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-rw-r--r--arch/x86_64/pci/mmconfig.c36
1 files changed, 34 insertions, 2 deletions
diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c
index 22ff1b0..9c4f907 100644
--- a/arch/x86_64/pci/mmconfig.c
+++ b/arch/x86_64/pci/mmconfig.c
@@ -8,10 +8,13 @@
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/acpi.h>
+#include <linux/bitmap.h>
#include "pci.h"
#define MMCONFIG_APER_SIZE (256*1024*1024)
+static DECLARE_BITMAP(fallback_slots, 32);
+
/* Static virtual mapping of the MMCONFIG aperture */
struct mmcfg_virt {
struct acpi_table_mcfg_config *cfg;
@@ -40,9 +43,12 @@ static char *get_virt(unsigned int seg, unsigned bus)
}
}
-static inline char *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
+static char *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
{
- char *addr = get_virt(seg, bus);
+ char *addr;
+ if (seg == 0 && bus == 0 && test_bit(PCI_SLOT(devfn), &fallback_slots))
+ return NULL;
+ addr = get_virt(seg, bus);
if (!addr)
return NULL;
return addr + ((bus << 20) | (devfn << 12));
@@ -109,6 +115,30 @@ static struct pci_raw_ops pci_mmcfg = {
.write = pci_mmcfg_write,
};
+/* K8 systems have some devices (typically in the builtin northbridge)
+ that are only accessible using type1
+ Normally this can be expressed in the MCFG by not listing them
+ and assigning suitable _SEGs, but this isn't implemented in some BIOS.
+ Instead try to discover all devices on bus 0 that are unreachable using MM
+ and fallback for them.
+ We only do this for bus 0/seg 0 */
+static __init void unreachable_devices(void)
+{
+ int i;
+ for (i = 0; i < 32; i++) {
+ u32 val1;
+ char *addr;
+
+ pci_conf1_read(0, 0, PCI_DEVFN(i,0), 0, 4, &val1);
+ if (val1 == 0xffffffff)
+ continue;
+ addr = pci_dev_base(0, 0, PCI_DEVFN(i, 0));
+ if (addr == NULL|| readl(addr) != val1) {
+ set_bit(i, &fallback_slots);
+ }
+ }
+}
+
static int __init pci_mmcfg_init(void)
{
int i;
@@ -139,6 +169,8 @@ static int __init pci_mmcfg_init(void)
printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_config[i].base_address);
}
+ unreachable_devices();
+
raw_pci_ops = &pci_mmcfg;
pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
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