generic.c

linux-2.6.15.6

/*
 * AGPGART driver.
 * Copyright (C) 2004 Silicon Graphics, Inc.
 * Copyright (C) 2002-2005 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.
 *
 * TODO:
 * - Allocate more than order 0 pages to avoid too much linear map splitting.
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/miscdevice.h>
#include <linux/pm.h>
#include <linux/agp_backend.h>
#include <linux/vmalloc.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include "agp.h"

__u32 *agp_gatt_table;
int agp_memory_reserved;

/*
 * Needed by the Nforce GART driver for the time being. Would be
 * nice to do this some other way instead of needing this export.
 */
EXPORT_SYMBOL_GPL(agp_memory_reserved);

#if defined(CONFIG_X86)
int map_page_into_agp(struct page *page)
{
	int i;
	i = change_page_attr(page, 1, PAGE_KERNEL_NOCACHE);
	/* Caller's responsibility to call global_flush_tlb() for
	 * performance reasons */
	return i;
}
EXPORT_SYMBOL_GPL(map_page_into_agp);

int unmap_page_from_agp(struct page *page)
{
	int i;
	i = change_page_attr(page, 1, PAGE_KERNEL);
	/* Caller's responsibility to call global_flush_tlb() for
	 * performance reasons */
	return i;
}
EXPORT_SYMBOL_GPL(unmap_page_from_agp);
#endif

/*
 * Generic routines for handling agp_memory structures -
 * They use the basic page allocation routines to do the brunt of the work.
 */

void agp_free_key(int key)
{
	if (key < 0)
		return;

	if (key < MAXKEY)
		clear_bit(key, agp_bridge->key_list);
}
EXPORT_SYMBOL(agp_free_key);


static int agp_get_key(void)
{
	int bit;

	bit = find_first_zero_bit(agp_bridge->key_list, MAXKEY);
	if (bit < MAXKEY) {
		set_bit(bit, agp_bridge->key_list);
		return bit;
	}
	return -1;
}


struct agp_memory *agp_create_memory(int scratch_pages)
{
	struct agp_memory *new;

	new = kzalloc(sizeof(struct agp_memory), GFP_KERNEL);
	if (new == NULL)
		return NULL;

	new->key = agp_get_key();

	if (new->key < 0) {
		kfree(new);
		return NULL;
	}
	new->memory = vmalloc(PAGE_SIZE * scratch_pages);

	if (new->memory == NULL) {
		agp_free_key(new->key);
		kfree(new);
		return NULL;
	}
	new->num_scratch_pages = scratch_pages;
	return new;
}
EXPORT_SYMBOL(agp_create_memory);

/**
 *	agp_free_memory - free memory associated with an agp_memory pointer.
 *
 *	@curr:		agp_memory pointer to be freed.
 *
 *	It is the only function that can be called when the backend is not owned
 *	by the caller.  (So it can free memory on client death.)
 */
void agp_free_memory(struct agp_memory *curr)
{
	size_t i;

	if (curr == NULL)
		return;

	if (curr->is_bound == TRUE)
		agp_unbind_memory(curr);

	if (curr->type != 0) {
		curr->bridge->driver->free_by_type(curr);
		return;
	}
	if (curr->page_count != 0) {
		for (i = 0; i < curr->page_count; i++) {
			curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]));
		}
		flush_agp_mappings();
	}
	agp_free_key(curr->key);
	vfree(curr->memory);
	kfree(curr);
}
EXPORT_SYMBOL(agp_free_memory);

#define ENTRIES_PER_PAGE		(PAGE_SIZE / sizeof(unsigned long))

/**
 *	agp_allocate_memory  -  allocate a group of pages of a certain type.
 *
 *	@page_count:	size_t argument of the number of pages
 *	@type:	u32 argument of the type of memory to be allocated.
 *
 *	Every agp bridge device will allow you to allocate AGP_NORMAL_MEMORY which
 *	maps to physical ram.  Any other type is device dependent.
 *
 *	It returns NULL whenever memory is unavailable.
 */
struct agp_memory *agp_allocate_memory(struct agp_bridge_data *bridge,
					size_t page_count, u32 type)
{
	int scratch_pages;
	struct agp_memory *new;
	size_t i;

	if (!bridge)
		return NULL;

	if ((atomic_read(&bridge->current_memory_agp) + page_count) > bridge->max_memory_agp)
		return NULL;

	if (type != 0) {
		new = bridge->driver->alloc_by_type(page_count, type);
		if (new)
			new->bridge = bridge;
		return new;
	}

	scratch_pages = (page_count + ENTRIES_PER_PAGE - 1) / ENTRIES_PER_PAGE;

	new = agp_create_memory(scratch_pages);

	if (new == NULL)
		return NULL;

	for (i = 0; i < page_count; i++) {
		void *addr = bridge->driver->agp_alloc_page(bridge);

		if (addr == NULL) {
			agp_free_memory(new);
			return NULL;
		}
		new->memory[i] = virt_to_gart(addr);
		new->page_count++;
	}
	new->bridge = bridge;

	flush_agp_mappings();

	return new;
}
EXPORT_SYMBOL(agp_allocate_memory);


