[PATCH] I2O: Clean up some pretty bad driver model abuses in the i2o code

[linux-2.6/linux-loongson.git] / drivers / message / i2o / iop.c

/*
 *      Functions to handle I2O controllers and I2O message handling
 *
 *      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.
 *
 *      A lot of the I2O message side code from this is taken from the
 *      Red Creek RCPCI45 adapter driver by Red Creek Communications
 *
 *      Fixes/additions:
 *              Philipp Rumpf
 *              Juha Sievänen <Juha.Sievanen@cs.Helsinki.FI>
 *              Auvo Häkkinen <Auvo.Hakkinen@cs.Helsinki.FI>
 *              Deepak Saxena <deepak@plexity.net>
 *              Boji T Kannanthanam <boji.t.kannanthanam@intel.com>
 *              Alan Cox <alan@redhat.com>:
 *                      Ported to Linux 2.5.
 *              Markus Lidel <Markus.Lidel@shadowconnect.com>:
 *                      Minor fixes for 2.6.
 */

#include <linux/module.h>
#include <linux/i2o.h>
#include <linux/delay.h>
#include "core.h"

#define OSM_NAME        "i2o"
#define OSM_VERSION     "1.288"
#define OSM_DESCRIPTION "I2O subsystem"

/* global I2O controller list */
LIST_HEAD(i2o_controllers);

/*
 * global I2O System Table. Contains information about all the IOPs in the
 * system. Used to inform IOPs about each others existence.
 */
static struct i2o_dma i2o_systab;

static int i2o_hrt_get(struct i2o_controller *c);

/**
 *      i2o_msg_nop - Returns a message which is not used
 *      @c: I2O controller from which the message was created
 *      @m: message which should be returned
 *
 *      If you fetch a message via i2o_msg_get, and can't use it, you must
 *      return the message with this function. Otherwise the message frame
 *      is lost.
 */
void i2o_msg_nop(struct i2o_controller *c, u32 m)
{
        struct i2o_message __iomem *msg = i2o_msg_in_to_virt(c, m);

        writel(THREE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
        writel(I2O_CMD_UTIL_NOP << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);
        writel(0, &msg->u.head[2]);
        writel(0, &msg->u.head[3]);
        i2o_msg_post(c, m);
};

/**
 *      i2o_msg_get_wait - obtain an I2O message from the IOP
 *      @c: I2O controller
 *      @msg: pointer to a I2O message pointer
 *      @wait: how long to wait until timeout
 *
 *      This function waits up to wait seconds for a message slot to be
 *      available.
 *
 *      On a success the message is returned and the pointer to the message is
 *      set in msg. The returned message is the physical page frame offset
 *      address from the read port (see the i2o spec). If no message is
 *      available returns I2O_QUEUE_EMPTY and msg is leaved untouched.
 */
u32 i2o_msg_get_wait(struct i2o_controller *c,
                     struct i2o_message __iomem ** msg, int wait)
{
        unsigned long timeout = jiffies + wait * HZ;
        u32 m;

        while ((m = i2o_msg_get(c, msg)) == I2O_QUEUE_EMPTY) {
                if (time_after(jiffies, timeout)) {
                        osm_debug("%s: Timeout waiting for message frame.\n",
                                  c->name);
                        return I2O_QUEUE_EMPTY;
                }
                set_current_state(TASK_UNINTERRUPTIBLE);
                schedule_timeout(1);
        }

        return m;
};

#if BITS_PER_LONG == 64
/**
 *      i2o_cntxt_list_add - Append a pointer to context list and return a id
 *      @c: controller to which the context list belong
 *      @ptr: pointer to add to the context list
 *
 *      Because the context field in I2O is only 32-bit large, on 64-bit the
 *      pointer is to large to fit in the context field. The i2o_cntxt_list
 *      functions therefore map pointers to context fields.
 *
 *      Returns context id > 0 on success or 0 on failure.
 */
u32 i2o_cntxt_list_add(struct i2o_controller * c, void *ptr)
{
        struct i2o_context_list_element *entry;
        unsigned long flags;

        if (!ptr)
                osm_err("%s: couldn't add NULL pointer to context list!\n",
                        c->name);

        entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
        if (!entry) {
                osm_err("%s: Could not allocate memory for context list element"
                        "\n", c->name);
                return 0;
        }

        entry->ptr = ptr;
        entry->timestamp = jiffies;
        INIT_LIST_HEAD(&entry->list);

        spin_lock_irqsave(&c->context_list_lock, flags);

        if (unlikely(atomic_inc_and_test(&c->context_list_counter)))
                atomic_inc(&c->context_list_counter);

        entry->context = atomic_read(&c->context_list_counter);

        list_add(&entry->list, &c->context_list);

        spin_unlock_irqrestore(&c->context_list_lock, flags);

        osm_debug("%s: Add context to list %p -> %d\n", c->name, ptr, context);

        return entry->context;
};

