ACPICA: Add new statistics interface.

This patch ports new counters and statistics interface, already
implemented in ACPICA upstream, to Linux.  That helps to reduce
source code differences between Linux and ACPICA upstream.

[rjw: Changelog]
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/acglobal.h

@@ -406,7 +406,9 @@ extern u32 acpi_gbl_nesting_level;
 
 /* Event counters */
 
+ACPI_EXTERN u32 acpi_method_count;
 ACPI_EXTERN u32 acpi_gpe_count;
+ACPI_EXTERN u32 acpi_sci_count;
 ACPI_EXTERN u32 acpi_fixed_event_count[ACPI_NUM_FIXED_EVENTS];
 
 /* Support for dynamic control method tracing mechanism */

drivers/acpi/acpica/dsmethod.c

@@ -292,6 +292,7 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 	 * reentered one more time (even if it is the same thread)
 	 */
 	obj_desc->method.thread_count++;
+	acpi_method_count++;
 	return_ACPI_STATUS(status);
 
 cleanup:

drivers/acpi/acpica/evsci.c

@@ -137,6 +137,7 @@ static u32 ACPI_SYSTEM_XFACE acpi_ev_sci_xrupt_handler(void *context)
 
 	interrupt_handled |= acpi_ev_sci_dispatch();
 
+	acpi_sci_count++;
 	return_UINT32(interrupt_handled);
 }
 

drivers/acpi/acpica/utglobal.c

@@ -289,6 +289,16 @@ acpi_status acpi_ut_init_globals(void)
 
 	acpi_gbl_owner_id_mask[ACPI_NUM_OWNERID_MASKS - 1] = 0x80000000;
 
+	/* Event counters */
+
+	acpi_method_count = 0;
+	acpi_sci_count = 0;
+	acpi_gpe_count = 0;
+
+	for (i = 0; i < ACPI_NUM_FIXED_EVENTS; i++) {
+		acpi_fixed_event_count[i] = 0;
+	}
+
 #if (!ACPI_REDUCED_HARDWARE)
 
 	/* GPE/SCI support */
@@ -383,4 +393,6 @@ ACPI_EXPORT_SYMBOL(acpi_dbg_level)
 
 ACPI_EXPORT_SYMBOL(acpi_dbg_layer)
 
+ACPI_EXPORT_SYMBOL(acpi_gpe_count)
+
 ACPI_EXPORT_SYMBOL(acpi_current_gpe_count)

drivers/acpi/acpica/utxface.c

@@ -208,6 +208,44 @@ acpi_status acpi_get_system_info(struct acpi_buffer * out_buffer)
 
 ACPI_EXPORT_SYMBOL(acpi_get_system_info)
 
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_get_statistics
+ *
+ * PARAMETERS:  stats           - Where the statistics are returned
+ *
+ * RETURN:      status          - the status of the call
+ *
+ * DESCRIPTION: Get the contents of the various system counters
+ *
+ ******************************************************************************/
+acpi_status acpi_get_statistics(struct acpi_statistics *stats)
+{
+	ACPI_FUNCTION_TRACE(acpi_get_statistics);
+
+	/* Parameter validation */
+
+	if (!stats) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	/* Various interrupt-based event counters */
+
+	stats->sci_count = acpi_sci_count;
+	stats->gpe_count = acpi_gpe_count;
+
+	ACPI_MEMCPY(stats->fixed_event_count, acpi_fixed_event_count,
+		    sizeof(acpi_fixed_event_count));
+
+	/* Other counters */
+
+	stats->method_count = acpi_method_count;
+
+	return_ACPI_STATUS(AE_OK);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_statistics)
+
 /*****************************************************************************
  *
  * FUNCTION:    acpi_install_initialization_handler

include/acpi/acpixf.h

@@ -140,6 +140,8 @@ ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status acpi_disable(void))
 acpi_status acpi_get_system_info(struct acpi_buffer *ret_buffer);
 #endif
 
+acpi_status acpi_get_statistics(struct acpi_statistics *stats);
+
 const char *acpi_format_exception(acpi_status exception);
 
 acpi_status acpi_purge_cached_objects(void);

include/acpi/actypes.h

@@ -973,6 +973,16 @@ struct acpi_system_info {
 	u32 debug_layer;
 };
 
+/*
+ * System statistics returned by acpi_get_statistics()
+ */
+struct acpi_statistics {
+	u32 sci_count;
+	u32 gpe_count;
+	u32 fixed_event_count[ACPI_NUM_FIXED_EVENTS];
+	u32 method_count;
+};
+
 /* Table Event Types */
 
 #define ACPI_TABLE_EVENT_LOAD           0x0