Input: evdev - never leave the client buffer empty after write

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / infiniband / core / device.c

/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>

#include "core_priv.h"

MODULE_AUTHOR("Roland Dreier");
MODULE_DESCRIPTION("core kernel InfiniBand API");
MODULE_LICENSE("Dual BSD/GPL");

struct ib_client_data {
        struct list_head  list;
        struct ib_client *client;
        void *            data;
};

static LIST_HEAD(device_list);
static LIST_HEAD(client_list);

/*
 * device_mutex protects access to both device_list and client_list.
 * There's no real point to using multiple locks or something fancier
 * like an rwsem: we always access both lists, and we're always
 * modifying one list or the other list.  In any case this is not a
 * hot path so there's no point in trying to optimize.
 */
static DEFINE_MUTEX(device_mutex);

static int ib_device_check_mandatory(struct ib_device *device)
{
#define IB_MANDATORY_FUNC(x) { offsetof(struct ib_device, x), #x }
        static const struct {
                size_t offset;
                char  *name;
        } mandatory_table[] = {
                IB_MANDATORY_FUNC(query_device),
                IB_MANDATORY_FUNC(query_port),
                IB_MANDATORY_FUNC(query_pkey),
                IB_MANDATORY_FUNC(query_gid),
                IB_MANDATORY_FUNC(alloc_pd),
                IB_MANDATORY_FUNC(dealloc_pd),
                IB_MANDATORY_FUNC(create_ah),
                IB_MANDATORY_FUNC(destroy_ah),
                IB_MANDATORY_FUNC(create_qp),
                IB_MANDATORY_FUNC(modify_qp),
                IB_MANDATORY_FUNC(destroy_qp),
                IB_MANDATORY_FUNC(post_send),
                IB_MANDATORY_FUNC(post_recv),
                IB_MANDATORY_FUNC(create_cq),
                IB_MANDATORY_FUNC(destroy_cq),
                IB_MANDATORY_FUNC(poll_cq),
                IB_MANDATORY_FUNC(req_notify_cq),
                IB_MANDATORY_FUNC(get_dma_mr),
                IB_MANDATORY_FUNC(dereg_mr)
        };
        int i;

        for (i = 0; i < ARRAY_SIZE(mandatory_table); ++i) {
                if (!*(void **) ((void *) device + mandatory_table[i].offset)) {
                        printk(KERN_WARNING "Device %s is missing mandatory function %s\n",
                               device->name, mandatory_table[i].name);
                        return -EINVAL;
                }
        }

        return 0;
}

static struct ib_device *__ib_device_get_by_name(const char *name)
{
        struct ib_device *device;

        list_for_each_entry(device, &device_list, core_list)
                if (!strncmp(name, device->name, IB_DEVICE_NAME_MAX))
                        return device;

        return NULL;
}


static int alloc_name(char *name)
{
        unsigned long *inuse;
        char buf[IB_DEVICE_NAME_MAX];
        struct ib_device *device;
        int i;

        inuse = (unsigned long *) get_zeroed_page(GFP_KERNEL);
        if (!inuse)
                return -ENOMEM;

        list_for_each_entry(device, &device_list, core_list) {
                if (!sscanf(device->name, name, &i))
                        continue;
                if (i < 0 || i >= PAGE_SIZE * 8)
                        continue;
                snprintf(buf, sizeof buf, name, i);
                if (!strncmp(buf, device->name, IB_DEVICE_NAME_MAX))
                        set_bit(i, inuse);
        }

        i = find_first_zero_bit(inuse, PAGE_SIZE * 8);
        free_page((unsigned long) inuse);
        snprintf(buf, sizeof buf, name, i);

        if (__ib_device_get_by_name(buf))
                return -ENFILE;

        strlcpy(name, buf, IB_DEVICE_NAME_MAX);
        return 0;
}

static int start_port(struct ib_device *device)
{
        return (device->node_type == RDMA_NODE_IB_SWITCH) ? 0 : 1;
}


static int end_port(struct ib_device *device)
{
        return (device->node_type == RDMA_NODE_IB_SWITCH) ?
                0 : device->phys_port_cnt;
}

