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/*
* Firmware replacement code.
*
* Work around broken BIOSes that don't set an aperture, only set the
* aperture in the AGP bridge, or set too small aperture.
*
* If all fails map the aperture over some low memory. This is cheaper than
* doing bounce buffering. The memory is lost. This is done at early boot
* because only the bootmem allocator can allocate 32+MB.
*
* Copyright 2002 Andi Kleen, SuSE Labs.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mmzone.h>
#include <linux/pci_ids.h>
#include <linux/pci.h>
#include <linux/bitops.h>
#include <linux/ioport.h>
#include <linux/suspend.h>
#include <asm/e820.h>
#include <asm/io.h>
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/pci-direct.h>
#include <asm/dma.h>
#include <asm/k8.h>
int gart_iommu_aperture;
int gart_iommu_aperture_disabled __initdata;
int gart_iommu_aperture_allowed __initdata;
int fallback_aper_order __initdata = 1; /* 64MB */
int fallback_aper_force __initdata;
int fix_aperture __initdata = 1;
struct bus_dev_range {
int bus;
int dev_base;
int dev_limit;
};
static struct bus_dev_range bus_dev_ranges[] __initdata = {
{ 0x00, 0x18, 0x20},
{ 0xff, 0x00, 0x20},
{ 0xfe, 0x00, 0x20}
};
static struct resource gart_resource = {
.name = "GART",
.flags = IORESOURCE_MEM,
};
static void __init insert_aperture_resource(u32 aper_base, u32 aper_size)
{
gart_resource.start = aper_base;
gart_resource.end = aper_base + aper_size - 1;
insert_resource(&iomem_resource, &gart_resource);
}
/* This code runs before the PCI subsystem is initialized, so just
access the northbridge directly. */
static u32 __init allocate_aperture(void)
{
u32 aper_size;
void *p;
/* aper_size should <= 1G */
if (fallback_aper_order > 5)
fallback_aper_order = 5;
aper_size = (32 * 1024 * 1024) << fallback_aper_order;
/*
* Aperture has to be naturally aligned. This means a 2GB aperture
* won't have much chance of finding a place in the lower 4GB of
* memory. Unfortunately we cannot move it up because that would
* make the IOMMU useless.
*/
/*
* using 512M as goal, in case kexec will load kernel_big
* that will do the on position decompress, and could overlap with
* that positon with gart that is used.
* sequende:
* kernel_small
* ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
* ==> kernel_small(gart area become e820_reserved)
* ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
* ==> kerne_big (uncompressed size will be big than 64M or 128M)
* so don't use 512M below as gart iommu, leave the space for kernel
* code for safe
*/
p = __alloc_bootmem_nopanic(aper_size, aper_size, 512ULL<<20);
if (!p || __pa(p)+aper_size > 0xffffffff) {
printk(KERN_ERR
"Cannot allocate aperture memory hole (%p,%uK)\n",
p, aper_size>>10);
if (p)
free_bootmem(__pa(p), aper_size);
return 0;
}
printk(KERN_INFO "Mapping aperture over %d KB of RAM @ %lx\n",
aper_size >> 10, __pa(p));
insert_aperture_resource((u32)__pa(p), aper_size);
register_nosave_region((u32)__pa(p) >> PAGE_SHIFT,
(u32)__pa(p+aper_size) >> PAGE_SHIFT);
return (u32)__pa(p);
}
/* Find a PCI capability */
static u32 __init find_cap(int bus, int slot, int func, int cap)
{
int bytes;
u8 pos;
if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) &
PCI_STATUS_CAP_LIST))
return 0;
pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST);
for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
u8 id;
pos &= ~3;
id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID);
if (id == 0xff)
break;
if (id == cap)
return pos;
pos = read_pci_config_byte(bus, slot, func,
pos+PCI_CAP_LIST_NEXT);
}
return 0;
}
/* Read a standard AGPv3 bridge header */
static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order)
{
u32 apsize;
u32 apsizereg;
int nbits;
u32 aper_low, aper_hi;
u64 aper;
u32 old_order;
printk(KERN_INFO "AGP bridge at %02x:%02x:%02x\n", bus, slot, func);
apsizereg = read_pci_config_16(bus, slot, func, cap + 0x14);
if (apsizereg == 0xffffffff) {
printk(KERN_ERR "APSIZE in AGP bridge unreadable\n");
return 0;
}
/* old_order could be the value from NB gart setting */
old_order = *order;
apsize = apsizereg & 0xfff;
/* Some BIOS use weird encodings not in the AGPv3 table. */
if (apsize & 0xff)
apsize |= 0xf00;
nbits = hweight16(apsize);
*order = 7 - nbits;
if ((int)*order < 0) /* < 32MB */
*order = 0;
aper_low = read_pci_config(bus, slot, func, 0x10);
aper_hi = read_pci_config(bus, slot, func, 0x14);
aper = (aper_low & ~((1<<22)-1)) | ((u64)aper_hi << 32);
/*
* On some sick chips, APSIZE is 0. It means it wants 4G
* so let double check that order, and lets trust AMD NB settings:
*/
printk(KERN_INFO "Aperture from AGP @ %Lx old size %u MB\n",
aper, 32 << old_order);
if (aper + (32ULL<<(20 + *order)) > 0x100000000ULL) {
printk(KERN_INFO "Aperture size %u MB (APSIZE %x) is not right, using settings from NB\n",
32 << *order, apsizereg);
*order = old_order;
}
printk(KERN_INFO "Aperture from AGP @ %Lx size %u MB (APSIZE %x)\n",
aper, 32 << *order, apsizereg);
if (!aperture_valid(aper, (32*1024*1024) << *order, 32<<20))
return 0;
return (u32)aper;
}
/*
* Look for an AGP bridge. Windows only expects the aperture in the
* AGP bridge and some BIOS forget to initialize the Northbridge too.
* Work around this here.
*
* Do an PCI bus scan by hand because we're running before the PCI
* subsystem.
*
* All K8 AGP bridges are AGPv3 compliant, so we can do this scan
* generically. It's probably overkill to always scan all slots because
* the AGP bridges should be always an own bus on the HT hierarchy,
* but do it here for future safety.
*/
static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
{
int bus, slot, func;
/* Poor man's PCI discovery */
for (bus = 0; bus < 256; bus++) {
for (slot = 0; slot < 32; slot++) {
for (func = 0; func < 8; func++) {
u32 class, cap;
u8 type;
class = read_pci_config(bus, slot, func,
PCI_CLASS_REVISION);
if (class == 0xffffffff)
break;
switch (class >> 16) {
case PCI_CLASS_BRIDGE_HOST:
case PCI_CLASS_BRIDGE_OTHER: /* needed? */
/* AGP bridge? */
cap = find_cap(bus, slot, func,
PCI_CAP_ID_AGP);
if (!cap)
break;
*valid_agp = 1;
return read_agp(bus, slot, func, cap,
order);
}
/* No multi-function device? */
type = read_pci_config_byte(bus, slot, func,
PCI_HEADER_TYPE);
if (!(type & 0x80))
break;
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