/**
 *      i2o_cntxt_list_remove - Remove a pointer from the context list
 *      @c: controller to which the context list belong
 *      @ptr: pointer which should be removed from the context list
 *
 *      Removes a previously added pointer from the context list and returns
 *      the matching context id.
 *
 *      Returns context id on succes or 0 on failure.
 */
u32 i2o_cntxt_list_remove(struct i2o_controller * c, void *ptr)
{
        struct i2o_context_list_element *entry;
        u32 context = 0;
        unsigned long flags;

        spin_lock_irqsave(&c->context_list_lock, flags);
        list_for_each_entry(entry, &c->context_list, list)
            if (entry->ptr == ptr) {
                list_del(&entry->list);
                context = entry->context;
                kfree(entry);
                break;
        }
        spin_unlock_irqrestore(&c->context_list_lock, flags);

        if (!context)
                osm_warn("%s: Could not remove nonexistent ptr %p\n", c->name,
                         ptr);

        osm_debug("%s: remove ptr from context list %d -> %p\n", c->name,
                  context, ptr);

        return context;
};

/**
 *      i2o_cntxt_list_get - Get a pointer from the context list and remove it
 *      @c: controller to which the context list belong
 *      @context: context id to which the pointer belong
 *
 *      Returns pointer to the matching context id on success or NULL on
 *      failure.
 */
void *i2o_cntxt_list_get(struct i2o_controller *c, u32 context)
{
        struct i2o_context_list_element *entry;
        unsigned long flags;
        void *ptr = NULL;

        spin_lock_irqsave(&c->context_list_lock, flags);
        list_for_each_entry(entry, &c->context_list, list)
            if (entry->context == context) {
                list_del(&entry->list);
                ptr = entry->ptr;
                kfree(entry);
                break;
        }
        spin_unlock_irqrestore(&c->context_list_lock, flags);

        if (!ptr)
                osm_warn("%s: context id %d not found\n", c->name, context);

        osm_debug("%s: get ptr from context list %d -> %p\n", c->name, context,
                  ptr);

        return ptr;
};

/**
 *      i2o_cntxt_list_get_ptr - Get a context id from the context list
 *      @c: controller to which the context list belong
 *      @ptr: pointer to which the context id should be fetched
 *
 *      Returns context id which matches to the pointer on succes or 0 on
 *      failure.
 */
u32 i2o_cntxt_list_get_ptr(struct i2o_controller * c, void *ptr)
{
        struct i2o_context_list_element *entry;
        u32 context = 0;
        unsigned long flags;

        spin_lock_irqsave(&c->context_list_lock, flags);
        list_for_each_entry(entry, &c->context_list, list)
            if (entry->ptr == ptr) {
                context = entry->context;
                break;
        }
        spin_unlock_irqrestore(&c->context_list_lock, flags);

        if (!context)
                osm_warn("%s: Could not find nonexistent ptr %p\n", c->name,
                         ptr);

        osm_debug("%s: get context id from context list %p -> %d\n", c->name,
                  ptr, context);

        return context;
};
#endif

/**
 *      i2o_iop_find - Find an I2O controller by id
 *      @unit: unit number of the I2O controller to search for
 *
 *      Lookup the I2O controller on the controller list.
 *
 *      Returns pointer to the I2O controller on success or NULL if not found.
 */
struct i2o_controller *i2o_find_iop(int unit)
{
        struct i2o_controller *c;

        list_for_each_entry(c, &i2o_controllers, list) {
                if (c->unit == unit)
                        return c;
        }

        return NULL;
};

/**
 *      i2o_iop_find_device - Find a I2O device on an I2O controller
 *      @c: I2O controller where the I2O device hangs on
 *      @tid: TID of the I2O device to search for
 *
 *      Searches the devices of the I2O controller for a device with TID tid and
 *      returns it.
 *
 *      Returns a pointer to the I2O device if found, otherwise NULL.
 */
struct i2o_device *i2o_iop_find_device(struct i2o_controller *c, u16 tid)
{
        struct i2o_device *dev;

        list_for_each_entry(dev, &c->devices, list)
            if (dev->lct_data.tid == tid)
                return dev;

        return NULL;
};

/**
 *      i2o_quiesce_controller - quiesce controller
 *      @c: controller
 *
 *      Quiesce an IOP. Causes IOP to make external operation quiescent
 *      (i2o 'READY' state). Internal operation of the IOP continues normally.
 *
 *      Returns 0 on success or negative error code on failure.
 */
static int i2o_iop_quiesce(struct i2o_controller *c)
{
        struct i2o_message __iomem *msg;
        u32 m;
        i2o_status_block *sb = c->status_block.virt;
        int rc;

        i2o_status_get(c);

        /* SysQuiesce discarded if IOP not in READY or OPERATIONAL state */
        if ((sb->iop_state != ADAPTER_STATE_READY) &&
            (sb->iop_state != ADAPTER_STATE_OPERATIONAL))
                return 0;

        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_SYS_QUIESCE << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);

        /* Long timeout needed for quiesce if lots of devices */
        if ((rc = i2o_msg_post_wait(c, m, 240)))
                osm_info("%s: Unable to quiesce (status=%#x).\n", c->name, -rc);
        else
                osm_debug("%s: Quiesced.\n", c->name);

        i2o_status_get(c);      // Entered READY state

        return rc;
};

