ACPI: Add CPU hotplug support for processor device objects

acpi_processor_install_hotplug_notify() registers processor objects to
receive ACPI CPU hotplug event notifications. This patch additionally
registers processor device objects (ACPI0007) to receive the notifications
as well.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 38 insertions, 10 deletions

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 8ae05ce18500..50be27739fe8 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -68,6 +68,7 @@
 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
 #define ACPI_PROCESSOR_NOTIFY_POWER     0x81
 #define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
+#define ACPI_PROCESSOR_DEVICE_HID       "ACPI0007"
 
 #define ACPI_PROCESSOR_LIMIT_USER       0
 #define ACPI_PROCESSOR_LIMIT_THERMAL    1
@@ -88,7 +89,7 @@ static int acpi_processor_start(struct acpi_processor *pr);
 
 static const struct acpi_device_id processor_device_ids[] = {
         {ACPI_PROCESSOR_OBJECT_HID, 0},
-        {"ACPI0007", 0},
+        {ACPI_PROCESSOR_DEVICE_HID, 0},
         {"", 0},
 };
 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
@@ -741,20 +742,46 @@ static void acpi_processor_hotplug_notify(acpi_handle handle,
         return;
 }
 
+static acpi_status is_processor_device(acpi_handle handle)
+{
+        struct acpi_device_info *info;
+        char *hid;
+        acpi_status status;
+
+        status = acpi_get_object_info(handle, &info);
+        if (ACPI_FAILURE(status))
+                return status;
+
+        if (info->type == ACPI_TYPE_PROCESSOR) {
+                kfree(info);
+                return AE_OK;   /* found a processor object */
+        }
+
+        if (!(info->valid & ACPI_VALID_HID)) {
+                kfree(info);
+                return AE_ERROR;
+        }
+
+        hid = info->hardware_id.string;
+        if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
+                kfree(info);
+                return AE_ERROR;
+        }
+
+        kfree(info);
+        return AE_OK;   /* found a processor device object */
+}
+
 static acpi_status
 processor_walk_namespace_cb(acpi_handle handle,
                             u32 lvl, void *context, void **rv)
 {
         acpi_status status;
         int *action = context;
-        acpi_object_type type = 0;
 
-        status = acpi_get_type(handle, &type);
+        status = is_processor_device(handle);
         if (ACPI_FAILURE(status))
-                return (AE_OK);
-
-        if (type != ACPI_TYPE_PROCESSOR)
-                return (AE_OK);
+                return AE_OK;   /* not a processor; continue to walk */
 
         switch (*action) {
         case INSTALL_NOTIFY_HANDLER:
@@ -772,7 +799,8 @@ processor_walk_namespace_cb(acpi_handle handle,
                 break;
         }
 
-        return (AE_OK);
+        /* found a processor; skip walking underneath */
+        return AE_CTRL_DEPTH;
 }
 
 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
@@ -830,7 +858,7 @@ void acpi_processor_install_hotplug_notify(void)
 {
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
         int action = INSTALL_NOTIFY_HANDLER;
-        acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
+        acpi_walk_namespace(ACPI_TYPE_ANY,
                             ACPI_ROOT_OBJECT,
                             ACPI_UINT32_MAX,
                             processor_walk_namespace_cb, NULL, &action, NULL);
@@ -843,7 +871,7 @@ void acpi_processor_uninstall_hotplug_notify(void)
 {
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
         int action = UNINSTALL_NOTIFY_HANDLER;
-        acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
+        acpi_walk_namespace(ACPI_TYPE_ANY,
                             ACPI_ROOT_OBJECT,
                             ACPI_UINT32_MAX,
                             processor_walk_namespace_cb, NULL, &action, NULL);