Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / acpi / acpica / evgpe.c
diff --git a/kernel/drivers/acpi/acpica/evgpe.c b/kernel/drivers/acpi/acpica/evgpe.c
new file mode 100644 (file)
index 0000000..ccf7932
--- /dev/null
@@ -0,0 +1,798 @@
+/******************************************************************************
+ *
+ * Module Name: evgpe - General Purpose Event handling and dispatch
+ *
+ *****************************************************************************/
+
+/*
+ * Copyright (C) 2000 - 2015, Intel Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    substantially similar to the "NO WARRANTY" disclaimer below
+ *    ("Disclaimer") and any redistribution must be conditioned upon
+ *    including a substantially similar Disclaimer requirement for further
+ *    binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ *    of any contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGES.
+ */
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acevents.h"
+#include "acnamesp.h"
+
+#define _COMPONENT          ACPI_EVENTS
+ACPI_MODULE_NAME("evgpe")
+#if (!ACPI_REDUCED_HARDWARE)   /* Entire module */
+/* Local prototypes */
+static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
+
+static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context);
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_update_gpe_enable_mask
+ *
+ * PARAMETERS:  gpe_event_info          - GPE to update
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Updates GPE register enable mask based upon whether there are
+ *              runtime references to this GPE
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ev_update_gpe_enable_mask(struct acpi_gpe_event_info *gpe_event_info)
+{
+       struct acpi_gpe_register_info *gpe_register_info;
+       u32 register_bit;
+
+       ACPI_FUNCTION_TRACE(ev_update_gpe_enable_mask);
+
+       gpe_register_info = gpe_event_info->register_info;
+       if (!gpe_register_info) {
+               return_ACPI_STATUS(AE_NOT_EXIST);
+       }
+
+       register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
+
+       /* Clear the run bit up front */
+
+       ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
+
+       /* Set the mask bit only if there are references to this GPE */
+
+       if (gpe_event_info->runtime_count) {
+               ACPI_SET_BIT(gpe_register_info->enable_for_run,
+                            (u8)register_bit);
+       }
+       gpe_register_info->enable_mask = gpe_register_info->enable_for_run;
+
+       return_ACPI_STATUS(AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_enable_gpe
+ *
+ * PARAMETERS:  gpe_event_info          - GPE to enable
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Clear a GPE of stale events and enable it.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
+{
+       acpi_status status;
+
+       ACPI_FUNCTION_TRACE(ev_enable_gpe);
+
+       /* Clear the GPE (of stale events) */
+
+       status = acpi_hw_clear_gpe(gpe_event_info);
+       if (ACPI_FAILURE(status)) {
+               return_ACPI_STATUS(status);
+       }
+
+       /* Enable the requested GPE */
+
+       status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
+       return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_add_gpe_reference
+ *
+ * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
+ *              hardware-enabled.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
+{
+       acpi_status status = AE_OK;
+
+       ACPI_FUNCTION_TRACE(ev_add_gpe_reference);
+
+       if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
+               return_ACPI_STATUS(AE_LIMIT);
+       }
+
+       gpe_event_info->runtime_count++;
+       if (gpe_event_info->runtime_count == 1) {
+
+               /* Enable on first reference */
+
+               status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
+               if (ACPI_SUCCESS(status)) {
+                       status = acpi_ev_enable_gpe(gpe_event_info);
+               }
+
+               if (ACPI_FAILURE(status)) {
+                       gpe_event_info->runtime_count--;
+               }
+       }
+
+       return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_remove_gpe_reference
+ *
+ * PARAMETERS:  gpe_event_info          - Remove a reference to this GPE
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Remove a reference to a GPE. When the last reference is
+ *              removed, the GPE is hardware-disabled.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
+{
+       acpi_status status = AE_OK;
+
+       ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
+
+       if (!gpe_event_info->runtime_count) {
+               return_ACPI_STATUS(AE_LIMIT);
+       }
+
+       gpe_event_info->runtime_count--;
+       if (!gpe_event_info->runtime_count) {
+
+               /* Disable on last reference */
+
+               status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
+               if (ACPI_SUCCESS(status)) {
+                       status =
+                           acpi_hw_low_set_gpe(gpe_event_info,
+                                               ACPI_GPE_DISABLE);
+               }
+
+               if (ACPI_FAILURE(status)) {
+                       gpe_event_info->runtime_count++;
+               }
+       }
+
+       return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_low_get_gpe_info
+ *
+ * PARAMETERS:  gpe_number          - Raw GPE number
+ *              gpe_block           - A GPE info block
+ *
+ * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
+ *              is not within the specified GPE block)
+ *
+ * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
+ *              the low-level implementation of ev_get_gpe_event_info.