/**
 *      i2o_iop_enable - move controller from ready to OPERATIONAL
 *      @c: I2O controller
 *
 *      Enable IOP. This allows the IOP to resume external operations and
 *      reverses the effect of a quiesce. Returns zero or an error code if
 *      an error occurs.
 */
static int i2o_iop_enable(struct i2o_controller *c)
{
        struct i2o_message __iomem *msg;
        u32 m;
        i2o_status_block *sb = c->status_block.virt;
        int rc;

        i2o_status_get(c);

        /* Enable only allowed on READY state */
        if (sb->iop_state != ADAPTER_STATE_READY)
                return -EINVAL;

        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_SYS_ENABLE << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);

        /* How long of a timeout do we need? */
        if ((rc = i2o_msg_post_wait(c, m, 240)))
                osm_err("%s: Could not enable (status=%#x).\n", c->name, -rc);
        else
                osm_debug("%s: Enabled.\n", c->name);

        i2o_status_get(c);      // entered OPERATIONAL state

        return rc;
};

/**
 *      i2o_iop_quiesce_all - Quiesce all I2O controllers on the system
 *
 *      Quiesce all I2O controllers which are connected to the system.
 */
static inline void i2o_iop_quiesce_all(void)
{
        struct i2o_controller *c, *tmp;

        list_for_each_entry_safe(c, tmp, &i2o_controllers, list) {
                if (!c->no_quiesce)
                        i2o_iop_quiesce(c);
        }
};

/**
 *      i2o_iop_enable_all - Enables all controllers on the system
 *
 *      Enables all I2O controllers which are connected to the system.
 */
static inline void i2o_iop_enable_all(void)
{
        struct i2o_controller *c, *tmp;

        list_for_each_entry_safe(c, tmp, &i2o_controllers, list)
            i2o_iop_enable(c);
};

/**
 *      i2o_clear_controller - Bring I2O controller into HOLD state
 *      @c: controller
 *
 *      Clear an IOP to HOLD state, ie. terminate external operations, clear all
 *      input queues and prepare for a system restart. IOP's internal operation
 *      continues normally and the outbound queue is alive. The IOP is not
 *      expected to rebuild its LCT.
 *
 *      Returns 0 on success or negative error code on failure.
 */
static int i2o_iop_clear(struct i2o_controller *c)
{
        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;

        /* Quiesce all IOPs first */
        i2o_iop_quiesce_all();

        writel(FOUR_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
        writel(I2O_CMD_ADAPTER_CLEAR << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);

        if ((rc = i2o_msg_post_wait(c, m, 30)))
                osm_info("%s: Unable to clear (status=%#x).\n", c->name, -rc);
        else
                osm_debug("%s: Cleared.\n", c->name);

        /* Enable all IOPs */
        i2o_iop_enable_all();

        return rc;
}

/**
 *      i2o_iop_init_outbound_queue - setup the outbound message queue
 *      @c: I2O controller
 *
 *      Clear and (re)initialize IOP's outbound queue and post the message
 *      frames to the IOP.
 *
 *      Returns 0 on success or a negative errno code on failure.
 */
static int i2o_iop_init_outbound_queue(struct i2o_controller *c)
{
        volatile u8 *status = c->status.virt;
        u32 m;
        struct i2o_message __iomem *msg;
        ulong timeout;
        int i;

        osm_debug("%s: Initializing Outbound Queue...\n", c->name);

        memset(c->status.virt, 0, 4);

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

        writel(EIGHT_WORD_MSG_SIZE | SGL_OFFSET_6, &msg->u.head[0]);
        writel(I2O_CMD_OUTBOUND_INIT << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);
        writel(i2o_exec_driver.context, &msg->u.s.icntxt);
        writel(0x00000000, &msg->u.s.tcntxt);
        writel(PAGE_SIZE, &msg->body[0]);
        /* Outbound msg frame size in words and Initcode */
        writel(I2O_OUTBOUND_MSG_FRAME_SIZE << 16 | 0x80, &msg->body[1]);
        writel(0xd0000004, &msg->body[2]);
        writel(i2o_dma_low(c->status.phys), &msg->body[3]);
        writel(i2o_dma_high(c->status.phys), &msg->body[4]);

        i2o_msg_post(c, m);

        timeout = jiffies + I2O_TIMEOUT_INIT_OUTBOUND_QUEUE * HZ;
        while (*status <= I2O_CMD_IN_PROGRESS) {
                if (time_after(jiffies, timeout)) {
                        osm_warn("%s: Timeout Initializing\n", c->name);
                        return -ETIMEDOUT;
                }
                set_current_state(TASK_UNINTERRUPTIBLE);
                schedule_timeout(1);
        }

        m = c->out_queue.phys;

