1 files changed, 1068 insertions, 0 deletions

diff --git a/drivers/char/agp/frontend.c b/drivers/char/agp/frontend.c
new file mode 100644
index 000000000..09f17eb73
--- /dev/null
+++ b/drivers/char/agp/frontend.c
@@ -0,0 +1,1068 @@
+/*
+ * AGPGART driver frontend
+ * Copyright (C) 2004 Silicon Graphics, Inc.
+ * Copyright (C) 2002-2003 Dave Jones
+ * Copyright (C) 1999 Jeff Hartmann
+ * Copyright (C) 1999 Precision Insight, Inc.
+ * Copyright (C) 1999 Xi Graphics, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * JEFF HARTMANN, OR ANY OTHER CONTRIBUTORS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mman.h>
+#include <linux/pci.h>
+#include <linux/miscdevice.h>
+#include <linux/agp_backend.h>
+#include <linux/agpgart.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include "agp.h"
+
+struct agp_front_data agp_fe;
+
+struct agp_memory *agp_find_mem_by_key(int key)
+{
+	struct agp_memory *curr;
+
+	if (agp_fe.current_controller == NULL)
+		return NULL;
+
+	curr = agp_fe.current_controller->pool;
+
+	while (curr != NULL) {
+		if (curr->key == key)
+			break;
+		curr = curr->next;
+	}
+
+	DBG("key=%d -> mem=%p", key, curr);
+	return curr;
+}
+
+static void agp_remove_from_pool(struct agp_memory *temp)
+{
+	struct agp_memory *prev;
+	struct agp_memory *next;
+
+	/* Check to see if this is even in the memory pool */
+
+	DBG("mem=%p", temp);
+	if (agp_find_mem_by_key(temp->key) != NULL) {
+		next = temp->next;
+		prev = temp->prev;
+
+		if (prev != NULL) {
+			prev->next = next;
+			if (next != NULL)
+				next->prev = prev;
+
+		} else {
+			/* This is the first item on the list */
+			if (next != NULL)
+				next->prev = NULL;
+
+			agp_fe.current_controller->pool = next;
+		}
+	}
+}
+
+/*
+ * Routines for managing each client's segment list -
+ * These routines handle adding and removing segments
+ * to each auth'ed client.
+ */
+
+static struct
+agp_segment_priv *agp_find_seg_in_client(const struct agp_client *client,
+						unsigned long offset,
+					    int size, pgprot_t page_prot)
+{
+	struct agp_segment_priv *seg;
+	int num_segments, i;
+	off_t pg_start;
+	size_t pg_count;
+
+	pg_start = offset / 4096;
+	pg_count = size / 4096;
+	seg = *(client->segments);
+	num_segments = client->num_segments;
+
+	for (i = 0; i < client->num_segments; i++) {
+		if ((seg[i].pg_start == pg_start) &&
+		    (seg[i].pg_count == pg_count) &&
+		    (pgprot_val(seg[i].prot) == pgprot_val(page_prot))) {
+			return seg + i;
+		}
+	}
+
+	return NULL;
+}
+
+static void agp_remove_seg_from_client(struct agp_client *client)
+{
+	DBG("client=%p", client);
+
+	if (client->segments != NULL) {
+		if (*(client->segments) != NULL) {
+			DBG("Freeing %p from client %p", *(client->segments), client);
+			kfree(*(client->segments));
+		}
+		DBG("Freeing %p from client %p", client->segments, client);
+		kfree(client->segments);
+		client->segments = NULL;
