PCI hotplug: introduce functions for ACPI slot detection

[linux-2.6-omap-h63xx.git] / drivers / pci / hotplug / acpi_pcihp.c

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index 93e37f0666ab5e2786484a775f107bbffd9b3ecd..c62ab8d240aa42b787d4632605dd1166fc9aebf9 100644 (file)
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -382,7 +382,7 @@ EXPORT_SYMBOL_GPL(acpi_get_hp_params_from_firmware);
 int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
 {
        acpi_status status;
-       acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
+       acpi_handle chandle, handle;
        struct pci_dev *pdev = dev;
        struct pci_bus *parent;
        struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
@@ -399,10 +399,25 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
         * 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,
+        * To handle different BIOS behavior, we look for _OSC on a root
+        * bridge preferentially (according to PCI fw spec). Later for
+        * OSHP within the scope of the hotplug controller and its parents,
         * upto the host bridge under which this controller exists.
         */
+       handle = acpi_find_root_bridge_handle(pdev);
+       if (handle) {
+               acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+               dbg("Trying to get hotplug control for %s\n",
+                               (char *)string.pointer);
+               status = pci_osc_control_set(handle, flags);
+               if (ACPI_SUCCESS(status))
+                       goto got_one;
+               kfree(string.pointer);
+               string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
+       }
+
+       pdev = dev;
+       handle = DEVICE_ACPI_HANDLE(&dev->dev);
        while (!handle) {
                /*
                 * This hotplug controller was not listed in the ACPI name
@@ -427,15 +442,9 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
                acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
                dbg("Trying to get hotplug control for %s \n",
                    (char *)string.pointer);
-               status = pci_osc_control_set(handle, flags);
-               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), (char *)string.pointer);
-                       kfree(string.pointer);
-                       return 0;
-               }
+               status = acpi_run_oshp(handle);
+               if (ACPI_SUCCESS(status))
+                       goto got_one;
                if (acpi_root_bridge(handle))
                        break;
                chandle = handle;
@@ -449,6 +458,11 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
 
        kfree(string.pointer);
        return -ENODEV;
+got_one:
+       dbg("Gained control for hotplug HW for pci %s (%s)\n", pci_name(dev),
+                       (char *)string.pointer);
+       kfree(string.pointer);
+       return 0;
 }
 EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);
 
@@ -487,5 +501,74 @@ int acpi_root_bridge(acpi_handle handle)
 }
 EXPORT_SYMBOL_GPL(acpi_root_bridge);
 
+
+static int is_ejectable(acpi_handle handle)
+{
+       acpi_status status;
+       acpi_handle tmp;
+       unsigned long long removable;
+       status = acpi_get_handle(handle, "_ADR", &tmp);
+       if (ACPI_FAILURE(status))
+               return 0;
+       status = acpi_get_handle(handle, "_EJ0", &tmp);
+       if (ACPI_SUCCESS(status))
+               return 1;
+       status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
+       if (ACPI_SUCCESS(status) && removable)
+               return 1;
+       return 0;
+}
+
+/**
+ * acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
+ * @pbus: the PCI bus of the PCI slot corresponding to 'handle'
+ * @handle: ACPI handle to check
+ *
+ * Return 1 if handle is ejectable PCI slot, 0 otherwise.
+ */
+int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
+{
+       acpi_handle bridge_handle, parent_handle;
+
+       if (!(bridge_handle = acpi_pci_get_bridge_handle(pbus)))
+               return 0;
+       if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
+               return 0;
+       if (bridge_handle != parent_handle)
+               return 0;
+       return is_ejectable(handle);
+}
+EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable);
+
+static acpi_status
+check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+       int *found = (int *)context;
+       if (is_ejectable(handle)) {
+               *found = 1;
+               return AE_CTRL_TERMINATE;
+       }
+       return AE_OK;
+}
+
+/**
+ * acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
+ * @pbus - PCI bus to scan
+ *
+ * Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
+ */
+int acpi_pci_detect_ejectable(struct pci_bus *pbus)
+{
+       acpi_handle handle;
+       int found = 0;
+
+       if (!(handle = acpi_pci_get_bridge_handle(pbus)))
+               return 0;
+       acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
+                           check_hotplug, (void *)&found, NULL);
+       return found;
+}
+EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable);
+
 module_param(debug_acpi, bool, 0644);
 MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not");