[TG3]: Set minimal hw interrupt mitigation.

[linux-2.6/verdex.git] / drivers / message / i2o / driver.c

/*
 *      Functions to handle I2O drivers (OSMs) and I2O bus type for sysfs
 *
 *      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/device.h>
#include <linux/module.h>
#include <linux/rwsem.h>
#include <linux/i2o.h>

/* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
module_param_named(max_drivers, i2o_max_drivers, uint, 0);
MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");

/* I2O drivers lock and array */
static spinlock_t i2o_drivers_lock;
static struct i2o_driver **i2o_drivers;

/**
 *      i2o_bus_match - Tell if a I2O device class id match the class ids of
 *                      the I2O driver (OSM)
 *
 *      @dev: device which should be verified
 *      @drv: the driver to match against
 *
 *      Used by the bus to check if the driver wants to handle the device.
 *
 *      Returns 1 if the class ids of the driver match the class id of the
 *      device, otherwise 0.
 */
static int i2o_bus_match(struct device *dev, struct device_driver *drv)
{
        struct i2o_device *i2o_dev = to_i2o_device(dev);
        struct i2o_driver *i2o_drv = to_i2o_driver(drv);
        struct i2o_class_id *ids = i2o_drv->classes;

        if (ids)
                while (ids->class_id != I2O_CLASS_END) {
                        if (ids->class_id == i2o_dev->lct_data.class_id)
                                return 1;
                        ids++;
                }
        return 0;
};

/* I2O bus type */
struct bus_type i2o_bus_type = {
        .name = "i2o",
        .match = i2o_bus_match,
};

/**
 *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
 *      @drv: I2O driver which should be registered
 *
 *      Registers the OSM drv in the I2O core and creates an event queues if
 *      necessary.
 *
 *      Returns 0 on success or negative error code on failure.
 */
int i2o_driver_register(struct i2o_driver *drv)
{
        struct i2o_controller *c;
        int i;
        int rc = 0;
        unsigned long flags;

        pr_debug("i2o: Register driver %s\n", drv->name);

        if (drv->event) {
                drv->event_queue = create_workqueue(drv->name);
                if (!drv->event_queue) {
                        printk(KERN_ERR "i2o: Could not initialize event queue "
                               "for driver %s\n", drv->name);
                        return -EFAULT;
                }
                pr_debug("i2o: Event queue initialized for driver %s\n",
                         drv->name);
        } else
                drv->event_queue = NULL;

        drv->driver.name = drv->name;
        drv->driver.bus = &i2o_bus_type;

        spin_lock_irqsave(&i2o_drivers_lock, flags);

        for (i = 0; i2o_drivers[i]; i++)
                if (i >= i2o_max_drivers) {
                        printk(KERN_ERR "i2o: too many drivers registered, "
                               "increase max_drivers\n");
                        spin_unlock_irqrestore(&i2o_drivers_lock, flags);
                        return -EFAULT;
                }

        drv->context = i;
        i2o_drivers[i] = drv;

        spin_unlock_irqrestore(&i2o_drivers_lock, flags);

        pr_debug("i2o: driver %s gets context id %d\n", drv->name,
                 drv->context);

        list_for_each_entry(c, &i2o_controllers, list) {
                struct i2o_device *i2o_dev;

                i2o_driver_notify_controller_add(drv, c);
                list_for_each_entry(i2o_dev, &c->devices, list)
                        i2o_driver_notify_device_add(drv, i2o_dev);
        }


        rc = driver_register(&drv->driver);
        if (rc)
                destroy_workqueue(drv->event_queue);

        return rc;
};

/**
 *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
 *      @drv: I2O driver which should be unregistered
 *
 *      Unregisters the OSM drv from the I2O core and cleanup event queues if
 *      necessary.
 */
void i2o_driver_unregister(struct i2o_driver *drv)
{
        struct i2o_controller *c;
        unsigned long flags;

        pr_debug("i2o: unregister driver %s\n", drv->name);

        driver_unregister(&drv->driver);

        list_for_each_entry(c, &i2o_controllers, list) {
                struct i2o_device *i2o_dev;

                list_for_each_entry(i2o_dev, &c->devices, list)
                    i2o_driver_notify_device_remove(drv, i2o_dev);

                i2o_driver_notify_controller_remove(drv, c);
        }

        spin_lock_irqsave(&i2o_drivers_lock, flags);
        i2o_drivers[drv->context] = NULL;
        spin_unlock_irqrestore(&i2o_drivers_lock, flags);

        if (drv->event_queue) {
                destroy_workqueue(drv->event_queue);
                drv->event_queue = NULL;
                pr_debug("i2o: event queue removed for %s\n", drv->name);
        }
};

