4 files changed, 145 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3f0173f45019..e9acd5540d29 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 1dd6f3fc077d..c6fd3a6afa42 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 7c4d75e3c5f3..7d6a9a5aa7cd 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 057f335fa3f6..ac56d3916c50 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;