core-cdev.c

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/*
 * Char device for device raw access
 *
 * Copyright (C) 2005-2007  Kristian Hoegsberg <[email protected]>
 *
 * 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) {
        fw_notice(client->device->card, "out of memory when allocating event\n");
        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)
{
    unsigned long flags;
    int ret;

 retry:
    if (idr_pre_get(&client->resource_idr, gfp_mask) == 0)
        return -ENOMEM;

    spin_lock_irqsave(&client->lock, flags);
    if (client->in_shutdown)
        ret = -ECANCELED;
    else
        ret = idr_get_new(&client->resource_idr, resource,
                  &resource->handle);
    if (ret >= 0) {
        client_get(client);
        schedule_if_iso_resource(resource);
    }
    spin_unlock_irqrestore(&client->lock, flags);

    if (ret == -EAGAIN)
        goto retry;

    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) {
        fw_notice(card, "out of memory when allocating event\n");
        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) {
        fw_notice(context->card, "out of memory when allocating event\n");
        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) {
        fw_notice(context->card, "out of memory when allocating event\n");
        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 ||
        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     = 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);
    }
    request->handle = r->resource.handle;

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

    return ret;
}

static int ioctl_allocate_iso_resource(struct client *client,
                       union ioctl_arg *arg)
{
    return init_iso_resource(client,
            &arg->allocate_iso_resource, ISO_RES_ALLOC);
}

static int ioctl_deallocate_iso_resource(struct client *client,
                     union ioctl_arg *arg)
{
    return release_client_resource(client,
            arg->deallocate.handle, release_iso_resource, NULL);
}

static int ioctl_allocate_iso_resource_once(struct client *client,
                        union ioctl_arg *arg)
{
    return init_iso_resource(client,
            &arg->allocate_iso_resource, ISO_RES_ALLOC_ONCE);
}

static int ioctl_deallocate_iso_resource_once(struct client *client,
                          union ioctl_arg *arg)
{
    return init_iso_resource(client,
            &arg->allocate_iso_resource, ISO_RES_DEALLOC_ONCE);
}

/*
 * Returns a speed code:  Maximum speed to or from this device,
 * limited by the device's link speed, the local node's link speed,
 * and all PHY port speeds between the two links.
 */
static int ioctl_get_speed(struct client *client, union ioctl_arg *arg)
{
    return client->device->max_speed;
}

static int ioctl_send_broadcast_request(struct client *client,
                    union ioctl_arg *arg)
{
    struct fw_cdev_send_request *a = &arg->send_request;

    switch (a->tcode) {
    case TCODE_WRITE_QUADLET_REQUEST:
    case TCODE_WRITE_BLOCK_REQUEST:
        break;
    default:
        return -EINVAL;
    }

    /* Security policy: Only allow accesses to Units Space. */
    if (a->offset < CSR_REGISTER_BASE + CSR_CONFIG_ROM_END)
        return -EACCES;

    return init_request(client, a, LOCAL_BUS | 0x3f, SCODE_100);
}

static int ioctl_send_stream_packet(struct client *client, union ioctl_arg *arg)
{
    struct fw_cdev_send_stream_packet *a = &arg->send_stream_packet;
    struct fw_cdev_send_request request;
    int dest;

    if (a->speed > client->device->card->link_speed ||
        a->length > 1024 << a->speed)
        return -EIO;

    if (a->tag > 3 || a->channel > 63 || a->sy > 15)
        return -EINVAL;

    dest = fw_stream_packet_destination_id(a->tag, a->channel, a->sy);
    request.tcode       = TCODE_STREAM_DATA;
    request.length      = a->length;
    request.closure     = a->closure;
    request.data        = a->data;
    request.generation  = a->generation;

    return init_request(client, &request, dest, a->speed);
}

static void outbound_phy_packet_callback(struct fw_packet *packet,
                     struct fw_card *card, int status)
{
    struct outbound_phy_packet_event *e =
        container_of(packet, struct outbound_phy_packet_event, p);

