ACPICA: Minimize the differences between linux GPE code and ACPICA code base

We have ported Rafael's major GPE changes
(ACPI: Use GPE reference counting to support shared GPEs) into ACPICA code base.
But the port and Rafael's original patch have some differences, so we made
below patch to make linux GPE code consistent with ACPICA code base.

Most changes are about comments and coding styles.
Other noticeable changes are based on:

Rafael: Reduce code duplication related to GPE lookup
https://patchwork.kernel.org/patch/86237/

Rafael: Always use the same lock for GPE locking
https://patchwork.kernel.org/patch/90471/

A new field gpe_count in struct acpi_gpe_block_info to record the number
of individual GPEs in block.

Rename acpi_ev_save_method_info to acpi_ev_match_gpe_method.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Robert Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

7 files changed, 316 insertions, 230 deletions

diff --git a/drivers/acpi/acpica/acevents.h b/drivers/acpi/acpica/acevents.h
index 3e6ba99e4053..5e094a28cf54 100644
--- a/drivers/acpi/acpica/acevents.h
+++ b/drivers/acpi/acpica/acevents.h
@@ -85,6 +85,10 @@ acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info);
 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 						       u32 gpe_number);
 
+struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
+						     struct acpi_gpe_block_info
+						     *gpe_block);
+
 /*
  * evgpeblk
  */
@@ -118,9 +122,6 @@ acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info,
 
 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info *gpe_xrupt_list);
 
-acpi_status
-acpi_ev_check_for_wake_only_gpe(struct acpi_gpe_event_info *gpe_event_info);
-
 acpi_status acpi_ev_gpe_initialize(void);
 
 /*
diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
index 24b8faa5c395..5a6203a40c3e 100644
--- a/drivers/acpi/acpica/aclocal.h
+++ b/drivers/acpi/acpica/aclocal.h
@@ -427,8 +427,8 @@ struct acpi_gpe_event_info {
 	struct acpi_gpe_register_info *register_info;	/* Backpointer to register info */
 	u8 flags;		/* Misc info about this GPE */
 	u8 gpe_number;		/* This GPE */
-	u8 runtime_count;
-	u8 wakeup_count;
+	u8 runtime_count;	/* References to a run GPE */
+	u8 wakeup_count;	/* References to a wake GPE */
 };
 
 /* Information about a GPE register pair, one per each status/enable pair in an array */
@@ -454,6 +454,7 @@ struct acpi_gpe_block_info {
 	struct acpi_gpe_event_info *event_info;	/* One for each GPE */
 	struct acpi_generic_address block_address;	/* Base address of the block */
 	u32 register_count;	/* Number of register pairs in block */
+	u16 gpe_count;		/* Number of individual GPEs in block */
 	u8 block_base_number;	/* Base GPE number for this block */
 };
 
diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index b9d50ef9f3ec..deb26f4c6623 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -60,7 +60,8 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Updates GPE register enable masks based on the GPE type
+ * DESCRIPTION: Updates GPE register enable masks based upon whether there are
+ *              references (either wake or run) to this GPE
  *
  ******************************************************************************/
 
@@ -81,14 +82,20 @@ acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info)
 	    (1 <<
 	     (gpe_event_info->gpe_number - gpe_register_info->base_gpe_number));
 
+	/* Clear the wake/run bits up front */
+
 	ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake, register_bit);
 	ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 
-	if (gpe_event_info->runtime_count)
+	/* Set the mask bits only if there are references to this GPE */
+
+	if (gpe_event_info->runtime_count) {
 		ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
+	}
 
-	if (gpe_event_info->wakeup_count)
+	if (gpe_event_info->wakeup_count) {
 		ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
+	}
 
 	return_ACPI_STATUS(AE_OK);
 }
@@ -101,7 +108,10 @@ acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info)
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Enable a GPE based on the GPE type
+ * DESCRIPTION: Hardware-enable a GPE. Always enables the GPE, regardless
+ *              of type or number of references.
+ *
+ * Note: The GPE lock should be already acquired when this function is called.
  *
  ******************************************************************************/
 
@@ -109,20 +119,36 @@ acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 {
 	acpi_status status;
 
+
 	ACPI_FUNCTION_TRACE(ev_enable_gpe);
 
-	/* Make sure HW enable masks are updated */
+
+	/*
+	 * We will only allow a GPE to be enabled if it has either an
+	 * associated method (_Lxx/_Exx) or a handler. Otherwise, the
+	 * GPE will be immediately disabled by acpi_ev_gpe_dispatch the
+	 * first time it fires.
+	 */
+	if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)) {
+		return_ACPI_STATUS(AE_NO_HANDLER);
+	}
+
+	/* Ensure the HW enable masks are current */
 
 	status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
+	}
+
+	/* Clear the GPE (of stale events) */
 
-	/* Clear the GPE (of stale events), then enable it */
 	status = acpi_hw_clear_gpe(gpe_event_info);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
+	}
 
