ACPICA: fix AML mutex re-entrancy

ACPI AML supports "serialized" methods which are protected
by an implicit mutex.  The mutex is re-entrant for that AML thread
to allow recursion.

However, Linux implements notify() by creating a new AML thread.
So for systems where notify() re-enters a serialized method,
deadlock results.

The fix is to use the Linux thread_id as the key to allowing
re-entrancy, not the AML thread pointer.

http://bugzilla.kernel.org/show_bug.cgi?id=5534

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 3 insertions, 2 deletions

diff --git a/include/acpi/acinterp.h b/include/acpi/acinterp.h
index ce7c9d653910..73967c8152d3 100644
--- a/include/acpi/acinterp.h
+++ b/include/acpi/acinterp.h
@@ -253,7 +253,8 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 
 void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread);
 
-void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc);
+void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc,
+                          struct acpi_thread_state *thread);
 
 /*
  * exprep - ACPI AML execution - prep utilities
diff --git a/include/acpi/acobject.h b/include/acpi/acobject.h
index 04e9735a6742..5206d61d74a6 100644
--- a/include/acpi/acobject.h
+++ b/include/acpi/acobject.h
@@ -155,7 +155,7 @@ struct acpi_object_event {
 struct acpi_object_mutex {
         ACPI_OBJECT_COMMON_HEADER u8 sync_level;        /* 0-15, specified in Mutex() call */
         u16 acquisition_depth;  /* Allow multiple Acquires, same thread */
-        struct acpi_thread_state *owner_thread; /* Current owner of the mutex */
+        acpi_thread_id owner_thread_id; /* Current owner of the mutex */
         acpi_mutex os_mutex;    /* Actual OS synchronization object */
         union acpi_operand_object *prev;        /* Link for list of acquired mutexes */
         union acpi_operand_object *next;        /* Link for list of acquired mutexes */