frontend.c

linux-2.6.15.6

/*
 * 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 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;
}

/* Originally taken from linux/mm/mmap.c from the array
 * protection_map.
 * The original really should be exported to modules, or
 * some routine which does the conversion for you
 */

static const pgprot_t my_protect_map[16] =
{
	__P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
	__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
};

static pgprot_t agp_convert_mmap_flags(int prot)
{
#define _trans(x,bit1,bit2) \
((bit1==bit2)?(x&bit1):(x&bit1)?bit2:0)

	unsigned long prot_bits;
	pgprot_t temp;

	prot_bits = _trans(prot, PROT_READ, VM_READ) |
	    _trans(prot, PROT_WRITE, VM_WRITE) |
	    _trans(prot, PROT_EXEC, VM_EXEC);

	prot_bits |= VM_SHARED;

	temp = my_protect_map[prot_bits & 0x0000000f];

	return temp;
}

static 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 */

static 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.
 */
static void agp_free_memory_wrap(struct agp_memory *memory)
{
	agp_remove_from_pool(memory);
	agp_free_memory(memory);
}

static 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;
}

static 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++;
}

static 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;
}

static int agp_remove_client(pid_t id)
{