/*
 *      Functions to handle I2O devices
 *
 *      Copyright (C) 2004      Markus Lidel <Markus.Lidel@shadowconnect.com>
 *
 *      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.
 *
 *      Fixes/additions:
 *              Markus Lidel <Markus.Lidel@shadowconnect.com>
 *                      initial version.
 */

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

/**
 *      i2o_device_issue_claim - claim or release a device
 *      @dev: I2O device to claim or release
 *      @cmd: claim or release command
 *      @type: type of claim
 *
 *      Issue I2O UTIL_CLAIM or UTIL_RELEASE messages. The message to be sent
 *      is set by cmd. dev is the I2O device which should be claim or
 *      released and the type is the claim type (see the I2O spec).
 *
 *      Returs 0 on success or negative error code on failure.
 */
static inline int i2o_device_issue_claim(struct i2o_device *dev, u32 cmd,
                                         u32 type)
{
        struct i2o_message *msg;

        msg = i2o_msg_get_wait(dev->iop, I2O_TIMEOUT_MESSAGE_GET);
        if (IS_ERR(msg))
                return PTR_ERR(msg);

        msg->u.head[0] = cpu_to_le32(FIVE_WORD_MSG_SIZE | SGL_OFFSET_0);
        msg->u.head[1] =
            cpu_to_le32(cmd << 24 | HOST_TID << 12 | dev->lct_data.tid);
        msg->body[0] = cpu_to_le32(type);

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

/**
 *      i2o_device_claim - claim a device for use by an OSM
 *      @dev: I2O device to claim
 *
 *      Do the leg work to assign a device to a given OSM. If the claim succeeds,
 *      the owner is the primary. If the attempt fails a negative errno code
 *      is returned. On success zero is returned.
 */
int i2o_device_claim(struct i2o_device *dev)
{
        int rc = 0;

        mutex_lock(&dev->lock);

        rc = i2o_device_issue_claim(dev, I2O_CMD_UTIL_CLAIM, I2O_CLAIM_PRIMARY);
        if (!rc)
                pr_debug("i2o: claim of device %d succeeded\n",
                         dev->lct_data.tid);
        else
                pr_debug("i2o: claim of device %d failed %d\n",
                         dev->lct_data.tid, rc);

        mutex_unlock(&dev->lock);

        return rc;
}

/**
 *      i2o_device_claim_release - release a device that the OSM is using
 *      @dev: device to release
 *
 *      Drop a claim by an OSM on a given I2O device.
 *
 *      AC - some devices seem to want to refuse an unclaim until they have
 *      finished internal processing. It makes sense since you don't want a
 *      new device to go reconfiguring the entire system until you are done.
 *      Thus we are prepared to wait briefly.
 *
 *      Returns 0 on success or negative error code on failure.
 */
int i2o_device_claim_release(struct i2o_device *dev)
{
        int tries;
        int rc = 0;

        mutex_lock(&dev->lock);

        /*
         *      If the controller takes a nonblocking approach to
         *      releases we have to sleep/poll for a few times.
         */
        for (tries = 0; tries < 10; tries++) {
                rc = i2o_device_issue_claim(dev, I2O_CMD_UTIL_RELEASE,
                                            I2O_CLAIM_PRIMARY);
                if (!rc)
                        break;

                ssleep(1);
        }

        if (!rc)
                pr_debug("i2o: claim release of device %d succeeded\n",
                         dev->lct_data.tid);
        else
                pr_debug("i2o: claim release of device %d failed %d\n",
                         dev->lct_data.tid, rc);

        mutex_unlock(&dev->lock);

        return rc;
}

/**
 *      i2o_device_release - release the memory for a I2O device
 *      @dev: I2O device which should be released
 *
 *      Release the allocated memory. This function is called if refcount of
 *      device reaches 0 automatically.
 */
static void i2o_device_release(struct device *dev)
{
        struct i2o_device *i2o_dev = to_i2o_device(dev);