    switch (status) {
    /* expected: */
    case ACK_COMPLETE:  e->phy_packet.rcode = RCODE_COMPLETE;   break;
    /* should never happen with PHY packets: */
    case ACK_PENDING:   e->phy_packet.rcode = RCODE_COMPLETE;   break;
    case ACK_BUSY_X:
    case ACK_BUSY_A:
    case ACK_BUSY_B:    e->phy_packet.rcode = RCODE_BUSY;   break;
    case ACK_DATA_ERROR:    e->phy_packet.rcode = RCODE_DATA_ERROR; break;
    case ACK_TYPE_ERROR:    e->phy_packet.rcode = RCODE_TYPE_ERROR; break;
    /* stale generation; cancelled; on certain controllers: no ack */
    default:        e->phy_packet.rcode = status;       break;
    }
    e->phy_packet.data[0] = packet->timestamp;

    queue_event(e->client, &e->event, &e->phy_packet,
            sizeof(e->phy_packet) + e->phy_packet.length, NULL, 0);
    client_put(e->client);
}

static int ioctl_send_phy_packet(struct client *client, union ioctl_arg *arg)
{
    struct fw_cdev_send_phy_packet *a = &arg->send_phy_packet;
    struct fw_card *card = client->device->card;
    struct outbound_phy_packet_event *e;

    /* Access policy: Allow this ioctl only on local nodes' device files. */
    if (!client->device->is_local)
        return -ENOSYS;

    e = kzalloc(sizeof(*e) + 4, GFP_KERNEL);
    if (e == NULL)
        return -ENOMEM;

    client_get(client);
    e->client       = client;
    e->p.speed      = SCODE_100;
    e->p.generation     = a->generation;
    e->p.header[0]      = TCODE_LINK_INTERNAL << 4;
    e->p.header[1]      = a->data[0];
    e->p.header[2]      = a->data[1];
    e->p.header_length  = 12;
    e->p.callback       = outbound_phy_packet_callback;
    e->phy_packet.closure   = a->closure;
    e->phy_packet.type  = FW_CDEV_EVENT_PHY_PACKET_SENT;
    if (is_ping_packet(a->data))
            e->phy_packet.length = 4;

    card->driver->send_request(card, &e->p);

    return 0;
}

static int ioctl_receive_phy_packets(struct client *client, union ioctl_arg *arg)
{
    struct fw_cdev_receive_phy_packets *a = &arg->receive_phy_packets;
    struct fw_card *card = client->device->card;

    /* Access policy: Allow this ioctl only on local nodes' device files. */
    if (!client->device->is_local)
        return -ENOSYS;

    spin_lock_irq(&card->lock);

    list_move_tail(&client->phy_receiver_link, &card->phy_receiver_list);
    client->phy_receiver_closure = a->closure;

    spin_unlock_irq(&card->lock);

    return 0;
}

void fw_cdev_handle_phy_packet(struct fw_card *card, struct fw_packet *p)
{
    struct client *client;
    struct inbound_phy_packet_event *e;
    unsigned long flags;

    spin_lock_irqsave(&card->lock, flags);

    list_for_each_entry(client, &card->phy_receiver_list, phy_receiver_link) {
        e = kmalloc(sizeof(*e) + 8, GFP_ATOMIC);
        if (e == NULL) {
            fw_notice(card, "out of memory when allocating event\n");
            break;
        }
        e->phy_packet.closure   = client->phy_receiver_closure;
        e->phy_packet.type  = FW_CDEV_EVENT_PHY_PACKET_RECEIVED;
        e->phy_packet.rcode = RCODE_COMPLETE;
        e->phy_packet.length    = 8;
        e->phy_packet.data[0]   = p->header[1];
        e->phy_packet.data[1]   = p->header[2];
        queue_event(client, &e->event,
                &e->phy_packet, sizeof(e->phy_packet) + 8, NULL, 0);
    }