        /* Post frames */
        for (i = 0; i < I2O_MAX_OUTBOUND_MSG_FRAMES; i++) {
                i2o_flush_reply(c, m);
                udelay(1);      /* Promise */
                m += I2O_OUTBOUND_MSG_FRAME_SIZE * sizeof(u32);
        }

        return 0;
}

/**
 *      i2o_iop_reset - reset an I2O controller
 *      @c: controller to reset
 *
 *      Reset the IOP into INIT state and wait until IOP gets into RESET state.
 *      Terminate all external operations, clear IOP's inbound and outbound
 *      queues, terminate all DDMs, and reload the IOP's operating environment
 *      and all local DDMs. The IOP rebuilds its LCT.
 */
static int i2o_iop_reset(struct i2o_controller *c)
{
        volatile u8 *status = c->status.virt;
        struct i2o_message __iomem *msg;
        u32 m;
        unsigned long timeout;
        i2o_status_block *sb = c->status_block.virt;
        int rc = 0;

        osm_debug("%s: Resetting controller\n", c->name);

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

        memset(c->status_block.virt, 0, 8);

        /* Quiesce all IOPs first */
        i2o_iop_quiesce_all();

        writel(EIGHT_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
        writel(I2O_CMD_ADAPTER_RESET << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);
        writel(i2o_exec_driver.context, &msg->u.s.icntxt);
        writel(0, &msg->u.s.tcntxt);    //FIXME: use reasonable transaction context
        writel(0, &msg->body[0]);
        writel(0, &msg->body[1]);
        writel(i2o_dma_low(c->status.phys), &msg->body[2]);
        writel(i2o_dma_high(c->status.phys), &msg->body[3]);

        i2o_msg_post(c, m);

        /* Wait for a reply */
        timeout = jiffies + I2O_TIMEOUT_RESET * HZ;
        while (!*status) {
                if (time_after(jiffies, timeout))
                        break;

                set_current_state(TASK_UNINTERRUPTIBLE);
                schedule_timeout(1);
        }

        switch (*status) {
        case I2O_CMD_REJECTED:
                osm_warn("%s: IOP reset rejected\n", c->name);
                rc = -EPERM;
                break;

        case I2O_CMD_IN_PROGRESS:
                /*
                 * Once the reset is sent, the IOP goes into the INIT state
                 * which is indeterminate. We need to wait until the IOP has
                 * rebooted before we can let the system talk to it. We read
                 * the inbound Free_List until a message is available. If we
                 * can't read one in the given ammount of time, we assume the
                 * IOP could not reboot properly.
                 */
                osm_debug("%s: Reset in progress, waiting for reboot...\n",
                          c->name);

                m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_RESET);
                while (m == I2O_QUEUE_EMPTY) {
                        if (time_after(jiffies, timeout)) {
                                osm_err("%s: IOP reset timeout.\n", c->name);
                                rc = -ETIMEDOUT;
                                goto exit;
                        }
                        set_current_state(TASK_UNINTERRUPTIBLE);
                        schedule_timeout(1);

                        m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_RESET);
                }
                i2o_msg_nop(c, m);

                /* from here all quiesce commands are safe */
                c->no_quiesce = 0;

                /* verify if controller is in state RESET */
                i2o_status_get(c);

                if (!c->promise && (sb->iop_state != ADAPTER_STATE_RESET))
                        osm_warn("%s: reset completed, but adapter not in RESET"
                                 " state.\n", c->name);
                else
                        osm_debug("%s: reset completed.\n", c->name);

                break;

        default:
                osm_err("%s: IOP reset timeout.\n", c->name);
                rc = -ETIMEDOUT;
                break;
        }

      exit:
        /* Enable all IOPs */
        i2o_iop_enable_all();

        return rc;
};

/**
 *      i2o_iop_activate - Bring controller up to HOLD
 *      @c: controller
 *
 *      This function brings an I2O controller into HOLD state. The adapter
 *      is reset if necessary and then the queues and resource table are read.
 *
 *      Returns 0 on success or negative error code on failure.
 */
static int i2o_iop_activate(struct i2o_controller *c)
{
        i2o_status_block *sb = c->status_block.virt;
        int rc;
        int state;

        /* In INIT state, Wait Inbound Q to initialize (in i2o_status_get) */
        /* In READY state, Get status */

        rc = i2o_status_get(c);
        if (rc) {
                osm_info("%s: Unable to obtain status, attempting a reset.\n",
                         c->name);
                rc = i2o_iop_reset(c);
                if (rc)
                        return rc;
        }

        if (sb->i2o_version > I2OVER15) {
                osm_err("%s: Not running version 1.5 of the I2O Specification."
                        "\n", c->name);
                return -ENODEV;
        }

        switch (sb->iop_state) {
        case ADAPTER_STATE_FAULTED:
                osm_err("%s: hardware fault\n", c->name);
                return -EFAULT;

        case ADAPTER_STATE_READY:
        case ADAPTER_STATE_OPERATIONAL:
        case ADAPTER_STATE_HOLD:
        case ADAPTER_STATE_FAILED:
                osm_debug("%s: already running, trying to reset...\n", c->name);
                rc = i2o_iop_reset(c);
                if (rc)
                        return rc;
        }

