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evmisc.c

/******************************************************************************
 *
 * Module Name: evmisc - Miscellaneous event manager support functions
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * 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 <acpi/acevents.h>
#include <acpi/acnamesp.h>
#include <acpi/acinterp.h>

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evmisc")

/* Names for Notify() values, used for debug output */
#ifdef ACPI_DEBUG_OUTPUT
static const char *acpi_notify_value_names[] = {
      "Bus Check",
      "Device Check",
      "Device Wake",
      "Eject Request",
      "Device Check Light",
      "Frequency Mismatch",
      "Bus Mode Mismatch",
      "Power Fault"
};
#endif

/* Pointer to FACS needed for the Global Lock */

static struct acpi_table_facs *facs = NULL;

/* Local prototypes */

static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context);

static u32 acpi_ev_global_lock_handler(void *context);

static acpi_status acpi_ev_remove_global_lock_handler(void);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_is_notify_object
 *
 * PARAMETERS:  Node            - Node to check
 *
 * RETURN:      TRUE if notifies allowed on this object
 *
 * DESCRIPTION: Check type of node for a object that supports notifies.
 *
 *              TBD: This could be replaced by a flag bit in the node.
 *
 ******************************************************************************/

u8 acpi_ev_is_notify_object(struct acpi_namespace_node *node)
{
      switch (node->type) {
      case ACPI_TYPE_DEVICE:
      case ACPI_TYPE_PROCESSOR:
      case ACPI_TYPE_POWER:
      case ACPI_TYPE_THERMAL:
            /*
             * These are the ONLY objects that can receive ACPI notifications
             */
            return (TRUE);

      default:
            return (FALSE);
      }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_queue_notify_request
 *
 * PARAMETERS:  Node            - NS node for the notified object
 *              notify_value    - Value from the Notify() request
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Dispatch a device notification event to a previously
 *              installed handler.
 *
 ******************************************************************************/

acpi_status
acpi_ev_queue_notify_request(struct acpi_namespace_node * node,
                       u32 notify_value)
{
      union acpi_operand_object *obj_desc;
      union acpi_operand_object *handler_obj = NULL;
      union acpi_generic_state *notify_info;
      acpi_status status = AE_OK;

      ACPI_FUNCTION_NAME(ev_queue_notify_request);

      /*
       * For value 3 (Ejection Request), some device method may need to be run.
       * For value 2 (Device Wake) if _PRW exists, the _PS0 method may need
       *   to be run.
       * For value 0x80 (Status Change) on the power button or sleep button,
       *   initiate soft-off or sleep operation?
       */
      ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                    "Dispatching Notify(%X) on node %p\n", notify_value,
                    node));

      if (notify_value <= 7) {
            ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notify value: %s\n",
                          acpi_notify_value_names[notify_value]));
      } else {
            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Notify value: 0x%2.2X **Device Specific**\n",
                          notify_value));
      }

      /* Get the notify object attached to the NS Node */

      obj_desc = acpi_ns_get_attached_object(node);
      if (obj_desc) {

            /* We have the notify object, Get the right handler */

            switch (node->type) {
            case ACPI_TYPE_DEVICE:
            case ACPI_TYPE_THERMAL:
            case ACPI_TYPE_PROCESSOR:
            case ACPI_TYPE_POWER:

                  if (notify_value <= ACPI_MAX_SYS_NOTIFY) {
                        handler_obj =
                            obj_desc->common_notify.system_notify;
                  } else {
                        handler_obj =
                            obj_desc->common_notify.device_notify;
                  }
                  break;

            default:
                  /* All other types are not supported */
                  return (AE_TYPE);
            }
      }