+ *
+ ******************************************************************************/
+
+struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
+                                                    struct acpi_gpe_block_info
+                                                    *gpe_block)
+{
+       u32 gpe_index;
+
+       /*
+        * Validate that the gpe_number is within the specified gpe_block.
+        * (Two steps)
+        */
+       if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
+               return (NULL);
+       }
+
+       gpe_index = gpe_number - gpe_block->block_base_number;
+       if (gpe_index >= gpe_block->gpe_count) {
+               return (NULL);
+       }
+
+       return (&gpe_block->event_info[gpe_index]);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_get_gpe_event_info
+ *
+ * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
+ *              gpe_number          - Raw GPE number
+ *
+ * RETURN:      A GPE event_info struct. NULL if not a valid GPE
+ *
+ * DESCRIPTION: Returns the event_info struct associated with this GPE.
+ *              Validates the gpe_block and the gpe_number
+ *
+ *              Should be called only when the GPE lists are semaphore locked
+ *              and not subject to change.
+ *
+ ******************************************************************************/
+
+struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
+                                                      u32 gpe_number)
+{
+       union acpi_operand_object *obj_desc;
+       struct acpi_gpe_event_info *gpe_info;
+       u32 i;
+
+       ACPI_FUNCTION_ENTRY();
+
+       /* A NULL gpe_device means use the FADT-defined GPE block(s) */
+
+       if (!gpe_device) {
+
+               /* Examine GPE Block 0 and 1 (These blocks are permanent) */
+
+               for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
+                       gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
+                                                           acpi_gbl_gpe_fadt_blocks
+                                                           [i]);
+                       if (gpe_info) {
+                               return (gpe_info);
+                       }
+               }
+
+               /* The gpe_number was not in the range of either FADT GPE block */
+
+               return (NULL);
+       }
+
+       /* A Non-NULL gpe_device means this is a GPE Block Device */
+
+       obj_desc =
+           acpi_ns_get_attached_object((struct acpi_namespace_node *)
+                                              gpe_device);
+       if (!obj_desc || !obj_desc->device.gpe_block) {
+               return (NULL);
+       }
+
+       return (acpi_ev_low_get_gpe_info
+               (gpe_number, obj_desc->device.gpe_block));
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_gpe_detect
+ *
+ * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
+ *                                    Can have multiple GPE blocks attached.
+ *
+ * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
+ *
+ * DESCRIPTION: Detect if any GP events have occurred. This function is
+ *              executed at interrupt level.
+ *
+ ******************************************************************************/
+
+u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info *gpe_xrupt_list)
+{
+       acpi_status status;
+       struct acpi_gpe_block_info *gpe_block;
+       struct acpi_namespace_node *gpe_device;
+       struct acpi_gpe_register_info *gpe_register_info;
+       struct acpi_gpe_event_info *gpe_event_info;
+       u32 gpe_number;
+       struct acpi_gpe_handler_info *gpe_handler_info;
+       u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
+       u8 enabled_status_byte;
+       u32 status_reg;
+       u32 enable_reg;
+       acpi_cpu_flags flags;
+       u32 i;
+       u32 j;
+
+       ACPI_FUNCTION_NAME(ev_gpe_detect);
+
+       /* Check for the case where there are no GPEs */
+
+       if (!gpe_xrupt_list) {
+               return (int_status);
+       }
+
+       /*
+        * We need to obtain the GPE lock for both the data structs and registers
+        * Note: Not necessary to obtain the hardware lock, since the GPE
+        * registers are owned by the gpe_lock.
+        */
+       flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+       /* Examine all GPE blocks attached to this interrupt level */
+
+       gpe_block = gpe_xrupt_list->gpe_block_list_head;
+       while (gpe_block) {
+               gpe_device = gpe_block->node;
+
+               /*
+                * Read all of the 8-bit GPE status and enable registers in this GPE
+                * block, saving all of them. Find all currently active GP events.