/**
 * ib_alloc_device - allocate an IB device struct
 * @size:size of structure to allocate
 *
 * Low-level drivers should use ib_alloc_device() to allocate &struct
 * ib_device.  @size is the size of the structure to be allocated,
 * including any private data used by the low-level driver.
 * ib_dealloc_device() must be used to free structures allocated with
 * ib_alloc_device().
 */
struct ib_device *ib_alloc_device(size_t size)
{
        BUG_ON(size < sizeof (struct ib_device));

        return kzalloc(size, GFP_KERNEL);
}
EXPORT_SYMBOL(ib_alloc_device);

/**
 * ib_dealloc_device - free an IB device struct
 * @device:structure to free
 *
 * Free a structure allocated with ib_alloc_device().
 */
void ib_dealloc_device(struct ib_device *device)
{
        if (device->reg_state == IB_DEV_UNINITIALIZED) {
                kfree(device);
                return;
        }

        BUG_ON(device->reg_state != IB_DEV_UNREGISTERED);

        kobject_put(&device->dev.kobj);
}
EXPORT_SYMBOL(ib_dealloc_device);

static int add_client_context(struct ib_device *device, struct ib_client *client)
{
        struct ib_client_data *context;
        unsigned long flags;

        context = kmalloc(sizeof *context, GFP_KERNEL);
        if (!context) {
                printk(KERN_WARNING "Couldn't allocate client context for %s/%s\n",
                       device->name, client->name);
                return -ENOMEM;
        }

        context->client = client;
        context->data   = NULL;

        spin_lock_irqsave(&device->client_data_lock, flags);
        list_add(&context->list, &device->client_data_list);
        spin_unlock_irqrestore(&device->client_data_lock, flags);

        return 0;
}

static int read_port_table_lengths(struct ib_device *device)
{
        struct ib_port_attr *tprops = NULL;
        int num_ports, ret = -ENOMEM;
        u8 port_index;

        tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
        if (!tprops)
                goto out;

        num_ports = end_port(device) - start_port(device) + 1;

        device->pkey_tbl_len = kmalloc(sizeof *device->pkey_tbl_len * num_ports,
                                       GFP_KERNEL);
        device->gid_tbl_len = kmalloc(sizeof *device->gid_tbl_len * num_ports,
                                      GFP_KERNEL);
        if (!device->pkey_tbl_len || !device->gid_tbl_len)
                goto err;

        for (port_index = 0; port_index < num_ports; ++port_index) {
                ret = ib_query_port(device, port_index + start_port(device),
                                        tprops);
                if (ret)
                        goto err;
                device->pkey_tbl_len[port_index] = tprops->pkey_tbl_len;
                device->gid_tbl_len[port_index]  = tprops->gid_tbl_len;
        }

        ret = 0;
        goto out;

err:
        kfree(device->gid_tbl_len);
        kfree(device->pkey_tbl_len);
out:
        kfree(tprops);
        return ret;
}

/**
 * ib_register_device - Register an IB device with IB core
 * @device:Device to register
 *
 * Low-level drivers use ib_register_device() to register their
 * devices with the IB core.  All registered clients will receive a
 * callback for each device that is added. @device must be allocated
 * with ib_alloc_device().
 */
int ib_register_device(struct ib_device *device,
                       int (*port_callback)(struct ib_device *,
                                            u8, struct kobject *))
{
        int ret;

        mutex_lock(&device_mutex);

        if (strchr(device->name, '%')) {
                ret = alloc_name(device->name);
                if (ret)
                        goto out;
        }

        if (ib_device_check_mandatory(device)) {
                ret = -EINVAL;
                goto out;
        }

        INIT_LIST_HEAD(&device->event_handler_list);
        INIT_LIST_HEAD(&device->client_data_list);
        spin_lock_init(&device->event_handler_lock);
        spin_lock_init(&device->client_data_lock);

        ret = read_port_table_lengths(device);
        if (ret) {
                printk(KERN_WARNING "Couldn't create table lengths cache for device %s\n",
                       device->name);
                goto out;
        }

        ret = ib_device_register_sysfs(device, port_callback);
        if (ret) {
                printk(KERN_WARNING "Couldn't register device %s with driver model\n",
                       device->name);
                kfree(device->gid_tbl_len);
                kfree(device->pkey_tbl_len);
                goto out;
        }

        list_add_tail(&device->core_list, &device_list);

        device->reg_state = IB_DEV_REGISTERED;

