path: root/drivers/char/agp/frontend.c

/*
 * 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/init.h>
#include <linux/miscdevice.h>
#include <linux/agp_backend.h>
#include <linux/agpgart.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include "agp.h"

static struct agp_front_data agp_fe;

static 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 a