/*
   * Char device for device raw access

   *

   * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>

   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   */

  #include <linux/bug.h>

  #include <linux/compat.h>
  #include <linux/delay.h>
  #include <linux/device.h>

  #include <linux/dma-mapping.h>

  #include <linux/errno.h>

  #include <linux/firewire.h>

  #include <linux/firewire-cdev.h>
  #include <linux/idr.h>

  #include <linux/irqflags.h>

  #include <linux/jiffies.h>

  #include <linux/kernel.h>

  #include <linux/kref.h>

  #include <linux/mm.h>
  #include <linux/module.h>

  #include <linux/mutex.h>

  #include <linux/poll.h>

  #include <linux/sched.h> /* required for linux/wait.h */

  #include <linux/slab.h>

  #include <linux/spinlock.h>

  #include <linux/string.h>

  #include <linux/time.h>

  #include <linux/uaccess.h>

  #include <linux/vmalloc.h>
  #include <linux/wait.h>

  #include <linux/workqueue.h>

  #include "core.h"

  /*
   * ABI version history is documented in linux/firewire-cdev.h.
   */

  #define FW_CDEV_KERNEL_VERSION			5

  #define FW_CDEV_VERSION_EVENT_REQUEST2		4
  #define FW_CDEV_VERSION_ALLOCATE_REGION_END	4

  struct client {

  	u32 version;

  	struct fw_device *device;

  	spinlock_t lock;

  	bool in_shutdown;
  	struct idr resource_idr;

  	struct list_head event_list;

  	wait_queue_head_t wait;

  	wait_queue_head_t tx_flush_wait;

  	u64 bus_reset_closure;

  	struct fw_iso_context *iso_context;

  	u64 iso_closure;

  	struct fw_iso_buffer buffer;
  	unsigned long vm_start;

  	bool buffer_is_mapped;

  	struct list_head phy_receiver_link;
  	u64 phy_receiver_closure;

  	struct list_head link;

  	struct kref kref;

  };

  static inline void client_get(struct client *client)
  {
  	kref_get(&client->kref);
  }
  
  static void client_release(struct kref *kref)
  {
  	struct client *client = container_of(kref, struct client, kref);
  
  	fw_device_put(client->device);
  	kfree(client);
  }
  
  static void client_put(struct client *client)
  {
  	kref_put(&client->kref, client_release);
  }

  struct client_resource;
  typedef void (*client_resource_release_fn_t)(struct client *,
  					     struct client_resource *);
  struct client_resource {
  	client_resource_release_fn_t release;
  	int handle;
  };
  
  struct address_handler_resource {
  	struct client_resource resource;
  	struct fw_address_handler handler;
  	__u64 closure;
  	struct client *client;
  };
  
  struct outbound_transaction_resource {
  	struct client_resource resource;
  	struct fw_transaction transaction;
  };
  
  struct inbound_transaction_resource {
  	struct client_resource resource;

  	struct fw_card *card;

  	struct fw_request *request;
  	void *data;
  	size_t length;
  };
  
  struct descriptor_resource {
  	struct client_resource resource;
  	struct fw_descriptor descriptor;
  	u32 data[0];
  };

  struct iso_resource {
  	struct client_resource resource;
  	struct client *client;
  	/* Schedule work and access todo only with client->lock held. */
  	struct delayed_work work;

  	enum {ISO_RES_ALLOC, ISO_RES_REALLOC, ISO_RES_DEALLOC,
  	      ISO_RES_ALLOC_ONCE, ISO_RES_DEALLOC_ONCE,} todo;

  	int generation;
  	u64 channels;
  	s32 bandwidth;
  	struct iso_resource_event *e_alloc, *e_dealloc;
  };

  static void release_iso_resource(struct client *, struct client_resource *);

  static void schedule_iso_resource(struct iso_resource *r, unsigned long delay)
  {
  	client_get(r->client);

  	if (!queue_delayed_work(fw_workqueue, &r->work, delay))

  		client_put(r->client);
  }
  
  static void schedule_if_iso_resource(struct client_resource *resource)
  {
  	if (resource->release == release_iso_resource)
  		schedule_iso_resource(container_of(resource,
  					struct iso_resource, resource), 0);
  }

  /*
   * dequeue_event() just kfree()'s the event, so the event has to be
   * the first field in a struct XYZ_event.
   */
  struct event {
  	struct { void *data; size_t size; } v[2];
  	struct list_head link;
  };
  
  struct bus_reset_event {
  	struct event event;
  	struct fw_cdev_event_bus_reset reset;
  };
  
  struct outbound_transaction_event {
  	struct event event;
  	struct client *client;
  	struct outbound_transaction_resource r;
  	struct fw_cdev_event_response response;
  };
  
  struct inbound_transaction_event {
  	struct event event;

  	union {
  		struct fw_cdev_event_request request;
  		struct fw_cdev_event_request2 request2;
  	} req;

  };
  
  struct iso_interrupt_event {
  	struct event event;
  	struct fw_cdev_event_iso_interrupt interrupt;
  };

  struct iso_interrupt_mc_event {
  	struct event event;
  	struct fw_cdev_event_iso_interrupt_mc interrupt;
  };

  struct iso_resource_event {
  	struct event event;

  	struct fw_cdev_event_iso_resource iso_resource;