+                */
+               for (i = 0; i < gpe_block->register_count; i++) {
+
+                       /* Get the next status/enable pair */
+
+                       gpe_register_info = &gpe_block->register_info[i];
+
+                       /*
+                        * Optimization: If there are no GPEs enabled within this
+                        * register, we can safely ignore the entire register.
+                        */
+                       if (!(gpe_register_info->enable_for_run |
+                             gpe_register_info->enable_for_wake)) {
+                               ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
+                                                 "Ignore disabled registers for GPE %02X-%02X: "
+                                                 "RunEnable=%02X, WakeEnable=%02X\n",
+                                                 gpe_register_info->
+                                                 base_gpe_number,
+                                                 gpe_register_info->
+                                                 base_gpe_number +
+                                                 (ACPI_GPE_REGISTER_WIDTH - 1),
+                                                 gpe_register_info->
+                                                 enable_for_run,
+                                                 gpe_register_info->
+                                                 enable_for_wake));
+                               continue;
+                       }
+
+                       /* Read the Status Register */
+
+                       status =
+                           acpi_hw_read(&status_reg,
+                                        &gpe_register_info->status_address);
+                       if (ACPI_FAILURE(status)) {
+                               goto unlock_and_exit;
+                       }
+
+                       /* Read the Enable Register */
+
+                       status =
+                           acpi_hw_read(&enable_reg,
+                                        &gpe_register_info->enable_address);
+                       if (ACPI_FAILURE(status)) {
+                               goto unlock_and_exit;
+                       }
+
+                       ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
+                                         "Read registers for GPE %02X-%02X: Status=%02X, Enable=%02X, "
+                                         "RunEnable=%02X, WakeEnable=%02X\n",
+                                         gpe_register_info->base_gpe_number,
+                                         gpe_register_info->base_gpe_number +
+                                         (ACPI_GPE_REGISTER_WIDTH - 1),
+                                         status_reg, enable_reg,
+                                         gpe_register_info->enable_for_run,
+                                         gpe_register_info->enable_for_wake));
+
+                       /* Check if there is anything active at all in this register */
+
+                       enabled_status_byte = (u8)(status_reg & enable_reg);
+                       if (!enabled_status_byte) {
+
+                               /* No active GPEs in this register, move on */
+
+                               continue;
+                       }
+
+                       /* Now look at the individual GPEs in this byte register */
+
+                       for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
+
+                               /* Examine one GPE bit */
+
+                               gpe_event_info =
+                                   &gpe_block->
+                                   event_info[((acpi_size) i *
+                                               ACPI_GPE_REGISTER_WIDTH) + j];
+                               gpe_number =
+                                   j + gpe_register_info->base_gpe_number;
+
+                               if (enabled_status_byte & (1 << j)) {
+
+                                       /* Invoke global event handler if present */
+
+                                       acpi_gpe_count++;
+                                       if (acpi_gbl_global_event_handler) {
+                                               acpi_gbl_global_event_handler
+                                                   (ACPI_EVENT_TYPE_GPE,
+                                                    gpe_device, gpe_number,
+                                                    acpi_gbl_global_event_handler_context);
+                                       }
+
+                                       /* Found an active GPE */
+
+                                       if (ACPI_GPE_DISPATCH_TYPE
+                                           (gpe_event_info->flags) ==
+                                           ACPI_GPE_DISPATCH_RAW_HANDLER) {
+
+                                               /* Dispatch the event to a raw handler */
+
+                                               gpe_handler_info =
+                                                   gpe_event_info->dispatch.
+                                                   handler;
+
+                                               /*
+                                                * There is no protection around the namespace node
+                                                * and the GPE handler to ensure a safe destruction
+                                                * because:
+                                                * 1. The namespace node is expected to always
+                                                *    exist after loading a table.
+                                                * 2. The GPE handler is expected to be flushed by
+                                                *    acpi_os_wait_events_complete() before the
+                                                *    destruction.
+                                                */
+                                               acpi_os_release_lock
+                                                   (acpi_gbl_gpe_lock, flags);
+                                               int_status |=
+                                                   gpe_handler_info->
+                                                   address(gpe_device,
+                                                           gpe_number,
+                                                           gpe_handler_info->
+                                                           context);
+                                               flags =
+                                                   acpi_os_acquire_lock
+                                                   (acpi_gbl_gpe_lock);
+                                       } else {
+                                               /*
+                                                * Dispatch the event to a standard handler or
+                                                * method.