        pr_debug("i2o: device %s released\n", dev_name(dev));

        kfree(i2o_dev);
}

/**
 *      class_id_show - Displays class id of I2O device
 *      @dev: device of which the class id should be displayed
 *      @attr: pointer to device attribute
 *      @buf: buffer into which the class id should be printed
 *
 *      Returns the number of bytes which are printed into the buffer.
 */
static ssize_t class_id_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
{
        struct i2o_device *i2o_dev = to_i2o_device(dev);

        sprintf(buf, "0x%03x\n", i2o_dev->lct_data.class_id);
        return strlen(buf) + 1;
}
static DEVICE_ATTR_RO(class_id);

/**
 *      tid_show - Displays TID of I2O device
 *      @dev: device of which the TID should be displayed
 *      @attr: pointer to device attribute
 *      @buf: buffer into which the TID should be printed
 *
 *      Returns the number of bytes which are printed into the buffer.
 */
static ssize_t tid_show(struct device *dev, struct device_attribute *attr,
                        char *buf)
{
        struct i2o_device *i2o_dev = to_i2o_device(dev);

        sprintf(buf, "0x%03x\n", i2o_dev->lct_data.tid);
        return strlen(buf) + 1;
}
static DEVICE_ATTR_RO(tid);

/* I2O device attributes */
static struct attribute *i2o_device_attrs[] = {
        &dev_attr_class_id.attr,
        &dev_attr_tid.attr,
        NULL,
};

static const struct attribute_group i2o_device_group = {
        .attrs = i2o_device_attrs,
};

const struct attribute_group *i2o_device_groups[] = {
        &i2o_device_group,
        NULL,
};

/**
 *      i2o_device_alloc - Allocate a I2O device and initialize it
 *
 *      Allocate the memory for a I2O device and initialize locks and lists
 *
 *      Returns the allocated I2O device or a negative error code if the device
 *      could not be allocated.
 */
static struct i2o_device *i2o_device_alloc(void)
{
        struct i2o_device *dev;

        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (!dev)
                return ERR_PTR(-ENOMEM);

        INIT_LIST_HEAD(&dev->list);
        mutex_init(&dev->lock);

        dev->device.bus = &i2o_bus_type;
        dev->device.release = &i2o_device_release;

        return dev;
}

/**
 *      i2o_device_add - allocate a new I2O device and add it to the IOP
 *      @c: I2O controller that the device is on
 *      @entry: LCT entry of the I2O device
 *
 *      Allocate a new I2O device and initialize it with the LCT entry. The
 *      device is appended to the device list of the controller.
 *
 *      Returns zero on success, or a -ve errno.
 */
static int i2o_device_add(struct i2o_controller *c, i2o_lct_entry *entry)
{
        struct i2o_device *i2o_dev, *tmp;
        int rc;

        i2o_dev = i2o_device_alloc();
        if (IS_ERR(i2o_dev)) {
                printk(KERN_ERR "i2o: unable to allocate i2o device\n");
                return PTR_ERR(i2o_dev);
        }

        i2o_dev->lct_data = *entry;

        dev_set_name(&i2o_dev->device, "%d:%03x", c->unit,
                     i2o_dev->lct_data.tid);

        i2o_dev->iop = c;
        i2o_dev->device.parent = &c->device;

        rc = device_register(&i2o_dev->device);
        if (rc)
                goto err;

        list_add_tail(&i2o_dev->list, &c->devices);

        /* create user entries for this device */
        tmp = i2o_iop_find_device(i2o_dev->iop, i2o_dev->lct_data.user_tid);
        if (tmp && (tmp != i2o_dev)) {
                rc = sysfs_create_link(&i2o_dev->device.kobj,
                                       &tmp->device.kobj, "user");
                if (rc)
                        goto unreg_dev;
        }

