3 files changed, 23 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 2b2407d9a6d0..4fac69beeb4f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1970,6 +1970,8 @@ and is between 256 and 4096 characters. It is defined in the file
                 norom           [X86] Do not assign address space to
                                 expansion ROMs that do not already have
                                 BIOS assigned address ranges.
+                nobar           [X86] Do not assign address space to the
+                                BARs that weren't assigned by the BIOS.
                 irqmask=0xMMMM  [X86] Set a bit mask of IRQs allowed to be
                                 assigned automatically to PCI devices. You can
                                 make the kernel exclude IRQs of your ISA cards
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index cd2a31dc5fb8..49c7219826f9 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -30,6 +30,7 @@
 #define PCI_HAS_IO_ECS          0x40000
 #define PCI_NOASSIGN_ROMS       0x80000
 #define PCI_ROOT_NO_CRS         0x100000
+#define PCI_NOASSIGN_BARS       0x200000
 
 extern unsigned int pci_probe;
 extern unsigned long pirq_table_addr;
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 215a27ae050d..a0772af64efb 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -125,6 +125,23 @@ void __init dmi_check_skip_isa_align(void)
 static void __devinit pcibios_fixup_device_resources(struct pci_dev *dev)
 {
         struct resource *rom_r = &dev->resource[PCI_ROM_RESOURCE];
+        struct resource *bar_r;
+        int bar;
+
+        if (pci_probe & PCI_NOASSIGN_BARS) {
+                /*
+                * If the BIOS did not assign the BAR, zero out the
+                * resource so the kernel doesn't attmept to assign
+                * it later on in pci_assign_unassigned_resources
+                */
+                for (bar = 0; bar <= PCI_STD_RESOURCE_END; bar++) {
+                        bar_r = &dev->resource[bar];
+                        if (bar_r->start == 0 && bar_r->end != 0) {
+                                bar_r->flags = 0;
+                                bar_r->end = 0;
+                        }
+                }
+        }
 
         if (pci_probe & PCI_NOASSIGN_ROMS) {
                 if (rom_r->parent)
@@ -509,6 +526,9 @@ char * __devinit  pcibios_setup(char *str)
         } else if (!strcmp(str, "norom")) {
                 pci_probe |= PCI_NOASSIGN_ROMS;
                 return NULL;
+        } else if (!strcmp(str, "nobar")) {
+                pci_probe |= PCI_NOASSIGN_BARS;
+                return NULL;
         } else if (!strcmp(str, "assign-busses")) {
                 pci_probe |= PCI_ASSIGN_ALL_BUSSES;
                 return NULL;