      /* If there is any handler to run, schedule the dispatcher */

      if ((acpi_gbl_system_notify.handler
           && (notify_value <= ACPI_MAX_SYS_NOTIFY))
          || (acpi_gbl_device_notify.handler
            && (notify_value > ACPI_MAX_SYS_NOTIFY)) || handler_obj) {
            notify_info = acpi_ut_create_generic_state();
            if (!notify_info) {
                  return (AE_NO_MEMORY);
            }

            notify_info->common.descriptor_type =
                ACPI_DESC_TYPE_STATE_NOTIFY;
            notify_info->notify.node = node;
            notify_info->notify.value = (u16) notify_value;
            notify_info->notify.handler_obj = handler_obj;

            status =
                acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_ev_notify_dispatch,
                            notify_info);
            if (ACPI_FAILURE(status)) {
                  acpi_ut_delete_generic_state(notify_info);
            }
      }

      if (!handler_obj) {
            /*
             * There is no per-device notify handler for this device.
             * This may or may not be a problem.
             */
            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "No notify handler for Notify(%4.4s, %X) node %p\n",
                          acpi_ut_get_node_name(node), notify_value,
                          node));
      }

      return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_notify_dispatch
 *
 * PARAMETERS:  Context         - To be passed to the notify handler
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Dispatch a device notification event to a previously
 *              installed handler.
 *
 ******************************************************************************/

static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context)
{
      union acpi_generic_state *notify_info =
          (union acpi_generic_state *)context;
      acpi_notify_handler global_handler = NULL;
      void *global_context = NULL;
      union acpi_operand_object *handler_obj;

      ACPI_FUNCTION_ENTRY();

      /*
       * We will invoke a global notify handler if installed.
       * This is done _before_ we invoke the per-device handler attached
       * to the device.
       */
      if (notify_info->notify.value <= ACPI_MAX_SYS_NOTIFY) {

            /* Global system notification handler */

            if (acpi_gbl_system_notify.handler) {
                  global_handler = acpi_gbl_system_notify.handler;
                  global_context = acpi_gbl_system_notify.context;
            }
      } else {
            /* Global driver notification handler */

            if (acpi_gbl_device_notify.handler) {
                  global_handler = acpi_gbl_device_notify.handler;
                  global_context = acpi_gbl_device_notify.context;
            }
      }

      /* Invoke the system handler first, if present */

      if (global_handler) {
            global_handler(notify_info->notify.node,
                         notify_info->notify.value, global_context);
      }

      /* Now invoke the per-device handler, if present */

      handler_obj = notify_info->notify.handler_obj;
      if (handler_obj) {
            handler_obj->notify.handler(notify_info->notify.node,
                                  notify_info->notify.value,
                                  handler_obj->notify.context);
      }

      /* All done with the info object */

      acpi_ut_delete_generic_state(notify_info);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_global_lock_handler
 *
 * PARAMETERS:  Context         - From thread interface, not used
 *
 * RETURN:      ACPI_INTERRUPT_HANDLED
 *
 * DESCRIPTION: Invoked directly from the SCI handler when a global lock
 *              release interrupt occurs. Attempt to acquire the global lock,
 *              if successful, signal the thread waiting for the lock.
 *
 * NOTE: Assumes that the semaphore can be signaled from interrupt level. If
 * this is not possible for some reason, a separate thread will have to be
 * scheduled to do this.
 *
 ******************************************************************************/

static u32 acpi_ev_global_lock_handler(void *context)
{
      u8 acquired = FALSE;

      /*
       * Attempt to get the lock.
       *
       * If we don't get it now, it will be marked pending and we will
       * take another interrupt when it becomes free.
       */
      ACPI_ACQUIRE_GLOBAL_LOCK(facs, acquired);
      if (acquired) {

            /* Got the lock, now wake all threads waiting for it */

            acpi_gbl_global_lock_acquired = TRUE;
            /* Send a unit to the semaphore */

            if (ACPI_FAILURE
                (acpi_os_signal_semaphore
                 (acpi_gbl_global_lock_semaphore, 1))) {
                  ACPI_ERROR((AE_INFO,
                            "Could not signal Global Lock semaphore"));
            }
      }

      return (ACPI_INTERRUPT_HANDLED);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_init_global_lock_handler
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install a handler for the global lock release event
 *
 ******************************************************************************/

acpi_status acpi_ev_init_global_lock_handler(void)
{
      acpi_status status;