        /* create user entries referring to this device */
        list_for_each_entry(tmp, &c->devices, list)
            if ((tmp->lct_data.user_tid == i2o_dev->lct_data.tid)
                && (tmp != i2o_dev)) {
                rc = sysfs_create_link(&tmp->device.kobj,
                                       &i2o_dev->device.kobj, "user");
                if (rc)
                        goto rmlink1;
        }

        /* create parent entries for this device */
        tmp = i2o_iop_find_device(i2o_dev->iop, i2o_dev->lct_data.parent_tid);
        if (tmp && (tmp != i2o_dev)) {
                rc = sysfs_create_link(&i2o_dev->device.kobj,
                                       &tmp->device.kobj, "parent");
                if (rc)
                        goto rmlink1;
        }

        /* create parent entries referring to this device */
        list_for_each_entry(tmp, &c->devices, list)
            if ((tmp->lct_data.parent_tid == i2o_dev->lct_data.tid)
                && (tmp != i2o_dev)) {
                rc = sysfs_create_link(&tmp->device.kobj,
                                       &i2o_dev->device.kobj, "parent");
                if (rc)
                        goto rmlink2;
        }

        i2o_driver_notify_device_add_all(i2o_dev);

        pr_debug("i2o: device %s added\n", dev_name(&i2o_dev->device));

        return 0;

rmlink2:
        /* If link creating failed halfway, we loop whole list to cleanup.
         * And we don't care wrong removing of link, because sysfs_remove_link
         * will take care of it.
         */
        list_for_each_entry(tmp, &c->devices, list) {
                if (tmp->lct_data.parent_tid == i2o_dev->lct_data.tid)
                        sysfs_remove_link(&tmp->device.kobj, "parent");
        }
        sysfs_remove_link(&i2o_dev->device.kobj, "parent");
rmlink1:
        list_for_each_entry(tmp, &c->devices, list)
                if (tmp->lct_data.user_tid == i2o_dev->lct_data.tid)
                        sysfs_remove_link(&tmp->device.kobj, "user");
        sysfs_remove_link(&i2o_dev->device.kobj, "user");
unreg_dev:
        list_del(&i2o_dev->list);
        device_unregister(&i2o_dev->device);
err:
        kfree(i2o_dev);
        return rc;
}

/**
 *      i2o_device_remove - remove an I2O device from the I2O core
 *      @i2o_dev: I2O device which should be released
 *
 *      Is used on I2O controller removal or LCT modification, when the device
 *      is removed from the system. Note that the device could still hang
 *      around until the refcount reaches 0.
 */
void i2o_device_remove(struct i2o_device *i2o_dev)
{
        struct i2o_device *tmp;
        struct i2o_controller *c = i2o_dev->iop;

        i2o_driver_notify_device_remove_all(i2o_dev);

        sysfs_remove_link(&i2o_dev->device.kobj, "parent");
        sysfs_remove_link(&i2o_dev->device.kobj, "user");

        list_for_each_entry(tmp, &c->devices, list) {
                if (tmp->lct_data.parent_tid == i2o_dev->lct_data.tid)
                        sysfs_remove_link(&tmp->device.kobj, "parent");
                if (tmp->lct_data.user_tid == i2o_dev->lct_data.tid)
                        sysfs_remove_link(&tmp->device.kobj, "user");
        }
        list_del(&i2o_dev->list);

        device_unregister(&i2o_dev->device);
}

/**
 *      i2o_device_parse_lct - Parse a previously fetched LCT and create devices
 *      @c: I2O controller from which the LCT should be parsed.
 *
 *      The Logical Configuration Table tells us what we can talk to on the
 *      board. For every entry we create an I2O device, which is registered in
 *      the I2O core.
 *
 *      Returns 0 on success or negative error code on failure.
 */
int i2o_device_parse_lct(struct i2o_controller *c)
{
        struct i2o_device *dev, *tmp;
        i2o_lct *lct;
        u32 *dlct = c->dlct.virt;
        int max = 0, i = 0;
        u16 table_size;
        u32 buf;