+                                                */
+                                               int_status |=
+                                                   acpi_ev_gpe_dispatch
+                                                   (gpe_device, gpe_event_info,
+                                                    gpe_number);
+                                       }
+                               }
+                       }
+               }
+
+               gpe_block = gpe_block->next;
+       }
+
+unlock_and_exit:
+
+       acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+       return (int_status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_asynch_execute_gpe_method
+ *
+ * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Perform the actual execution of a GPE control method. This
+ *              function is called from an invocation of acpi_os_execute and
+ *              therefore does NOT execute at interrupt level - so that
+ *              the control method itself is not executed in the context of
+ *              an interrupt handler.
+ *
+ ******************************************************************************/
+
+static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
+{
+       struct acpi_gpe_event_info *gpe_event_info = context;
+       acpi_status status = AE_OK;
+       struct acpi_evaluate_info *info;
+       struct acpi_gpe_notify_info *notify;
+
+       ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
+
+       /* Do the correct dispatch - normal method or implicit notify */
+
+       switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
+       case ACPI_GPE_DISPATCH_NOTIFY:
+               /*
+                * Implicit notify.
+                * Dispatch a DEVICE_WAKE notify to the appropriate handler.
+                * NOTE: the request is queued for execution after this method
+                * completes. The notify handlers are NOT invoked synchronously
+                * from this thread -- because handlers may in turn run other
+                * control methods.
+                *
+                * June 2012: Expand implicit notify mechanism to support
+                * notifies on multiple device objects.
+                */
+               notify = gpe_event_info->dispatch.notify_list;
+               while (ACPI_SUCCESS(status) && notify) {
+                       status =
+                           acpi_ev_queue_notify_request(notify->device_node,
+                                                        ACPI_NOTIFY_DEVICE_WAKE);
+
+                       notify = notify->next;
+               }
+
+               break;
+
+       case ACPI_GPE_DISPATCH_METHOD:
+
+               /* Allocate the evaluation information block */
+
+               info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
+               if (!info) {
+                       status = AE_NO_MEMORY;
+               } else {
+                       /*
+                        * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the
+                        * _Lxx/_Exx control method that corresponds to this GPE
+                        */
+                       info->prefix_node =
+                           gpe_event_info->dispatch.method_node;
+                       info->flags = ACPI_IGNORE_RETURN_VALUE;
+
+                       status = acpi_ns_evaluate(info);
+                       ACPI_FREE(info);
+               }
+
+               if (ACPI_FAILURE(status)) {
+                       ACPI_EXCEPTION((AE_INFO, status,
+                                       "while evaluating GPE method [%4.4s]",
+                                       acpi_ut_get_node_name(gpe_event_info->
+                                                             dispatch.
+                                                             method_node)));
+               }
+               break;
+
+       default:
+
+               goto error_exit;        /* Should never happen */
+       }
+
+       /* Defer enabling of GPE until all notify handlers are done */
+
+       status = acpi_os_execute(OSL_NOTIFY_HANDLER,
+                                acpi_ev_asynch_enable_gpe, gpe_event_info);
+       if (ACPI_SUCCESS(status)) {
+               return_VOID;
+       }
+
+error_exit:
+       acpi_ev_asynch_enable_gpe(gpe_event_info);
+       return_VOID;
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_asynch_enable_gpe
+ *
+ * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
+ *              Callback from acpi_os_execute
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
+ *              complete (i.e., finish execution of Notify)
+ *
+ ******************************************************************************/
+
+static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
+{
+       struct acpi_gpe_event_info *gpe_event_info = context;
+       acpi_cpu_flags flags;
+
+       flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+       (void)acpi_ev_finish_gpe(gpe_event_info);
+       acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+
+       return;
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_finish_gpe
+ *
+ * PARAMETERS:  gpe_event_info      - Info for this GPE
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Clear/Enable a GPE. Common code that is used after execution
+ *              of a GPE method or a synchronous or asynchronous GPE handler.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info * gpe_event_info)
+{
+       acpi_status status;
+
+       if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
+           ACPI_GPE_LEVEL_TRIGGERED) {
+               /*
+                * GPE is level-triggered, we clear the GPE status bit after
+                * handling the event.