    spin_unlock_irqrestore(&card->lock, flags);
}

static int (* const ioctl_handlers[])(struct client *, union ioctl_arg *) = {
    [0x00] = ioctl_get_info,
    [0x01] = ioctl_send_request,
    [0x02] = ioctl_allocate,
    [0x03] = ioctl_deallocate,
    [0x04] = ioctl_send_response,
    [0x05] = ioctl_initiate_bus_reset,
    [0x06] = ioctl_add_descriptor,
    [0x07] = ioctl_remove_descriptor,
    [0x08] = ioctl_create_iso_context,
    [0x09] = ioctl_queue_iso,
    [0x0a] = ioctl_start_iso,
    [0x0b] = ioctl_stop_iso,
    [0x0c] = ioctl_get_cycle_timer,
    [0x0d] = ioctl_allocate_iso_resource,
    [0x0e] = ioctl_deallocate_iso_resource,
    [0x0f] = ioctl_allocate_iso_resource_once,
    [0x10] = ioctl_deallocate_iso_resource_once,
    [0x11] = ioctl_get_speed,
    [0x12] = ioctl_send_broadcast_request,
    [0x13] = ioctl_send_stream_packet,
    [0x14] = ioctl_get_cycle_timer2,
    [0x15] = ioctl_send_phy_packet,
    [0x16] = ioctl_receive_phy_packets,
    [0x17] = ioctl_set_iso_channels,
    [0x18] = ioctl_flush_iso,
};

static int dispatch_ioctl(struct client *client,
              unsigned int cmd, void __user *arg)
{
    union ioctl_arg buffer;
    int ret;

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

    if (_IOC_TYPE(cmd) != '#' ||
        _IOC_NR(cmd) >= ARRAY_SIZE(ioctl_handlers) ||
        _IOC_SIZE(cmd) > sizeof(buffer))
        return -ENOTTY;

    if (_IOC_DIR(cmd) == _IOC_READ)
        memset(&buffer, 0, _IOC_SIZE(cmd));

    if (_IOC_DIR(cmd) & _IOC_WRITE)
        if (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 (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)
{
    return dispatch_ioctl(file->private_data, cmd, (void __user *)arg);
}

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

    ret = fw_iso_buffer_alloc(&client->buffer, page_count);
    if (ret < 0)
        return ret;

    spin_lock_irq(&client->lock);
    if (client->iso_context) {
        ret = fw_iso_buffer_map_dma(&client->buffer,
                client->device->card,
                iso_dma_direction(client->iso_context));
        client->buffer_is_mapped = (ret == 0);
    }
    spin_unlock_irq(&client->lock);
    if (ret < 0)
        goto fail;

    ret = fw_iso_buffer_map_vma(&client->buffer, vma);
    if (ret < 0)
        goto fail;

    return 0;
 fail:
    fw_iso_buffer_destroy(&client->buffer, client->device->card);
    return ret;
}

static int is_outbound_transaction_resource(int id, void *p, void *data)
{
    struct client_resource *resource = p;

    return resource->release == release_transaction;
}

static int has_outbound_transactions(struct client *client)
{
    int ret;

    spin_lock_irq(&client->lock);
    ret = idr_for_each(&client->resource_idr,
               is_outbound_transaction_resource, NULL);
    spin_unlock_irq(&client->lock);

    return ret;
}

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

    resource->release(client, resource);
    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 *event, *next_event;

    spin_lock_irq(&client->device->card->lock);
    list_del(&client->phy_receiver_link);
    spin_unlock_irq(&client->device->card->lock);

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

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

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

    /* Freeze client->resource_idr and client->event_list */
    spin_lock_irq(&client->lock);
    client->in_shutdown = true;
    spin_unlock_irq(&client->lock);

    wait_event(client->tx_flush_wait, !has_outbound_transactions(client));

    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(event, next_event, &client->event_list, link)
        kfree(event);

    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,
    .llseek     = no_llseek,
    .open       = fw_device_op_open,
    .read       = fw_device_op_read,
    .unlocked_ioctl = fw_device_op_ioctl,
    .mmap       = fw_device_op_mmap,
    .release    = fw_device_op_release,
    .poll       = fw_device_op_poll,
#ifdef CONFIG_COMPAT
    .compat_ioctl   = fw_device_op_compat_ioctl,
#endif
};