fw-cdev.c

	bus_time = card->driver->get_bus_time(card);
	do_gettimeofday(&tv);

	local_irq_restore(flags);
	preempt_enable();

	request->local_time = tv.tv_sec * 1000000ULL + tv.tv_usec;
	request->cycle_timer = bus_time & 0xffffffff;
	return 0;
}

static void iso_resource_work(struct work_struct *work)
{
	struct iso_resource_event *e;
	struct iso_resource *r =
			container_of(work, struct iso_resource, work.work);
	struct client *client = r->client;
	int generation, channel, bandwidth, todo;
	bool skip, free, success;

	spin_lock_irq(&client->lock);
	generation = client->device->generation;
	todo = r->todo;
	/* Allow 1000ms grace period for other reallocations. */
	if (todo == ISO_RES_ALLOC &&
	    time_is_after_jiffies(client->device->card->reset_jiffies + HZ)) {
		if (schedule_delayed_work(&r->work, DIV_ROUND_UP(HZ, 3)))
			client_get(client);
		skip = true;
	} else {
		/* We could be called twice within the same generation. */
		skip = todo == ISO_RES_REALLOC &&
		       r->generation == generation;
	}
	free = todo == ISO_RES_DEALLOC;
	r->generation = generation;
	spin_unlock_irq(&client->lock);

	if (skip)
		goto out;

	bandwidth = r->bandwidth;

	fw_iso_resource_manage(client->device->card, generation,
			r->channels, &channel, &bandwidth,
			todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC);
	/*
	 * Is this generation outdated already?  As long as this resource sticks
	 * in the idr, it will be scheduled again for a newer generation or at
	 * shutdown.
	 */
	if (channel == -EAGAIN &&
	    (todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC))
		goto out;

	success = channel >= 0 || bandwidth > 0;

	spin_lock_irq(&client->lock);
	/*
	 * Transit from allocation to reallocation, except if the client
	 * requested deallocation in the meantime.
	 */
	if (r->todo == ISO_RES_ALLOC)
		r->todo = ISO_RES_REALLOC;
	/*
	 * Allocation or reallocation failure?  Pull this resource out of the
	 * idr and prepare for deletion, unless the client is shutting down.
	 */
	if (r->todo == ISO_RES_REALLOC && !success &&
	    !client->in_shutdown &&
	    idr_find(&client->resource_idr, r->resource.handle)) {
		idr_remove(&client->resource_idr, r->resource.handle);
		client_put(client);
		free = true;
	}
	spin_unlock_irq(&client->lock);

	if (todo == ISO_RES_ALLOC && channel >= 0)
		r->channels = 1ULL << (63 - channel);

	if (todo == ISO_RES_REALLOC && success)
		goto out;

	if (todo == ISO_RES_ALLOC) {
		e = r->e_alloc;
		r->e_alloc = NULL;
	} else {
		e = r->e_dealloc;
		r->e_dealloc = NULL;
	}
	e->resource.handle	= r->resource.handle;
	e->resource.channel	= channel;
	e->resource.bandwidth	= bandwidth;

	queue_event(client, &e->event,
		    &e->resource, sizeof(e->resource), NULL, 0);

	if (free) {
		cancel_delayed_work(&r->work);
		kfree(r->e_alloc);
		kfree(r->e_dealloc);
		kfree(r);
	}
 out:
	client_put(client);
}

static void schedule_iso_resource(struct iso_resource *r)
{
	if (schedule_delayed_work(&r->work, 0))
		client_get(r->client);
}

static void release_iso_resource(struct client *client,
				 struct client_resource *resource)
{
	struct iso_resource *r =
		container_of(resource, struct iso_resource, resource);

	spin_lock_irq(&client->lock);
	r->todo = ISO_RES_DEALLOC;
	schedule_iso_resource(r);
	spin_unlock_irq(&client->lock);
}

static int ioctl_allocate_iso_resource(struct client *client, void *buffer)
{
	struct fw_cdev_allocate_iso_resource *request = buffer;
	struct iso_resource_event *e1, *e2;
	struct iso_resource *r;
	int ret;

	if ((request->channels == 0 && request->bandwidth == 0) ||
	    request->bandwidth > BANDWIDTH_AVAILABLE_INITIAL ||
	    request->bandwidth < 0)
		return -EINVAL;

	r  = kmalloc(sizeof(*r), GFP_KERNEL);
	e1 = kmalloc(sizeof(*e1), GFP_KERNEL);
	e2 = kmalloc(sizeof(*e2), GFP_KERNEL);
	if (r == NULL || e1 == NULL || e2 == NULL) {
		ret = -ENOMEM;
		goto fail;
	}

	INIT_DELAYED_WORK(&r->work, iso_resource_work);
	r->client	= client;
	r->todo		= ISO_RES_ALLOC;
	r->generation	= -1;
	r->channels	= request->channels;
	r->bandwidth	= request->bandwidth;
	r->e_alloc	= e1;
	r->e_dealloc	= e2;

	e1->resource.closure	= request->closure;
	e1->resource.type	= FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED;
	e2->resource.closure	= request->closure;
	e2->resource.type	= FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED;

	r->resource.release = release_iso_resource;
	ret = add_client_resource(client, &r->resource, GFP_KERNEL);
	if (ret < 0)
		goto fail;
	request->handle = r->resource.handle;

	return 0;
 fail:
	kfree(r);
	kfree(e1);
	kfree(e2);