 	/* Enable the requested GPE */
+
 	status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
 	return_ACPI_STATUS(status);
 }
@@ -135,7 +161,10 @@ acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Disable a GPE based on the GPE type
+ * DESCRIPTION: Hardware-disable a GPE. Always disables the requested GPE,
+ *              regardless of the type or number of references.
+ *
+ * Note: The GPE lock should be already acquired when this function is called.
  *
  ******************************************************************************/
 
@@ -145,24 +174,71 @@ acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 
 	ACPI_FUNCTION_TRACE(ev_disable_gpe);
 
-	/* Make sure HW enable masks are updated */
+
+	/*
+	 * Note: Always disable the GPE, even if we think that that it is already
+	 * disabled. It is possible that the AML or some other code has enabled
+	 * the GPE behind our back.
+	 */
+
+	/* Ensure the HW enable masks are current */
 
 	status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
+	}
 
 	/*
-	 * Even if we don't know the GPE type, make sure that we always
-	 * disable it. low_disable_gpe will just clear the enable bit for this
-	 * GPE and write it. It will not write out the current GPE enable mask,
-	 * since this may inadvertently enable GPEs too early, if a rogue GPE has
-	 * come in during ACPICA initialization - possibly as a result of AML or
-	 * other code that has enabled the GPE.
+	 * Always H/W disable this GPE, even if we don't know the GPE type.
+	 * Simply clear the enable bit for this particular GPE, but do not
+	 * write out the current GPE enable mask since this may inadvertently
+	 * enable GPEs too early. An example is a rogue GPE that has arrived
+	 * during ACPICA initialization - possibly because AML or other code
+	 * has enabled the GPE.
 	 */
 	status = acpi_hw_low_disable_gpe(gpe_event_info);
 	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
@@ -184,7 +260,7 @@ 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_block_info *gpe_block;
+	struct acpi_gpe_event_info *gpe_info;
 	u32 i;
 
 	ACPI_FUNCTION_ENTRY();
@@ -196,17 +272,11 @@ struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 		/* Examine GPE Block 0 and 1 (These blocks are permanent) */
 
 		for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
-			gpe_block = acpi_gbl_gpe_fadt_blocks[i];
-			if (gpe_block) {
-				if ((gpe_number >= gpe_block->block_base_number)
-				    && (gpe_number <
-					gpe_block->block_base_number +
-					(gpe_block->register_count * 8))) {
-					return (&gpe_block->
-						event_info[gpe_number -
-							   gpe_block->
-							   block_base_number]);
-				}
+			gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
+							    acpi_gbl_gpe_fadt_blocks
+							    [i]);
+			if (gpe_info) {
+				return (gpe_info);
 			}
 		}
 
@@ -223,16 +293,8 @@ struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 		return (NULL);
 	}
 
-	gpe_block = obj_desc->device.gpe_block;
-
-	if ((gpe_number >= gpe_block->block_base_number) &&
-	    (gpe_number <
-	     gpe_block->block_base_number + (gpe_block->register_count * 8))) {
-		return (&gpe_block->
-			event_info[gpe_number - gpe_block->block_base_number]);
-	}
-
-	return (NULL);
+	return (acpi_ev_low_get_gpe_info
+		(gpe_number, obj_desc->device.gpe_block));
 }
 
 /*******************************************************************************
@@ -389,7 +451,7 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 		return_VOID;
 	}
 
-	/* Set the GPE flags for return to enabled state */
+	/* Update the GPE register masks for return to enabled state */
 
 	(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);
 
@@ -569,15 +631,18 @@ acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 
 	default:
 
-		/* No handler or method to run! */
-
+		/*
+		 * 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[0x%2X], disabling event",
 			    gpe_number));
 
 		/*
-		 * Disable the GPE. The GPE will remain disabled until the ACPICA
-		 * Core Subsystem is restarted, or a handler is installed.
+		 * Disable the GPE. The GPE will remain disabled a handler
+		 * is installed or ACPICA is restarted.
 		 */
 		status = acpi_ev_disable_gpe(gpe_event_info);
 		if (ACPI_FAILURE(status)) {
diff --git a/drivers/acpi/acpica/evgpeblk.c b/drivers/acpi/acpica/evgpeblk.c
index fa47e3522abe..85ded1f2540d 100644
--- a/drivers/acpi/acpica/evgpeblk.c
+++ b/drivers/acpi/acpica/evgpeblk.c
@@ -51,7 +51,7 @@ ACPI_MODULE_NAME("evgpeblk")
 
 /* Local prototypes */
 static acpi_status
-acpi_ev_save_method_info(acpi_handle obj_handle,
+acpi_ev_match_gpe_method(acpi_handle obj_handle,
 			 u32 level, void *obj_desc, void **return_value);
 
 static acpi_status
@@ -104,9 +104,7 @@ u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info)
 