  };

  struct outbound_phy_packet_event {
  	struct event event;
  	struct client *client;
  	struct fw_packet p;
  	struct fw_cdev_event_phy_packet phy_packet;
  };

  struct inbound_phy_packet_event {
  	struct event event;
  	struct fw_cdev_event_phy_packet phy_packet;
  };

  #ifdef CONFIG_COMPAT
  static void __user *u64_to_uptr(u64 value)
  {
  	if (is_compat_task())
  		return compat_ptr(value);
  	else
  		return (void __user *)(unsigned long)value;
  }
  
  static u64 uptr_to_u64(void __user *ptr)
  {
  	if (is_compat_task())
  		return ptr_to_compat(ptr);
  	else
  		return (u64)(unsigned long)ptr;
  }
  #else
  static inline void __user *u64_to_uptr(u64 value)

  {
  	return (void __user *)(unsigned long)value;
  }

  static inline u64 uptr_to_u64(void __user *ptr)

  {

  	return (u64)(unsigned long)ptr;

  }

  #endif /* CONFIG_COMPAT */

  
  static int fw_device_op_open(struct inode *inode, struct file *file)
  {
  	struct fw_device *device;
  	struct client *client;

  	device = fw_device_get_by_devt(inode->i_rdev);

  	if (device == NULL)
  		return -ENODEV;

  	if (fw_device_is_shutdown(device)) {
  		fw_device_put(device);
  		return -ENODEV;
  	}

  	client = kzalloc(sizeof(*client), GFP_KERNEL);

  	if (client == NULL) {
  		fw_device_put(device);

  		return -ENOMEM;

  	}

  	client->device = device;

  	spin_lock_init(&client->lock);

  	idr_init(&client->resource_idr);
  	INIT_LIST_HEAD(&client->event_list);

  	init_waitqueue_head(&client->wait);

  	init_waitqueue_head(&client->tx_flush_wait);

  	INIT_LIST_HEAD(&client->phy_receiver_link);

  	INIT_LIST_HEAD(&client->link);

  	kref_init(&client->kref);

  
  	file->private_data = client;

  	return nonseekable_open(inode, file);

  }
  
  static void queue_event(struct client *client, struct event *event,
  			void *data0, size_t size0, void *data1, size_t size1)
  {
  	unsigned long flags;
  
  	event->v[0].data = data0;
  	event->v[0].size = size0;
  	event->v[1].data = data1;
  	event->v[1].size = size1;
  
  	spin_lock_irqsave(&client->lock, flags);

  	if (client->in_shutdown)
  		kfree(event);
  	else
  		list_add_tail(&event->link, &client->event_list);

  	spin_unlock_irqrestore(&client->lock, flags);

  
  	wake_up_interruptible(&client->wait);

  }

  static int dequeue_event(struct client *client,
  			 char __user *buffer, size_t count)

  {

  	struct event *event;
  	size_t size, total;

  	int i, ret;

  	ret = wait_event_interruptible(client->wait,
  			!list_empty(&client->event_list) ||
  			fw_device_is_shutdown(client->device));
  	if (ret < 0)
  		return ret;

  	if (list_empty(&client->event_list) &&
  		       fw_device_is_shutdown(client->device))
  		return -ENODEV;

  	spin_lock_irq(&client->lock);

  	event = list_first_entry(&client->event_list, struct event, link);

  	list_del(&event->link);

  	spin_unlock_irq(&client->lock);

  	total = 0;
  	for (i = 0; i < ARRAY_SIZE(event->v) && total < count; i++) {
  		size = min(event->v[i].size, count - total);

  		if (copy_to_user(buffer + total, event->v[i].data, size)) {

  			ret = -EFAULT;

  			goto out;

  		}

  		total += size;
  	}

  	ret = total;

  
   out:
  	kfree(event);

  	return ret;

  }

  static ssize_t fw_device_op_read(struct file *file, char __user *buffer,
  				 size_t count, loff_t *offset)

  {
  	struct client *client = file->private_data;
  
  	return dequeue_event(client, buffer, count);
  }

  static void fill_bus_reset_event(struct fw_cdev_event_bus_reset *event,
  				 struct client *client)

  {

  	struct fw_card *card = client->device->card;

  	spin_lock_irq(&card->lock);

  	event->closure	     = client->bus_reset_closure;

  	event->type          = FW_CDEV_EVENT_BUS_RESET;

  	event->generation    = client->device->generation;

  	event->node_id       = client->device->node_id;

  	event->local_node_id = card->local_node->node_id;

  	event->bm_node_id    = card->bm_node_id;

  	event->irm_node_id   = card->irm_node->node_id;
  	event->root_node_id  = card->root_node->node_id;

  	spin_unlock_irq(&card->lock);

  }

  static void for_each_client(struct fw_device *device,
  			    void (*callback)(struct client *client))

  {

  	struct client *c;

  	mutex_lock(&device->client_list_mutex);

  	list_for_each_entry(c, &device->client_list, link)
  		callback(c);

  	mutex_unlock(&device->client_list_mutex);

