drivers/char/agp/backend.c - linux - Git at Google

 /*
  * AGPGART driver backend routines.
  * 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, DAVE JONES, 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.
  *
  * TODO:
  * - Allocate more than order 0 pages to avoid too much linear map splitting.
  */
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/pagemap.h>
 #include <linux/miscdevice.h>
 #include <linux/pm.h>
 #include <linux/agp_backend.h>
 #include <linux/agpgart.h>
 #include <linux/vmalloc.h>
 #include <asm/io.h>
 #include "agp.h"

 /* Due to XFree86 brain-damage, we can't go to 1.0 until they
  * fix some real stupidity. It's only by chance we can bump
  * past 0.99 at all due to some boolean logic error. */
 #define AGPGART_VERSION_MAJOR 0
 #define AGPGART_VERSION_MINOR 103
 static const struct agp_version agp_current_version =
 {
 	.major = AGPGART_VERSION_MAJOR,
 	.minor = AGPGART_VERSION_MINOR,
 };

 struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) =
 	&agp_generic_find_bridge;

 struct agp_bridge_data *agp_bridge;
 LIST_HEAD(agp_bridges);
 EXPORT_SYMBOL(agp_bridge);
 EXPORT_SYMBOL(agp_bridges);
 EXPORT_SYMBOL(agp_find_bridge);

 /**
  *	agp_backend_acquire  -  attempt to acquire an agp backend.
  *
  */
 struct agp_bridge_data *agp_backend_acquire(struct pci_dev *pdev)
 {
 	struct agp_bridge_data *bridge;

 	bridge = agp_find_bridge(pdev);

 	if (!bridge)
 		return NULL;

 	if (atomic_read(&bridge->agp_in_use))
 		return NULL;
 	atomic_inc(&bridge->agp_in_use);
 	return bridge;
 }
 EXPORT_SYMBOL(agp_backend_acquire);


 /**
  *	agp_backend_release  -  release the lock on the agp backend.
  *
  *	The caller must insure that the graphics aperture translation table
  *	is read for use by another entity.
  *
  *	(Ensure that all memory it bound is unbound.)
  */
 void agp_backend_release(struct agp_bridge_data *bridge)
 {

 	if (bridge)
 		atomic_dec(&bridge->agp_in_use);
 }
 EXPORT_SYMBOL(agp_backend_release);


 static const struct { int mem, agp; } maxes_table[] = {
 	{0, 0},
 	{32, 4},
 	{64, 28},
 	{128, 96},
 	{256, 204},
 	{512, 440},
 	{1024, 942},
 	{2048, 1920},
 	{4096, 3932}
 };

 static int agp_find_max(void)
 {
 	long memory, index, result;

 #if PAGE_SHIFT < 20
 	memory = totalram_pages >> (20 - PAGE_SHIFT);
 #else
 	memory = totalram_pages << (PAGE_SHIFT - 20);
 #endif
 	index = 1;

 	while ((memory > maxes_table[index].mem) && (index < 8))
 		index++;

 	result = maxes_table[index - 1].agp +
 	   ( (memory - maxes_table[index - 1].mem)  *
 	     (maxes_table[index].agp - maxes_table[index - 1].agp)) /
 	   (maxes_table[index].mem - maxes_table[index - 1].mem);

 	result = result << (20 - PAGE_SHIFT);
 	return result;
 }


 static int agp_backend_initialize(struct agp_bridge_data *bridge)
 {
 	int size_value, rc, got_gatt=0, got_keylist=0;

 	bridge->max_memory_agp = agp_find_max();
 	bridge->version = &agp_current_version;

 	if (bridge->driver->needs_scratch_page) {
 		struct page *page = bridge->driver->agp_alloc_page(bridge);

 		if (!page) {
 			dev_err(&bridge->dev->dev,
 				"can't get memory for scratch page\n");
 			return -ENOMEM;
 		}

 		bridge->scratch_page_page = page;
 		bridge->scratch_page_dma = page_to_phys(page);

 		bridge->scratch_page = bridge->driver->mask_memory(bridge,
 						   bridge->scratch_page_dma, 0);
 	}

 	size_value = bridge->driver->fetch_size();
 	if (size_value == 0) {
 		dev_err(&bridge->dev->dev, "can't determine aperture size\n");
 		rc = -EINVAL;
 		goto err_out;
 	}
 	if (bridge->driver->create_gatt_table(bridge)) {
 		dev_err(&bridge->dev->dev,
 			"can't get memory for graphics translation table\n");
 		rc = -ENOMEM;
 		goto err_out;
 	}
 	got_gatt = 1;

 	bridge->key_list = vzalloc(PAGE_SIZE * 4);
 	if (bridge->key_list == NULL) {
 		dev_err(&bridge->dev->dev,
 			"can't allocate memory for key lists\n");
 		rc = -ENOMEM;
 		goto err_out;
 	}
 	got_keylist = 1;