 		while (gpe_block) {
 			if ((&gpe_block->event_info[0] <= gpe_event_info) &&
-			    (&gpe_block->event_info[((acpi_size)
-						     gpe_block->
-						     register_count) * 8] >
+			    (&gpe_block->event_info[gpe_block->gpe_count] >
 			     gpe_event_info)) {
 				return (TRUE);
 			}
@@ -229,7 +227,7 @@ acpi_ev_delete_gpe_handlers(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_ev_save_method_info
+ * FUNCTION:    acpi_ev_match_gpe_method
  *
  * PARAMETERS:  Callback from walk_namespace
  *
@@ -241,8 +239,7 @@ acpi_ev_delete_gpe_handlers(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
  *              information for quick lookup during GPE dispatch
  *
  *              The name of each GPE control method is of the form:
- *              "_Lxx" or "_Exx"
- *              Where:
+ *              "_Lxx" or "_Exx", where:
  *                  L      - means that the GPE is level triggered
  *                  E      - means that the GPE is edge triggered
  *                  xx     - is the GPE number [in HEX]
@@ -250,9 +247,11 @@ acpi_ev_delete_gpe_handlers(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
  ******************************************************************************/
 
 static acpi_status
-acpi_ev_save_method_info(acpi_handle obj_handle,
+acpi_ev_match_gpe_method(acpi_handle obj_handle,
 			 u32 level, void *obj_desc, void **return_value)
 {
+	struct acpi_namespace_node *method_node =
+	    ACPI_CAST_PTR(struct acpi_namespace_node, obj_handle);
 	struct acpi_gpe_block_info *gpe_block = (void *)obj_desc;
 	struct acpi_gpe_event_info *gpe_event_info;
 	u32 gpe_number;
@@ -262,21 +261,25 @@ acpi_ev_save_method_info(acpi_handle obj_handle,
 	ACPI_FUNCTION_TRACE(ev_save_method_info);
 
 	/*
-	 * _Lxx and _Exx GPE method support
+	 * Match and decode the _Lxx and _Exx GPE method names
 	 *
-	 * 1) Extract the name from the object and convert to a string
+	 * 1) Extract the method name and null terminate it
 	 */
-	ACPI_MOVE_32_TO_32(name,
-			   &((struct acpi_namespace_node *)obj_handle)->name.
-			   integer);
+	ACPI_MOVE_32_TO_32(name, &method_node->name.integer);
 	name[ACPI_NAME_SIZE] = 0;
 
+	/* 2) Name must begin with an underscore */
+
+	if (name[0] != '_') {
+		return_ACPI_STATUS(AE_OK);	/* Ignore this method */
+	}
+
 	/*
-	 * 2) Edge/Level determination is based on the 2nd character
+	 * 3) Edge/Level determination is based on the 2nd character
 	 *    of the method name
 	 *
-	 * NOTE: Default GPE type is RUNTIME. May be changed later to WAKE
-	 * if a _PRW object is found that points to this GPE.
+	 * NOTE: Default GPE type is RUNTIME only. Later, if a _PRW object is
+	 * found that points to this GPE, the ACPI_GPE_CAN_WAKE flag is set.
 	 */
 	switch (name[1]) {
 	case 'L':
@@ -288,7 +291,7 @@ acpi_ev_save_method_info(acpi_handle obj_handle,
 		break;
 
 	default:
-		/* Unknown method type, just ignore it! */
+		/* Unknown method type, just ignore it */
 
 		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
 				  "Ignoring unknown GPE method type: %s "
@@ -296,7 +299,7 @@ acpi_ev_save_method_info(acpi_handle obj_handle,
 		return_ACPI_STATUS(AE_OK);
 	}
 
-	/* Convert the last two characters of the name to the GPE Number */
+	/* 4) The last two characters of the name are the hex GPE Number */
 
 	gpe_number = ACPI_STRTOUL(&name[2], NULL, 16);
 	if (gpe_number == ACPI_UINT32_MAX) {
@@ -311,28 +314,22 @@ acpi_ev_save_method_info(acpi_handle obj_handle,
 
 	/* Ensure that we have a valid GPE number for this GPE block */
 
-	if ((gpe_number < gpe_block->block_base_number) ||
-	    (gpe_number >= (gpe_block->block_base_number +
-			    (gpe_block->register_count * 8)))) {
+	gpe_event_info = acpi_ev_low_get_gpe_info(gpe_number, gpe_block);
+	if (!gpe_event_info) {
 		/*
-		 * Not valid for this GPE block, just ignore it. However, it may be
-		 * valid for a different GPE block, since GPE0 and GPE1 methods both
-		 * appear under \_GPE.
+		 * This gpe_number is not valid for this GPE block, just ignore it.
+		 * However, it may be valid for a different GPE block, since GPE0
+		 * and GPE1 methods both appear under \_GPE.
 		 */
 		return_ACPI_STATUS(AE_OK);
 	}
 
 	/*
-	 * Now we can add this information to the gpe_event_info block for use
-	 * during dispatch of this GPE.
+	 * Add the GPE information from above to the gpe_event_info block for
+	 * use during dispatch of this GPE.
 	 */
-	gpe_event_info =
-	    &gpe_block->event_info[gpe_number - gpe_block->block_base_number];
-
-	gpe_event_info->flags = (u8) (type | ACPI_GPE_DISPATCH_METHOD);
-
-	gpe_event_info->dispatch.method_node =
-	    (struct acpi_namespace_node *)obj_handle;
+	gpe_event_info->flags = (u8)(type | ACPI_GPE_DISPATCH_METHOD);
+	gpe_event_info->dispatch.method_node = method_node;
 