  }

  static int schedule_reallocations(int id, void *p, void *data)
  {

  	schedule_if_iso_resource(p);

  	return 0;
  }

  static void queue_bus_reset_event(struct client *client)

  {

  	struct bus_reset_event *e;

  	e = kzalloc(sizeof(*e), GFP_KERNEL);

  	if (e == NULL)

  		return;

  	fill_bus_reset_event(&e->reset, client);

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

  
  	spin_lock_irq(&client->lock);
  	idr_for_each(&client->resource_idr, schedule_reallocations, client);
  	spin_unlock_irq(&client->lock);

  }
  
  void fw_device_cdev_update(struct fw_device *device)
  {

  	for_each_client(device, queue_bus_reset_event);
  }

  static void wake_up_client(struct client *client)
  {
  	wake_up_interruptible(&client->wait);
  }

  void fw_device_cdev_remove(struct fw_device *device)
  {
  	for_each_client(device, wake_up_client);

  }

  union ioctl_arg {
  	struct fw_cdev_get_info			get_info;
  	struct fw_cdev_send_request		send_request;
  	struct fw_cdev_allocate			allocate;
  	struct fw_cdev_deallocate		deallocate;
  	struct fw_cdev_send_response		send_response;
  	struct fw_cdev_initiate_bus_reset	initiate_bus_reset;
  	struct fw_cdev_add_descriptor		add_descriptor;
  	struct fw_cdev_remove_descriptor	remove_descriptor;
  	struct fw_cdev_create_iso_context	create_iso_context;
  	struct fw_cdev_queue_iso		queue_iso;
  	struct fw_cdev_start_iso		start_iso;
  	struct fw_cdev_stop_iso			stop_iso;
  	struct fw_cdev_get_cycle_timer		get_cycle_timer;
  	struct fw_cdev_allocate_iso_resource	allocate_iso_resource;
  	struct fw_cdev_send_stream_packet	send_stream_packet;
  	struct fw_cdev_get_cycle_timer2		get_cycle_timer2;

  	struct fw_cdev_send_phy_packet		send_phy_packet;

  	struct fw_cdev_receive_phy_packets	receive_phy_packets;

  	struct fw_cdev_set_iso_channels		set_iso_channels;

  	struct fw_cdev_flush_iso		flush_iso;

  };
  
  static int ioctl_get_info(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_get_info *a = &arg->get_info;

  	struct fw_cdev_event_bus_reset bus_reset;

  	unsigned long ret = 0;

  	client->version = a->version;

  	a->version = FW_CDEV_KERNEL_VERSION;

  	a->card = client->device->card->index;

  	down_read(&fw_device_rwsem);

  	if (a->rom != 0) {
  		size_t want = a->rom_length;

  		size_t have = client->device->config_rom_length * 4;

  		ret = copy_to_user(u64_to_uptr(a->rom),
  				   client->device->config_rom, min(want, have));

  	}

  	a->rom_length = client->device->config_rom_length * 4;

  	up_read(&fw_device_rwsem);
  
  	if (ret != 0)
  		return -EFAULT;

  	mutex_lock(&client->device->client_list_mutex);

  	client->bus_reset_closure = a->bus_reset_closure;
  	if (a->bus_reset != 0) {

  		fill_bus_reset_event(&bus_reset, client);

  		/* unaligned size of bus_reset is 36 bytes */
  		ret = copy_to_user(u64_to_uptr(a->bus_reset), &bus_reset, 36);

  	}

  	if (ret == 0 && list_empty(&client->link))
  		list_add_tail(&client->link, &client->device->client_list);

  	mutex_unlock(&client->device->client_list_mutex);
  
  	return ret ? -EFAULT : 0;

  }

  static int add_client_resource(struct client *client,
  			       struct client_resource *resource, gfp_t gfp_mask)

  {

  	bool preload = gfp_mask & __GFP_WAIT;

  	unsigned long flags;

  	int ret;

  	if (preload)
  		idr_preload(gfp_mask);

  	spin_lock_irqsave(&client->lock, flags);

  	if (client->in_shutdown)
  		ret = -ECANCELED;
  	else

  		ret = idr_alloc(&client->resource_idr, resource, 0, 0,
  				GFP_NOWAIT);

  	if (ret >= 0) {

  		resource->handle = ret;

  		client_get(client);

  		schedule_if_iso_resource(resource);

  	}

  	spin_unlock_irqrestore(&client->lock, flags);
  	if (preload)
  		idr_preload_end();

  
  	return ret < 0 ? ret : 0;

  }

  static int release_client_resource(struct client *client, u32 handle,
  				   client_resource_release_fn_t release,

  				   struct client_resource **return_resource)

  {

  	struct client_resource *resource;

  	spin_lock_irq(&client->lock);

  	if (client->in_shutdown)

  		resource = NULL;

  	else

  		resource = idr_find(&client->resource_idr, handle);
  	if (resource && resource->release == release)

  		idr_remove(&client->resource_idr, handle);

  	spin_unlock_irq(&client->lock);

  	if (!(resource && resource->release == release))

  		return -EINVAL;

  	if (return_resource)
  		*return_resource = resource;

  	else

  		resource->release(client, resource);

  	client_put(client);

  	return 0;
  }

  static void release_transaction(struct client *client,
  				struct client_resource *resource)