+	}
+}
+
+static void agp_add_seg_to_client(struct agp_client *client,
+			       struct agp_segment_priv ** seg, int num_segments)
+{
+	struct agp_segment_priv **prev_seg;
+
+	prev_seg = client->segments;
+
+	if (prev_seg != NULL)
+		agp_remove_seg_from_client(client);
+
+	DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
+	client->num_segments = num_segments;
+	client->segments = seg;
+}
+
+static pgprot_t agp_convert_mmap_flags(int prot)
+{
+	unsigned long prot_bits;
+
+	prot_bits = calc_vm_prot_bits(prot) | VM_SHARED;
+	return vm_get_page_prot(prot_bits);
+}
+
+int agp_create_segment(struct agp_client *client, struct agp_region *region)
+{
+	struct agp_segment_priv **ret_seg;
+	struct agp_segment_priv *seg;
+	struct agp_segment *user_seg;
+	size_t i;
+
+	seg = kzalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
+	if (seg == NULL) {
+		kfree(region->seg_list);
+		region->seg_list = NULL;
+		return -ENOMEM;
+	}
+	user_seg = region->seg_list;
+
+	for (i = 0; i < region->seg_count; i++) {
+		seg[i].pg_start = user_seg[i].pg_start;
+		seg[i].pg_count = user_seg[i].pg_count;
+		seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
+	}
+	kfree(region->seg_list);
+	region->seg_list = NULL;
+
+	ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
+	if (ret_seg == NULL) {
+		kfree(seg);
+		return -ENOMEM;
+	}
+	*ret_seg = seg;
+	agp_add_seg_to_client(client, ret_seg, region->seg_count);
+	return 0;
+}
+
+/* End - Routines for managing each client's segment list */
+
+/* This function must only be called when current_controller != NULL */
+static void agp_insert_into_pool(struct agp_memory * temp)
+{
+	struct agp_memory *prev;
+
+	prev = agp_fe.current_controller->pool;
+
+	if (prev != NULL) {
+		prev->prev = temp;
+		temp->next = prev;
+	}
+	agp_fe.current_controller->pool = temp;
+}
+
+
+/* File private list routines */
+
+struct agp_file_private *agp_find_private(pid_t pid)
+{
+	struct agp_file_private *curr;
+
+	curr = agp_fe.file_priv_list;
+
+	while (curr != NULL) {
+		if (curr->my_pid == pid)
+			return curr;
+		curr = curr->next;
+	}
+
+	return NULL;
+}
+
+static void agp_insert_file_private(struct agp_file_private * priv)
+{
+	struct agp_file_private *prev;
+
+	prev = agp_fe.file_priv_list;
+
+	if (prev != NULL)
+		prev->prev = priv;
+	priv->next = prev;
+	agp_fe.file_priv_list = priv;
+}
+
+static void agp_remove_file_private(struct agp_file_private * priv)
+{
+	struct agp_file_private *next;
+	struct agp_file_private *prev;
+
+	next = priv->next;
+	prev = priv->prev;
+
+	if (prev != NULL) {
+		prev->next = next;
+
+		if (next != NULL)
+			next->prev = prev;
+
+	} else {
+		if (next != NULL)
+			next->prev = NULL;
+
+		agp_fe.file_priv_list = next;
+	}
+}
+
+/* End - File flag list routines */
+
+/*
+ * Wrappers for agp_free_memory & agp_allocate_memory
+ * These make sure that internal lists are kept updated.