 	ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
 			  "Registered GPE method %s as GPE number 0x%.2X\n",
@@ -351,7 +348,7 @@ acpi_ev_save_method_info(acpi_handle obj_handle,
  *
  * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
  *              Device. Run the _PRW method. If present, extract the GPE
- *              number and mark the GPE as a WAKE GPE.
+ *              number and mark the GPE as a CAN_WAKE GPE.
  *
  ******************************************************************************/
 
@@ -377,7 +374,7 @@ acpi_ev_match_prw_and_gpe(acpi_handle obj_handle,
 					 ACPI_BTYPE_PACKAGE, &pkg_desc);
 	if (ACPI_FAILURE(status)) {
 
-		/* Ignore all errors from _PRW, we don't want to abort the subsystem */
+		/* Ignore all errors from _PRW, we don't want to abort the walk */
 
 		return_ACPI_STATUS(AE_OK);
 	}
@@ -439,13 +436,13 @@ acpi_ev_match_prw_and_gpe(acpi_handle obj_handle,
 	 *     2) The GPE index(number) is within the range of the Gpe Block
 	 *          associated with the GPE device.
 	 */
-	if ((gpe_device == target_gpe_device) &&
-	    (gpe_number >= gpe_block->block_base_number) &&
-	    (gpe_number < gpe_block->block_base_number +
-	     (gpe_block->register_count * 8))) {
-		gpe_event_info = &gpe_block->event_info[gpe_number -
-							gpe_block->
-							block_base_number];
+	if (gpe_device != target_gpe_device) {
+		goto cleanup;
+	}
+
+	gpe_event_info = acpi_ev_low_get_gpe_info(gpe_number, gpe_block);
+	if (gpe_event_info) {
+		/* This GPE can wake the system */
 
 		gpe_event_info->flags |= ACPI_GPE_CAN_WAKE;
 	}
@@ -705,8 +702,7 @@ acpi_status acpi_ev_delete_gpe_block(struct acpi_gpe_block_info *gpe_block)
 		acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 	}
 
-	acpi_current_gpe_count -=
-	    gpe_block->register_count * ACPI_GPE_REGISTER_WIDTH;
+	acpi_current_gpe_count -= gpe_block->gpe_count;
 
 	/* Free the gpe_block */
 
@@ -760,9 +756,7 @@ acpi_ev_create_gpe_info_blocks(struct acpi_gpe_block_info *gpe_block)
 	 * Allocate the GPE event_info block. There are eight distinct GPEs
 	 * per register. Initialization to zeros is sufficient.
 	 */
-	gpe_event_info = ACPI_ALLOCATE_ZEROED(((acpi_size) gpe_block->
-					       register_count *
-					       ACPI_GPE_REGISTER_WIDTH) *
+	gpe_event_info = ACPI_ALLOCATE_ZEROED((acpi_size) gpe_block->gpe_count *
 					      sizeof(struct
 						     acpi_gpe_event_info));
 	if (!gpe_event_info) {
@@ -897,6 +891,7 @@ acpi_ev_create_gpe_block(struct acpi_namespace_node *gpe_device,
 	/* Initialize the new GPE block */
 
 	gpe_block->node = gpe_device;
+	gpe_block->gpe_count = (u16)(register_count * ACPI_GPE_REGISTER_WIDTH);
 	gpe_block->register_count = register_count;
 	gpe_block->block_base_number = gpe_block_base_number;
 
@@ -925,7 +920,7 @@ acpi_ev_create_gpe_block(struct acpi_namespace_node *gpe_device,
 
 	status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD, gpe_device,
 					ACPI_UINT32_MAX, ACPI_NS_WALK_NO_UNLOCK,
-					acpi_ev_save_method_info, NULL,
+					acpi_ev_match_gpe_method, NULL,
 					gpe_block, NULL);
 
 	/* Return the new block */
@@ -938,14 +933,13 @@ acpi_ev_create_gpe_block(struct acpi_namespace_node *gpe_device,
 			  "GPE %02X to %02X [%4.4s] %u regs on int 0x%X\n",
 			  (u32) gpe_block->block_base_number,
 			  (u32) (gpe_block->block_base_number +
-				 ((gpe_block->register_count *
-				   ACPI_GPE_REGISTER_WIDTH) - 1)),
+				(gpe_block->gpe_count - 1)),
 			  gpe_device->name.ascii, gpe_block->register_count,
 			  interrupt_number));
 
 	/* Update global count of currently available GPEs */
 
-	acpi_current_gpe_count += register_count * ACPI_GPE_REGISTER_WIDTH;
+	acpi_current_gpe_count += gpe_block->gpe_count;
 	return_ACPI_STATUS(AE_OK);
 }
 
@@ -969,10 +963,13 @@ acpi_status
 acpi_ev_initialize_gpe_block(struct acpi_namespace_node *gpe_device,
 			     struct acpi_gpe_block_info *gpe_block)
 {
+	acpi_status status;
 	struct acpi_gpe_event_info *gpe_event_info;
 	struct acpi_gpe_walk_info gpe_info;
 	u32 wake_gpe_count;
 	u32 gpe_enabled_count;
+	u32 gpe_index;
+	u32 gpe_number;
 	u32 i;
 	u32 j;
 