  {

  }

  static void complete_transaction(struct fw_card *card, int rcode,
  				 void *payload, size_t length, void *data)

  {

  	struct outbound_transaction_event *e = data;
  	struct fw_cdev_event_response *rsp = &e->response;
  	struct client *client = e->client;

  	unsigned long flags;

  	if (length < rsp->length)
  		rsp->length = length;

  	if (rcode == RCODE_COMPLETE)

  		memcpy(rsp->data, payload, rsp->length);

  	spin_lock_irqsave(&client->lock, flags);

  	idr_remove(&client->resource_idr, e->r.resource.handle);
  	if (client->in_shutdown)
  		wake_up(&client->tx_flush_wait);

  	spin_unlock_irqrestore(&client->lock, flags);

  	rsp->type = FW_CDEV_EVENT_RESPONSE;
  	rsp->rcode = rcode;

  
  	/*

  	 * In the case that sizeof(*rsp) doesn't align with the position of the

  	 * data, and the read is short, preserve an extra copy of the data
  	 * to stay compatible with a pre-2.6.27 bug.  Since the bug is harmless
  	 * for short reads and some apps depended on it, this is both safe
  	 * and prudent for compatibility.
  	 */

  	if (rsp->length <= sizeof(*rsp) - offsetof(typeof(*rsp), data))
  		queue_event(client, &e->event, rsp, sizeof(*rsp),
  			    rsp->data, rsp->length);

  	else

  		queue_event(client, &e->event, rsp, sizeof(*rsp) + rsp->length,

  			    NULL, 0);

  	/* Drop the idr's reference */
  	client_put(client);

  }

  static int init_request(struct client *client,
  			struct fw_cdev_send_request *request,
  			int destination_id, int speed)

  {

  	struct outbound_transaction_event *e;

  	int ret;

  	if (request->tcode != TCODE_STREAM_DATA &&
  	    (request->length > 4096 || request->length > 512 << speed))

  		return -EIO;

  	if (request->tcode == TCODE_WRITE_QUADLET_REQUEST &&
  	    request->length < 4)
  		return -EINVAL;

  	e = kmalloc(sizeof(*e) + request->length, GFP_KERNEL);
  	if (e == NULL)

  		return -ENOMEM;

  	e->client = client;
  	e->response.length = request->length;
  	e->response.closure = request->closure;

  	if (request->data &&

  	    copy_from_user(e->response.data,

  			   u64_to_uptr(request->data), request->length)) {

  		ret = -EFAULT;

  		goto failed;

  	}

  	e->r.resource.release = release_transaction;
  	ret = add_client_resource(client, &e->r.resource, GFP_KERNEL);

  	if (ret < 0)
  		goto failed;

  	fw_send_request(client->device->card, &e->r.transaction,

  			request->tcode, destination_id, request->generation,
  			speed, request->offset, e->response.data,
  			request->length, complete_transaction, e);
  	return 0;

   failed:

  	kfree(e);

  
  	return ret;

  }

  static int ioctl_send_request(struct client *client, union ioctl_arg *arg)

  {

  	switch (arg->send_request.tcode) {

  	case TCODE_WRITE_QUADLET_REQUEST:
  	case TCODE_WRITE_BLOCK_REQUEST:
  	case TCODE_READ_QUADLET_REQUEST:
  	case TCODE_READ_BLOCK_REQUEST:
  	case TCODE_LOCK_MASK_SWAP:
  	case TCODE_LOCK_COMPARE_SWAP:
  	case TCODE_LOCK_FETCH_ADD:
  	case TCODE_LOCK_LITTLE_ADD:
  	case TCODE_LOCK_BOUNDED_ADD:
  	case TCODE_LOCK_WRAP_ADD:
  	case TCODE_LOCK_VENDOR_DEPENDENT:
  		break;
  	default:
  		return -EINVAL;
  	}

  	return init_request(client, &arg->send_request, client->device->node_id,

  			    client->device->max_speed);
  }

  static inline bool is_fcp_request(struct fw_request *request)
  {
  	return request == NULL;
  }

  static void release_request(struct client *client,
  			    struct client_resource *resource)

  {

  	struct inbound_transaction_resource *r = container_of(resource,
  			struct inbound_transaction_resource, resource);

  	if (is_fcp_request(r->request))
  		kfree(r->data);
  	else

  		fw_send_response(r->card, r->request, RCODE_CONFLICT_ERROR);

  
  	fw_card_put(r->card);

  	kfree(r);

  }

  static void handle_request(struct fw_card *card, struct fw_request *request,

  			   int tcode, int destination, int source,

  			   int generation, unsigned long long offset,

  			   void *payload, size_t length, void *callback_data)

  {

  	struct address_handler_resource *handler = callback_data;
  	struct inbound_transaction_resource *r;
  	struct inbound_transaction_event *e;

  	size_t event_size0;

  	void *fcp_frame = NULL;

  	int ret;