        mutex_lock(&c->lct_lock);

        kfree(c->lct);

        buf = le32_to_cpu(*dlct++);
        table_size = buf & 0xffff;

        lct = c->lct = kmalloc(table_size * 4, GFP_KERNEL);
        if (!lct) {
                mutex_unlock(&c->lct_lock);
                return -ENOMEM;
        }

        lct->lct_ver = buf >> 28;
        lct->boot_tid = buf >> 16 & 0xfff;
        lct->table_size = table_size;
        lct->change_ind = le32_to_cpu(*dlct++);
        lct->iop_flags = le32_to_cpu(*dlct++);

        table_size -= 3;

        pr_debug("%s: LCT has %d entries (LCT size: %d)\n", c->name, max,
                 lct->table_size);

        while (table_size > 0) {
                i2o_lct_entry *entry = &lct->lct_entry[max];
                int found = 0;

                buf = le32_to_cpu(*dlct++);
                entry->entry_size = buf & 0xffff;
                entry->tid = buf >> 16 & 0xfff;

                entry->change_ind = le32_to_cpu(*dlct++);
                entry->device_flags = le32_to_cpu(*dlct++);

                buf = le32_to_cpu(*dlct++);
                entry->class_id = buf & 0xfff;
                entry->version = buf >> 12 & 0xf;
                entry->vendor_id = buf >> 16;

                entry->sub_class = le32_to_cpu(*dlct++);

                buf = le32_to_cpu(*dlct++);
                entry->user_tid = buf & 0xfff;
                entry->parent_tid = buf >> 12 & 0xfff;
                entry->bios_info = buf >> 24;

                memcpy(&entry->identity_tag, dlct, 8);
                dlct += 2;

                entry->event_capabilities = le32_to_cpu(*dlct++);

                /* add new devices, which are new in the LCT */
                list_for_each_entry_safe(dev, tmp, &c->devices, list) {
                        if (entry->tid == dev->lct_data.tid) {
                                found = 1;
                                break;
                        }
                }

                if (!found)
                        i2o_device_add(c, entry);

                table_size -= 9;
                max++;
        }

        /* remove devices, which are not in the LCT anymore */
        list_for_each_entry_safe(dev, tmp, &c->devices, list) {
                int found = 0;

                for (i = 0; i < max; i++) {
                        if (lct->lct_entry[i].tid == dev->lct_data.tid) {
                                found = 1;
                                break;
                        }
                }

                if (!found)
                        i2o_device_remove(dev);
        }

        mutex_unlock(&c->lct_lock);

        return 0;
}

/*
 *      Run time support routines
 */

/*      Issue UTIL_PARAMS_GET or UTIL_PARAMS_SET
 *
 *      This function can be used for all UtilParamsGet/Set operations.
 *      The OperationList is given in oplist-buffer,
 *      and results are returned in reslist-buffer.
 *      Note that the minimum sized reslist is 8 bytes and contains
 *      ResultCount, ErrorInfoSize, BlockStatus and BlockSize.
 */
int i2o_parm_issue(struct i2o_device *i2o_dev, int cmd, void *oplist,
                   int oplen, void *reslist, int reslen)
{
        struct i2o_message *msg;
        int i = 0;
        int rc;
        struct i2o_dma res;
        struct i2o_controller *c = i2o_dev->iop;
        struct device *dev = &c->pdev->dev;

        res.virt = NULL;

        if (i2o_dma_alloc(dev, &res, reslen))
                return -ENOMEM;

        msg = i2o_msg_get_wait(c, I2O_TIMEOUT_MESSAGE_GET);
        if (IS_ERR(msg)) {
                i2o_dma_free(dev, &res);
                return PTR_ERR(msg);
        }

