diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3f0173f45019a99bfa0616e3a290c7feb7a100ad..e9acd5540d297dbd7f5bf2e5a6d48c7d46696053 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1318,6 +1318,8 @@ and is between 256 and 4096 characters. It is defined in the file
IRQ routing is enabled.
noacpi [X86-32] Do not use ACPI for IRQ routing
or for PCI scanning.
+ use_crs [X86-32] Use _CRS for PCI resource
+ allocation.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 1dd6f3fc077db0724aaea14752577c6882b23bed..c6fd3a6afa4268b5aca819561365723e67902d7c 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -45,6 +45,142 @@ static struct dmi_system_id acpi_pciprobe_dmi_table[] = {
{}
};
+struct pci_root_info {
+ char *name;
+ unsigned int res_num;
+ struct resource *res;
+ struct pci_bus *bus;
+ int busnum;
+};
+
+static acpi_status
+resource_to_addr(struct acpi_resource *resource,
+ struct acpi_resource_address64 *addr)
+{
+ acpi_status status;
+
+ status = acpi_resource_to_address64(resource, addr);
+ if (ACPI_SUCCESS(status) &&
+ (addr->resource_type == ACPI_MEMORY_RANGE ||
+ addr->resource_type == ACPI_IO_RANGE) &&
+ addr->address_length > 0 &&
+ addr->producer_consumer == ACPI_PRODUCER) {
+ return AE_OK;
+ }
+ return AE_ERROR;
+}
+
+static acpi_status
+count_resource(struct acpi_resource *acpi_res, void *data)
+{
+ struct pci_root_info *info = data;
+ struct acpi_resource_address64 addr;
+ acpi_status status;
+
+ status = resource_to_addr(acpi_res, &addr);
+ if (ACPI_SUCCESS(status))
+ info->res_num++;
+ return AE_OK;
+}
+
+static acpi_status
+setup_resource(struct acpi_resource *acpi_res, void *data)
+{
+ struct pci_root_info *info = data;
+ struct resource *res;
+ struct acpi_resource_address64 addr;
+ acpi_status status;
+ unsigned long flags;
+ struct resource *root;
+
+ status = resource_to_addr(acpi_res, &addr);
+ if (!ACPI_SUCCESS(status))
+ return AE_OK;
+
+ if (addr.resource_type == ACPI_MEMORY_RANGE) {
+ root = &iomem_resource;
+ flags = IORESOURCE_MEM;
+ if (addr.info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
+ flags |= IORESOURCE_PREFETCH;
+ } else if (addr.resource_type == ACPI_IO_RANGE) {
+ root = &ioport_resource;
+ flags = IORESOURCE_IO;
+ } else
+ return AE_OK;
+
+ res = &info->res[info->res_num];
+ res->name = info->name;
+ res->flags = flags;
+ res->start = addr.minimum + addr.translation_offset;
+ res->end = res->start + addr.address_length - 1;
+ res->child = NULL;
+
+ if (insert_resource(root, res)) {
+ printk(KERN_ERR "PCI: Failed to allocate 0x%lx-0x%lx "
+ "from %s for %s\n", (unsigned long) res->start,
+ (unsigned long) res->end, root->name, info->name);
+ } else {
+ info->bus->resource[info->res_num] = res;
+ info->res_num++;
+ }
+ return AE_OK;
+}
+
+static void
+adjust_transparent_bridge_resources(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ int i;
+ u16 class = dev->class >> 8;
+
+ if (class == PCI_CLASS_BRIDGE_PCI && dev->transparent) {
+ for(i = 3; i < PCI_BUS_NUM_RESOURCES; i++)
+ dev->subordinate->resource[i] =
+ dev->bus->resource[i - 3];
+ }
+ }
+}
+
+static void
+get_current_resources(struct acpi_device *device, int busnum,
+ struct pci_bus *bus)
+{
+ struct pci_root_info info;
+ size_t size;
+
+ info.bus = bus;
+ info.res_num = 0;
+ acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_resource,
+ &info);
+ if (!info.res_num)
+ return;
+
+ size = sizeof(*info.res) * info.res_num;
+ info.res = kmalloc(size, GFP_KERNEL);
+ if (!info.res)
+ goto res_alloc_fail;
+
+ info.name = kmalloc(12, GFP_KERNEL);
+ if (!info.name)
+ goto name_alloc_fail;
+ sprintf(info.name, "PCI Bus #%02x", busnum);
+
+ info.res_num = 0;
+ acpi_walk_resources(device->handle, METHOD_NAME__CRS, setup_resource,
+ &info);
+ if (info.res_num)
+ adjust_transparent_bridge_resources(bus);
+
+ return;
+
+name_alloc_fail:
+ kfree(info.res);
+res_alloc_fail:
+ return;
+}
+
struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int domain, int busnum)
{
struct pci_bus *bus;
@@ -89,6 +225,9 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int do
}
}
#endif
+
+ if (bus && (pci_probe & PCI_USE__CRS))
+ get_current_resources(device, busnum, bus);
return bus;
}
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 7c4d75e3c5f3dc4e207af3ee5c7c30ddda72c022..7d6a9a5aa7cdcd326273e586cd45f49a492c8497 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -436,6 +436,9 @@ char * __devinit pcibios_setup(char *str)
} else if (!strcmp(str, "assign-busses")) {
pci_probe |= PCI_ASSIGN_ALL_BUSSES;
return NULL;
+ } else if (!strcmp(str, "use_crs")) {
+ pci_probe |= PCI_USE__CRS;
+ return NULL;
} else if (!strcmp(str, "routeirq")) {
pci_routeirq = 1;
return NULL;
diff --git a/arch/x86/pci/pci.h b/arch/x86/pci/pci.h
index 057f335fa3f6d1aa8d84ac049865d421aed83235..ac56d3916c50e3491ff6ca0421950a3f3a3efc39 100644
--- a/arch/x86/pci/pci.h
+++ b/arch/x86/pci/pci.h
@@ -27,6 +27,7 @@
#define PCI_BIOS_IRQ_SCAN 0x2000
#define PCI_ASSIGN_ALL_BUSSES 0x4000
#define PCI_CAN_SKIP_ISA_ALIGN 0x8000
+#define PCI_USE__CRS 0x10000
extern unsigned int pci_probe;
extern unsigned long pirq_table_addr;