  	/* card may be different from handler->client->device->card */
  	fw_card_get(card);

  	r = kmalloc(sizeof(*r), GFP_ATOMIC);

  	e = kmalloc(sizeof(*e), GFP_ATOMIC);

  	if (r == NULL || e == NULL)

  		goto failed;

  	r->card    = card;

  	r->request = request;
  	r->data    = payload;
  	r->length  = length;

  	if (is_fcp_request(request)) {
  		/*
  		 * FIXME: Let core-transaction.c manage a
  		 * single reference-counted copy?
  		 */
  		fcp_frame = kmemdup(payload, length, GFP_ATOMIC);
  		if (fcp_frame == NULL)
  			goto failed;
  
  		r->data = fcp_frame;
  	}

  	r->resource.release = release_request;
  	ret = add_client_resource(handler->client, &r->resource, GFP_ATOMIC);

  	if (ret < 0)
  		goto failed;

  	if (handler->client->version < FW_CDEV_VERSION_EVENT_REQUEST2) {
  		struct fw_cdev_event_request *req = &e->req.request;
  
  		if (tcode & 0x10)
  			tcode = TCODE_LOCK_REQUEST;
  
  		req->type	= FW_CDEV_EVENT_REQUEST;
  		req->tcode	= tcode;
  		req->offset	= offset;
  		req->length	= length;
  		req->handle	= r->resource.handle;
  		req->closure	= handler->closure;
  		event_size0	= sizeof(*req);
  	} else {
  		struct fw_cdev_event_request2 *req = &e->req.request2;
  
  		req->type	= FW_CDEV_EVENT_REQUEST2;
  		req->tcode	= tcode;
  		req->offset	= offset;
  		req->source_node_id = source;
  		req->destination_node_id = destination;
  		req->card	= card->index;
  		req->generation	= generation;
  		req->length	= length;
  		req->handle	= r->resource.handle;
  		req->closure	= handler->closure;
  		event_size0	= sizeof(*req);
  	}

  	queue_event(handler->client, &e->event,

  		    &e->req, event_size0, r->data, length);

  	return;
  
   failed:

  	kfree(r);

  	kfree(e);

  	kfree(fcp_frame);
  
  	if (!is_fcp_request(request))

  		fw_send_response(card, request, RCODE_CONFLICT_ERROR);

  
  	fw_card_put(card);

  }

  static void release_address_handler(struct client *client,
  				    struct client_resource *resource)

  {

  	struct address_handler_resource *r =
  	    container_of(resource, struct address_handler_resource, resource);

  	fw_core_remove_address_handler(&r->handler);
  	kfree(r);

  }

  static int ioctl_allocate(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_allocate *a = &arg->allocate;

  	struct address_handler_resource *r;

  	struct fw_address_region region;

  	int ret;

  	r = kmalloc(sizeof(*r), GFP_KERNEL);
  	if (r == NULL)

  		return -ENOMEM;

  	region.start = a->offset;

  	if (client->version < FW_CDEV_VERSION_ALLOCATE_REGION_END)
  		region.end = a->offset + a->length;
  	else
  		region.end = a->region_end;

  	r->handler.length           = a->length;

  	r->handler.address_callback = handle_request;

  	r->handler.callback_data    = r;
  	r->closure   = a->closure;
  	r->client    = client;

  	ret = fw_core_add_address_handler(&r->handler, &region);

  	if (ret < 0) {

  		kfree(r);

  		return ret;

  	}

  	a->offset = r->handler.offset;

  	r->resource.release = release_address_handler;
  	ret = add_client_resource(client, &r->resource, GFP_KERNEL);

  	if (ret < 0) {

  		release_address_handler(client, &r->resource);

  		return ret;
  	}

  	a->handle = r->resource.handle;

  
  	return 0;
  }

  static int ioctl_deallocate(struct client *client, union ioctl_arg *arg)

  {

  	return release_client_resource(client, arg->deallocate.handle,

  				       release_address_handler, NULL);

  }

  static int ioctl_send_response(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_send_response *a = &arg->send_response;

  	struct client_resource *resource;

  	struct inbound_transaction_resource *r;

  	int ret = 0;

  	if (release_client_resource(client, a->handle,

  				    release_request, &resource) < 0)

  		return -EINVAL;

  	r = container_of(resource, struct inbound_transaction_resource,
  			 resource);

  	if (is_fcp_request(r->request))
  		goto out;

  	if (a->length != fw_get_response_length(r->request)) {
  		ret = -EINVAL;
  		kfree(r->request);
  		goto out;
  	}
  	if (copy_from_user(r->data, u64_to_uptr(a->data), a->length)) {

  		ret = -EFAULT;
  		kfree(r->request);
  		goto out;

  	}

  	fw_send_response(r->card, r->request, a->rcode);

   out:

  	fw_card_put(r->card);

  	kfree(r);

  	return ret;

  }

  static int ioctl_initiate_bus_reset(struct client *client, union ioctl_arg *arg)

  {

  	fw_schedule_bus_reset(client->device->card, true,

  			arg->initiate_bus_reset.type == FW_CDEV_SHORT_RESET);

  	return 0;

