fw-cdev.c

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/*
 * Char device for device raw access
 *
 * Copyright (C) 2005-2007  Kristian Hoegsberg <[e-mail]>
 *
 * 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/preempt.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/idr.h>
#include <linux/compat.h>
#include <linux/firewire-cdev.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "fw-transaction.h"
#include "fw-topology.h"
#include "fw-device.h"

struct client;
struct client_resource {
	struct list_head link;
	void (*release)(struct client *client, struct client_resource *r);
	u32 handle;
};

/*
 * 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 client_resource resource;
	struct fw_cdev_event_response response;
};

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

struct client {
	u32 version;
	struct fw_device *device;
	spinlock_t lock;
	u32 resource_handle;
	struct list_head resource_list;
	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;
};

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 = fw_device_from_devt(inode->i_rdev);
	if (device == NULL)
		return -ENODEV;

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

	client->device = fw_device_get(device);
	INIT_LIST_HEAD(&client->event_list);
	INIT_LIST_HEAD(&client->resource_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);
	spin_unlock_irqrestore(&client->lock, flags);

	wake_up_interruptible(&client->wait);
}

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;

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

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

	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);

	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)) {
			retval = -EFAULT;
			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
fill_bus_reset_event(struct fw_cdev_event_bus_reset *event,
		     struct client *client)
{
	struct fw_card *card = client->device->card;

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

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

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

static void
queue_bus_reset_event(struct client *client)
{
	struct bus_reset *bus_reset;

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

	fill_bus_reset_event(&bus_reset->reset, client);

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

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);
}

static int ioctl_get_info(struct client *client, void *buffer)
{
	struct fw_cdev_get_info *get_info = buffer;
	struct fw_cdev_event_bus_reset bus_reset;

	client->version = get_info->version;
	get_info->version = FW_CDEV_VERSION;

	if (get_info->rom != 0) {
		void __user *uptr = u64_to_uptr(get_info->rom);
		size_t want = get_info->rom_length;
		size_t have = client->device->config_rom_length * 4;

		if (copy_to_user(uptr, client->device->config_rom,
				 min(want, have)))
			return -EFAULT;
	}
	get_info->rom_length = client->device->config_rom_length * 4;

	client->bus_reset_closure = get_info->bus_reset_closure;
	if (get_info->bus_reset != 0) {
		void __user *uptr = u64_to_uptr(get_info->bus_reset);

		fill_bus_reset_event(&bus_reset, client);
		if (copy_to_user(uptr, &bus_reset, sizeof(bus_reset)))
			return -EFAULT;
	}

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

	return 0;
}

static void
add_client_resource(struct client *client, struct client_resource *resource)
{
	unsigned long flags;

	spin_lock_irqsave(&client->lock, flags);
	list_add_tail(&resource->link, &client->resource_list);
	resource->handle = client->resource_handle++;
	spin_unlock_irqrestore(&client->lock, flags);
}

static int
release_client_resource(struct client *client, u32 handle,
			struct client_resource **resource)
{
	struct client_resource *r;
	unsigned long flags;

	spin_lock_irqsave(&client->lock, flags);
	list_for_each_entry(r, &client->resource_list, link) {
		if (r->handle == handle) {
			list_del(&r->link);
			break;
		}
	}
	spin_unlock_irqrestore(&client->lock, flags);

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

	if (resource)
		*resource = r;
	else
		r->release(client, r);

	return 0;
}

static void
release_transaction(struct client *client, struct client_resource *resource)
{
	struct response *response =
		container_of(resource, struct response, resource);

	fw_cancel_transaction(client->device->card, &response->transaction);
}

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;
	unsigned long flags;

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

	spin_lock_irqsave(&client->lock, flags);
	list_del(&response->resource.link);
	spin_unlock_irqrestore(&client->lock, flags);

	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 int ioctl_send_request(struct client *client, void *buffer)
{
	struct fw_device *device = client->device;
	struct fw_cdev_send_request *request = buffer;
	struct response *response;

	/* 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;
	}

	response->resource.release = release_transaction;
	add_client_resource(client, &response->resource);

	fw_send_request(device->card, &response->transaction,
			request->tcode & 0x1f,
			device->node->node_id,
			request->generation,
			device->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 client_resource resource;
};

struct request {
	struct fw_request *request;
	void *data;
	size_t length;
	struct client_resource resource;
};

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

static void
release_request(struct client *client, struct client_resource *resource)
{
	struct request *request =
		container_of(resource, struct request, resource);

	fw_send_response(client->device->card, request->request,
			 RCODE_CONFLICT_ERROR);
	kfree(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;
	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;

	request->resource.release = release_request;
	add_client_resource(client, &request->resource);

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

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

static void
release_address_handler(struct client *client,
			struct client_resource *resource)
{
	struct address_handler *handler =
		container_of(resource, struct address_handler, resource);

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

static int ioctl_allocate(struct client *client, void *buffer)
{
	struct fw_cdev_allocate *request = buffer;
	struct address_handler *handler;
	struct fw_address_region region;

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

	region.start = request->offset;