      ACPI_FUNCTION_TRACE(ev_init_global_lock_handler);

      status =
          acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
                            (struct acpi_table_header **)&facs);
      if (ACPI_FAILURE(status)) {
            return_ACPI_STATUS(status);
      }

      acpi_gbl_global_lock_present = TRUE;
      status = acpi_install_fixed_event_handler(ACPI_EVENT_GLOBAL,
                                      acpi_ev_global_lock_handler,
                                      NULL);

      /*
       * If the global lock does not exist on this platform, the attempt
       * to enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick)
       * Map to AE_OK, but mark global lock as not present.
       * Any attempt to actually use the global lock will be flagged
       * with an error.
       */
      if (status == AE_NO_HARDWARE_RESPONSE) {
            ACPI_ERROR((AE_INFO,
                      "No response from Global Lock hardware, disabling lock"));

            acpi_gbl_global_lock_present = FALSE;
            status = AE_OK;
      }

      return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_remove_global_lock_handler
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove the handler for the Global Lock
 *
 ******************************************************************************/

static acpi_status acpi_ev_remove_global_lock_handler(void)
{
      acpi_status status;

      ACPI_FUNCTION_TRACE(ev_remove_global_lock_handler);

      acpi_gbl_global_lock_present = FALSE;
      status = acpi_remove_fixed_event_handler(ACPI_EVENT_GLOBAL,
                                     acpi_ev_global_lock_handler);

      return_ACPI_STATUS(status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ev_acquire_global_lock
 *
 * PARAMETERS:  Timeout         - Max time to wait for the lock, in millisec.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Attempt to gain ownership of the Global Lock.
 *
 * MUTEX:       Interpreter must be locked
 *
 * Note: The original implementation allowed multiple threads to "acquire" the
 * Global Lock, and the OS would hold the lock until the last thread had
 * released it. However, this could potentially starve the BIOS out of the
 * lock, especially in the case where there is a tight handshake between the
 * Embedded Controller driver and the BIOS. Therefore, this implementation
 * allows only one thread to acquire the HW Global Lock at a time, and makes
 * the global lock appear as a standard mutex on the OS side.
 *
 *****************************************************************************/
static acpi_thread_id acpi_ev_global_lock_thread_id;
static int acpi_ev_global_lock_acquired;

acpi_status acpi_ev_acquire_global_lock(u16 timeout)
{
      acpi_status status = AE_OK;
      u8 acquired = FALSE;

      ACPI_FUNCTION_TRACE(ev_acquire_global_lock);

      /*
       * Only one thread can acquire the GL at a time, the global_lock_mutex
       * enforces this. This interface releases the interpreter if we must wait.
       */
      status = acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex, 0);
      if (status == AE_TIME) {
            if (acpi_ev_global_lock_thread_id == acpi_os_get_thread_id()) {
                  acpi_ev_global_lock_acquired++;
                  return AE_OK;
            }
      }

      if (ACPI_FAILURE(status)) {
            status =
                acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex,
                                    timeout);
      }
      if (ACPI_FAILURE(status)) {
            return_ACPI_STATUS(status);
      }

      acpi_ev_global_lock_thread_id = acpi_os_get_thread_id();
      acpi_ev_global_lock_acquired++;

      /*
       * Make sure that a global lock actually exists. If not, just treat
       * the lock as a standard mutex.
       */
      if (!acpi_gbl_global_lock_present) {
            acpi_gbl_global_lock_acquired = TRUE;
            return_ACPI_STATUS(AE_OK);
      }

      /* Attempt to acquire the actual hardware lock */

      ACPI_ACQUIRE_GLOBAL_LOCK(facs, acquired);
      if (acquired) {

            /* We got the lock */

            ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                          "Acquired hardware Global Lock\n"));

            acpi_gbl_global_lock_acquired = TRUE;
            return_ACPI_STATUS(AE_OK);
      }

