1 files changed, 73 insertions, 1 deletions

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 2427b0862cb..22dcd12e4c1 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -38,7 +38,10 @@
 
 #include "../pci.h"
 #include "pciehp.h"
-
+#include <acpi/acpi.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/actypes.h>
+#include <linux/pci-acpi.h>
 #ifdef DEBUG
 #define DBG_K_TRACE_ENTRY      ((unsigned int)0x00000001)	/* On function entry */
 #define DBG_K_TRACE_EXIT       ((unsigned int)0x00000002)	/* On function exit */
@@ -1236,6 +1239,75 @@ static struct hpc_ops pciehp_hpc_ops = {
 	.check_lnk_status		= hpc_check_lnk_status,
 };
 
+#ifdef CONFIG_ACPI
+int pciehp_acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev)
+{
+	acpi_status status;
+	acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
+	struct pci_dev *pdev = dev;
+	struct pci_bus *parent;
+	u8 *path_name = NULL;
+
+	/*
+	 * Per PCI firmware specification, we should run the ACPI _OSC
+	 * 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.
+	 */
+	while (!handle) {
+		/*
+		 * This hotplug controller was not listed in the ACPI name
+		 * space at all. Try to get acpi handle of parent pci bus.
+		 */
+		if (!pdev || !pdev->bus->parent)
+			break;
+		parent = pdev->bus->parent;
+		dbg("Could not find %s in acpi namespace, trying parent\n",
+				pci_name(pdev));
+		if (!parent->self)
+			/* Parent must be a host bridge */
+			handle = acpi_get_pci_rootbridge_handle(
+					pci_domain_nr(parent),
+					parent->number);
+		else
+			handle = DEVICE_ACPI_HANDLE(
+					&(parent->self->dev));
+		pdev = parent->self;
+	}
+
+	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);
+			acpi_os_free(path_name);
+			return 0;
+		}
+		if (acpi_root_bridge(handle))
+			break;
+		chandle = handle;
+		status = acpi_get_parent(chandle, &handle);
+		if (ACPI_FAILURE(status))
+			break;
+	}
+
+	err("Cannot get control of hotplug hardware for pci %s\n",
+			pci_name(dev));
+	if (path_name)
+		acpi_os_free(path_name);
+	return -1;
+}
+#endif
+
+
+
 int pcie_init(struct controller * ctrl, struct pcie_device *dev)
 {
 	struct php_ctlr_state_s *php_ctlr, *p;