@@ -998,50 +995,62 @@ acpi_ev_initialize_gpe_block(struct acpi_namespace_node *gpe_device,
 		gpe_info.gpe_block = gpe_block;
 		gpe_info.gpe_device = gpe_device;
 
-		acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+		status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 					   ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
 					   acpi_ev_match_prw_and_gpe, NULL,
 					   &gpe_info, NULL);
+		if (ACPI_FAILURE(status)) {
+			ACPI_EXCEPTION((AE_INFO, status,
+					"While executing _PRW methods"));
+		}
 	}
 
 	/*
-	 * Enable all GPEs that have a corresponding method and aren't
+	 * Enable all GPEs that have a corresponding method and are not
 	 * capable of generating wakeups. Any other GPEs within this block
-	 * must be enabled via the acpi_enable_gpe() interface.
+	 * must be enabled via the acpi_enable_gpe interface.
 	 */
 	wake_gpe_count = 0;
 	gpe_enabled_count = 0;
-	if (gpe_device == acpi_gbl_fadt_gpe_device)
+
+	if (gpe_device == acpi_gbl_fadt_gpe_device) {
 		gpe_device = NULL;
+	}
 
 	for (i = 0; i < gpe_block->register_count; i++) {
 		for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
-			acpi_status status;
-			acpi_size gpe_index;
-			int gpe_number;
 
 			/* Get the info block for this particular GPE */
-			gpe_index = (acpi_size)i * ACPI_GPE_REGISTER_WIDTH + j;
+
+			gpe_index = (i * ACPI_GPE_REGISTER_WIDTH) + j;
 			gpe_event_info = &gpe_block->event_info[gpe_index];
 
 			if (gpe_event_info->flags & ACPI_GPE_CAN_WAKE) {
 				wake_gpe_count++;
-				if (acpi_gbl_leave_wake_gpes_disabled)
+				if (acpi_gbl_leave_wake_gpes_disabled) {
 					continue;
+				}
 			}
 
-			if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_METHOD))
+			/* Ignore GPEs that have no corresponding _Lxx/_Exx method */
+
+			if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_METHOD)) {
 				continue;
+			}
+
+			/* Enable this GPE */
 
 			gpe_number = gpe_index + gpe_block->block_base_number;
 			status = acpi_enable_gpe(gpe_device, gpe_number,
-						ACPI_GPE_TYPE_RUNTIME);
-			if (ACPI_FAILURE(status))
-				ACPI_ERROR((AE_INFO,
-						"Failed to enable GPE %02X\n",
+						 ACPI_GPE_TYPE_RUNTIME);
+			if (ACPI_FAILURE(status)) {
+				ACPI_EXCEPTION((AE_INFO, status,
+						"Could not enable GPE 0x%02X",
 						gpe_number));
-			else
-				gpe_enabled_count++;
+				continue;
+			}
+
+			gpe_enabled_count++;
 		}
 	}
 
diff --git a/drivers/acpi/acpica/evxface.c b/drivers/acpi/acpica/evxface.c
index ca048233d8d3..cc825023012a 100644
--- a/drivers/acpi/acpica/evxface.c
+++ b/drivers/acpi/acpica/evxface.c
@@ -682,14 +682,13 @@ acpi_install_gpe_handler(acpi_handle gpe_device,
 
 	/* Parameter validation */
 
-	if ((!address) || (type > ACPI_GPE_XRUPT_TYPE_MASK)) {
-		status = AE_BAD_PARAMETER;
-		goto exit;
+	if ((!address) || (type & ~ACPI_GPE_XRUPT_TYPE_MASK)) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
 
 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 	if (ACPI_FAILURE(status)) {
-		goto exit;
+		return_ACPI_STATUS(status);
 	}
 
 	/* Ensure that we have a valid GPE number */
@@ -720,6 +719,13 @@ acpi_install_gpe_handler(acpi_handle gpe_device,
 	handler->context = context;
 	handler->method_node = gpe_event_info->dispatch.method_node;
 
+	/* Disable the GPE before installing the handler */
+
+	status = acpi_ev_disable_gpe(gpe_event_info);
+	if (ACPI_FAILURE (status)) {
+		goto unlock_and_exit;
+	}
+
 	/* Install the handler */
 
 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
@@ -733,12 +739,8 @@ acpi_install_gpe_handler(acpi_handle gpe_device,
 
