[deliverable/linux.git] / drivers / firewire / fw-device-cdev.c

/*                                              -*- c-basic-offset: 8 -*-
 *
 * fw-device-cdev.c - Char device for device raw access
 *
 * Copyright (C) 2005-2006  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/module.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/vmalloc.h>
#include <linux/poll.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/compat.h>
#include <asm/uaccess.h>
#include "fw-transaction.h"
#include "fw-topology.h"
#include "fw-device.h"
#include "fw-device-cdev.h"

/*
 * todo
 *
 * - bus resets sends a new packet with new generation and node id
 *
 */

/* dequeue_event() just kfree()'s the event, so the event has to be
 * the first field in the struct. */

struct event {
        struct { void *data; size_t size; } v[2];
        struct list_head link;
};

struct bus_reset {
        struct event event;
        struct fw_cdev_event_bus_reset reset;
};

struct response {
        struct event event;
        struct fw_transaction transaction;
        struct client *client;
        struct fw_cdev_event_response response;
};

struct iso_interrupt {
        struct event event;
        struct fw_cdev_event_iso_interrupt interrupt;
};

struct client {
        struct fw_device *device;
        spinlock_t lock;
        struct list_head handler_list;
        struct list_head request_list;
        u32 request_serial;
        struct list_head event_list;
        struct semaphore event_list_sem;
        wait_queue_head_t wait;

        struct fw_iso_context *iso_context;
        struct fw_iso_buffer buffer;
        unsigned long vm_start;

        struct list_head link;
};

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;
}

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

        device = container_of(inode->i_cdev, struct fw_device, cdev);

        client = kzalloc(sizeof *client, GFP_KERNEL);
        if (client == NULL)
                return -ENOMEM;

        client->device = fw_device_get(device);
        INIT_LIST_HEAD(&client->event_list);
        sema_init(&client->event_list_sem, 0);
        INIT_LIST_HEAD(&client->handler_list);
        INIT_LIST_HEAD(&client->request_list);
        spin_lock_init(&client->lock);
        init_waitqueue_head(&client->wait);

        file->private_data = client;

        spin_lock_irqsave(&device->card->lock, flags);
        list_add_tail(&client->link, &device->client_list);
        spin_unlock_irqrestore(&device->card->lock, flags);

        return 0;
}

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);

        list_add_tail(&event->link, &client->event_list);

        up(&client->event_list_sem);
        wake_up_interruptible(&client->wait);

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

static int dequeue_event(struct client *client, char __user *buffer, size_t count)
{
        unsigned long flags;
        struct event *event;
        size_t size, total;
        int i, retval = -EFAULT;

        if (down_interruptible(&client->event_list_sem) < 0)
                return -EINTR;

        spin_lock_irqsave(&client->lock, flags);

        event = container_of(client->event_list.next, struct event, link);
        list_del(&event->link);

        spin_unlock_irqrestore(&client->lock, flags);

        if (buffer == NULL)
                goto out;

        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))
                        goto out;
                total += size;
        }
        retval = total;

 out:
        kfree(event);

        return retval;
}

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
queue_bus_reset_event(struct client *client)
{
        struct bus_reset *bus_reset;
        struct fw_device *device = client->device;
        struct fw_card *card = device->card;

        bus_reset = kzalloc(sizeof *bus_reset, GFP_ATOMIC);
        if (bus_reset == NULL) {
                fw_notify("Out of memory when allocating bus reset event\n");
                return;
        }

        bus_reset->reset.type          = FW_CDEV_EVENT_BUS_RESET;
        bus_reset->reset.node_id       = device->node_id;
        bus_reset->reset.local_node_id = card->local_node->node_id;
        bus_reset->reset.bm_node_id    = 0; /* FIXME: We don't track the BM. */
        bus_reset->reset.irm_node_id   = card->irm_node->node_id;
        bus_reset->reset.root_node_id  = card->root_node->node_id;
        bus_reset->reset.generation    = card->generation;

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

void fw_device_cdev_update(struct fw_device *device)
{
        struct fw_card *card = device->card;
        struct client *c;
        unsigned long flags;

        spin_lock_irqsave(&card->lock, flags);

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

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

static int ioctl_config_rom(struct client *client, void __user *arg)
{
        struct fw_cdev_get_config_rom rom;

        rom.length = client->device->config_rom_length;
        memcpy(rom.data, client->device->config_rom, rom.length * 4);
        if (copy_to_user(arg, &rom,
                         (char *)&rom.data[rom.length] - (char *)&rom))
                return -EFAULT;

        return 0;
}

static void
complete_transaction(struct fw_card *card, int rcode,
                     void *payload, size_t length, void *data)
{
        struct response *response = data;
        struct client *client = response->client;

        if (length < response->response.length)
                response->response.length = length;
        if (rcode == RCODE_COMPLETE)
                memcpy(response->response.data, payload,
                       response->response.length);

        response->response.type   = FW_CDEV_EVENT_RESPONSE;
        response->response.rcode  = rcode;
        queue_event(client, &response->event,
                    &response->response, sizeof response->response,
                    response->response.data, response->response.length);
}

static ssize_t ioctl_send_request(struct client *client, void __user *arg)
{
        struct fw_device *device = client->device;
        struct fw_cdev_send_request request;
        struct response *response;

        if (copy_from_user(&request, arg, sizeof request))
                return -EFAULT;

