linux/drivers/char/agp/backend.c
Keir Fraser 07eee78ea8 [PATCH] AGP fix for Xen VMM
When Linux is running on the Xen virtual machine monitor, physical
addresses are virtualised and cannot be directly referenced by the AGP
GART.  This patch fixes the GART driver for Xen by adding a layer of
abstraction between physical addresses and 'GART addresses'.

Architecture-specific functions are also defined for allocating and freeing
the GATT.  Xen requires this to ensure that table really is contiguous from
the point of view of the GART.

These extra interface functions are defined as 'no-ops' for all existing
architectures that use the GART driver.

Signed-off-by: Keir Fraser <keir@xensource.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-06-07 12:35:43 -07:00

349 lines
8.5 KiB
C

/*
* 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/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 101
static 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 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 = num_physpages >> (20 - PAGE_SHIFT);
#else
memory = num_physpages << (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) {
void *addr = bridge->driver->agp_alloc_page(bridge);
if (!addr) {
printk(KERN_ERR PFX "unable to get memory for scratch page.\n");
return -ENOMEM;
}
bridge->scratch_page_real = virt_to_gart(addr);
bridge->scratch_page =
bridge->driver->mask_memory(bridge, bridge->scratch_page_real, 0);
}
size_value = bridge->driver->fetch_size();
if (size_value == 0) {
printk(KERN_ERR PFX "unable to determine aperture size.\n");
rc = -EINVAL;
goto err_out;
}
if (bridge->driver->create_gatt_table(bridge)) {
printk(KERN_ERR PFX
"unable to get memory for graphics translation table.\n");
rc = -ENOMEM;
goto err_out;
}
got_gatt = 1;
bridge->key_list = vmalloc(PAGE_SIZE * 4);
if (bridge->key_list == NULL) {
printk(KERN_ERR PFX "error allocating memory for key lists.\n");
rc = -ENOMEM;
goto err_out;
}
got_keylist = 1;
/* FIXME vmalloc'd memory not guaranteed contiguous */
memset(bridge->key_list, 0, PAGE_SIZE * 4);
if (bridge->driver->configure()) {
printk(KERN_ERR PFX "error configuring host chipset.\n");
rc = -EINVAL;
goto err_out;
}
return 0;
err_out:
if (bridge->driver->needs_scratch_page)
bridge->driver->agp_destroy_page(
gart_to_virt(bridge->scratch_page_real));
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);
if (bridge->key_list) {
vfree(bridge->key_list);
bridge->key_list = NULL;
}
if (bridge->driver->agp_destroy_page &&
bridge->driver->needs_scratch_page)
bridge->driver->agp_destroy_page(
gart_to_virt(bridge->scratch_page_real));
}
/* 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 = kmalloc(sizeof(*bridge), GFP_KERNEL);
if (!bridge)
return NULL;
memset(bridge, 0, sizeof(*bridge));
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)
return -ENODEV;
if (!bridge->dev) {
printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
return -EINVAL;
}
/* Grab reference on the chipset driver. */
if (!try_module_get(bridge->driver->owner)) {
printk (KERN_INFO PFX "Couldn't lock chipset driver.\n");
return -EINVAL;
}
error = agp_backend_initialize(bridge);
if (error) {
printk (KERN_INFO PFX "agp_backend_initialize() failed.\n");
goto err_out;
}
if (list_empty(&agp_bridges)) {
error = agp_frontend_initialize();
if (error) {
printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
goto frontend_err;
}
printk(KERN_INFO PFX "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);
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 (c) Dave Jones\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 <davej@codemonkey.org.uk>");
MODULE_DESCRIPTION("AGP GART driver");
MODULE_LICENSE("GPL and additional rights");
MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
module_init(agp_init);
module_exit(agp_exit);