        {
                struct ib_client *client;

                list_for_each_entry(client, &client_list, list)
                        if (client->add && !add_client_context(device, client))
                                client->add(device);
        }

 out:
        mutex_unlock(&device_mutex);
        return ret;
}
EXPORT_SYMBOL(ib_register_device);

/**
 * ib_unregister_device - Unregister an IB device
 * @device:Device to unregister
 *
 * Unregister an IB device.  All clients will receive a remove callback.
 */
void ib_unregister_device(struct ib_device *device)
{
        struct ib_client *client;
        struct ib_client_data *context, *tmp;
        unsigned long flags;

        mutex_lock(&device_mutex);

        list_for_each_entry_reverse(client, &client_list, list)
                if (client->remove)
                        client->remove(device);

        list_del(&device->core_list);

        kfree(device->gid_tbl_len);
        kfree(device->pkey_tbl_len);

        mutex_unlock(&device_mutex);

        ib_device_unregister_sysfs(device);

        spin_lock_irqsave(&device->client_data_lock, flags);
        list_for_each_entry_safe(context, tmp, &device->client_data_list, list)
                kfree(context);
        spin_unlock_irqrestore(&device->client_data_lock, flags);

        device->reg_state = IB_DEV_UNREGISTERED;
}
EXPORT_SYMBOL(ib_unregister_device);

/**
 * ib_register_client - Register an IB client
 * @client:Client to register
 *
 * Upper level users of the IB drivers can use ib_register_client() to
 * register callbacks for IB device addition and removal.  When an IB
 * device is added, each registered client's add method will be called
 * (in the order the clients were registered), and when a device is
 * removed, each client's remove method will be called (in the reverse
 * order that clients were registered).  In addition, when
 * ib_register_client() is called, the client will receive an add
 * callback for all devices already registered.
 */
int ib_register_client(struct ib_client *client)
{
        struct ib_device *device;

        mutex_lock(&device_mutex);

        list_add_tail(&client->list, &client_list);
        list_for_each_entry(device, &device_list, core_list)
                if (client->add && !add_client_context(device, client))
                        client->add(device);

        mutex_unlock(&device_mutex);

        return 0;
}
EXPORT_SYMBOL(ib_register_client);

/**
 * ib_unregister_client - Unregister an IB client
 * @client:Client to unregister
 *
 * Upper level users use ib_unregister_client() to remove their client
 * registration.  When ib_unregister_client() is called, the client
 * will receive a remove callback for each IB device still registered.
 */
void ib_unregister_client(struct ib_client *client)
{
        struct ib_client_data *context, *tmp;
        struct ib_device *device;
        unsigned long flags;

        mutex_lock(&device_mutex);

        list_for_each_entry(device, &device_list, core_list) {
                if (client->remove)
                        client->remove(device);

                spin_lock_irqsave(&device->client_data_lock, flags);
                list_for_each_entry_safe(context, tmp, &device->client_data_list, list)
                        if (context->client == client) {
                                list_del(&context->list);
                                kfree(context);
                        }
                spin_unlock_irqrestore(&device->client_data_lock, flags);
        }
        list_del(&client->list);

        mutex_unlock(&device_mutex);
}
EXPORT_SYMBOL(ib_unregister_client);

/**
 * ib_get_client_data - Get IB client context
 * @device:Device to get context for
 * @client:Client to get context for
 *
 * ib_get_client_data() returns client context set with
 * ib_set_client_data().
 */
void *ib_get_client_data(struct ib_device *device, struct ib_client *client)
{
        struct ib_client_data *context;
        void *ret = NULL;
        unsigned long flags;

        spin_lock_irqsave(&device->client_data_lock, flags);
        list_for_each_entry(context, &device->client_data_list, list)
                if (context->client == client) {
                        ret = context->data;
                        break;
                }
        spin_unlock_irqrestore(&device->client_data_lock, flags);

        return ret;
}
EXPORT_SYMBOL(ib_get_client_data);