	return ret;
}

static int ioctl_deallocate_iso_resource(struct client *client, void *buffer)
{
	struct fw_cdev_deallocate *request = buffer;

	return release_client_resource(client, request->handle,
				       release_iso_resource, NULL);
}

static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
	ioctl_get_info,
	ioctl_send_request,
	ioctl_allocate,
	ioctl_deallocate,
	ioctl_send_response,
	ioctl_initiate_bus_reset,
	ioctl_add_descriptor,
	ioctl_remove_descriptor,
	ioctl_create_iso_context,
	ioctl_queue_iso,
	ioctl_start_iso,
	ioctl_stop_iso,
	ioctl_get_cycle_timer,
	ioctl_allocate_iso_resource,
	ioctl_deallocate_iso_resource,
};

static int dispatch_ioctl(struct client *client,
			  unsigned int cmd, void __user *arg)
{
	char buffer[256];
	int ret;

	if (_IOC_TYPE(cmd) != '#' ||
	    _IOC_NR(cmd) >= ARRAY_SIZE(ioctl_handlers))
		return -EINVAL;

	if (_IOC_DIR(cmd) & _IOC_WRITE) {
		if (_IOC_SIZE(cmd) > sizeof(buffer) ||
		    copy_from_user(buffer, arg, _IOC_SIZE(cmd)))
			return -EFAULT;
	}

	ret = ioctl_handlers[_IOC_NR(cmd)](client, buffer);
	if (ret < 0)
		return ret;

	if (_IOC_DIR(cmd) & _IOC_READ) {
		if (_IOC_SIZE(cmd) > sizeof(buffer) ||
		    copy_to_user(arg, buffer, _IOC_SIZE(cmd)))
			return -EFAULT;
	}

	return ret;
}

static long fw_device_op_ioctl(struct file *file,
			       unsigned int cmd, unsigned long arg)
{
	struct client *client = file->private_data;

	if (fw_device_is_shutdown(client->device))
		return -ENODEV;

	return dispatch_ioctl(client, cmd, (void __user *) arg);
}

#ifdef CONFIG_COMPAT
static long fw_device_op_compat_ioctl(struct file *file,
				      unsigned int cmd, unsigned long arg)
{
	struct client *client = file->private_data;

	if (fw_device_is_shutdown(client->device))
		return -ENODEV;

	return dispatch_ioctl(client, cmd, compat_ptr(arg));
}
#endif

static int fw_device_op_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct client *client = file->private_data;
	enum dma_data_direction direction;
	unsigned long size;
	int page_count, ret;

	if (fw_device_is_shutdown(client->device))
		return -ENODEV;

	/* FIXME: We could support multiple buffers, but we don't. */
	if (client->buffer.pages != NULL)
		return -EBUSY;

	if (!(vma->vm_flags & VM_SHARED))
		return -EINVAL;

	if (vma->vm_start & ~PAGE_MASK)
		return -EINVAL;

	client->vm_start = vma->vm_start;
	size = vma->vm_end - vma->vm_start;
	page_count = size >> PAGE_SHIFT;
	if (size & ~PAGE_MASK)
		return -EINVAL;

	if (vma->vm_flags & VM_WRITE)
		direction = DMA_TO_DEVICE;
	else
		direction = DMA_FROM_DEVICE;

	ret = fw_iso_buffer_init(&client->buffer, client->device->card,
				 page_count, direction);
	if (ret < 0)
		return ret;

	ret = fw_iso_buffer_map(&client->buffer, vma);
	if (ret < 0)
		fw_iso_buffer_destroy(&client->buffer, client->device->card);

	return ret;
}

static int shutdown_resource(int id, void *p, void *data)
{
	struct client_resource *r = p;
	struct client *client = data;

	r->release(client, r);
	client_put(client);

	return 0;
}

static int fw_device_op_release(struct inode *inode, struct file *file)
{
	struct client *client = file->private_data;
	struct event *e, *next_e;
	unsigned long flags;

	mutex_lock(&client->device->client_list_mutex);
	list_del(&client->link);
	mutex_unlock(&client->device->client_list_mutex);

	if (client->buffer.pages)
		fw_iso_buffer_destroy(&client->buffer, client->device->card);

	if (client->iso_context)
		fw_iso_context_destroy(client->iso_context);

	/* Freeze client->resource_idr and client->event_list */
	spin_lock_irqsave(&client->lock, flags);
	client->in_shutdown = true;
	spin_unlock_irqrestore(&client->lock, flags);

	idr_for_each(&client->resource_idr, shutdown_resource, client);
	idr_remove_all(&client->resource_idr);
	idr_destroy(&client->resource_idr);

	list_for_each_entry_safe(e, next_e, &client->event_list, link)
		kfree(e);

	client_put(client);

	return 0;
}

static unsigned int fw_device_op_poll(struct file *file, poll_table * pt)
{
	struct client *client = file->private_data;
	unsigned int mask = 0;

	poll_wait(file, &client->wait, pt);

	if (fw_device_is_shutdown(client->device))
		mask |= POLLHUP | POLLERR;
	if (!list_empty(&client->event_list))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

const struct file_operations fw_device_ops = {
	.owner		= THIS_MODULE,
	.open		= fw_device_op_open,
	.read		= fw_device_op_read,
	.unlocked_ioctl	= fw_device_op_ioctl,
	.poll		= fw_device_op_poll,
	.release	= fw_device_op_release,
	.mmap		= fw_device_op_mmap,

#ifdef CONFIG_COMPAT
	.compat_ioctl	= fw_device_op_compat_ioctl,
#endif
};