 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 
-      unlock_and_exit:
+unlock_and_exit:
 	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
-      exit:
-	if (ACPI_FAILURE(status))
-		ACPI_EXCEPTION((AE_INFO, status,
-				"Installing notify handler failed"));
 	return_ACPI_STATUS(status);
 }
 
diff --git a/drivers/acpi/acpica/evxfevnt.c b/drivers/acpi/acpica/evxfevnt.c
index 5ff32c78ea2d..7c7bbb4d402c 100644
--- a/drivers/acpi/acpica/evxfevnt.c
+++ b/drivers/acpi/acpica/evxfevnt.c
@@ -203,21 +203,26 @@ ACPI_EXPORT_SYMBOL(acpi_enable_event)
  *
  * FUNCTION:    acpi_set_gpe
  *
- * PARAMETERS:  gpe_device      - Parent GPE Device
+ * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
  *              gpe_number      - GPE level within the GPE block
- *              action          - Enable or disable
- *                                Called from ISR or not
+ *              action          - ACPI_GPE_ENABLE or ACPI_GPE_DISABLE
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Enable or disable an ACPI event (general purpose)
+ * DESCRIPTION: Enable or disable an individual GPE. This function bypasses
+ *              the reference count mechanism used in the acpi_enable_gpe and
+ *              acpi_disable_gpe interfaces -- and should be used with care.
+ *
+ * Note: Typically used to disable a runtime GPE for short period of time,
+ * then re-enable it, without disturbing the existing reference counts. This
+ * is useful, for example, in the Embedded Controller (EC) driver.
  *
  ******************************************************************************/
 acpi_status acpi_set_gpe(acpi_handle gpe_device, u32 gpe_number, u8 action)
 {
-	acpi_status status = AE_OK;
-	acpi_cpu_flags flags;
 	struct acpi_gpe_event_info *gpe_event_info;
+	acpi_status status;
+	acpi_cpu_flags flags;
 
 	ACPI_FUNCTION_TRACE(acpi_set_gpe);
 
@@ -243,7 +248,6 @@ acpi_status acpi_set_gpe(acpi_handle gpe_device, u32 gpe_number, u8 action)
 		break;
 
 	default:
-		ACPI_ERROR((AE_INFO, "Invalid action\n"));
 		status = AE_BAD_PARAMETER;
 		break;
 	}
@@ -259,25 +263,31 @@ ACPI_EXPORT_SYMBOL(acpi_set_gpe)
  *
  * FUNCTION:    acpi_enable_gpe
  *
- * PARAMETERS:  gpe_device      - Parent GPE Device
+ * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
  *              gpe_number      - GPE level within the GPE block
- *              type            - Purpose the GPE will be used for
+ *              gpe_type        - ACPI_GPE_TYPE_RUNTIME or ACPI_GPE_TYPE_WAKE
+ *                                or both
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Take a reference to a GPE and enable it if necessary
+ * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
+ *              hardware-enabled (for runtime GPEs), or the GPE register mask
+ *              is updated (for wake GPEs).
  *
  ******************************************************************************/
-acpi_status acpi_enable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 type)
+acpi_status acpi_enable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 gpe_type)
 {
 	acpi_status status = AE_OK;
-	acpi_cpu_flags flags;
 	struct acpi_gpe_event_info *gpe_event_info;
+	acpi_cpu_flags flags;
 
 	ACPI_FUNCTION_TRACE(acpi_enable_gpe);
 
-	if (type & ~ACPI_GPE_TYPE_WAKE_RUN)
+	/* Parameter validation */
+
+	if (!gpe_type || (gpe_type & ~ACPI_GPE_TYPE_WAKE_RUN)) {
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
 
 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 
@@ -289,26 +299,43 @@ acpi_status acpi_enable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 type)
 		goto unlock_and_exit;
 	}
 
-	if (type & ACPI_GPE_TYPE_RUNTIME) {
-		if (++gpe_event_info->runtime_count == 1) {
+	if (gpe_type & ACPI_GPE_TYPE_RUNTIME) {
+		if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
+			status = AE_LIMIT;	/* Too many references */
+			goto unlock_and_exit;
+		}
+
+		gpe_event_info->runtime_count++;
+		if (gpe_event_info->runtime_count == 1) {
 			status = acpi_ev_enable_gpe(gpe_event_info);
-			if (ACPI_FAILURE(status))
+			if (ACPI_FAILURE(status)) {
 				gpe_event_info->runtime_count--;
+				goto unlock_and_exit;
+			}
 		}
 	}
 
-	if (type & ACPI_GPE_TYPE_WAKE) {
+	if (gpe_type & ACPI_GPE_TYPE_WAKE) {
+		/* The GPE must have the ability to wake the system */
+
 		if (!(gpe_event_info->flags & ACPI_GPE_CAN_WAKE)) {
-			status = AE_BAD_PARAMETER;
+			status = AE_TYPE;
+			goto unlock_and_exit;
+		}
+
+		if (gpe_event_info->wakeup_count == ACPI_UINT8_MAX) {
+			status = AE_LIMIT;	/* Too many references */
 			goto unlock_and_exit;
 		}
 
