1 files changed, 37 insertions, 16 deletions

diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c
index e616500207e4..a2060e4d5de6 100644
--- a/arch/x86_64/pci/mmconfig.c
+++ b/arch/x86_64/pci/mmconfig.c
@@ -9,11 +9,16 @@
 #include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/bitmap.h>
+#include <asm/e820.h>
+
 #include "pci.h"
 
 #define MMCONFIG_APER_SIZE (256*1024*1024)
+/* Verify the first 16 busses. We assume that systems with more busses
+   get MCFG right. */
+#define MAX_CHECK_BUS 16
 
-static DECLARE_BITMAP(fallback_slots, 32);
+static DECLARE_BITMAP(fallback_slots, 32*MAX_CHECK_BUS);
 
 /* Static virtual mapping of the MMCONFIG aperture */
 struct mmcfg_virt {
@@ -55,7 +60,8 @@ static char __iomem *get_virt(unsigned int seg, unsigned bus)
 static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
 {
         char __iomem *addr;
-        if (seg == 0 && bus == 0 && test_bit(PCI_SLOT(devfn), fallback_slots))
+        if (seg == 0 && bus < MAX_CHECK_BUS &&
+                test_bit(32*bus + PCI_SLOT(devfn), fallback_slots))
                 return NULL;
         addr = get_virt(seg, bus);
         if (!addr)
@@ -69,8 +75,10 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
         char __iomem *addr;
 
         /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
-        if (unlikely(!value || (bus > 255) || (devfn > 255) || (reg > 4095)))
+        if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
+                *value = -1;
                 return -EINVAL;
+        }
 
         addr = pci_dev_base(seg, bus, devfn);
         if (!addr)
@@ -129,21 +137,26 @@ static struct pci_raw_ops pci_mmcfg = {
    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 */
+   and fallback for them. */
 static __init void unreachable_devices(void)
 {
-        int i;
-        for (i = 0; i < 32; i++) {
-                u32 val1;
-                char __iomem *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);
+        int i, k;
+        /* Use the max bus number from ACPI here? */
+        for (k = 0; k < MAX_CHECK_BUS; k++) {
+                for (i = 0; i < 32; i++) {
+                        u32 val1;
+                        char __iomem *addr;
+
+                        pci_conf1_read(0, k, PCI_DEVFN(i,0), 0, 4, &val1);
+                        if (val1 == 0xffffffff)
+                                continue;
+                        addr = pci_dev_base(0, k, PCI_DEVFN(i, 0));
+                        if (addr == NULL|| readl(addr) != val1) {
+                                set_bit(i + 32*k, fallback_slots);
+                                printk(KERN_NOTICE
+                                "PCI: No mmconfig possible on device %x:%x\n",
+                                        k, i);
+                        }
                 }
         }
 }
@@ -161,6 +174,14 @@ void __init pci_mmcfg_init(void)
             (pci_mmcfg_config[0].base_address == 0))
                 return;
 
+        if (!e820_all_mapped(pci_mmcfg_config[0].base_address,
+                        pci_mmcfg_config[0].base_address + MMCONFIG_APER_SIZE,
+                        E820_RESERVED)) {
+                printk(KERN_ERR "PCI: BIOS Bug: MCFG area is not E820-reserved\n");
+                printk(KERN_ERR "PCI: Not using MMCONFIG.\n");
+                return;
+        }
+
         /* RED-PEN i386 doesn't do _nocache right now */
         pci_mmcfg_virt = kmalloc(sizeof(*pci_mmcfg_virt) * pci_mmcfg_config_num, GFP_KERNEL);
         if (pci_mmcfg_virt == NULL) {