android_kernel_motorola_sm6225/arch/x86_64/kernel/k8.c
Ben Collins 3c6df2a917 Avoid zero size allocation in cache_k8_northbridges()
kmalloc for flush_words resulted in zero size allocation when no
k8_northbridges existed.  Short circuit the code path for this case.

Also remove uneeded zeroing of num_k8_northbridges just after checking if
it is zero.

Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:12 -07:00

123 lines
2.8 KiB
C

/*
* Shared support code for AMD K8 northbridges and derivates.
* Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
*/
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/k8.h>
int num_k8_northbridges;
EXPORT_SYMBOL(num_k8_northbridges);
static u32 *flush_words;
struct pci_device_id k8_nb_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1103) },
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1203) },
{}
};
EXPORT_SYMBOL(k8_nb_ids);
struct pci_dev **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 (num_k8_northbridges)
return 0;
dev = NULL;
while ((dev = next_k8_northbridge(dev)) != NULL)
num_k8_northbridges++;
k8_northbridges = kmalloc((num_k8_northbridges + 1) * sizeof(void *),
GFP_KERNEL);
if (!k8_northbridges)
return -ENOMEM;
if (!num_k8_northbridges) {
k8_northbridges[0] = NULL;
return 0;
}
flush_words = kmalloc(num_k8_northbridges * sizeof(u32), GFP_KERNEL);
if (!flush_words) {
kfree(k8_northbridges);
return -ENOMEM;
}
dev = NULL;
i = 0;
while ((dev = next_k8_northbridge(dev)) != NULL) {
k8_northbridges[i] = dev;
pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
}
k8_northbridges[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);
/* 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 < num_k8_northbridges; i++) {
pci_write_config_dword(k8_northbridges[i], 0x9c,
flush_words[i]|1);
flushed++;
}
for (i = 0; i < num_k8_northbridges; i++) {
u32 w;
/* Make sure the hardware actually executed the flush*/
for (;;) {
pci_read_config_dword(k8_northbridges[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);