        /* preserve state */
        state = sb->iop_state;

        rc = i2o_iop_init_outbound_queue(c);
        if (rc)
                return rc;

        /* if adapter was not in RESET state clear now */
        if (state != ADAPTER_STATE_RESET)
                i2o_iop_clear(c);

        i2o_status_get(c);

        if (sb->iop_state != ADAPTER_STATE_HOLD) {
                osm_err("%s: failed to bring IOP into HOLD state\n", c->name);
                return -EIO;
        }

        return i2o_hrt_get(c);
};

/**
 *      i2o_iop_systab_set - Set the I2O System Table of the specified IOP
 *      @c: I2O controller to which the system table should be send
 *
 *      Before the systab could be set i2o_systab_build() must be called.
 *
 *      Returns 0 on success or negative error code on failure.
 */
static int i2o_iop_systab_set(struct i2o_controller *c)
{
        struct i2o_message __iomem *msg;
        u32 m;
        i2o_status_block *sb = c->status_block.virt;
        struct device *dev = &c->pdev->dev;
        struct resource *root;
        int rc;

        if (sb->current_mem_size < sb->desired_mem_size) {
                struct resource *res = &c->mem_resource;
                res->name = c->pdev->bus->name;
                res->flags = IORESOURCE_MEM;
                res->start = 0;
                res->end = 0;
                osm_info("%s: requires private memory resources.\n", c->name);
                root = pci_find_parent_resource(c->pdev, res);
                if (root == NULL)
                        osm_warn("%s: Can't find parent resource!\n", c->name);
                if (root && allocate_resource(root, res, sb->desired_mem_size, sb->desired_mem_size, sb->desired_mem_size, 1 << 20,     /* Unspecified, so use 1Mb and play safe */
                                              NULL, NULL) >= 0) {
                        c->mem_alloc = 1;
                        sb->current_mem_size = 1 + res->end - res->start;
                        sb->current_mem_base = res->start;
                        osm_info("%s: allocated %ld bytes of PCI memory at "
                                 "0x%08lX.\n", c->name,
                                 1 + res->end - res->start, res->start);
                }
        }

        if (sb->current_io_size < sb->desired_io_size) {
                struct resource *res = &c->io_resource;
                res->name = c->pdev->bus->name;
                res->flags = IORESOURCE_IO;
                res->start = 0;
                res->end = 0;
                osm_info("%s: requires private memory resources.\n", c->name);
                root = pci_find_parent_resource(c->pdev, res);
                if (root == NULL)
                        osm_warn("%s: Can't find parent resource!\n", c->name);
                if (root && allocate_resource(root, res, sb->desired_io_size, sb->desired_io_size, sb->desired_io_size, 1 << 20,        /* Unspecified, so use 1Mb and play safe */
                                              NULL, NULL) >= 0) {
                        c->io_alloc = 1;
                        sb->current_io_size = 1 + res->end - res->start;
                        sb->current_mem_base = res->start;
                        osm_info("%s: allocated %ld bytes of PCI I/O at 0x%08lX"
                                 ".\n", c->name, 1 + res->end - res->start,
                                 res->start);
                }
        }

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

        i2o_systab.phys = dma_map_single(dev, i2o_systab.virt, i2o_systab.len,
                                         PCI_DMA_TODEVICE);
        if (!i2o_systab.phys) {
                i2o_msg_nop(c, m);
                return -ENOMEM;
        }

        writel(I2O_MESSAGE_SIZE(12) | SGL_OFFSET_6, &msg->u.head[0]);
        writel(I2O_CMD_SYS_TAB_SET << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);

        /*
         * Provide three SGL-elements:
         * System table (SysTab), Private memory space declaration and
         * Private i/o space declaration
         *
         * FIXME: is this still true?
         * Nasty one here. We can't use dma_alloc_coherent to send the
         * same table to everyone. We have to go remap it for them all
         */

        writel(c->unit + 2, &msg->body[0]);
        writel(0, &msg->body[1]);
        writel(0x54000000 | i2o_systab.len, &msg->body[2]);
        writel(i2o_systab.phys, &msg->body[3]);
        writel(0x54000000 | sb->current_mem_size, &msg->body[4]);
        writel(sb->current_mem_base, &msg->body[5]);
        writel(0xd4000000 | sb->current_io_size, &msg->body[6]);
        writel(sb->current_io_base, &msg->body[6]);

        rc = i2o_msg_post_wait(c, m, 120);

        dma_unmap_single(dev, i2o_systab.phys, i2o_systab.len,
                         PCI_DMA_TODEVICE);

        if (rc < 0)
                osm_err("%s: Unable to set SysTab (status=%#x).\n", c->name,
                        -rc);
        else
                osm_debug("%s: SysTab set.\n", c->name);

        i2o_status_get(c);      // Entered READY state

        return rc;
}

/**
 *      i2o_iop_online - Bring a controller online into OPERATIONAL state.
 *      @c: I2O controller
 *
 *      Send the system table and enable the I2O controller.
 *
 *      Returns 0 on success or negativer error code on failure.
 */
static int i2o_iop_online(struct i2o_controller *c)
{
        int rc;

        rc = i2o_iop_systab_set(c);
        if (rc)
                return rc;