+ */
+void agp_free_memory_wrap(struct agp_memory *memory)
+{
+	agp_remove_from_pool(memory);
+	agp_free_memory(memory);
+}
+
+struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
+{
+	struct agp_memory *memory;
+
+	memory = agp_allocate_memory(agp_bridge, pg_count, type);
+	if (memory == NULL)
+		return NULL;
+
+	agp_insert_into_pool(memory);
+	return memory;
+}
+
+/* Routines for managing the list of controllers -
+ * These routines manage the current controller, and the list of
+ * controllers
+ */
+
+static struct agp_controller *agp_find_controller_by_pid(pid_t id)
+{
+	struct agp_controller *controller;
+
+	controller = agp_fe.controllers;
+
+	while (controller != NULL) {
+		if (controller->pid == id)
+			return controller;
+		controller = controller->next;
+	}
+
+	return NULL;
+}
+
+static struct agp_controller *agp_create_controller(pid_t id)
+{
+	struct agp_controller *controller;
+
+	controller = kzalloc(sizeof(struct agp_controller), GFP_KERNEL);
+	if (controller == NULL)
+		return NULL;
+
+	controller->pid = id;
+	return controller;
+}
+
+static int agp_insert_controller(struct agp_controller *controller)
+{
+	struct agp_controller *prev_controller;
+
+	prev_controller = agp_fe.controllers;
+	controller->next = prev_controller;
+
+	if (prev_controller != NULL)
+		prev_controller->prev = controller;
+
+	agp_fe.controllers = controller;
+
+	return 0;
+}
+
+static void agp_remove_all_clients(struct agp_controller *controller)
+{
+	struct agp_client *client;
+	struct agp_client *temp;
+
+	client = controller->clients;
+
+	while (client) {
+		struct agp_file_private *priv;
+
+		temp = client;
+		agp_remove_seg_from_client(temp);
+		priv = agp_find_private(temp->pid);
+
+		if (priv != NULL) {
+			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
+			clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
+		}
+		client = client->next;
+		kfree(temp);
+	}
+}
+
+static void agp_remove_all_memory(struct agp_controller *controller)
+{
+	struct agp_memory *memory;
+	struct agp_memory *temp;
+
+	memory = controller->pool;
+
+	while (memory) {
+		temp = memory;
+		memory = memory->next;
+		agp_free_memory_wrap(temp);
+	}
+}
+
+static int agp_remove_controller(struct agp_controller *controller)
+{
+	struct agp_controller *prev_controller;
+	struct agp_controller *next_controller;
+
+	prev_controller = controller->prev;
+	next_controller = controller->next;
+
+	if (prev_controller != NULL) {
+		prev_controller->next = next_controller;
+		if (next_controller != NULL)
+			next_controller->prev = prev_controller;
+
+	} else {
+		if (next_controller != NULL)
+			next_controller->prev = NULL;
+
+		agp_fe.controllers = next_controller;
+	}
+
+	agp_remove_all_memory(controller);
+	agp_remove_all_clients(controller);
+
+	if (agp_fe.current_controller == controller) {
+		agp_fe.current_controller = NULL;
+		agp_fe.backend_acquired = false;
+		agp_backend_release(agp_bridge);
+	}
+	kfree(controller);
+	return 0;
+}
+
+static void agp_controller_make_current(struct agp_controller *controller)
+{
+	struct agp_client *clients;
+
+	clients = controller->clients;
+
+	while (clients != NULL) {
+		struct agp_file_private *priv;
+
+		priv = agp_find_private(clients->pid);
+
+		if (priv != NULL) {
+			set_bit(AGP_FF_IS_VALID, &priv->access_flags);
+			set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
+		}
+		clients = clients->next;
+	}
+
+	agp_fe.current_controller = controller;
+}
+
+static void agp_controller_release_current(struct agp_controller *controller,
+				      struct agp_file_private *controller_priv)
+{
+	struct agp_client *clients;
+
+	clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
+	clients = controller->clients;
+
+	while (clients != NULL) {
+		struct agp_file_private *priv;
+
+		priv = agp_find_private(clients->pid);
+
+		if (priv != NULL)
+			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
+
+		clients = clients->next;
+	}
+
+	agp_fe.current_controller = NULL;
+	agp_fe.used_by_controller = false;
+	agp_backend_release(agp_bridge);
+}
+
+/*
+ * Routines for managing client lists -
+ * These routines are for managing the list of auth'ed clients.