/* End - Generic routines for handling agp_memory structures */


static int agp_return_size(void)
{
	int current_size;
	void *temp;

	temp = agp_bridge->current_size;

	switch (agp_bridge->driver->size_type) {
	case U8_APER_SIZE:
		current_size = A_SIZE_8(temp)->size;
		break;
	case U16_APER_SIZE:
		current_size = A_SIZE_16(temp)->size;
		break;
	case U32_APER_SIZE:
		current_size = A_SIZE_32(temp)->size;
		break;
	case LVL2_APER_SIZE:
		current_size = A_SIZE_LVL2(temp)->size;
		break;
	case FIXED_APER_SIZE:
		current_size = A_SIZE_FIX(temp)->size;
		break;
	default:
		current_size = 0;
		break;
	}

	current_size -= (agp_memory_reserved / (1024*1024));
	if (current_size <0)
		current_size = 0;
	return current_size;
}


int agp_num_entries(void)
{
	int num_entries;
	void *temp;

	temp = agp_bridge->current_size;

	switch (agp_bridge->driver->size_type) {
	case U8_APER_SIZE:
		num_entries = A_SIZE_8(temp)->num_entries;
		break;
	case U16_APER_SIZE:
		num_entries = A_SIZE_16(temp)->num_entries;
		break;
	case U32_APER_SIZE:
		num_entries = A_SIZE_32(temp)->num_entries;
		break;
	case LVL2_APER_SIZE:
		num_entries = A_SIZE_LVL2(temp)->num_entries;
		break;
	case FIXED_APER_SIZE:
		num_entries = A_SIZE_FIX(temp)->num_entries;
		break;
	default:
		num_entries = 0;
		break;
	}

	num_entries -= agp_memory_reserved>>PAGE_SHIFT;
	if (num_entries<0)
		num_entries = 0;
	return num_entries;
}
EXPORT_SYMBOL_GPL(agp_num_entries);


/**
 *	agp_copy_info  -  copy bridge state information
 *
 *	@info:		agp_kern_info pointer.  The caller should insure that this pointer is valid. 
 *
 *	This function copies information about the agp bridge device and the state of
 *	the agp backend into an agp_kern_info pointer.
 */
int agp_copy_info(struct agp_bridge_data *bridge, struct agp_kern_info *info)
{
	memset(info, 0, sizeof(struct agp_kern_info));
	if (!bridge) {
		info->chipset = NOT_SUPPORTED;
		return -EIO;
	}

	info->version.major = bridge->version->major;
	info->version.minor = bridge->version->minor;
	info->chipset = SUPPORTED;
	info->device = bridge->dev;
	if (bridge->mode & AGPSTAT_MODE_3_0)
		info->mode = bridge->mode & ~AGP3_RESERVED_MASK;
	else
		info->mode = bridge->mode & ~AGP2_RESERVED_MASK;
	info->aper_base = bridge->gart_bus_addr;
	info->aper_size = agp_return_size();
	info->max_memory = bridge->max_memory_agp;
	info->current_memory = atomic_read(&bridge->current_memory_agp);
	info->cant_use_aperture = bridge->driver->cant_use_aperture;
	info->vm_ops = bridge->vm_ops;
	info->page_mask = ~0UL;
	return 0;
}
EXPORT_SYMBOL(agp_copy_info);

/* End - Routine to copy over information structure */

/*
 * Routines for handling swapping of agp_memory into the GATT -
 * These routines take agp_memory and insert them into the GATT.
 * They call device specific routines to actually write to the GATT.
 */

/**
 *	agp_bind_memory  -  Bind an agp_memory structure into the GATT.
 *
 *	@curr:		agp_memory pointer
 *	@pg_start:	an offset into the graphics aperture translation table
 *
 *	It returns -EINVAL if the pointer == NULL.
 *	It returns -EBUSY if the area of the table requested is already in use.
 */
int agp_bind_memory(struct agp_memory *curr, off_t pg_start)
{
	int ret_val;

	if (curr == NULL)
		return -EINVAL;

	if (curr->is_bound == TRUE) {
		printk(KERN_INFO PFX "memory %p is already bound!\n", curr);
		return -EINVAL;
	}
	if (curr->is_flushed == FALSE) {
		curr->bridge->driver->cache_flush();
		curr->is_flushed = TRUE;
	}
	ret_val = curr->bridge->driver->insert_memory(curr, pg_start, curr->type);

	if (ret_val != 0)
		return ret_val;

	curr->is_bound = TRUE;
	curr->pg_start = pg_start;
	return 0;
}
EXPORT_SYMBOL(agp_bind_memory);


/**
 *	agp_unbind_memory  -  Removes an agp_memory structure from the GATT
 *
 * @curr:	agp_memory pointer to be removed from the GATT.
 *
 * It returns -EINVAL if this piece of agp_memory is not currently bound to
 * the graphics aperture translation table or if the agp_memory pointer == NULL
 */
int agp_unbind_memory(struct agp_memory *curr)
{
	int ret_val;

	if (curr == NULL)
		return -EINVAL;

	if (curr->is_bound != TRUE) {
		printk(KERN_INFO PFX "memory %p was not bound!\n", curr);
		return -EINVAL;
	}

	ret_val = curr->bridge->driver->remove_memory(curr, curr->pg_start, curr->type);

	if (ret_val != 0)
		return ret_val;

	curr->is_bound = FALSE;
	curr->pg_start = 0;