/**
 *      i2o_driver_dispatch - dispatch an I2O reply message
 *      @c: I2O controller of the message
 *      @m: I2O message number
 *      @msg: I2O message to be delivered
 *
 *      The reply is delivered to the driver from which the original message
 *      was. This function is only called from interrupt context.
 *
 *      Returns 0 on success and the message should not be flushed. Returns > 0
 *      on success and if the message should be flushed afterwords. Returns
 *      negative error code on failure (the message will be flushed too).
 */
int i2o_driver_dispatch(struct i2o_controller *c, u32 m,
                        struct i2o_message __iomem *msg)
{
        struct i2o_driver *drv;
        u32 context = readl(&msg->u.s.icntxt);

        if (likely(context < i2o_max_drivers)) {
                spin_lock(&i2o_drivers_lock);
                drv = i2o_drivers[context];
                spin_unlock(&i2o_drivers_lock);

                if (unlikely(!drv)) {
                        printk(KERN_WARNING "%s: Spurious reply to unknown "
                               "driver %d\n", c->name, context);
                        return -EIO;
                }

                if ((readl(&msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
                        struct i2o_device *dev, *tmp;
                        struct i2o_event *evt;
                        u16 size;
                        u16 tid;

                        tid = readl(&msg->u.head[1]) & 0x1fff;

                        pr_debug("%s: event received from device %d\n", c->name,
                                 tid);

                        /* cut of header from message size (in 32-bit words) */
                        size = (readl(&msg->u.head[0]) >> 16) - 5;

                        evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
                        if (!evt)
                                return -ENOMEM;
                        memset(evt, 0, size * 4 + sizeof(*evt));

                        evt->size = size;
                        memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt,
                                      (size + 2) * 4);

                        list_for_each_entry_safe(dev, tmp, &c->devices, list)
                            if (dev->lct_data.tid == tid) {
                                evt->i2o_dev = dev;
                                break;
                        }

                        INIT_WORK(&evt->work, (void (*)(void *))drv->event,
                                  evt);
                        queue_work(drv->event_queue, &evt->work);
                        return 1;
                }

                if (likely(drv->reply))
                        return drv->reply(c, m, msg);
                else
                        pr_debug("%s: Reply to driver %s, but no reply function"
                                 " defined!\n", c->name, drv->name);
                return -EIO;
        } else
                printk(KERN_WARNING "%s: Spurious reply to unknown driver "
                       "%d\n", c->name, readl(&msg->u.s.icntxt));
        return -EIO;
}

/**
 *      i2o_driver_notify_controller_add_all - Send notify of added controller
 *                                             to all I2O drivers
 *
 *      Send notifications to all registered drivers that a new controller was
 *      added.
 */
void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
{
        int i;
        struct i2o_driver *drv;

        for (i = 0; i < I2O_MAX_DRIVERS; i++) {
                drv = i2o_drivers[i];

                if (drv)
                        i2o_driver_notify_controller_add(drv, c);
        }
}

/**
 *      i2o_driver_notify_controller_remove_all - Send notify of removed
 *                                                controller to all I2O drivers
 *
 *      Send notifications to all registered drivers that a controller was
 *      removed.
 */
void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
{
        int i;
        struct i2o_driver *drv;

        for (i = 0; i < I2O_MAX_DRIVERS; i++) {
                drv = i2o_drivers[i];

                if (drv)
                        i2o_driver_notify_controller_remove(drv, c);
        }
}

/**
 *      i2o_driver_notify_device_add_all - Send notify of added device to all
 *                                         I2O drivers
 *
 *      Send notifications to all registered drivers that a device was added.
 */
void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
{
        int i;
        struct i2o_driver *drv;

        for (i = 0; i < I2O_MAX_DRIVERS; i++) {
                drv = i2o_drivers[i];

                if (drv)
                        i2o_driver_notify_device_add(drv, i2o_dev);
        }
}

/**
 *      i2o_driver_notify_device_remove_all - Send notify of removed device to
 *                                            all I2O drivers
 *
 *      Send notifications to all registered drivers that a device was removed.
 */
void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
{
        int i;
        struct i2o_driver *drv;

        for (i = 0; i < I2O_MAX_DRIVERS; i++) {
                drv = i2o_drivers[i];

                if (drv)
                        i2o_driver_notify_device_remove(drv, i2o_dev);
        }
}

/**
 *      i2o_driver_init - initialize I2O drivers (OSMs)
 *
 *      Registers the I2O bus and allocate memory for the array of OSMs.
 *
 *      Returns 0 on success or negative error code on failure.
 */
int __init i2o_driver_init(void)
{
        int rc = 0;

        spin_lock_init(&i2o_drivers_lock);

        if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
            ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
             (2 * i2o_max_drivers - 1))) {
                printk(KERN_WARNING "i2o: max_drivers set to %d, but must be "
                       ">=2 and <= 64 and a power of 2\n", i2o_max_drivers);
                i2o_max_drivers = I2O_MAX_DRIVERS;
        }
        printk(KERN_INFO "i2o: max drivers = %d\n", i2o_max_drivers);

        i2o_drivers =
            kmalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
        if (!i2o_drivers)
                return -ENOMEM;

        memset(i2o_drivers, 0, i2o_max_drivers * sizeof(*i2o_drivers));

        rc = bus_register(&i2o_bus_type);

        if (rc < 0)
                kfree(i2o_drivers);

        return rc;
};

/**
 *      i2o_driver_exit - clean up I2O drivers (OSMs)
 *
 *      Unregisters the I2O bus and free driver array.
 */
void __exit i2o_driver_exit(void)
{
        bus_unregister(&i2o_bus_type);
        kfree(i2o_drivers);
};

EXPORT_SYMBOL(i2o_driver_register);
EXPORT_SYMBOL(i2o_driver_unregister);
EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);