        /* What is the biggest size we'll accept, really? */
        if (request.length > 4096)
                return -EINVAL;

        response = kmalloc(sizeof *response + request.length, GFP_KERNEL);
        if (response == NULL)
                return -ENOMEM;

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

        if (request.data &&
            copy_from_user(response->response.data,
                           u64_to_uptr(request.data), request.length)) {
                kfree(response);
                return -EFAULT;
        }

        fw_send_request(device->card, &response->transaction,
                        request.tcode,
                        device->node->node_id,
                        device->card->generation,
                        device->node->max_speed,
                        request.offset,
                        response->response.data, request.length,
                        complete_transaction, response);

        if (request.data)
                return sizeof request + request.length;
        else
                return sizeof request;
}

struct address_handler {
        struct fw_address_handler handler;
        __u64 closure;
        struct client *client;
        struct list_head link;
};

struct request {
        struct fw_request *request;
        void *data;
        size_t length;
        u32 serial;
        struct list_head link;
};

struct request_event {
        struct event event;
        struct fw_cdev_event_request request;
};

static void
handle_request(struct fw_card *card, struct fw_request *r,
               int tcode, int destination, int source,
               int generation, int speed,
               unsigned long long offset,
               void *payload, size_t length, void *callback_data)
{
        struct address_handler *handler = callback_data;
        struct request *request;
        struct request_event *e;
        unsigned long flags;
        struct client *client = handler->client;

        request = kmalloc(sizeof *request, GFP_ATOMIC);
        e = kmalloc(sizeof *e, GFP_ATOMIC);
        if (request == NULL || e == NULL) {
                kfree(request);
                kfree(e);
                fw_send_response(card, r, RCODE_CONFLICT_ERROR);
                return;
        }

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

        spin_lock_irqsave(&client->lock, flags);
        request->serial = client->request_serial++;
        list_add_tail(&request->link, &client->request_list);
        spin_unlock_irqrestore(&client->lock, flags);

        e->request.type    = FW_CDEV_EVENT_REQUEST;
        e->request.tcode   = tcode;
        e->request.offset  = offset;
        e->request.length  = length;
        e->request.serial  = request->serial;
        e->request.closure = handler->closure;

        queue_event(client, &e->event,
                    &e->request, sizeof e->request, payload, length);
}

static int ioctl_allocate(struct client *client, void __user *arg)
{
        struct fw_cdev_allocate request;
        struct address_handler *handler;
        unsigned long flags;
        struct fw_address_region region;

        if (copy_from_user(&request, arg, sizeof request))
                return -EFAULT;

        handler = kmalloc(sizeof *handler, GFP_KERNEL);
        if (handler == NULL)
                return -ENOMEM;

        region.start = request.offset;
        region.end = request.offset + request.length;
        handler->handler.length = request.length;
        handler->handler.address_callback = handle_request;
        handler->handler.callback_data = handler;
        handler->closure = request.closure;
        handler->client = client;

        if (fw_core_add_address_handler(&handler->handler, &region) < 0) {
                kfree(handler);
                return -EBUSY;
        }

        spin_lock_irqsave(&client->lock, flags);
        list_add_tail(&handler->link, &client->handler_list);
        spin_unlock_irqrestore(&client->lock, flags);

        return 0;
}

static int ioctl_send_response(struct client *client, void __user *arg)
{
        struct fw_cdev_send_response request;
        struct request *r;
        unsigned long flags;

        if (copy_from_user(&request, arg, sizeof request))
                return -EFAULT;

        spin_lock_irqsave(&client->lock, flags);
        list_for_each_entry(r, &client->request_list, link) {
                if (r->serial == request.serial) {
                        list_del(&r->link);
                        break;
                }
        }
        spin_unlock_irqrestore(&client->lock, flags);

        if (&r->link == &client->request_list)
                return -EINVAL;

        if (request.length < r->length)
                r->length = request.length;
        if (copy_from_user(r->data, u64_to_uptr(request.data), r->length))
                return -EFAULT;

        fw_send_response(client->device->card, r->request, request.rcode);

        kfree(r);

        return 0;
}

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 *interrupt;

        interrupt = kzalloc(sizeof *interrupt + header_length, GFP_ATOMIC);
        if (interrupt == NULL)
                return;