+                */
+               status = acpi_hw_clear_gpe(gpe_event_info);
+               if (ACPI_FAILURE(status)) {
+                       return (status);
+               }
+       }
+
+       /*
+        * Enable this GPE, conditionally. This means that the GPE will
+        * only be physically enabled if the enable_mask bit is set
+        * in the event_info.
+        */
+       (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
+       return (AE_OK);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_gpe_dispatch
+ *
+ * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
+ *              gpe_event_info      - Info for this GPE
+ *              gpe_number          - Number relative to the parent GPE block
+ *
+ * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
+ *
+ * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
+ *              or method (e.g. _Lxx/_Exx) handler.
+ *
+ *              This function executes at interrupt level.
+ *
+ ******************************************************************************/
+
+u32
+acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
+                    struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
+{
+       acpi_status status;
+       u32 return_value;
+
+       ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
+
+       /*
+        * Always disable the GPE so that it does not keep firing before
+        * any asynchronous activity completes (either from the execution
+        * of a GPE method or an asynchronous GPE handler.)
+        *
+        * If there is no handler or method to run, just disable the
+        * GPE and leave it disabled permanently to prevent further such
+        * pointless events from firing.
+        */
+       status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
+       if (ACPI_FAILURE(status)) {
+               ACPI_EXCEPTION((AE_INFO, status,
+                               "Unable to disable GPE %02X", gpe_number));
+               return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
+       }
+
+       /*
+        * If edge-triggered, clear the GPE status bit now. Note that
+        * level-triggered events are cleared after the GPE is serviced.
+        */
+       if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
+           ACPI_GPE_EDGE_TRIGGERED) {
+               status = acpi_hw_clear_gpe(gpe_event_info);
+               if (ACPI_FAILURE(status)) {
+                       ACPI_EXCEPTION((AE_INFO, status,
+                                       "Unable to clear GPE %02X",
+                                       gpe_number));
+                       (void)acpi_hw_low_set_gpe(gpe_event_info,
+                                                 ACPI_GPE_CONDITIONAL_ENABLE);
+                       return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
+               }
+       }
+
+       /*
+        * Dispatch the GPE to either an installed handler or the control
+        * method associated with this GPE (_Lxx or _Exx). If a handler
+        * exists, we invoke it and do not attempt to run the method.
+        * If there is neither a handler nor a method, leave the GPE
+        * disabled.
+        */
+       switch (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)) {
+       case ACPI_GPE_DISPATCH_HANDLER:
+
+               /* Invoke the installed handler (at interrupt level) */
+
+               return_value =
+                   gpe_event_info->dispatch.handler->address(gpe_device,
+                                                             gpe_number,
+                                                             gpe_event_info->
+                                                             dispatch.handler->
+                                                             context);
+
+               /* If requested, clear (if level-triggered) and reenable the GPE */
+
+               if (return_value & ACPI_REENABLE_GPE) {
+                       (void)acpi_ev_finish_gpe(gpe_event_info);
+               }
+               break;
+
+       case ACPI_GPE_DISPATCH_METHOD:
+       case ACPI_GPE_DISPATCH_NOTIFY:
+               /*
+                * Execute the method associated with the GPE
+                * NOTE: Level-triggered GPEs are cleared after the method completes.
+                */
+               status = acpi_os_execute(OSL_GPE_HANDLER,
+                                        acpi_ev_asynch_execute_gpe_method,
+                                        gpe_event_info);
+               if (ACPI_FAILURE(status)) {
+                       ACPI_EXCEPTION((AE_INFO, status,
+                                       "Unable to queue handler for GPE %02X - event disabled",
+                                       gpe_number));
+               }
+               break;
+
+       default:
+               /*
+                * No handler or method to run!
+                * 03/2010: This case should no longer be possible. We will not allow
+                * a GPE to be enabled if it has no handler or method.
+                */
+               ACPI_ERROR((AE_INFO,
+                           "No handler or method for GPE %02X, disabling event",
+                           gpe_number));
+
+               break;
+       }
+
+       return_UINT32(ACPI_INTERRUPT_HANDLED);
+}
+
+#endif                         /* !ACPI_REDUCED_HARDWARE */