  }

  static void release_descriptor(struct client *client,
  			       struct client_resource *resource)
  {

  	struct descriptor_resource *r =
  		container_of(resource, struct descriptor_resource, resource);

  	fw_core_remove_descriptor(&r->descriptor);
  	kfree(r);

  }

  static int ioctl_add_descriptor(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_add_descriptor *a = &arg->add_descriptor;

  	struct descriptor_resource *r;

  	int ret;

  	/* Access policy: Allow this ioctl only on local nodes' device files. */

  	if (!client->device->is_local)

  		return -ENOSYS;

  	if (a->length > 256)

  		return -EINVAL;

  	r = kmalloc(sizeof(*r) + a->length * 4, GFP_KERNEL);

  	if (r == NULL)

  		return -ENOMEM;

  	if (copy_from_user(r->data, u64_to_uptr(a->data), a->length * 4)) {

  		ret = -EFAULT;
  		goto failed;

  	}

  	r->descriptor.length    = a->length;
  	r->descriptor.immediate = a->immediate;
  	r->descriptor.key       = a->key;

  	r->descriptor.data      = r->data;

  	ret = fw_core_add_descriptor(&r->descriptor);

  	if (ret < 0)
  		goto failed;

  	r->resource.release = release_descriptor;
  	ret = add_client_resource(client, &r->resource, GFP_KERNEL);

  	if (ret < 0) {

  		fw_core_remove_descriptor(&r->descriptor);

  		goto failed;
  	}

  	a->handle = r->resource.handle;

  
  	return 0;

   failed:

  	kfree(r);

  
  	return ret;

  }

  static int ioctl_remove_descriptor(struct client *client, union ioctl_arg *arg)

  {

  	return release_client_resource(client, arg->remove_descriptor.handle,

  				       release_descriptor, NULL);

  }

  static void iso_callback(struct fw_iso_context *context, u32 cycle,
  			 size_t header_length, void *header, void *data)

  {
  	struct client *client = data;

  	struct iso_interrupt_event *e;

  	e = kmalloc(sizeof(*e) + header_length, GFP_ATOMIC);

  	if (e == NULL)

  		return;

  	e->interrupt.type      = FW_CDEV_EVENT_ISO_INTERRUPT;
  	e->interrupt.closure   = client->iso_closure;
  	e->interrupt.cycle     = cycle;
  	e->interrupt.header_length = header_length;
  	memcpy(e->interrupt.header, header, header_length);
  	queue_event(client, &e->event, &e->interrupt,
  		    sizeof(e->interrupt) + header_length, NULL, 0);

  }

  static void iso_mc_callback(struct fw_iso_context *context,
  			    dma_addr_t completed, void *data)
  {
  	struct client *client = data;
  	struct iso_interrupt_mc_event *e;
  
  	e = kmalloc(sizeof(*e), GFP_ATOMIC);

  	if (e == NULL)

  		return;

  	e->interrupt.type      = FW_CDEV_EVENT_ISO_INTERRUPT_MULTICHANNEL;
  	e->interrupt.closure   = client->iso_closure;
  	e->interrupt.completed = fw_iso_buffer_lookup(&client->buffer,
  						      completed);
  	queue_event(client, &e->event, &e->interrupt,
  		    sizeof(e->interrupt), NULL, 0);
  }

  static enum dma_data_direction iso_dma_direction(struct fw_iso_context *context)
  {
  		if (context->type == FW_ISO_CONTEXT_TRANSMIT)
  			return DMA_TO_DEVICE;
  		else
  			return DMA_FROM_DEVICE;
  }

  static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_create_iso_context *a = &arg->create_iso_context;

  	struct fw_iso_context *context;

  	fw_iso_callback_t cb;

  	int ret;

  	BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT ||

  		     FW_CDEV_ISO_CONTEXT_RECEIVE  != FW_ISO_CONTEXT_RECEIVE  ||
  		     FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL !=
  					FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL);

  	switch (a->type) {

  	case FW_ISO_CONTEXT_TRANSMIT:
  		if (a->speed > SCODE_3200 || a->channel > 63)

  			return -EINVAL;

  
  		cb = iso_callback;

  		break;

  	case FW_ISO_CONTEXT_RECEIVE:
  		if (a->header_size < 4 || (a->header_size & 3) ||
  		    a->channel > 63)

  			return -EINVAL;

  
  		cb = iso_callback;
  		break;
  
  	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
  		cb = (fw_iso_callback_t)iso_mc_callback;

  		break;
  
  	default:

  		return -EINVAL;

  	}

  	context = fw_iso_context_create(client->device->card, a->type,

  			a->channel, a->speed, a->header_size, cb, client);

  	if (IS_ERR(context))
  		return PTR_ERR(context);