/**
 * ib_set_client_data - Set IB client context
 * @device:Device to set context for
 * @client:Client to set context for
 * @data:Context to set
 *
 * ib_set_client_data() sets client context that can be retrieved with
 * ib_get_client_data().
 */
void ib_set_client_data(struct ib_device *device, struct ib_client *client,
                        void *data)
{
        struct ib_client_data *context;
        unsigned long flags;

        spin_lock_irqsave(&device->client_data_lock, flags);
        list_for_each_entry(context, &device->client_data_list, list)
                if (context->client == client) {
                        context->data = data;
                        goto out;
                }

        printk(KERN_WARNING "No client context found for %s/%s\n",
               device->name, client->name);

out:
        spin_unlock_irqrestore(&device->client_data_lock, flags);
}
EXPORT_SYMBOL(ib_set_client_data);

/**
 * ib_register_event_handler - Register an IB event handler
 * @event_handler:Handler to register
 *
 * ib_register_event_handler() registers an event handler that will be
 * called back when asynchronous IB events occur (as defined in
 * chapter 11 of the InfiniBand Architecture Specification).  This
 * callback may occur in interrupt context.
 */
int ib_register_event_handler  (struct ib_event_handler *event_handler)
{
        unsigned long flags;

        spin_lock_irqsave(&event_handler->device->event_handler_lock, flags);
        list_add_tail(&event_handler->list,
                      &event_handler->device->event_handler_list);
        spin_unlock_irqrestore(&event_handler->device->event_handler_lock, flags);

        return 0;
}
EXPORT_SYMBOL(ib_register_event_handler);

/**
 * ib_unregister_event_handler - Unregister an event handler
 * @event_handler:Handler to unregister
 *
 * Unregister an event handler registered with
 * ib_register_event_handler().
 */
int ib_unregister_event_handler(struct ib_event_handler *event_handler)
{
        unsigned long flags;

        spin_lock_irqsave(&event_handler->device->event_handler_lock, flags);
        list_del(&event_handler->list);
        spin_unlock_irqrestore(&event_handler->device->event_handler_lock, flags);

        return 0;
}
EXPORT_SYMBOL(ib_unregister_event_handler);

/**
 * ib_dispatch_event - Dispatch an asynchronous event
 * @event:Event to dispatch
 *
 * Low-level drivers must call ib_dispatch_event() to dispatch the
 * event to all registered event handlers when an asynchronous event
 * occurs.
 */
void ib_dispatch_event(struct ib_event *event)
{
        unsigned long flags;
        struct ib_event_handler *handler;

        spin_lock_irqsave(&event->device->event_handler_lock, flags);

        list_for_each_entry(handler, &event->device->event_handler_list, list)
                handler->handler(handler, event);

        spin_unlock_irqrestore(&event->device->event_handler_lock, flags);
}
EXPORT_SYMBOL(ib_dispatch_event);

/**
 * ib_query_device - Query IB device attributes
 * @device:Device to query
 * @device_attr:Device attributes
 *
 * ib_query_device() returns the attributes of a device through the
 * @device_attr pointer.
 */
int ib_query_device(struct ib_device *device,
                    struct ib_device_attr *device_attr)
{
        return device->query_device(device, device_attr);
}
EXPORT_SYMBOL(ib_query_device);

/**
 * ib_query_port - Query IB port attributes
 * @device:Device to query
 * @port_num:Port number to query
 * @port_attr:Port attributes
 *
 * ib_query_port() returns the attributes of a port through the
 * @port_attr pointer.
 */
int ib_query_port(struct ib_device *device,
                  u8 port_num,
                  struct ib_port_attr *port_attr)
{
        if (port_num < start_port(device) || port_num > end_port(device))
                return -EINVAL;

        return device->query_port(device, port_num, port_attr);
}
EXPORT_SYMBOL(ib_query_port);

/**
 * ib_query_gid - Get GID table entry
 * @device:Device to query
 * @port_num:Port number to query
 * @index:GID table index to query
 * @gid:Returned GID
 *
 * ib_query_gid() fetches the specified GID table entry.
 */
int ib_query_gid(struct ib_device *device,
                 u8 port_num, int index, union ib_gid *gid)
{
        return device->query_gid(device, port_num, index, gid);
}
EXPORT_SYMBOL(ib_query_gid);