 	/* FIXME vmalloc'd memory not guaranteed contiguous */

 	if (bridge->driver->configure()) {
 		dev_err(&bridge->dev->dev, "error configuring host chipset\n");
 		rc = -EINVAL;
 		goto err_out;
 	}
 	INIT_LIST_HEAD(&bridge->mapped_list);
 	spin_lock_init(&bridge->mapped_lock);

 	return 0;

 err_out:
 	if (bridge->driver->needs_scratch_page) {
 		struct page *page = bridge->scratch_page_page;

 		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
 		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
 	}
 	if (got_gatt)
 		bridge->driver->free_gatt_table(bridge);
 	if (got_keylist) {
 		vfree(bridge->key_list);
 		bridge->key_list = NULL;
 	}
 	return rc;
 }

 /* cannot be __exit b/c as it could be called from __init code */
 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
 {
 	if (bridge->driver->cleanup)
 		bridge->driver->cleanup();
 	if (bridge->driver->free_gatt_table)
 		bridge->driver->free_gatt_table(bridge);

 	vfree(bridge->key_list);
 	bridge->key_list = NULL;

 	if (bridge->driver->agp_destroy_page &&
 	    bridge->driver->needs_scratch_page) {
 		struct page *page = bridge->scratch_page_page;

 		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
 		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
 	}
 }

 /* When we remove the global variable agp_bridge from all drivers
  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
  */

 struct agp_bridge_data *agp_alloc_bridge(void)
 {
 	struct agp_bridge_data *bridge;

 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
 	if (!bridge)
 		return NULL;

 	atomic_set(&bridge->agp_in_use, 0);
 	atomic_set(&bridge->current_memory_agp, 0);

 	if (list_empty(&agp_bridges))
 		agp_bridge = bridge;

 	return bridge;
 }
 EXPORT_SYMBOL(agp_alloc_bridge);


 void agp_put_bridge(struct agp_bridge_data *bridge)
 {
         kfree(bridge);

         if (list_empty(&agp_bridges))
                 agp_bridge = NULL;
 }
 EXPORT_SYMBOL(agp_put_bridge);


 int agp_add_bridge(struct agp_bridge_data *bridge)
 {
 	int error;

 	if (agp_off) {
 		error = -ENODEV;
 		goto err_put_bridge;
 	}

 	if (!bridge->dev) {
 		printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
 		error = -EINVAL;
 		goto err_put_bridge;
 	}

 	/* Grab reference on the chipset driver. */
 	if (!try_module_get(bridge->driver->owner)) {
 		dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
 		error = -EINVAL;
 		goto err_put_bridge;
 	}

 	error = agp_backend_initialize(bridge);
 	if (error) {
 		dev_info(&bridge->dev->dev,
 			 "agp_backend_initialize() failed\n");
 		goto err_out;
 	}

 	if (list_empty(&agp_bridges)) {
 		error = agp_frontend_initialize();
 		if (error) {
 			dev_info(&bridge->dev->dev,
 				 "agp_frontend_initialize() failed\n");
 			goto frontend_err;
 		}

 		dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
 			 bridge->driver->fetch_size(), bridge->gart_bus_addr);

 	}

 	list_add(&bridge->list, &agp_bridges);
 	return 0;

 frontend_err:
 	agp_backend_cleanup(bridge);
 err_out:
 	module_put(bridge->driver->owner);
 err_put_bridge:
 	agp_put_bridge(bridge);
 	return error;
 }
 EXPORT_SYMBOL_GPL(agp_add_bridge);


 void agp_remove_bridge(struct agp_bridge_data *bridge)
 {
 	agp_backend_cleanup(bridge);
 	list_del(&bridge->list);
 	if (list_empty(&agp_bridges))
 		agp_frontend_cleanup();
 	module_put(bridge->driver->owner);
 }
 EXPORT_SYMBOL_GPL(agp_remove_bridge);

 int agp_off;
 int agp_try_unsupported_boot;
 EXPORT_SYMBOL(agp_off);
 EXPORT_SYMBOL(agp_try_unsupported_boot);

 static int __init agp_init(void)
 {
 	if (!agp_off)
 		printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
 			AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
 	return 0;
 }

 static void __exit agp_exit(void)
 {
 }

 #ifndef MODULE
 static __init int agp_setup(char *s)
 {
 	if (!strcmp(s,"off"))
 		agp_off = 1;
 	if (!strcmp(s,"try_unsupported"))
 		agp_try_unsupported_boot = 1;
 	return 1;
 }
 __setup("agp=", agp_setup);
 #endif