        i = 0;
        msg->u.head[1] =
            cpu_to_le32(cmd << 24 | HOST_TID << 12 | i2o_dev->lct_data.tid);
        msg->body[i++] = cpu_to_le32(0x00000000);
        msg->body[i++] = cpu_to_le32(0x4C000000 | oplen);       /* OperationList */
        memcpy(&msg->body[i], oplist, oplen);
        i += (oplen / 4 + (oplen % 4 ? 1 : 0));
        msg->body[i++] = cpu_to_le32(0xD0000000 | res.len);     /* ResultList */
        msg->body[i++] = cpu_to_le32(res.phys);

        msg->u.head[0] =
            cpu_to_le32(I2O_MESSAGE_SIZE(i + sizeof(struct i2o_message) / 4) |
                        SGL_OFFSET_5);

        rc = i2o_msg_post_wait_mem(c, msg, 10, &res);

        /* This only looks like a memory leak - don't "fix" it. */
        if (rc == -ETIMEDOUT)
                return rc;

        memcpy(reslist, res.virt, res.len);
        i2o_dma_free(dev, &res);

        return rc;
}

/*
 *       Query one field group value or a whole scalar group.
 */
int i2o_parm_field_get(struct i2o_device *i2o_dev, int group, int field,
                       void *buf, int buflen)
{
        u32 opblk[] = { cpu_to_le32(0x00000001),
                cpu_to_le32((u16) group << 16 | I2O_PARAMS_FIELD_GET),
                cpu_to_le32((s16) field << 16 | 0x00000001)
        };
        u8 *resblk;             /* 8 bytes for header */
        int rc;

        resblk = kmalloc(buflen + 8, GFP_KERNEL);
        if (!resblk)
                return -ENOMEM;

        rc = i2o_parm_issue(i2o_dev, I2O_CMD_UTIL_PARAMS_GET, opblk,
                            sizeof(opblk), resblk, buflen + 8);

        memcpy(buf, resblk + 8, buflen);        /* cut off header */

        kfree(resblk);

        return rc;
}

/*
 *      if oper == I2O_PARAMS_TABLE_GET, get from all rows
 *              if fieldcount == -1 return all fields
 *                      ibuf and ibuflen are unused (use NULL, 0)
 *              else return specific fields
 *                      ibuf contains fieldindexes
 *
 *      if oper == I2O_PARAMS_LIST_GET, get from specific rows
 *              if fieldcount == -1 return all fields
 *                      ibuf contains rowcount, keyvalues
 *              else return specific fields
 *                      fieldcount is # of fieldindexes
 *                      ibuf contains fieldindexes, rowcount, keyvalues
 *
 *      You could also use directly function i2o_issue_params().
 */
int i2o_parm_table_get(struct i2o_device *dev, int oper, int group,
                       int fieldcount, void *ibuf, int ibuflen, void *resblk,
                       int reslen)
{
        u16 *opblk;
        int size;

        size = 10 + ibuflen;
        if (size % 4)
                size += 4 - size % 4;

        opblk = kmalloc(size, GFP_KERNEL);
        if (opblk == NULL) {
                printk(KERN_ERR "i2o: no memory for query buffer.\n");
                return -ENOMEM;
        }

        opblk[0] = 1;           /* operation count */
        opblk[1] = 0;           /* pad */
        opblk[2] = oper;
        opblk[3] = group;
        opblk[4] = fieldcount;
        memcpy(opblk + 5, ibuf, ibuflen);       /* other params */

        size = i2o_parm_issue(dev, I2O_CMD_UTIL_PARAMS_GET, opblk,
                              size, resblk, reslen);

        kfree(opblk);
        if (size > reslen)
                return reslen;

        return size;
}

EXPORT_SYMBOL(i2o_device_claim);
EXPORT_SYMBOL(i2o_device_claim_release);
EXPORT_SYMBOL(i2o_parm_field_get);
EXPORT_SYMBOL(i2o_parm_table_get);
EXPORT_SYMBOL(i2o_parm_issue);