 		/*
-		 * Wake-up GPEs are only enabled right prior to putting the
-		 * system into a sleep state.
+		 * Update the enable mask on the first wakeup reference. Wake GPEs
+		 * are only hardware-enabled just before sleeping.
 		 */
-		if (++gpe_event_info->wakeup_count == 1)
-			acpi_ev_update_gpe_enable_masks(gpe_event_info);
+		gpe_event_info->wakeup_count++;
+		if (gpe_event_info->wakeup_count == 1) {
+			(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);
+		}
 	}
 
 unlock_and_exit:
@@ -321,27 +348,34 @@ ACPI_EXPORT_SYMBOL(acpi_enable_gpe)
  *
  * FUNCTION:    acpi_disable_gpe
  *
- * PARAMETERS:  gpe_device      - Parent GPE Device
+ * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
  *              gpe_number      - GPE level within the GPE block
- *              type            - Purpose the GPE won't be used for any more
+ *              gpe_type        - ACPI_GPE_TYPE_RUNTIME or ACPI_GPE_TYPE_WAKE
+ *                                or both
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Release a reference to a GPE and disable it if necessary
+ * DESCRIPTION: Remove a reference to a GPE. When the last reference is
+ *              removed, only then is the GPE disabled (for runtime GPEs), or
+ *              the GPE mask bit disabled (for wake GPEs)
  *
  ******************************************************************************/
-acpi_status acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 type)
+acpi_status acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 gpe_type)
 {
 	acpi_status status = AE_OK;
-	acpi_cpu_flags flags;
 	struct acpi_gpe_event_info *gpe_event_info;
+	acpi_cpu_flags flags;
 
 	ACPI_FUNCTION_TRACE(acpi_disable_gpe);
 
-	if (type & ~ACPI_GPE_TYPE_WAKE_RUN)
+	/* Parameter validation */
+
+	if (!gpe_type || (gpe_type & ~ACPI_GPE_TYPE_WAKE_RUN)) {
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
 
 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
 	/* Ensure that we have a valid GPE number */
 
 	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
@@ -350,18 +384,39 @@ acpi_status acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 type)
 		goto unlock_and_exit;
 	}
 
-	if ((type & ACPI_GPE_TYPE_RUNTIME) && gpe_event_info->runtime_count) {
-		if (--gpe_event_info->runtime_count == 0)
+	/* Hardware-disable a runtime GPE on removal of the last reference */
+
+	if (gpe_type & ACPI_GPE_TYPE_RUNTIME) {
+		if (!gpe_event_info->runtime_count) {
+			status = AE_LIMIT;	/* There are no references to remove */
+			goto unlock_and_exit;
+		}
+
+		gpe_event_info->runtime_count--;
+		if (!gpe_event_info->runtime_count) {
 			status = acpi_ev_disable_gpe(gpe_event_info);
+			if (ACPI_FAILURE(status)) {
+				gpe_event_info->runtime_count++;
+				goto unlock_and_exit;
+			}
+		}
 	}
 
-	if ((type & ACPI_GPE_TYPE_WAKE) && gpe_event_info->wakeup_count) {
-		/*
-		 * Wake-up GPEs are not enabled after leaving system sleep
-		 * states, so we don't need to disable them here.
-		 */
-		if (--gpe_event_info->wakeup_count == 0)
-			acpi_ev_update_gpe_enable_masks(gpe_event_info);
+	/*
+	 * Update masks for wake GPE on removal of the last reference.
+	 * No need to hardware-disable wake GPEs here, they are not currently
+	 * enabled.
+	 */
+	if (gpe_type & ACPI_GPE_TYPE_WAKE) {
+		if (!gpe_event_info->wakeup_count) {
+			status = AE_LIMIT;	/* There are no references to remove */
+			goto unlock_and_exit;
+		}
+
+		gpe_event_info->wakeup_count--;
+		if (!gpe_event_info->wakeup_count) {
+			(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);
+		}
 	}
 
 unlock_and_exit:
@@ -465,30 +520,23 @@ ACPI_EXPORT_SYMBOL(acpi_clear_event)
  *
  * FUNCTION:    acpi_clear_gpe
  *
- * PARAMETERS:  gpe_device      - Parent GPE Device
+ * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
  *              gpe_number      - GPE level within the GPE block
- *              Flags           - Called from an ISR or not
  *
  * RETURN:      Status
  *
  * DESCRIPTION: Clear an ACPI event (general purpose)
  *
  ******************************************************************************/
-acpi_status acpi_clear_gpe(acpi_handle gpe_device, u32 gpe_number, u32 flags)
+acpi_status acpi_clear_gpe(acpi_handle gpe_device, u32 gpe_number)
 {
 	acpi_status status = AE_OK;
 	struct acpi_gpe_event_info *gpe_event_info;
+	acpi_cpu_flags flags;
 
 	ACPI_FUNCTION_TRACE(acpi_clear_gpe);
 
-	/* Use semaphore lock if not executing at interrupt level */
-
-	if (flags & ACPI_NOT_ISR) {
-		status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
-		if (ACPI_FAILURE(status)) {
-			return_ACPI_STATUS(status);
-		}
-	}
+	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 
 	/* Ensure that we have a valid GPE number */
 
@@ -501,9 +549,7 @@ acpi_status acpi_clear_gpe(acpi_handle gpe_device, u32 gpe_number, u32 flags)
 	status = acpi_hw_clear_gpe(gpe_event_info);
 
       unlock_and_exit:
-	if (flags & ACPI_NOT_ISR) {
-		(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
-	}
+	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 	return_ACPI_STATUS(status);
 }
 