 MODULE_AUTHOR("Dave Jones, Jeff Hartmann");
 MODULE_DESCRIPTION("AGP GART driver");
 MODULE_LICENSE("GPL and additional rights");
 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);

 module_init(agp_init);
 module_exit(agp_exit);
	/*
	* AGPGART driver backend routines.
	* 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, DAVE JONES, 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.
	*
	* TODO:
	* - Allocate more than order 0 pages to avoid too much linear map splitting.
	*/
	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/pagemap.h>
	#include <linux/miscdevice.h>
	#include <linux/pm.h>
	#include <linux/agp_backend.h>
	#include <linux/agpgart.h>
	#include <linux/vmalloc.h>
	#include <asm/io.h>
	#include "agp.h"

	/* Due to XFree86 brain-damage, we can't go to 1.0 until they
	* fix some real stupidity. It's only by chance we can bump
	* past 0.99 at all due to some boolean logic error. */
	#define AGPGART_VERSION_MAJOR 0
	#define AGPGART_VERSION_MINOR 103
	static const struct agp_version agp_current_version =
	{
	.major = AGPGART_VERSION_MAJOR,
	.minor = AGPGART_VERSION_MINOR,
	};

	struct agp_bridge_data (agp_find_bridge)(struct pci_dev *) =
	&agp_generic_find_bridge;

	struct agp_bridge_data *agp_bridge;
	LIST_HEAD(agp_bridges);
	EXPORT_SYMBOL(agp_bridge);
	EXPORT_SYMBOL(agp_bridges);
	EXPORT_SYMBOL(agp_find_bridge);

	/**
	* agp_backend_acquire - attempt to acquire an agp backend.
	*
	*/
	struct agp_bridge_data agp_backend_acquire(struct pci_dev pdev)
	{
	struct agp_bridge_data *bridge;

	bridge = agp_find_bridge(pdev);

	if (!bridge)
	return NULL;

	if (atomic_read(&bridge->agp_in_use))
	return NULL;
	atomic_inc(&bridge->agp_in_use);
	return bridge;
	}
	EXPORT_SYMBOL(agp_backend_acquire);


	/**
	* agp_backend_release - release the lock on the agp backend.
	*
	* The caller must insure that the graphics aperture translation table
	* is read for use by another entity.
	*
	* (Ensure that all memory it bound is unbound.)
	*/
	void agp_backend_release(struct agp_bridge_data *bridge)
	{

	if (bridge)
	atomic_dec(&bridge->agp_in_use);
	}
	EXPORT_SYMBOL(agp_backend_release);


	static const struct { int mem, agp; } maxes_table[] = {
	{0, 0},
	{32, 4},
	{64, 28},
	{128, 96},
	{256, 204},
	{512, 440},
	{1024, 942},
	{2048, 1920},
	{4096, 3932}
	};

	static int agp_find_max(void)
	{
	long memory, index, result;

	#if PAGE_SHIFT < 20
	memory = totalram_pages >> (20 - PAGE_SHIFT);
	#else
	memory = totalram_pages << (PAGE_SHIFT - 20);
	#endif
	index = 1;

	while ((memory > maxes_table[index].mem) && (index < 8))
	index++;

	result = maxes_table[index - 1].agp +
	( (memory - maxes_table[index - 1].mem) *
	(maxes_table[index].agp - maxes_table[index - 1].agp)) /
	(maxes_table[index].mem - maxes_table[index - 1].mem);

	result = result << (20 - PAGE_SHIFT);
	return result;
	}


	static int agp_backend_initialize(struct agp_bridge_data *bridge)
	{
	int size_value, rc, got_gatt=0, got_keylist=0;

	bridge->max_memory_agp = agp_find_max();
	bridge->version = &agp_current_version;

	if (bridge->driver->needs_scratch_page) {
	struct page *page = bridge->driver->agp_alloc_page(bridge);

	if (!page) {
	dev_err(&bridge->dev->dev,
	"can't get memory for scratch page\n");
	return -ENOMEM;
	}

	bridge->scratch_page_page = page;
	bridge->scratch_page_dma = page_to_phys(page);

	bridge->scratch_page = bridge->driver->mask_memory(bridge,
	bridge->scratch_page_dma, 0);
	}

	size_value = bridge->driver->fetch_size();
	if (size_value == 0) {
	dev_err(&bridge->dev->dev, "can't determine aperture size\n");
	rc = -EINVAL;
	goto err_out;
	}
	if (bridge->driver->create_gatt_table(bridge)) {
	dev_err(&bridge->dev->dev,
	"can't get memory for graphics translation table\n");
	rc = -ENOMEM;
	goto err_out;
	}
	got_gatt = 1;

	bridge->key_list = vzalloc(PAGE_SIZE * 4);
	if (bridge->key_list == NULL) {
	dev_err(&bridge->dev->dev,
	"can't allocate memory for key lists\n");
	rc = -ENOMEM;
	goto err_out;
	}
	got_keylist = 1;