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

static int ioctl_create_iso_context(struct client *client, void __user *arg)
{
        struct fw_cdev_create_iso_context request;

        if (copy_from_user(&request, arg, sizeof request))
                return -EFAULT;

        if (request.type > FW_ISO_CONTEXT_RECEIVE)
                return -EINVAL;

        if (request.channel > 63)
                return -EINVAL;

        if (request.sync > 15)
                return -EINVAL;

        if (request.tags == 0 || request.tags > 15)
                return -EINVAL;

        if (request.speed > SCODE_3200)
                return -EINVAL;

        client->iso_context = fw_iso_context_create(client->device->card,
                                                    request.type,
                                                    request.channel,
                                                    request.speed,
                                                    request.header_size,
                                                    request.sync,
                                                    request.tags,
                                                    iso_callback, client);
        if (IS_ERR(client->iso_context))
                return PTR_ERR(client->iso_context);

        return 0;
}

static int ioctl_queue_iso(struct client *client, void __user *arg)
{
        struct fw_cdev_queue_iso request;
        struct fw_cdev_iso_packet __user *p, *end, *next;
        struct fw_iso_context *ctx = client->iso_context;
        unsigned long payload, payload_end, header_length;
        int count;
        struct {
                struct fw_iso_packet packet;
                u8 header[256];
        } u;

        if (ctx == NULL)
                return -EINVAL;
        if (copy_from_user(&request, arg, sizeof request))
                return -EFAULT;

        /* 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 request.data pointer is ignored.*/

        payload = (unsigned long)request.data - client->vm_start;
        payload_end = payload + (client->buffer.page_count << PAGE_SHIFT);
        if (request.data == 0 || client->buffer.pages == NULL ||
            payload >= payload_end) {
                payload = 0;
                payload_end = 0;
        }

        if (!access_ok(VERIFY_READ, request.packets, request.size))
                return -EFAULT;

        p = (struct fw_cdev_iso_packet __user *)u64_to_uptr(request.packets);
        end = (void __user *)p + request.size;
        count = 0;
        while (p < end) {
                if (__copy_from_user(&u.packet, p, sizeof *p))
                        return -EFAULT;

                if (ctx->type == FW_ISO_CONTEXT_TRANSMIT) {
                        header_length = u.packet.header_length;
                } else {
                        /* We require that header_length is a multiple of
                         * the fixed header size, ctx->header_size */
                        if (ctx->header_size == 0) {
                                if (u.packet.header_length > 0)
                                        return -EINVAL;
                        } else if (u.packet.header_length % ctx->header_size != 0) {
                                return -EINVAL;
                        }
                        header_length = 0;
                }

                next = (struct fw_cdev_iso_packet __user *)
                        &p->header[header_length / 4];
                if (next > end)
                        return -EINVAL;
                if (__copy_from_user
                    (u.packet.header, p->header, header_length))
                        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 > payload_end)
                        return -EINVAL;

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

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

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

        if (copy_to_user(arg, &request, sizeof request))
                return -EFAULT;

        return count;
}

static int ioctl_start_iso(struct client *client, void __user *arg)
{
        struct fw_cdev_start_iso request;

        if (copy_from_user(&request, arg, sizeof request))
                return -EFAULT;

        return fw_iso_context_start(client->iso_context, request.cycle);
}

static int ioctl_stop_iso(struct client *client, void __user *arg)
{
        return fw_iso_context_stop(client->iso_context);
}

static int
dispatch_ioctl(struct client *client, unsigned int cmd, void __user *arg)
{
        switch (cmd) {
        case FW_CDEV_IOC_GET_CONFIG_ROM:
                return ioctl_config_rom(client, arg);
        case FW_CDEV_IOC_SEND_REQUEST:
                return ioctl_send_request(client, arg);
        case FW_CDEV_IOC_ALLOCATE:
                return ioctl_allocate(client, arg);
        case FW_CDEV_IOC_SEND_RESPONSE:
                return ioctl_send_response(client, arg);
        case FW_CDEV_IOC_CREATE_ISO_CONTEXT:
                return ioctl_create_iso_context(client, arg);
        case FW_CDEV_IOC_QUEUE_ISO:
                return ioctl_queue_iso(client, arg);
        case FW_CDEV_IOC_START_ISO:
                return ioctl_start_iso(client, arg);
        case FW_CDEV_IOC_STOP_ISO:
                return ioctl_stop_iso(client, arg);
        default:
                return -EINVAL;
        }
}

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

        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;

        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, retval;

        /* 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;

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

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

        return retval;
}

static int fw_device_op_release(struct inode *inode, struct file *file)
{
        struct client *client = file->private_data;
        struct address_handler *h, *next;
        struct request *r, *next_r;
        unsigned long flags;

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

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

        list_for_each_entry_safe(h, next, &client->handler_list, link) {
                fw_core_remove_address_handler(&h->handler);
                kfree(h);
        }

        list_for_each_entry_safe(r, next_r, &client->request_list, link) {
                fw_send_response(client->device->card, r->request,
                                 RCODE_CONFLICT_ERROR);
                kfree(r);
        }

        /* TODO: wait for all transactions to finish so
         * complete_transaction doesn't try to queue up responses
         * after we free client. */
        while (!list_empty(&client->event_list))
                dequeue_event(client, NULL, 0);

        spin_lock_irqsave(&client->device->card->lock, flags);
        list_del(&client->link);
        spin_unlock_irqrestore(&client->device->card->lock, flags);

        fw_device_put(client->device);
        kfree(client);

        return 0;
}

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

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

        if (!list_empty(&client->event_list))
                return POLLIN | POLLRDNORM;
        else
                return 0;
}

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
};