  	/* We only support one context at this time. */
  	spin_lock_irq(&client->lock);
  	if (client->iso_context != NULL) {
  		spin_unlock_irq(&client->lock);
  		fw_iso_context_destroy(context);

  		return -EBUSY;
  	}

  	if (!client->buffer_is_mapped) {
  		ret = fw_iso_buffer_map_dma(&client->buffer,
  					    client->device->card,
  					    iso_dma_direction(context));
  		if (ret < 0) {
  			spin_unlock_irq(&client->lock);
  			fw_iso_context_destroy(context);
  
  			return ret;
  		}
  		client->buffer_is_mapped = true;
  	}

  	client->iso_closure = a->closure;

  	client->iso_context = context;

  	spin_unlock_irq(&client->lock);

  	a->handle = 0;

  	return 0;
  }

  static int ioctl_set_iso_channels(struct client *client, union ioctl_arg *arg)
  {
  	struct fw_cdev_set_iso_channels *a = &arg->set_iso_channels;
  	struct fw_iso_context *ctx = client->iso_context;
  
  	if (ctx == NULL || a->handle != 0)
  		return -EINVAL;
  
  	return fw_iso_context_set_channels(ctx, &a->channels);
  }

  /* Macros for decoding the iso packet control header. */
  #define GET_PAYLOAD_LENGTH(v)	((v) & 0xffff)
  #define GET_INTERRUPT(v)	(((v) >> 16) & 0x01)
  #define GET_SKIP(v)		(((v) >> 17) & 0x01)

  #define GET_TAG(v)		(((v) >> 18) & 0x03)
  #define GET_SY(v)		(((v) >> 20) & 0x0f)

  #define GET_HEADER_LENGTH(v)	(((v) >> 24) & 0xff)

  static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_queue_iso *a = &arg->queue_iso;

  	struct fw_cdev_iso_packet __user *p, *end, *next;

  	struct fw_iso_context *ctx = client->iso_context;

  	unsigned long payload, buffer_end, transmit_header_bytes = 0;

  	u32 control;

  	int count;
  	struct {
  		struct fw_iso_packet packet;
  		u8 header[256];
  	} u;

  	if (ctx == NULL || a->handle != 0)

  		return -EINVAL;

  	/*
  	 * If the user passes a non-NULL data pointer, has mmap()'ed

  	 * the iso buffer, and the pointer points inside the buffer,
  	 * we setup the payload pointers accordingly.  Otherwise we

  	 * set them both to 0, which will still let packets with

  	 * payload_length == 0 through.  In other words, if no packets
  	 * use the indirect payload, the iso buffer need not be mapped

  	 * and the a->data pointer is ignored.

  	 */

  	payload = (unsigned long)a->data - client->vm_start;

  	buffer_end = client->buffer.page_count << PAGE_SHIFT;

  	if (a->data == 0 || client->buffer.pages == NULL ||

  	    payload >= buffer_end) {

  		payload = 0;

  		buffer_end = 0;

  	}

  	if (ctx->type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL && payload & 3)
  		return -EINVAL;

  	p = (struct fw_cdev_iso_packet __user *)u64_to_uptr(a->packets);

  	if (!access_ok(VERIFY_READ, p, a->size))

  		return -EFAULT;

  	end = (void __user *)p + a->size;

  	count = 0;
  	while (p < end) {

  		if (get_user(control, &p->control))

  			return -EFAULT;

  		u.packet.payload_length = GET_PAYLOAD_LENGTH(control);
  		u.packet.interrupt = GET_INTERRUPT(control);
  		u.packet.skip = GET_SKIP(control);
  		u.packet.tag = GET_TAG(control);
  		u.packet.sy = GET_SY(control);
  		u.packet.header_length = GET_HEADER_LENGTH(control);

  		switch (ctx->type) {
  		case FW_ISO_CONTEXT_TRANSMIT:
  			if (u.packet.header_length & 3)

  				return -EINVAL;

  			transmit_header_bytes = u.packet.header_length;

  			break;
  
  		case FW_ISO_CONTEXT_RECEIVE:

  			if (u.packet.header_length == 0 ||
  			    u.packet.header_length % ctx->header_size != 0)

  				return -EINVAL;

  			break;
  
  		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
  			if (u.packet.payload_length == 0 ||
  			    u.packet.payload_length & 3)

  				return -EINVAL;

  			break;

  		}

  		next = (struct fw_cdev_iso_packet __user *)

  			&p->header[transmit_header_bytes / 4];

  		if (next > end)
  			return -EINVAL;
  		if (__copy_from_user

  		    (u.packet.header, p->header, transmit_header_bytes))

  			return -EFAULT;

  		if (u.packet.skip && ctx->type == FW_ISO_CONTEXT_TRANSMIT &&

  		    u.packet.header_length + u.packet.payload_length > 0)
  			return -EINVAL;

  		if (payload + u.packet.payload_length > buffer_end)

  			return -EINVAL;

  		if (fw_iso_context_queue(ctx, &u.packet,
  					 &client->buffer, payload))

  			break;
  
  		p = next;
  		payload += u.packet.payload_length;
  		count++;
  	}

  	fw_iso_context_queue_flush(ctx);

  	a->size    -= uptr_to_u64(p) - a->packets;
  	a->packets  = uptr_to_u64(p);
  	a->data     = client->vm_start + payload;

  
  	return count;
  }

  static int ioctl_start_iso(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_start_iso *a = &arg->start_iso;