        /* In READY state */
        osm_debug("%s: Attempting to enable...\n", c->name);
        rc = i2o_iop_enable(c);
        if (rc)
                return rc;

        return 0;
};

/**
 *      i2o_iop_remove - Remove the I2O controller from the I2O core
 *      @c: I2O controller
 *
 *      Remove the I2O controller from the I2O core. If devices are attached to
 *      the controller remove these also and finally reset the controller.
 */
void i2o_iop_remove(struct i2o_controller *c)
{
        struct i2o_device *dev, *tmp;

        osm_debug("%s: deleting controller\n", c->name);

        i2o_driver_notify_controller_remove_all(c);

        list_del(&c->list);

        list_for_each_entry_safe(dev, tmp, &c->devices, list)
            i2o_device_remove(dev);

        class_device_unregister(c->classdev);
        device_del(&c->device);

        /* Ask the IOP to switch to RESET state */
        i2o_iop_reset(c);

        put_device(&c->device);
}

/**
 *      i2o_systab_build - Build system table
 *
 *      The system table contains information about all the IOPs in the system
 *      (duh) and is used by the Executives on the IOPs to establish peer2peer
 *      connections. We're not supporting peer2peer at the moment, but this
 *      will be needed down the road for things like lan2lan forwarding.
 *
 *      Returns 0 on success or negative error code on failure.
 */
static int i2o_systab_build(void)
{
        struct i2o_controller *c, *tmp;
        int num_controllers = 0;
        u32 change_ind = 0;
        int count = 0;
        struct i2o_sys_tbl *systab = i2o_systab.virt;

        list_for_each_entry_safe(c, tmp, &i2o_controllers, list)
            num_controllers++;

        if (systab) {
                change_ind = systab->change_ind;
                kfree(i2o_systab.virt);
        }

        /* Header + IOPs */
        i2o_systab.len = sizeof(struct i2o_sys_tbl) + num_controllers *
            sizeof(struct i2o_sys_tbl_entry);

        systab = i2o_systab.virt = kmalloc(i2o_systab.len, GFP_KERNEL);
        if (!systab) {
                osm_err("unable to allocate memory for System Table\n");
                return -ENOMEM;
        }
        memset(systab, 0, i2o_systab.len);

        systab->version = I2OVERSION;
        systab->change_ind = change_ind + 1;

        list_for_each_entry_safe(c, tmp, &i2o_controllers, list) {
                i2o_status_block *sb;

                if (count >= num_controllers) {
                        osm_err("controller added while building system table"
                                "\n");
                        break;
                }

                sb = c->status_block.virt;

                /*
                 * Get updated IOP state so we have the latest information
                 *
                 * We should delete the controller at this point if it
                 * doesn't respond since if it's not on the system table
                 * it is techninically not part of the I2O subsystem...
                 */
                if (unlikely(i2o_status_get(c))) {
                        osm_err("%s: Deleting b/c could not get status while "
                                "attempting to build system table\n", c->name);
                        i2o_iop_remove(c);
                        continue;       // try the next one
                }

                systab->iops[count].org_id = sb->org_id;
                systab->iops[count].iop_id = c->unit + 2;
                systab->iops[count].seg_num = 0;
                systab->iops[count].i2o_version = sb->i2o_version;
                systab->iops[count].iop_state = sb->iop_state;
                systab->iops[count].msg_type = sb->msg_type;
                systab->iops[count].frame_size = sb->inbound_frame_size;
                systab->iops[count].last_changed = change_ind;
                systab->iops[count].iop_capabilities = sb->iop_capabilities;
                systab->iops[count].inbound_low =
                    i2o_dma_low(c->base.phys + I2O_IN_PORT);
                systab->iops[count].inbound_high =
                    i2o_dma_high(c->base.phys + I2O_IN_PORT);

                count++;
        }

        systab->num_entries = count;

        return 0;
};

/**
 *      i2o_parse_hrt - Parse the hardware resource table.
 *      @c: I2O controller
 *
 *      We don't do anything with it except dumping it (in debug mode).
 *
 *      Returns 0.
 */
static int i2o_parse_hrt(struct i2o_controller *c)
{
        i2o_dump_hrt(c);
        return 0;
};

/**
 *      i2o_status_get - Get the status block from the I2O controller
 *      @c: I2O controller
 *
 *      Issue a status query on the controller. This updates the attached
 *      status block. The status block could then be accessed through
 *      c->status_block.
 *
 *      Returns 0 on sucess or negative error code on failure.
 */
int i2o_status_get(struct i2o_controller *c)
{
        struct i2o_message __iomem *msg;
        u32 m;
        volatile u8 *status_block;
        unsigned long timeout;

        status_block = (u8 *) c->status_block.virt;
        memset(c->status_block.virt, 0, sizeof(i2o_status_block));