@@ -569,9 +615,8 @@ ACPI_EXPORT_SYMBOL(acpi_get_event_status)
  *
  * FUNCTION:    acpi_get_gpe_status
  *
- * PARAMETERS:  gpe_device      - Parent GPE Device
+ * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
  *              gpe_number      - GPE level within the GPE block
- *              Flags           - Called from an ISR or not
  *              event_status    - Where the current status of the event will
  *                                be returned
  *
@@ -582,21 +627,15 @@ ACPI_EXPORT_SYMBOL(acpi_get_event_status)
  ******************************************************************************/
 acpi_status
 acpi_get_gpe_status(acpi_handle gpe_device,
-		    u32 gpe_number, u32 flags, acpi_event_status * event_status)
+		    u32 gpe_number, acpi_event_status *event_status)
 {
 	acpi_status status = AE_OK;
 	struct acpi_gpe_event_info *gpe_event_info;
+	acpi_cpu_flags flags;
 
 	ACPI_FUNCTION_TRACE(acpi_get_gpe_status);
 
-	/* Use semaphore lock if not executing at interrupt level */
-
-	if (flags & ACPI_NOT_ISR) {
-		status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
-		if (ACPI_FAILURE(status)) {
-			return_ACPI_STATUS(status);
-		}
-	}
+	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 
 	/* Ensure that we have a valid GPE number */
 
@@ -614,9 +653,7 @@ acpi_get_gpe_status(acpi_handle gpe_device,
 		*event_status |= ACPI_EVENT_FLAG_HANDLE;
 
       unlock_and_exit:
-	if (flags & ACPI_NOT_ISR) {
-		(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
-	}
+	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 	return_ACPI_STATUS(status);
 }
 
@@ -673,20 +710,15 @@ acpi_install_gpe_block(acpi_handle gpe_device,
 		goto unlock_and_exit;
 	}
 
-	/* Run the _PRW methods and enable the GPEs */
-
-	status = acpi_ev_initialize_gpe_block(node, gpe_block);
-	if (ACPI_FAILURE(status)) {
-		goto unlock_and_exit;
-	}
-
-	/* Get the device_object attached to the node */
+	/* Install block in the device_object attached to the node */
 
 	obj_desc = acpi_ns_get_attached_object(node);
 	if (!obj_desc) {
 
-		/* No object, create a new one */
-
+		/*
+		 * No object, create a new one (Device nodes do not always have
+		 * an attached object)
+		 */
 		obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_DEVICE);
 		if (!obj_desc) {
 			status = AE_NO_MEMORY;
@@ -705,10 +737,14 @@ acpi_install_gpe_block(acpi_handle gpe_device,
 		}
 	}
 
-	/* Install the GPE block in the device_object */
+	/* Now install the GPE block in the device_object */
 
 	obj_desc->device.gpe_block = gpe_block;
 
+	/* Run the _PRW methods and enable the runtime GPEs in the new block */
+
+	status = acpi_ev_initialize_gpe_block(node, gpe_block);
+
       unlock_and_exit:
 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 	return_ACPI_STATUS(status);
@@ -839,8 +875,7 @@ acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
 
 	/* Increment Index by the number of GPEs in this block */
 
-	info->next_block_base_index +=
-	    (gpe_block->register_count * ACPI_GPE_REGISTER_WIDTH);
+	info->next_block_base_index += gpe_block->gpe_count;
 
 	if (info->index < info->next_block_base_index) {
 		/*
diff --git a/drivers/acpi/acpica/exoparg2.c b/drivers/acpi/acpica/exoparg2.c
index 3f3f48bb2dc8..10e104cf0fb9 100644
--- a/drivers/acpi/acpica/exoparg2.c
+++ b/drivers/acpi/acpica/exoparg2.c
@@ -119,33 +119,6 @@ acpi_status acpi_ex_opcode_2A_0T_0R(struct acpi_walk_state *walk_state)
 			status = AE_AML_OPERAND_TYPE;
 			break;
 		}
-#ifdef ACPI_GPE_NOTIFY_CHECK
-		/*
-		 * GPE method wake/notify check.  Here, we want to ensure that we
-		 * don't receive any "DeviceWake" Notifies from a GPE _Lxx or _Exx
-		 * GPE method during system runtime.  If we do, the GPE is marked
-		 * as "wake-only" and disabled.
-		 *
-		 * 1) Is the Notify() value == device_wake?
-		 * 2) Is this a GPE deferred method?  (An _Lxx or _Exx method)
-		 * 3) Did the original GPE happen at system runtime?
-		 *    (versus during wake)
-		 *
-		 * If all three cases are true, this is a wake-only GPE that should
-		 * be disabled at runtime.
-		 */
-		if (value == 2) {	/* device_wake */
-			status =
-			    acpi_ev_check_for_wake_only_gpe(walk_state->
-							    gpe_event_info);
-			if (ACPI_FAILURE(status)) {
-
-				/* AE_WAKE_ONLY_GPE only error, means ignore this notify */
-
-				return_ACPI_STATUS(AE_OK)
-			}
-		}
-#endif
 
 		/*
 		 * Dispatch the notify to the appropriate handler