fw-cdev.c

/*
 * 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/compat.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firewire-cdev.h>
#include <linux/idr.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/preempt.h>
#include <linux/spinlock.h>
#include <linux/time.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/workqueue.h>

#include <asm/system.h>
#include <asm/uaccess.h>

#include "fw-device.h"
#include "fw-topology.h"
#include "fw-transaction.h"

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;
	u64 bus_reset_closure;

	struct fw_iso_context *iso_context;
	u64 iso_closure;
	struct fw_iso_buffer buffer;
	unsigned long vm_start;

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

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

/*
 * 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;
	struct fw_cdev_event_request request;
};

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

struct iso_resource_event {
	struct event event;
	struct fw_cdev_event_iso_resource resource;
};

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;

	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;