4 files changed, 88 insertions, 19 deletions

diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index e1c2cea305f8..e71f78318d6e 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -40,6 +40,7 @@
 extern int pciehp_poll_mode;
 extern int pciehp_poll_time;
 extern int pciehp_debug;
+extern int pciehp_force;
 
 /*#define dbg(format, arg...) do { if (pciehp_debug) printk(KERN_DEBUG "%s: " format, MY_NAME , ## arg); } while (0)*/
 #define dbg(format, arg...) do { if (pciehp_debug) printk("%s: " format, MY_NAME , ## arg); } while (0)
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 0bfc37325923..8df704860348 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -39,6 +39,7 @@
 int pciehp_debug;
 int pciehp_poll_mode;
 int pciehp_poll_time;
+int pciehp_force;
 struct controller *pciehp_ctrl_list;
 
 #define DRIVER_VERSION  "0.4"
@@ -52,9 +53,11 @@ MODULE_LICENSE("GPL");
 module_param(pciehp_debug, bool, 0644);
 module_param(pciehp_poll_mode, bool, 0644);
 module_param(pciehp_poll_time, int, 0644);
+module_param(pciehp_force, bool, 0644);
 MODULE_PARM_DESC(pciehp_debug, "Debugging mode enabled or not");
 MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
 MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");
+MODULE_PARM_DESC(pciehp_force, "Force pciehp, even if _OSC and OSHP are missing");
 
 #define PCIE_MODULE_NAME "pciehp"
 
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 5c812b858847..2d2539ba7303 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -1417,9 +1417,14 @@ int pcie_init(struct controller * ctrl, struct pcie_device *dev)
                 goto abort_free_ctlr;
         }
         
-        rc = get_hp_hw_control_from_firmware(ctrl->pci_dev);
-        if (rc)
-                goto abort_free_ctlr;
+        if (pciehp_force) {
+                dbg("Bypassing BIOS check for pciehp use on %s\n",
+                                pci_name(ctrl->pci_dev));
+        } else {
+                rc = get_hp_hw_control_from_firmware(ctrl->pci_dev);
+                if (rc)
+                        goto abort_free_ctlr;
+        }
 
         /*  Add this HPC instance into the HPC list */
         spin_lock(&list_lock);
diff --git a/drivers/pci/hotplug/pciehprm_acpi.c b/drivers/pci/hotplug/pciehprm_acpi.c
index 5acdae3d52b1..4d013f86b1a5 100644
--- a/drivers/pci/hotplug/pciehprm_acpi.c
+++ b/drivers/pci/hotplug/pciehprm_acpi.c
@@ -132,7 +132,7 @@ static acpi_status acpi_run_oshp(acpi_handle handle)
         /* run OSHP */
         status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
         if (ACPI_FAILURE(status)) {
-                err("%s:%s OSHP fails=0x%x\n", __FUNCTION__, path_name,
+                dbg("%s:%s OSHP fails=0x%x\n", __FUNCTION__, path_name,
                                 status);
         } else {
                 dbg("%s:%s OSHP passes\n", __FUNCTION__, path_name);
@@ -140,32 +140,92 @@ static acpi_status acpi_run_oshp(acpi_handle handle)
         return status;
 }
 
+static int is_root_bridge(acpi_handle handle)
+{
+        acpi_status status;
+        struct acpi_device_info *info;
+        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+        int i;
+
+        status = acpi_get_object_info(handle, &buffer);
+        if (ACPI_SUCCESS(status)) {
+                info = buffer.pointer;
+                if ((info->valid & ACPI_VALID_HID) &&
+                        !strcmp(PCI_ROOT_HID_STRING,
+                                        info->hardware_id.value)) {
+                        acpi_os_free(buffer.pointer);
+                        return 1;
+                }
+                if (info->valid & ACPI_VALID_CID) {
+                        for (i=0; i < info->compatibility_id.count; i++) {
+                                if (!strcmp(PCI_ROOT_HID_STRING,
+                                        info->compatibility_id.id[i].value)) {
+                                        acpi_os_free(buffer.pointer);
+                                        return 1;
+                                }
+                        }
+                }
+        }
+        return 0;
+}
+
 int get_hp_hw_control_from_firmware(struct pci_dev *dev)
 {
         acpi_status status;
-        acpi_handle handle = DEVICE_ACPI_HANDLE(&(dev->dev));
+        acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
+        struct pci_dev *pdev = dev;
+        u8 *path_name;
         /*
          * Per PCI firmware specification, we should run the ACPI _OSC
-         * method to get control of hotplug hardware before using it
+         * method to get control of hotplug hardware before using it.
+         * If an _OSC is missing, we look for an OSHP to do the same thing.
+         * To handle different BIOS behavior, we look for _OSC and OSHP
+         * within the scope of the hotplug controller and its parents, upto
+         * the host bridge under which this controller exists.
          */
-        status = pci_osc_control_set(handle,
-                        OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
-
-        /* Fixme: fail native hotplug if _OSC does not exist for root ports */
-        if (status == AE_NOT_FOUND) {
+        while (!handle) {
                 /*
-                 * Some older BIOS's don't support _OSC but support
-                 * OSHP to do the same thing
+                 * This hotplug controller was not listed in the ACPI name
+                 * space at all. Try to get acpi handle of parent pci bus.
                  */
-                status = acpi_run_oshp(handle);
+                if (!pdev || !pdev->bus->parent)
+                        break;
+                dbg("Could not find %s in acpi namespace, trying parent\n",
+                                pci_name(pdev));
+                if (!pdev->bus->parent->self)
+                        /* Parent must be a host bridge */
+                        handle = acpi_get_pci_rootbridge_handle(
+                                        pci_domain_nr(pdev->bus->parent),
+                                        pdev->bus->parent->number);
+                else
+                        handle = DEVICE_ACPI_HANDLE(
+                                        &(pdev->bus->parent->self->dev));
+                pdev = pdev->bus->parent->self;
         }
-        if (ACPI_FAILURE(status)) {
-                err("Cannot get control of hotplug hardware\n");
-                return -1;
+
+        while (handle) {
+                path_name = acpi_path_name(handle);
+                dbg("Trying to get hotplug control for %s \n", path_name);
+                status = pci_osc_control_set(handle,
+                                OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
+                if (status == AE_NOT_FOUND)
+                        status = acpi_run_oshp(handle);
+                if (ACPI_SUCCESS(status)) {
+                        dbg("Gained control for hotplug HW for pci %s (%s)\n",
+                                pci_name(dev), path_name);
+                        return 0;
+                }
+                if (is_root_bridge(handle))
+                        break;
+                chandle = handle;
+                status = acpi_get_parent(chandle, &handle);
+                if (ACPI_FAILURE(status))
+                        break;
         }
 
-        dbg("Sucess getting control of hotplug hardware\n");
-        return 0;
+        err("Cannot get control of hotplug hardware for pci %s\n",
+                        pci_name(dev));
+        return -1;
 }
 
 void get_hp_params_from_firmware(struct pci_dev *dev,