ACPICA: Events: Remove acpi_ev_valid_gpe_event() due to current restriction

ACPICA commit 8823b44ff53859ab24ecfcfd3fba8cc56b17d223

Currently we rely on the logic that GPE blocks will never be deleted,
otherwise we can be broken by the race between acpi_ev_create_gpe_block(),
acpi_ev_delete_gpe_block() and acpi_ev_gpe_detect().
On the other hand, if we want to protect GPE block creation/deletion, we
need to use a different synchronization facility to protect the period
between acpi_ev_gpe_dispatch() and acpi_ev_asynch_enable_gpe(). Which leaves us
no choice but abandoning the ACPI_MTX_EVENTS used during this period.

This patch removes ACPI_MTX_EVENTS used during this period and the
acpi_ev_valid_gpe_event() to reflect current restriction. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/8823b44f
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 15 insertions, 100 deletions

diff --git a/drivers/acpi/acpica/acevents.h b/drivers/acpi/acpica/acevents.h
index 7a7811a9fc26..38b94a1a5cf8 100644
--- a/drivers/acpi/acpica/acevents.h
+++ b/drivers/acpi/acpica/acevents.h
@@ -143,8 +143,6 @@ acpi_ev_match_gpe_method(acpi_handle obj_handle,
 acpi_status
 acpi_ev_walk_gpe_list(acpi_gpe_callback gpe_walk_callback, void *context);
 
-u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info);
-
 acpi_status
 acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
                        struct acpi_gpe_block_info *gpe_block, void *context);
diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index b2e63e785719..ddee96733403 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -474,51 +474,14 @@ 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;
-        struct acpi_gpe_event_info *local_gpe_event_info;
         struct acpi_evaluate_info *info;
         struct acpi_gpe_notify_info *notify;
 
         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 
-        /* Allocate a local GPE block */
-
-        local_gpe_event_info =
-            ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_event_info));
-        if (!local_gpe_event_info) {
-                ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY, "while handling a GPE"));
-                return_VOID;
-        }
-
-        status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
-        if (ACPI_FAILURE(status)) {
-                ACPI_FREE(local_gpe_event_info);
-                return_VOID;
-        }
-
-        /* Must revalidate the gpe_number/gpe_block */
-
-        if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
-                status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
-                ACPI_FREE(local_gpe_event_info);
-                return_VOID;
-        }
-
-        /*
-         * Take a snapshot of the GPE info for this level - we copy the info to
-         * prevent a race condition with remove_handler/remove_block.
-         */
-        ACPI_MEMCPY(local_gpe_event_info, gpe_event_info,
-                    sizeof(struct acpi_gpe_event_info));
-
-        status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
-        if (ACPI_FAILURE(status)) {
-                ACPI_FREE(local_gpe_event_info);
-                return_VOID;
-        }
-
         /* Do the correct dispatch - normal method or implicit notify */
 
-        switch (local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
+        switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
         case ACPI_GPE_DISPATCH_NOTIFY:
                 /*
                  * Implicit notify.
@@ -531,7 +494,7 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
                  * June 2012: Expand implicit notify mechanism to support
                  * notifies on multiple device objects.
                  */
-                notify = local_gpe_event_info->dispatch.notify_list;
+                notify = gpe_event_info->dispatch.notify_list;
                 while (ACPI_SUCCESS(status) && notify) {
                         status =
                             acpi_ev_queue_notify_request(notify->device_node,
@@ -555,7 +518,7 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
                          * _Lxx/_Exx control method that corresponds to this GPE
                          */
                         info->prefix_node =
-                            local_gpe_event_info->dispatch.method_node;
+                            gpe_event_info->dispatch.method_node;
                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 
                         status = acpi_ns_evaluate(info);
@@ -565,25 +528,27 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
                 if (ACPI_FAILURE(status)) {
                         ACPI_EXCEPTION((AE_INFO, status,
                                         "while evaluating GPE method [%4.4s]",
-                                        acpi_ut_get_node_name
-                                        (local_gpe_event_info->dispatch.
-                                         method_node)));
+                                        acpi_ut_get_node_name(gpe_event_info->
+                                                              dispatch.
+                                                              method_node)));
                 }
                 break;
 
         default:
 
-                return_VOID;    /* Should never happen */
+                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,
-                                 local_gpe_event_info);
-        if (ACPI_FAILURE(status)) {
-                ACPI_FREE(local_gpe_event_info);
+                                 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;
 }
 
@@ -611,7 +576,6 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
         (void)acpi_ev_finish_gpe(gpe_event_info);
         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 
-        ACPI_FREE(gpe_event_info);
         return;
 }
 
diff --git a/drivers/acpi/acpica/evgpeutil.c b/drivers/acpi/acpica/evgpeutil.c
index 9e2b94c8f7c4..3f1c5aa682a5 100644
--- a/drivers/acpi/acpica/evgpeutil.c
+++ b/drivers/acpi/acpica/evgpeutil.c
@@ -108,53 +108,6 @@ unlock_and_exit:
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_ev_valid_gpe_event
- *
- * PARAMETERS:  gpe_event_info              - Info for this GPE
- *
- * RETURN:      TRUE if the gpe_event is valid
- *
- * DESCRIPTION: Validate a GPE event. DO NOT CALL FROM INTERRUPT LEVEL.
- *              Should be called only when the GPE lists are semaphore locked
- *              and not subject to change.
- *
- ******************************************************************************/
-
-u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info)
-{
-        struct acpi_gpe_xrupt_info *gpe_xrupt_block;
-        struct acpi_gpe_block_info *gpe_block;
-
-        ACPI_FUNCTION_ENTRY();
-
-        /* No need for spin lock since we are not changing any list elements */
-
-        /* Walk the GPE interrupt levels */
-
-        gpe_xrupt_block = acpi_gbl_gpe_xrupt_list_head;
-        while (gpe_xrupt_block) {
-                gpe_block = gpe_xrupt_block->gpe_block_list_head;
-
-                /* Walk the GPE blocks on this interrupt level */
-
-                while (gpe_block) {
-                        if ((&gpe_block->event_info[0] <= gpe_event_info) &&
-                            (&gpe_block->event_info[gpe_block->gpe_count] >
-                             gpe_event_info)) {
-                                return (TRUE);
-                        }
-
-                        gpe_block = gpe_block->next;
-                }
-
-                gpe_xrupt_block = gpe_xrupt_block->next;
-        }
-
-        return (FALSE);
-}
-
-/*******************************************************************************
- *
  * FUNCTION:    acpi_ev_get_gpe_device
  *
  * PARAMETERS:  GPE_WALK_CALLBACK
@@ -167,8 +120,8 @@ u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info)
  ******************************************************************************/
 
 acpi_status
-acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info * gpe_xrupt_info,
-                       struct acpi_gpe_block_info * gpe_block, void *context)
+acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
+                       struct acpi_gpe_block_info *gpe_block, void *context)
 {
         struct acpi_gpe_device_info *info = context;