      /*
       * Did not get the lock. The pending bit was set above, and we must now
       * wait until we get the global lock released interrupt.
       */
      ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Waiting for hardware Global Lock\n"));

      /*
       * Wait for handshake with the global lock interrupt handler.
       * This interface releases the interpreter if we must wait.
       */
      status = acpi_ex_system_wait_semaphore(acpi_gbl_global_lock_semaphore,
                                     ACPI_WAIT_FOREVER);

      return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_release_global_lock
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Releases ownership of the Global Lock.
 *
 ******************************************************************************/

acpi_status acpi_ev_release_global_lock(void)
{
      u8 pending = FALSE;
      acpi_status status = AE_OK;

      ACPI_FUNCTION_TRACE(ev_release_global_lock);

      /* Lock must be already acquired */

      if (!acpi_gbl_global_lock_acquired) {
            ACPI_WARNING((AE_INFO,
                        "Cannot release the ACPI Global Lock, it has not been acquired"));
            return_ACPI_STATUS(AE_NOT_ACQUIRED);
      }

      acpi_ev_global_lock_acquired--;
      if (acpi_ev_global_lock_acquired > 0) {
            return AE_OK;
      }

      if (acpi_gbl_global_lock_present) {

            /* Allow any thread to release the lock */

            ACPI_RELEASE_GLOBAL_LOCK(facs, pending);

            /*
             * If the pending bit was set, we must write GBL_RLS to the control
             * register
             */
            if (pending) {
                  status =
                      acpi_set_register(ACPI_BITREG_GLOBAL_LOCK_RELEASE,
                                    1);
            }

            ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                          "Released hardware Global Lock\n"));
      }

      acpi_gbl_global_lock_acquired = FALSE;

      /* Release the local GL mutex */
      acpi_ev_global_lock_thread_id = NULL;
      acpi_ev_global_lock_acquired = 0;
      acpi_os_release_mutex(acpi_gbl_global_lock_mutex);
      return_ACPI_STATUS(status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_ev_terminate
 *
 * PARAMETERS:  none
 *
 * RETURN:      none
 *
 * DESCRIPTION: Disable events and free memory allocated for table storage.
 *
 ******************************************************************************/

void acpi_ev_terminate(void)
{
      acpi_native_uint i;
      acpi_status status;

      ACPI_FUNCTION_TRACE(ev_terminate);

      if (acpi_gbl_events_initialized) {
            /*
             * Disable all event-related functionality.
             * In all cases, on error, print a message but obviously we don't abort.
             */

            /* Disable all fixed events */

            for (i = 0; i < ACPI_NUM_FIXED_EVENTS; i++) {
                  status = acpi_disable_event((u32) i, 0);
                  if (ACPI_FAILURE(status)) {
                        ACPI_ERROR((AE_INFO,
                                  "Could not disable fixed event %d",
                                  (u32) i));
                  }
            }

            /* Disable all GPEs in all GPE blocks */

            status = acpi_ev_walk_gpe_list(acpi_hw_disable_gpe_block);

            /* Remove SCI handler */

            status = acpi_ev_remove_sci_handler();
            if (ACPI_FAILURE(status)) {
                  ACPI_ERROR((AE_INFO, "Could not remove SCI handler"));
            }

            status = acpi_ev_remove_global_lock_handler();
            if (ACPI_FAILURE(status)) {
                  ACPI_ERROR((AE_INFO,
                            "Could not remove Global Lock handler"));
            }
      }

      /* Deallocate all handler objects installed within GPE info structs */

      status = acpi_ev_walk_gpe_list(acpi_ev_delete_gpe_handlers);

      /* Return to original mode if necessary */

      if (acpi_gbl_original_mode == ACPI_SYS_MODE_LEGACY) {
            status = acpi_disable();
            if (ACPI_FAILURE(status)) {
                  ACPI_WARNING((AE_INFO, "AcpiDisable failed"));
            }
      }
      return_VOID;
}

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