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

        writel(NINE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
        writel(I2O_CMD_STATUS_GET << 24 | HOST_TID << 12 | ADAPTER_TID,
               &msg->u.head[1]);
        writel(i2o_exec_driver.context, &msg->u.s.icntxt);
        writel(0, &msg->u.s.tcntxt);    // FIXME: use resonable transaction context
        writel(0, &msg->body[0]);
        writel(0, &msg->body[1]);
        writel(i2o_dma_low(c->status_block.phys), &msg->body[2]);
        writel(i2o_dma_high(c->status_block.phys), &msg->body[3]);
        writel(sizeof(i2o_status_block), &msg->body[4]);        /* always 88 bytes */

        i2o_msg_post(c, m);

        /* Wait for a reply */
        timeout = jiffies + I2O_TIMEOUT_STATUS_GET * HZ;
        while (status_block[87] != 0xFF) {
                if (time_after(jiffies, timeout)) {
                        osm_err("%s: Get status timeout.\n", c->name);
                        return -ETIMEDOUT;
                }

                set_current_state(TASK_UNINTERRUPTIBLE);
                schedule_timeout(1);
        }

#ifdef DEBUG
        i2o_debug_state(c);
#endif

        return 0;
}

/*
 *      i2o_hrt_get - Get the Hardware Resource Table from the I2O controller
 *      @c: I2O controller from which the HRT should be fetched
 *
 *      The HRT contains information about possible hidden devices but is
 *      mostly useless to us.
 *
 *      Returns 0 on success or negativer error code on failure.
 */
static int i2o_hrt_get(struct i2o_controller *c)
{
        int rc;
        int i;
        i2o_hrt *hrt = c->hrt.virt;
        u32 size = sizeof(i2o_hrt);
        struct device *dev = &c->pdev->dev;

        for (i = 0; i < I2O_HRT_GET_TRIES; i++) {
                struct i2o_message __iomem *msg;
                u32 m;

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

                writel(SIX_WORD_MSG_SIZE | SGL_OFFSET_4, &msg->u.head[0]);
                writel(I2O_CMD_HRT_GET << 24 | HOST_TID << 12 | ADAPTER_TID,
                       &msg->u.head[1]);
                writel(0xd0000000 | c->hrt.len, &msg->body[0]);
                writel(c->hrt.phys, &msg->body[1]);

                rc = i2o_msg_post_wait_mem(c, m, 20, &c->hrt);

                if (rc < 0) {
                        osm_err("%s: Unable to get HRT (status=%#x)\n", c->name,
                                -rc);
                        return rc;
                }

                size = hrt->num_entries * hrt->entry_len << 2;
                if (size > c->hrt.len) {
                        if (i2o_dma_realloc(dev, &c->hrt, size, GFP_KERNEL))
                                return -ENOMEM;
                        else
                                hrt = c->hrt.virt;
                } else
                        return i2o_parse_hrt(c);
        }

        osm_err("%s: Unable to get HRT after %d tries, giving up\n", c->name,
                I2O_HRT_GET_TRIES);

        return -EBUSY;
}

/**
 *      i2o_iop_free - Free the i2o_controller struct
 *      @c: I2O controller to free
 */
void i2o_iop_free(struct i2o_controller *c)
{
        kfree(c);
};

/**
 *      i2o_iop_release - release the memory for a I2O controller
 *      @dev: I2O controller which should be released
 *
 *      Release the allocated memory. This function is called if refcount of
 *      device reaches 0 automatically.
 */
static void i2o_iop_release(struct device *dev)
{
        struct i2o_controller *c = to_i2o_controller(dev);

        i2o_iop_free(c);
};

/* I2O controller class */
static struct class *i2o_controller_class;

/**
 *      i2o_iop_alloc - Allocate and initialize a i2o_controller struct
 *
 *      Allocate the necessary memory for a i2o_controller struct and
 *      initialize the lists.
 *
 *      Returns a pointer to the I2O controller or a negative error code on
 *      failure.
 */
struct i2o_controller *i2o_iop_alloc(void)
{
        static int unit = 0;    /* 0 and 1 are NULL IOP and Local Host */
        struct i2o_controller *c;

        c = kmalloc(sizeof(*c), GFP_KERNEL);
        if (!c) {
                osm_err("i2o: Insufficient memory to allocate a I2O controller."
                        "\n");
                return ERR_PTR(-ENOMEM);
        }
        memset(c, 0, sizeof(*c));

        INIT_LIST_HEAD(&c->devices);
        spin_lock_init(&c->lock);
        init_MUTEX(&c->lct_lock);
        c->unit = unit++;
        sprintf(c->name, "iop%d", c->unit);

        device_initialize(&c->device);

        c->device.release = &i2o_iop_release;

        snprintf(c->device.bus_id, BUS_ID_SIZE, "iop%d", c->unit);

#if BITS_PER_LONG == 64
        spin_lock_init(&c->context_list_lock);
        atomic_set(&c->context_list_counter, 0);
        INIT_LIST_HEAD(&c->context_list);
#endif

        return c;
};