+ */
+
+static struct agp_client
+*agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
+{
+	struct agp_client *client;
+
+	if (controller == NULL)
+		return NULL;
+
+	client = controller->clients;
+
+	while (client != NULL) {
+		if (client->pid == id)
+			return client;
+		client = client->next;
+	}
+
+	return NULL;
+}
+
+static struct agp_controller *agp_find_controller_for_client(pid_t id)
+{
+	struct agp_controller *controller;
+
+	controller = agp_fe.controllers;
+
+	while (controller != NULL) {
+		if ((agp_find_client_in_controller(controller, id)) != NULL)
+			return controller;
+		controller = controller->next;
+	}
+
+	return NULL;
+}
+
+struct agp_client *agp_find_client_by_pid(pid_t id)
+{
+	struct agp_client *temp;
+
+	if (agp_fe.current_controller == NULL)
+		return NULL;
+
+	temp = agp_find_client_in_controller(agp_fe.current_controller, id);
+	return temp;
+}
+
+static void agp_insert_client(struct agp_client *client)
+{
+	struct agp_client *prev_client;
+
+	prev_client = agp_fe.current_controller->clients;
+	client->next = prev_client;
+
+	if (prev_client != NULL)
+		prev_client->prev = client;
+
+	agp_fe.current_controller->clients = client;
+	agp_fe.current_controller->num_clients++;
+}
+
+struct agp_client *agp_create_client(pid_t id)
+{
+	struct agp_client *new_client;
+
+	new_client = kzalloc(sizeof(struct agp_client), GFP_KERNEL);
+	if (new_client == NULL)
+		return NULL;
+
+	new_client->pid = id;
+	agp_insert_client(new_client);
+	return new_client;
+}
+
+int agp_remove_client(pid_t id)
+{
+	struct agp_client *client;
+	struct agp_client *prev_client;
+	struct agp_client *next_client;
+	struct agp_controller *controller;
+
+	controller = agp_find_controller_for_client(id);
+	if (controller == NULL)
+		return -EINVAL;
+
+	client = agp_find_client_in_controller(controller, id);
+	if (client == NULL)
+		return -EINVAL;
+
+	prev_client = client->prev;
+	next_client = client->next;
+
+	if (prev_client != NULL) {
+		prev_client->next = next_client;
+		if (next_client != NULL)
+			next_client->prev = prev_client;
+
+	} else {
+		if (next_client != NULL)
+			next_client->prev = NULL;
+		controller->clients = next_client;
+	}
+
+	controller->num_clients--;
+	agp_remove_seg_from_client(client);
+	kfree(client);
+	return 0;
+}
+
+/* End - Routines for managing client lists */
+
+/* File Operations */
+
+static int agp_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	unsigned int size, current_size;
+	unsigned long offset;
+	struct agp_client *client;
+	struct agp_file_private *priv = file->private_data;
+	struct agp_kern_info kerninfo;
+
+	mutex_lock(&(agp_fe.agp_mutex));
+
+	if (agp_fe.backend_acquired != true)
+		goto out_eperm;
+
+	if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
+		goto out_eperm;
+
+	agp_copy_info(agp_bridge, &kerninfo);
+	size = vma->vm_end - vma->vm_start;
+	current_size = kerninfo.aper_size;
+	current_size = current_size * 0x100000;
+	offset = vma->vm_pgoff << PAGE_SHIFT;
+	DBG("%lx:%lx", offset, offset+size);
+
+	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
+		if ((size + offset) > current_size)
+			goto out_inval;
+
+		client = agp_find_client_by_pid(current->pid);
+
+		if (client == NULL)
+			goto out_eperm;
+
+		if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
+			goto out_inval;
+
+		DBG("client vm_ops=%p", kerninfo.vm_ops);
+		if (kerninfo.vm_ops) {
+			vma->vm_ops = kerninfo.vm_ops;
+		} else if (io_remap_pfn_range(vma, vma->vm_start,
+				(kerninfo.aper_base + offset) >> PAGE_SHIFT,
+				size,
