device.c

linux-2.6.15.6

/*
 * 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.
 *
 * $Id: device.c 1349 2004-12-16 21:09:43Z roland $
 */

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

#include <asm/semaphore.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_sem 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 DECLARE_MUTEX(device_sem);

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 < sizeof mandatory_table / sizeof mandatory_table[0]; ++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)
{
	long *inuse;
	char buf[IB_DEVICE_NAME_MAX];
	struct ib_device *device;
	int i;

	inuse = (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;
}

/**
 * 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);

	ib_device_unregister_sysfs(device);
}
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;
}

/**
 * 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 ret;

	down(&device_sem);

	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 = ib_device_register_sysfs(device);
	if (ret) {
		printk(KERN_WARNING "Couldn't register device %s with driver model\n",
		       device->name);
		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:
	up(&device_sem);
	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;

	down(&device_sem);

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

	list_del(&device->core_list);

	up(&device_sem);

	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.
 */