linux-stable/arch/x86/kernel/k8.c
Andreas Herrmann 900f9ac9f1 x86, k8-gart: Decouple handling of garts and northbridges
So far we only provide num_k8_northbridges. This is required in
different areas (e.g. L3 cache index disable, GART). But not all AMD
CPUs provide a GART. Thus it is useful to split off the GART handling
from the generic caching of AMD northbridge misc devices.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100917160254.GC4958@loge.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-09-17 13:26:21 -07:00

145 lines
3.4 KiB
C

/*
* Shared support code for AMD K8 northbridges and derivates.
* Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/k8.h>
static u32 *flush_words;
struct pci_device_id k8_nb_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
{}
};
EXPORT_SYMBOL(k8_nb_ids);
struct k8_northbridge_info k8_northbridges;
EXPORT_SYMBOL(k8_northbridges);
static struct pci_dev *next_k8_northbridge(struct pci_dev *dev)
{
do {
dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
if (!dev)
break;
} while (!pci_match_id(&k8_nb_ids[0], dev));
return dev;
}
int cache_k8_northbridges(void)
{
int i;
struct pci_dev *dev;
if (k8_northbridges.num)
return 0;
dev = NULL;
while ((dev = next_k8_northbridge(dev)) != NULL)
k8_northbridges.num++;
/* some CPU families (e.g. family 0x11) do not support GART */
if (boot_cpu_data.x86 == 0xf || boot_cpu_data.x86 == 0x10)
k8_northbridges.gart_supported = 1;
k8_northbridges.nb_misc = kmalloc((k8_northbridges.num + 1) *
sizeof(void *), GFP_KERNEL);
if (!k8_northbridges.nb_misc)
return -ENOMEM;
if (!k8_northbridges.num) {
k8_northbridges.nb_misc[0] = NULL;
return 0;
}
if (k8_northbridges.gart_supported) {
flush_words = kmalloc(k8_northbridges.num * sizeof(u32),
GFP_KERNEL);
if (!flush_words) {
kfree(k8_northbridges.nb_misc);
return -ENOMEM;
}
}
dev = NULL;
i = 0;
while ((dev = next_k8_northbridge(dev)) != NULL) {
k8_northbridges.nb_misc[i] = dev;
if (k8_northbridges.gart_supported)
pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
}
k8_northbridges.nb_misc[i] = NULL;
return 0;
}
EXPORT_SYMBOL_GPL(cache_k8_northbridges);
/* Ignores subdevice/subvendor but as far as I can figure out
they're useless anyways */
int __init early_is_k8_nb(u32 device)
{
struct pci_device_id *id;
u32 vendor = device & 0xffff;
device >>= 16;
for (id = k8_nb_ids; id->vendor; id++)
if (vendor == id->vendor && device == id->device)
return 1;
return 0;
}
void k8_flush_garts(void)
{
int flushed, i;
unsigned long flags;
static DEFINE_SPINLOCK(gart_lock);
if (!k8_northbridges.gart_supported)
return;
/* Avoid races between AGP and IOMMU. In theory it's not needed
but I'm not sure if the hardware won't lose flush requests
when another is pending. This whole thing is so expensive anyways
that it doesn't matter to serialize more. -AK */
spin_lock_irqsave(&gart_lock, flags);
flushed = 0;
for (i = 0; i < k8_northbridges.num; i++) {
pci_write_config_dword(k8_northbridges.nb_misc[i], 0x9c,
flush_words[i]|1);
flushed++;
}
for (i = 0; i < k8_northbridges.num; i++) {
u32 w;
/* Make sure the hardware actually executed the flush*/
for (;;) {
pci_read_config_dword(k8_northbridges.nb_misc[i],
0x9c, &w);
if (!(w & 1))
break;
cpu_relax();
}
}
spin_unlock_irqrestore(&gart_lock, flags);
if (!flushed)
printk("nothing to flush?\n");
}
EXPORT_SYMBOL_GPL(k8_flush_garts);
static __init int init_k8_nbs(void)
{
int err = 0;
err = cache_k8_northbridges();
if (err < 0)
printk(KERN_NOTICE "K8 NB: Cannot enumerate AMD northbridges.\n");
return err;
}
/* This has to go after the PCI subsystem */
fs_initcall(init_k8_nbs);