+				pgprot_writecombine(vma->vm_page_prot))) {
+			goto out_again;
+		}
+		mutex_unlock(&(agp_fe.agp_mutex));
+		return 0;
+	}
+
+	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
+		if (size != current_size)
+			goto out_inval;
+
+		DBG("controller vm_ops=%p", kerninfo.vm_ops);
+		if (kerninfo.vm_ops) {
+			vma->vm_ops = kerninfo.vm_ops;
+		} else if (io_remap_pfn_range(vma, vma->vm_start,
+				kerninfo.aper_base >> PAGE_SHIFT,
+				size,
+				pgprot_writecombine(vma->vm_page_prot))) {
+			goto out_again;
+		}
+		mutex_unlock(&(agp_fe.agp_mutex));
+		return 0;
+	}
+
+out_eperm:
+	mutex_unlock(&(agp_fe.agp_mutex));
+	return -EPERM;
+
+out_inval:
+	mutex_unlock(&(agp_fe.agp_mutex));
+	return -EINVAL;
+
+out_again:
+	mutex_unlock(&(agp_fe.agp_mutex));
+	return -EAGAIN;
+}
+
+static int agp_release(struct inode *inode, struct file *file)
+{
+	struct agp_file_private *priv = file->private_data;
+
+	mutex_lock(&(agp_fe.agp_mutex));
+
+	DBG("priv=%p", priv);
+
+	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
+		struct agp_controller *controller;
+
+		controller = agp_find_controller_by_pid(priv->my_pid);
+
+		if (controller != NULL) {
+			if (controller == agp_fe.current_controller)
+				agp_controller_release_current(controller, priv);
+			agp_remove_controller(controller);
+			controller = NULL;
+		}
+	}
+
+	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
+		agp_remove_client(priv->my_pid);
+
+	agp_remove_file_private(priv);
+	kfree(priv);
+	file->private_data = NULL;
+	mutex_unlock(&(agp_fe.agp_mutex));
+	return 0;
+}
+
+static int agp_open(struct inode *inode, struct file *file)
+{
+	int minor = iminor(inode);
+	struct agp_file_private *priv;
+	struct agp_client *client;
+
+	if (minor != AGPGART_MINOR)
+		return -ENXIO;
+
+	mutex_lock(&(agp_fe.agp_mutex));
+
+	priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
+	if (priv == NULL) {
+		mutex_unlock(&(agp_fe.agp_mutex));
+		return -ENOMEM;
+	}
+
+	set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
+	priv->my_pid = current->pid;
+
+	if (capable(CAP_SYS_RAWIO))
+		/* Root priv, can be controller */
+		set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
+
+	client = agp_find_client_by_pid(current->pid);
+
+	if (client != NULL) {
+		set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
+		set_bit(AGP_FF_IS_VALID, &priv->access_flags);
+	}
+	file->private_data = (void *) priv;
+	agp_insert_file_private(priv);
+	DBG("private=%p, client=%p", priv, client);
+
+	mutex_unlock(&(agp_fe.agp_mutex));
+
+	return 0;
+}
+
+static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
+{
+	struct agp_info userinfo;
+	struct agp_kern_info kerninfo;
+
+	agp_copy_info(agp_bridge, &kerninfo);
+
+	memset(&userinfo, 0, sizeof(userinfo));
+	userinfo.version.major = kerninfo.version.major;
+	userinfo.version.minor = kerninfo.version.minor;
+	userinfo.bridge_id = kerninfo.device->vendor |
+	    (kerninfo.device->device << 16);
+	userinfo.agp_mode = kerninfo.mode;
+	userinfo.aper_base = kerninfo.aper_base;
+	userinfo.aper_size = kerninfo.aper_size;
+	userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
+	userinfo.pg_used = kerninfo.current_memory;
+
+	if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
+		return -EFAULT;
+
+	return 0;
+}
+
+int agpioc_acquire_wrap(struct agp_file_private *priv)
+{
+	struct agp_controller *controller;
+
+	DBG("");
+
+	if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
+		return -EPERM;
+
+	if (agp_fe.current_controller != NULL)
+		return -EBUSY;
+
+	if (!agp_bridge)
+		return -ENODEV;
+