  	BUILD_BUG_ON(
  	    FW_CDEV_ISO_CONTEXT_MATCH_TAG0 != FW_ISO_CONTEXT_MATCH_TAG0 ||
  	    FW_CDEV_ISO_CONTEXT_MATCH_TAG1 != FW_ISO_CONTEXT_MATCH_TAG1 ||
  	    FW_CDEV_ISO_CONTEXT_MATCH_TAG2 != FW_ISO_CONTEXT_MATCH_TAG2 ||
  	    FW_CDEV_ISO_CONTEXT_MATCH_TAG3 != FW_ISO_CONTEXT_MATCH_TAG3 ||
  	    FW_CDEV_ISO_CONTEXT_MATCH_ALL_TAGS != FW_ISO_CONTEXT_MATCH_ALL_TAGS);

  	if (client->iso_context == NULL || a->handle != 0)

  		return -EINVAL;

  	if (client->iso_context->type == FW_ISO_CONTEXT_RECEIVE &&
  	    (a->tags == 0 || a->tags > 15 || a->sync > 15))
  		return -EINVAL;

  	return fw_iso_context_start(client->iso_context,
  				    a->cycle, a->sync, a->tags);

  }

  static int ioctl_stop_iso(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_stop_iso *a = &arg->stop_iso;

  	if (client->iso_context == NULL || a->handle != 0)

  		return -EINVAL;

  	return fw_iso_context_stop(client->iso_context);
  }

  static int ioctl_flush_iso(struct client *client, union ioctl_arg *arg)
  {
  	struct fw_cdev_flush_iso *a = &arg->flush_iso;
  
  	if (client->iso_context == NULL || a->handle != 0)
  		return -EINVAL;
  
  	return fw_iso_context_flush_completions(client->iso_context);
  }

  static int ioctl_get_cycle_timer2(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_get_cycle_timer2 *a = &arg->get_cycle_timer2;

  	struct fw_card *card = client->device->card;

  	struct timespec ts = {0, 0};

  	u32 cycle_time;

  	int ret = 0;

  	local_irq_disable();

  	cycle_time = card->driver->read_csr(card, CSR_CYCLE_TIME);

  	switch (a->clk_id) {

  	case CLOCK_REALTIME:      getnstimeofday(&ts);                   break;
  	case CLOCK_MONOTONIC:     do_posix_clock_monotonic_gettime(&ts); break;
  	case CLOCK_MONOTONIC_RAW: getrawmonotonic(&ts);                  break;
  	default:
  		ret = -EINVAL;
  	}

  	local_irq_enable();

  	a->tv_sec      = ts.tv_sec;
  	a->tv_nsec     = ts.tv_nsec;
  	a->cycle_timer = cycle_time;

  
  	return ret;
  }

  static int ioctl_get_cycle_timer(struct client *client, union ioctl_arg *arg)

  {

  	struct fw_cdev_get_cycle_timer *a = &arg->get_cycle_timer;

  	struct fw_cdev_get_cycle_timer2 ct2;
  
  	ct2.clk_id = CLOCK_REALTIME;

  	ioctl_get_cycle_timer2(client, (union ioctl_arg *)&ct2);

  	a->local_time = ct2.tv_sec * USEC_PER_SEC + ct2.tv_nsec / NSEC_PER_USEC;
  	a->cycle_timer = ct2.cycle_timer;

  	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_before64(get_jiffies_64(),
  			  client->device->card->reset_jiffies + HZ)) {

  		schedule_iso_resource(r, DIV_ROUND_UP(HZ, 3));

  		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 ||
  	       todo == ISO_RES_ALLOC_ONCE ||
  	       todo == ISO_RES_DEALLOC_ONCE;

  	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 ||

  			todo == ISO_RES_ALLOC_ONCE);

  	/*
  	 * 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 << channel;

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

  	if (todo == ISO_RES_ALLOC || todo == ISO_RES_ALLOC_ONCE) {

  		e = r->e_alloc;
  		r->e_alloc = NULL;
  	} else {
  		e = r->e_dealloc;
  		r->e_dealloc = NULL;
  	}

  	e->iso_resource.handle    = r->resource.handle;
  	e->iso_resource.channel   = channel;
  	e->iso_resource.bandwidth = bandwidth;

  
  	queue_event(client, &e->event,

  		    &e->iso_resource, sizeof(e->iso_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 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, 0);

  	spin_unlock_irq(&client->lock);
  }

  static int init_iso_resource(struct client *client,
  		struct fw_cdev_allocate_iso_resource *request, int todo)

  {

  	struct iso_resource_event *e1, *e2;
  	struct iso_resource *r;
  	int ret;
  
  	if ((request->channels == 0 && request->bandwidth == 0) ||

  	    request->bandwidth > BANDWIDTH_AVAILABLE_INITIAL)

  		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		= todo;

  	r->generation	= -1;
  	r->channels	= request->channels;
  	r->bandwidth	= request->bandwidth;
  	r->e_alloc	= e1;
  	r->e_dealloc	= e2;

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

  	if (todo == ISO_RES_ALLOC) {
  		r->resource.release = release_iso_resource;
  		ret = add_client_resource(client, &r->resource, GFP_KERNEL);

  		if (ret < 0)
  			goto fail;

  	} else {
  		r->resource.release = NULL;
  		r->resource.handle = -1;

  		schedule_iso_resource(r, 0);

  	}