/**
 *      i2o_iop_add - Initialize the I2O controller and add him to the I2O core
 *      @c: controller
 *
 *      Initialize the I2O controller and if no error occurs add him to the I2O
 *      core.
 *
 *      Returns 0 on success or negative error code on failure.
 */
int i2o_iop_add(struct i2o_controller *c)
{
        int rc;

        if ((rc = device_add(&c->device))) {
                osm_err("%s: could not add controller\n", c->name);
                goto iop_reset;
        }

        c->classdev = class_device_create(i2o_controller_class, 0,
                        &c->device, "iop%d", c->unit);
        if (IS_ERR(c->classdev)) {
                osm_err("%s: could not add controller class\n", c->name);
                goto device_del;
        }

        osm_info("%s: Activating I2O controller...\n", c->name);
        osm_info("%s: This may take a few minutes if there are many devices\n",
                 c->name);

        if ((rc = i2o_iop_activate(c))) {
                osm_err("%s: could not activate controller\n", c->name);
                goto class_del;
        }

        osm_debug("%s: building sys table...\n", c->name);

        if ((rc = i2o_systab_build()))
                goto class_del;

        osm_debug("%s: online controller...\n", c->name);

        if ((rc = i2o_iop_online(c)))
                goto class_del;

        osm_debug("%s: getting LCT...\n", c->name);

        if ((rc = i2o_exec_lct_get(c)))
                goto class_del;

        list_add(&c->list, &i2o_controllers);

        i2o_driver_notify_controller_add_all(c);

        osm_info("%s: Controller added\n", c->name);

        return 0;

      class_del:
        class_device_unregister(c->classdev);

      device_del:
        device_del(&c->device);

      iop_reset:
        i2o_iop_reset(c);

        return rc;
};

/**
 *      i2o_event_register - Turn on/off event notification for a I2O device
 *      @dev: I2O device which should receive the event registration request
 *      @drv: driver which want to get notified
 *      @tcntxt: transaction context to use with this notifier
 *      @evt_mask: mask of events
 *
 *      Create and posts an event registration message to the task. No reply
 *      is waited for, or expected. If you do not want further notifications,
 *      call the i2o_event_register again with a evt_mask of 0.
 *
 *      Returns 0 on success or -ETIMEDOUT if no message could be fetched for
 *      sending the request.
 */
int i2o_event_register(struct i2o_device *dev, struct i2o_driver *drv,
                       int tcntxt, u32 evt_mask)
{
        struct i2o_controller *c = dev->iop;
        struct i2o_message __iomem *msg;
        u32 m;

        m = i2o_msg_get_wait(c, &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_UTIL_EVT_REGISTER << 24 | HOST_TID << 12 | dev->lct_data.
               tid, &msg->u.head[1]);
        writel(drv->context, &msg->u.s.icntxt);
        writel(tcntxt, &msg->u.s.tcntxt);
        writel(evt_mask, &msg->body[0]);

        i2o_msg_post(c, m);

        return 0;
};

/**
 *      i2o_iop_init - I2O main initialization function
 *
 *      Initialize the I2O drivers (OSM) functions, register the Executive OSM,
 *      initialize the I2O PCI part and finally initialize I2O device stuff.
 *
 *      Returns 0 on success or negative error code on failure.
 */
static int __init i2o_iop_init(void)
{
        int rc = 0;

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

        rc = i2o_device_init();
        if (rc)
                goto exit;

        i2o_controller_class = class_create(THIS_MODULE, "i2o_controller");
        if (IS_ERR(i2o_controller_class)) {
                osm_err("can't register class i2o_controller\n");
                goto device_exit;
        }

        if ((rc = i2o_driver_init()))
                goto class_exit;

        if ((rc = i2o_exec_init()))
                goto driver_exit;

        if ((rc = i2o_pci_init()))
                goto exec_exit;

        return 0;

      exec_exit:
        i2o_exec_exit();

      driver_exit:
        i2o_driver_exit();

      class_exit:
        class_destroy(i2o_controller_class);

      device_exit:
        i2o_device_exit();

      exit:
        return rc;
}

/**
 *      i2o_iop_exit - I2O main exit function
 *
 *      Removes I2O controllers from PCI subsystem and shut down OSMs.
 */
static void __exit i2o_iop_exit(void)
{
        i2o_pci_exit();
        i2o_exec_exit();
        i2o_driver_exit();
        class_destroy(i2o_controller_class);
        i2o_device_exit();
};

module_init(i2o_iop_init);
module_exit(i2o_iop_exit);

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

#if BITS_PER_LONG == 64
EXPORT_SYMBOL(i2o_cntxt_list_add);
EXPORT_SYMBOL(i2o_cntxt_list_get);
EXPORT_SYMBOL(i2o_cntxt_list_remove);
EXPORT_SYMBOL(i2o_cntxt_list_get_ptr);
#endif
EXPORT_SYMBOL(i2o_msg_get_wait);
EXPORT_SYMBOL(i2o_msg_nop);
EXPORT_SYMBOL(i2o_find_iop);
EXPORT_SYMBOL(i2o_iop_find_device);
EXPORT_SYMBOL(i2o_event_register);
EXPORT_SYMBOL(i2o_status_get);
EXPORT_SYMBOL(i2o_controllers);