+        if (atomic_read(&agp_bridge->agp_in_use))
+                return -EBUSY;
+
+	atomic_inc(&agp_bridge->agp_in_use);
+
+	agp_fe.backend_acquired = true;
+
+	controller = agp_find_controller_by_pid(priv->my_pid);
+
+	if (controller != NULL) {
+		agp_controller_make_current(controller);
+	} else {
+		controller = agp_create_controller(priv->my_pid);
+
+		if (controller == NULL) {
+			agp_fe.backend_acquired = false;
+			agp_backend_release(agp_bridge);
+			return -ENOMEM;
+		}
+		agp_insert_controller(controller);
+		agp_controller_make_current(controller);
+	}
+
+	set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
+	set_bit(AGP_FF_IS_VALID, &priv->access_flags);
+	return 0;
+}
+
+int agpioc_release_wrap(struct agp_file_private *priv)
+{
+	DBG("");
+	agp_controller_release_current(agp_fe.current_controller, priv);
+	return 0;
+}
+
+int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
+{
+	struct agp_setup mode;
+
+	DBG("");
+	if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
+		return -EFAULT;
+
+	agp_enable(agp_bridge, mode.agp_mode);
+	return 0;
+}
+
+static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
+{
+	struct agp_region reserve;
+	struct agp_client *client;
+	struct agp_file_private *client_priv;
+
+	DBG("");
+	if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
+		return -EFAULT;
+
+	if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
+		return -EFAULT;
+
+	client = agp_find_client_by_pid(reserve.pid);
+
+	if (reserve.seg_count == 0) {
+		/* remove a client */
+		client_priv = agp_find_private(reserve.pid);
+
+		if (client_priv != NULL) {
+			set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
+			set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
+		}
+		if (client == NULL) {
+			/* client is already removed */
+			return 0;
+		}
+		return agp_remove_client(reserve.pid);
+	} else {
+		struct agp_segment *segment;
+
+		if (reserve.seg_count >= 16384)
+			return -EINVAL;
+
+		segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
+				  GFP_KERNEL);
+
+		if (segment == NULL)
+			return -ENOMEM;
+
+		if (copy_from_user(segment, (void __user *) reserve.seg_list,
+				   sizeof(struct agp_segment) * reserve.seg_count)) {
+			kfree(segment);
+			return -EFAULT;
+		}
+		reserve.seg_list = segment;
+
+		if (client == NULL) {
+			/* Create the client and add the segment */
+			client = agp_create_client(reserve.pid);
+
+			if (client == NULL) {
+				kfree(segment);
+				return -ENOMEM;
+			}
+			client_priv = agp_find_private(reserve.pid);
+
+			if (client_priv != NULL) {
+				set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
+				set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
+			}
+		}
+		return agp_create_segment(client, &reserve);
+	}
+	/* Will never really happen */
+	return -EINVAL;
+}
+
+int agpioc_protect_wrap(struct agp_file_private *priv)
+{
+	DBG("");
+	/* This function is not currently implemented */
+	return -EINVAL;
+}
+
+static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
+{
+	struct agp_memory *memory;
+	struct agp_allocate alloc;
+
+	DBG("");
+	if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
+		return -EFAULT;
+
+	if (alloc.type >= AGP_USER_TYPES)
+		return -EINVAL;
+
+	memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
+
+	if (memory == NULL)
+		return -ENOMEM;
+
+	alloc.key = memory->key;
+	alloc.physical = memory->physical;
+
+	if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
+		agp_free_memory_wrap(memory);
+		return -EFAULT;
+	}
+	return 0;
+}
+
