BUSY;
        goto exit;
    }

    mptr = &msg->body[0];

#if 0 /* this code can't work */
#ifdef CONFIG_I2O_EXT_ADAPTEC
    if (c->adaptec) {
        u32 adpt_flags = 0;

        if (SCpnt->sc_request && SCpnt->sc_request->upper_private_data) {
            i2o_sg_io_hdr_t __user *usr_ptr =
                ((Sg_request *) (SCpnt->sc_request->
                         upper_private_data))->header.
                usr_ptr;

            if (usr_ptr)
                get_user(adpt_flags, &usr_ptr->flags);
        }

        switch (i2o_dev->lct_data.class_id) {
        case I2O_CLASS_EXECUTIVE:
        case I2O_CLASS_RANDOM_BLOCK_STORAGE:
            /* interpret flag has to be set for executive */
            adpt_flags ^= I2O_DPT_SG_FLAG_INTERPRET;
            break;

        default:
            break;
        }

        /*
         * for Adaptec controllers we use the PRIVATE command, because
         * the normal SCSI EXEC doesn't support all SCSI commands on
         * all controllers (for example READ CAPACITY).
         */
        if (sgl_offset == SGL_OFFSET_10)
            sgl_offset = SGL_OFFSET_12;
        cmd = I2O_CMD_PRIVATE << 24;
        *mptr++ = cpu_to_le32(I2O_VENDOR_DPT << 16 | I2O_CMD_SCSI_EXEC);
        *mptr++ = cpu_to_le32(adpt_flags | tid);
    }
#endif
#endif

    msg->u.head[1] = cpu_to_le32(cmd | HOST_TID << 12 | tid);
    msg->u.s.icntxt = cpu_to_le32(i2o_scsi_driver.context);

    /* We want the SCSI control block back */
    msg->u.s.tcntxt = cpu_to_le32(i2o_cntxt_list_add(c, SCpnt));

    /* LSI_920_PCI_QUIRK
     *
     *      Intermittant observations of msg frame word data corruption
     *      observed on msg[4] after:
     *        WRITE, READ-MODIFY-WRITE
     *      operations.  19990606 -sralston
     *
     *      (Hence we build this word via tag. Its good practice anyway
     *       we don't want fetches over PCI needlessly)
     */

    /* Attach tags to the devices */
    /* FIXME: implement
       if(SCpnt->device->tagged_supported) {
       if(SCpnt->tag == HEAD_OF_QUEUE_TAG)
       scsi_flags |= 0x01000000;
       else if(SCpnt->tag == ORDERED_QUEUE_TAG)
       scsi_flags |= 0x01800000;
       }
     */

    *mptr++ = cpu_to_le32(scsi_flags | SCpnt->cmd_len);

    /* Write SCSI command into the message - always 16 byte block */
    memcpy(mptr, SCpnt->cmnd, 16);
    mptr += 4;

    if (sgl_offset != SGL_OFFSET_0) {
        /* write size of data addressed by SGL */
        *mptr++ = cpu_to_le32(scsi_bufflen(SCpnt));

        /* Now fill in the SGList and command */

        if (scsi_sg_count(SCpnt)) {
            if (!i2o_dma_map_sg(c, scsi_sglist(SCpnt),
                        scsi_sg_count(SCpnt),
                        SCpnt->sc_data_direction, &mptr))
                goto nomem;
        }
    }

    /* Stick the headers on */
    msg->u.head[0] =
        cpu_to_le32(I2O_MESSAGE_SIZE(mptr - &msg->u.head[0]) | sgl_offset);

    /* Queue the message */
    i2o_msg_post(c, msg);

    osm_debug("Issued %0x%p\n", SCpnt);

    return 0;

      nomem:
    rc = -ENOMEM;
    i2o_msg_nop(c, msg);

      exit:
    return rc;
}

static DEF_SCSI_QCMD(i2o_scsi_queuecommand)


static int i2o_scsi_abort(struct scsi_cmnd *SCpnt)
{
    struct i2o_device *i2o_dev;
    struct i2o_controller *c;
    struct i2o_message *msg;
    int tid;
    int status = FAILED;

    osm_warn("Aborting command block.\n");

    i2o_dev = SCpnt->device->hostdata;
    c = i2o_dev->iop;
    tid = i2o_dev->lct_data.tid;

    msg = i2o_msg_get_wait(c, I2O_TIMEOUT_MESSAGE_GET);
    if (IS_ERR(msg))
        return SCSI_MLQUEUE_HOST_BUSY;

    msg->u.head[0] = cpu_to_le32(FIVE_WORD_MSG_SIZE | SGL_OFFSET_0);
    msg->u.head[1] =
        cpu_to_le32(I2O_CMD_SCSI_ABORT << 24 | HOST_TID << 12 | tid);
    msg->body[0] = cpu_to_le32(i2o_cntxt_list_get_ptr(c, SCpnt));

    if (!i2o_msg_post_wait(c, msg, I2O_TIMEOUT_SCSI_SCB_ABORT))
        status = SUCCESS;

    return status;
}

static int i2o_scsi_bios_param(struct scsi_device *sdev,
                   struct block_device *dev, sector_t capacity,
                   int *ip)
{
    int size;

    size = capacity;
    ip[0] = 64;     /* heads                        */
    ip[1] = 32;     /* sectors                      */
    if ((ip[2] = size >> 11) > 1024) {  /* cylinders, test for big disk */
        ip[0] = 255;    /* heads                        */
        ip[1] = 63; /* sectors                      */
        ip[2] = size / (255 * 63);  /* cylinders                    */
    }
    return 0;
}

static struct scsi_host_template i2o_scsi_host_template = {
    .proc_name = OSM_NAME,
    .name = OSM_DESCRIPTION,
    .info = i2o_scsi_info,
    .queuecommand = i2o_scsi_queuecommand,
    .eh_abort_handler = i2o_scsi_abort,
    .bios_param = i2o_scsi_bios_param,
    .can_queue = I2O_SCSI_CAN_QUEUE,
    .sg_tablesize = 8,
    .cmd_per_lun = 6,
    .use_clustering = ENABLE_CLUSTERING,
};

static int __init i2o_scsi_init(void)
{
    int rc;

    printk(KERN_INFO OSM_DESCRIPTION " v" OSM_VERSION "\n");

    /* Register SCSI OSM into I2O core */
    rc = i2o_driver_register(&i2o_scsi_driver);
    if (rc) {
        osm_err("Could not register SCSI driver\n");
        return rc;
    }

    return 0;
};

static void __exit i2o_scsi_exit(void)
{
    /* Unregister I2O SCSI OSM from I2O core */
    i2o_driver_unregister(&i2o_scsi_driver);
};

MODULE_AUTHOR("Red Hat Software");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION(OSM_DESCRIPTION);
MODULE_VERSION(OSM_VERSION);

module_init(i2o_scsi_init);
module_exit(i2o_scsi_exit);