	/* FIXME vmalloc'd memory not guaranteed contiguous */

	if (bridge->driver->configure()) {
	dev_err(&bridge->dev->dev, "error configuring host chipset\n");
	rc = -EINVAL;
	goto err_out;
	}
	INIT_LIST_HEAD(&bridge->mapped_list);
	spin_lock_init(&bridge->mapped_lock);

	return 0;

	err_out:
	if (bridge->driver->needs_scratch_page) {
	struct page *page = bridge->scratch_page_page;

	bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
	bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
	}
	if (got_gatt)
	bridge->driver->free_gatt_table(bridge);
	if (got_keylist) {
	vfree(bridge->key_list);
	bridge->key_list = NULL;
	}
	return rc;
	}

	/* cannot be __exit b/c as it could be called from __init code */
	static void agp_backend_cleanup(struct agp_bridge_data *bridge)
	{
	if (bridge->driver->cleanup)
	bridge->driver->cleanup();
	if (bridge->driver->free_gatt_table)
	bridge->driver->free_gatt_table(bridge);

	vfree(bridge->key_list);
	bridge->key_list = NULL;

	if (bridge->driver->agp_destroy_page &&
	bridge->driver->needs_scratch_page) {
	struct page *page = bridge->scratch_page_page;

	bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
	bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
	}
	}

	/* When we remove the global variable agp_bridge from all drivers
	* then agp_alloc_bridge and agp_generic_find_bridge need to be updated
	*/

	struct agp_bridge_data *agp_alloc_bridge(void)
	{
	struct agp_bridge_data *bridge;

	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
	if (!bridge)
	return NULL;

	atomic_set(&bridge->agp_in_use, 0);
	atomic_set(&bridge->current_memory_agp, 0);

	if (list_empty(&agp_bridges))
	agp_bridge = bridge;

	return bridge;
	}
	EXPORT_SYMBOL(agp_alloc_bridge);


	void agp_put_bridge(struct agp_bridge_data *bridge)
	{
	kfree(bridge);

	if (list_empty(&agp_bridges))
	agp_bridge = NULL;
	}
	EXPORT_SYMBOL(agp_put_bridge);


	int agp_add_bridge(struct agp_bridge_data *bridge)
	{
	int error;

	if (agp_off) {
	error = -ENODEV;
	goto err_put_bridge;
	}

	if (!bridge->dev) {
	printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
	error = -EINVAL;
	goto err_put_bridge;
	}

	/* Grab reference on the chipset driver. */
	if (!try_module_get(bridge->driver->owner)) {
	dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
	error = -EINVAL;
	goto err_put_bridge;
	}

	error = agp_backend_initialize(bridge);
	if (error) {
	dev_info(&bridge->dev->dev,
	"agp_backend_initialize() failed\n");
	goto err_out;
	}

	if (list_empty(&agp_bridges)) {
	error = agp_frontend_initialize();
	if (error) {
	dev_info(&bridge->dev->dev,
	"agp_frontend_initialize() failed\n");
	goto frontend_err;
	}

	dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
	bridge->driver->fetch_size(), bridge->gart_bus_addr);

	}

	list_add(&bridge->list, &agp_bridges);
	return 0;

	frontend_err:
	agp_backend_cleanup(bridge);
	err_out:
	module_put(bridge->driver->owner);
	err_put_bridge:
	agp_put_bridge(bridge);
	return error;
	}
	EXPORT_SYMBOL_GPL(agp_add_bridge);


	void agp_remove_bridge(struct agp_bridge_data *bridge)
	{
	agp_backend_cleanup(bridge);
	list_del(&bridge->list);
	if (list_empty(&agp_bridges))
	agp_frontend_cleanup();
	module_put(bridge->driver->owner);
	}
	EXPORT_SYMBOL_GPL(agp_remove_bridge);

	int agp_off;
	int agp_try_unsupported_boot;
	EXPORT_SYMBOL(agp_off);
	EXPORT_SYMBOL(agp_try_unsupported_boot);

	static int __init agp_init(void)
	{
	if (!agp_off)
	printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
	AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
	return 0;
	}

	static void __exit agp_exit(void)
	{
	}

	#ifndef MODULE
	static __init int agp_setup(char *s)
	{
	if (!strcmp(s,"off"))
	agp_off = 1;
	if (!strcmp(s,"try_unsupported"))
	agp_try_unsupported_boot = 1;
	return 1;
	}
	__setup("agp=", agp_setup);
	#endif

	MODULE_AUTHOR("Dave Jones, Jeff Hartmann");
	MODULE_DESCRIPTION("AGP GART driver");
	MODULE_LICENSE("GPL and additional rights");
	MODULE_ALIAS_MISCDEV(AGPGART_MINOR);

	module_init(agp_init);
	module_exit(agp_exit);