+int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
+{
+	struct agp_memory *memory;
+
+	DBG("");
+	memory = agp_find_mem_by_key(arg);
+
+	if (memory == NULL)
+		return -EINVAL;
+
+	agp_free_memory_wrap(memory);
+	return 0;
+}
+
+static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
+{
+	struct agp_bind bind_info;
+	struct agp_memory *memory;
+
+	DBG("");
+	if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
+		return -EFAULT;
+
+	memory = agp_find_mem_by_key(bind_info.key);
+
+	if (memory == NULL)
+		return -EINVAL;
+
+	return agp_bind_memory(memory, bind_info.pg_start);
+}
+
+static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
+{
+	struct agp_memory *memory;
+	struct agp_unbind unbind;
+
+	DBG("");
+	if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
+		return -EFAULT;
+
+	memory = agp_find_mem_by_key(unbind.key);
+
+	if (memory == NULL)
+		return -EINVAL;
+
+	return agp_unbind_memory(memory);
+}
+
+static long agp_ioctl(struct file *file,
+		     unsigned int cmd, unsigned long arg)
+{
+	struct agp_file_private *curr_priv = file->private_data;
+	int ret_val = -ENOTTY;
+
+	DBG("priv=%p, cmd=%x", curr_priv, cmd);
+	mutex_lock(&(agp_fe.agp_mutex));
+
+	if ((agp_fe.current_controller == NULL) &&
+	    (cmd != AGPIOC_ACQUIRE)) {
+		ret_val = -EINVAL;
+		goto ioctl_out;
+	}
+	if ((agp_fe.backend_acquired != true) &&
+	    (cmd != AGPIOC_ACQUIRE)) {
+		ret_val = -EBUSY;
+		goto ioctl_out;
+	}
+	if (cmd != AGPIOC_ACQUIRE) {
+		if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
+			ret_val = -EPERM;
+			goto ioctl_out;
+		}
+		/* Use the original pid of the controller,
+		 * in case it's threaded */
+
+		if (agp_fe.current_controller->pid != curr_priv->my_pid) {
+			ret_val = -EBUSY;
+			goto ioctl_out;
+		}
+	}
+
+	switch (cmd) {
+	case AGPIOC_INFO:
+		ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
+		break;
+
+	case AGPIOC_ACQUIRE:
+		ret_val = agpioc_acquire_wrap(curr_priv);
+		break;
+
+	case AGPIOC_RELEASE:
+		ret_val = agpioc_release_wrap(curr_priv);
+		break;
+
+	case AGPIOC_SETUP:
+		ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
+		break;
+
+	case AGPIOC_RESERVE:
+		ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
+		break;
+
+	case AGPIOC_PROTECT:
+		ret_val = agpioc_protect_wrap(curr_priv);
+		break;
+
+	case AGPIOC_ALLOCATE:
+		ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
+		break;
+
+	case AGPIOC_DEALLOCATE:
+		ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
+		break;
+
+	case AGPIOC_BIND:
+		ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
+		break;
+
+	case AGPIOC_UNBIND:
+		ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
+		break;
+	       
+	case AGPIOC_CHIPSET_FLUSH:
+		break;
+	}
+
+ioctl_out:
+	DBG("ioctl returns %d\n", ret_val);
+	mutex_unlock(&(agp_fe.agp_mutex));
+	return ret_val;
+}
+
+static const struct file_operations agp_fops =
+{
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.unlocked_ioctl	= agp_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= compat_agp_ioctl,
+#endif
+	.mmap		= agp_mmap,
+	.open		= agp_open,
+	.release	= agp_release,
+};
+
+static struct miscdevice agp_miscdev =
+{
+	.minor	= AGPGART_MINOR,
+	.name	= "agpgart",
+	.fops	= &agp_fops
+};
+
+int agp_frontend_initialize(void)
+{
+	memset(&agp_fe, 0, sizeof(struct agp_front_data));
+	mutex_init(&(agp_fe.agp_mutex));
+
+	if (misc_register(&agp_miscdev)) {
+		printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
+		return -EIO;
+	}
+	return 0;
+}
+
+void agp_frontend_cleanup(void)
+{
+	misc_deregister(&agp_miscdev);
+}