/**
 * ib_query_pkey - Get P_Key table entry
 * @device:Device to query
 * @port_num:Port number to query
 * @index:P_Key table index to query
 * @pkey:Returned P_Key
 *
 * ib_query_pkey() fetches the specified P_Key table entry.
 */
int ib_query_pkey(struct ib_device *device,
                  u8 port_num, u16 index, u16 *pkey)
{
        return device->query_pkey(device, port_num, index, pkey);
}
EXPORT_SYMBOL(ib_query_pkey);

/**
 * ib_modify_device - Change IB device attributes
 * @device:Device to modify
 * @device_modify_mask:Mask of attributes to change
 * @device_modify:New attribute values
 *
 * ib_modify_device() changes a device's attributes as specified by
 * the @device_modify_mask and @device_modify structure.
 */
int ib_modify_device(struct ib_device *device,
                     int device_modify_mask,
                     struct ib_device_modify *device_modify)
{
        return device->modify_device(device, device_modify_mask,
                                     device_modify);
}
EXPORT_SYMBOL(ib_modify_device);

/**
 * ib_modify_port - Modifies the attributes for the specified port.
 * @device: The device to modify.
 * @port_num: The number of the port to modify.
 * @port_modify_mask: Mask used to specify which attributes of the port
 *   to change.
 * @port_modify: New attribute values for the port.
 *
 * ib_modify_port() changes a port's attributes as specified by the
 * @port_modify_mask and @port_modify structure.
 */
int ib_modify_port(struct ib_device *device,
                   u8 port_num, int port_modify_mask,
                   struct ib_port_modify *port_modify)
{
        if (port_num < start_port(device) || port_num > end_port(device))
                return -EINVAL;

        return device->modify_port(device, port_num, port_modify_mask,
                                   port_modify);
}
EXPORT_SYMBOL(ib_modify_port);

/**
 * ib_find_gid - Returns the port number and GID table index where
 *   a specified GID value occurs.
 * @device: The device to query.
 * @gid: The GID value to search for.
 * @port_num: The port number of the device where the GID value was found.
 * @index: The index into the GID table where the GID was found.  This
 *   parameter may be NULL.
 */
int ib_find_gid(struct ib_device *device, union ib_gid *gid,
                u8 *port_num, u16 *index)
{
        union ib_gid tmp_gid;
        int ret, port, i;

        for (port = start_port(device); port <= end_port(device); ++port) {
                for (i = 0; i < device->gid_tbl_len[port - start_port(device)]; ++i) {
                        ret = ib_query_gid(device, port, i, &tmp_gid);
                        if (ret)
                                return ret;
                        if (!memcmp(&tmp_gid, gid, sizeof *gid)) {
                                *port_num = port;
                                if (index)
                                        *index = i;
                                return 0;
                        }
                }
        }

        return -ENOENT;
}
EXPORT_SYMBOL(ib_find_gid);

/**
 * ib_find_pkey - Returns the PKey table index where a specified
 *   PKey value occurs.
 * @device: The device to query.
 * @port_num: The port number of the device to search for the PKey.
 * @pkey: The PKey value to search for.
 * @index: The index into the PKey table where the PKey was found.
 */
int ib_find_pkey(struct ib_device *device,
                 u8 port_num, u16 pkey, u16 *index)
{
        int ret, i;
        u16 tmp_pkey;

        for (i = 0; i < device->pkey_tbl_len[port_num - start_port(device)]; ++i) {
                ret = ib_query_pkey(device, port_num, i, &tmp_pkey);
                if (ret)
                        return ret;

                if ((pkey & 0x7fff) == (tmp_pkey & 0x7fff)) {
                        *index = i;
                        return 0;
                }
        }

        return -ENOENT;
}
EXPORT_SYMBOL(ib_find_pkey);

static int __init ib_core_init(void)
{
        int ret;

        ret = ib_sysfs_setup();
        if (ret)
                printk(KERN_WARNING "Couldn't create InfiniBand device class\n");

        ret = ib_cache_setup();
        if (ret) {
                printk(KERN_WARNING "Couldn't set up InfiniBand P_Key/GID cache\n");
                ib_sysfs_cleanup();
        }

        return ret;
}

static void __exit ib_core_cleanup(void)
{
        ib_cache_cleanup();
        ib_sysfs_cleanup();
        /* Make sure that any pending umem accounting work is done. */
        flush_scheduled_work();
}

module_init(ib_core_init);
module_exit(ib_core_cleanup);