1 files changed, 44 insertions, 23 deletions

diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c
index 613789071f30..6b1ea0c9a570 100644
--- a/arch/i386/pci/mmconfig.c
+++ b/arch/i386/pci/mmconfig.c
@@ -12,14 +12,20 @@
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/acpi.h>
+#include <asm/e820.h>
 #include "pci.h"
 
+#define MMCONFIG_APER_SIZE (256*1024*1024)
+
+/* Assume systems with more busses have correct MCFG */
+#define MAX_CHECK_BUS 16
+
 #define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
 
 /* The base address of the last MMCONFIG device accessed */
 static u32 mmcfg_last_accessed_device;
 
-static DECLARE_BITMAP(fallback_slots, 32);
+static DECLARE_BITMAP(fallback_slots, MAX_CHECK_BUS*32);
 
 /*
  * Functions for accessing PCI configuration space with MMCONFIG accesses
@@ -29,8 +35,8 @@ static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
         int cfg_num = -1;
         struct acpi_table_mcfg_config *cfg;
 
-        if (seg == 0 && bus == 0 &&
-            test_bit(PCI_SLOT(devfn), fallback_slots))
+        if (seg == 0 && bus < MAX_CHECK_BUS &&
+            test_bit(PCI_SLOT(devfn) + 32*bus, fallback_slots))
                 return 0;
 
         while (1) {
@@ -74,8 +80,10 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
         unsigned long flags;
         u32 base;
 
-        if (!value || (bus > 255) || (devfn > 255) || (reg > 4095))
+        if ((bus > 255) || (devfn > 255) || (reg > 4095)) {
+                *value = -1;
                 return -EINVAL;
+        }
 
         base = get_base_addr(seg, bus, devfn);
         if (!base)
@@ -146,29 +154,34 @@ 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;
+        int i, k;
         unsigned long flags;
 
-        for (i = 0; i < 32; i++) {
-                u32 val1;
-                u32 addr;
-
-                pci_conf1_read(0, 0, PCI_DEVFN(i, 0), 0, 4, &val1);
-                if (val1 == 0xffffffff)
-                        continue;
-
-                /* Locking probably not needed, but safer */
-                spin_lock_irqsave(&pci_config_lock, flags);
-                addr = get_base_addr(0, 0, PCI_DEVFN(i, 0));
-                if (addr != 0)
-                        pci_exp_set_dev_base(addr, 0, PCI_DEVFN(i, 0));
-                if (addr == 0 || readl((u32 __iomem *)mmcfg_virt_addr) != val1)
-                        set_bit(i, fallback_slots);
-                spin_unlock_irqrestore(&pci_config_lock, flags);
+        for (k = 0; k < MAX_CHECK_BUS; k++) {
+                for (i = 0; i < 32; i++) {
+                        u32 val1;
+                        u32 addr;
+
+                        pci_conf1_read(0, k, PCI_DEVFN(i, 0), 0, 4, &val1);
+                        if (val1 == 0xffffffff)
+                                continue;
+
+                        /* Locking probably not needed, but safer */
+                        spin_lock_irqsave(&pci_config_lock, flags);
+                        addr = get_base_addr(0, k, PCI_DEVFN(i, 0));
+                        if (addr != 0)
+                                pci_exp_set_dev_base(addr, k, PCI_DEVFN(i, 0));
+                        if (addr == 0 ||
+                            readl((u32 __iomem *)mmcfg_virt_addr) != val1) {
+                                set_bit(i, fallback_slots);
+                                printk(KERN_NOTICE
+                        "PCI: No mmconfig possible on %x:%x\n", k, i);
+                        }
+                        spin_unlock_irqrestore(&pci_config_lock, flags);
+                }
         }
 }
 
@@ -183,6 +196,14 @@ 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;
+        }
+
         printk(KERN_INFO "PCI: Using MMCONFIG\n");
         raw_pci_ops = &pci_mmcfg;
         pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;