ACPI: acpi_os_get_thread_id() returns current

Linux mutexes and the debug code that that reference
acpi_os_get_thread_id() are happy with 0.
But the AML mutexes in exmutex.c expect a unique non-zero
number for each thread - as they track this thread_id
to permit the mutex re-entrancy defined by the ACPI spec.

http://bugzilla.kernel.org/show_bug.cgi?id=6687

Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 4 insertions, 3 deletions

diff --git a/include/acpi/aclocal.h b/include/acpi/aclocal.h
index 56b802486161..fbafee6e56d3 100644
--- a/include/acpi/aclocal.h
+++ b/include/acpi/aclocal.h
@@ -127,7 +127,7 @@ typedef u8 acpi_owner_id;
 
 /* This Thread ID means that the mutex is not in use (unlocked) */
 
-#define ACPI_MUTEX_NOT_ACQUIRED         (u32) -1
+#define ACPI_MUTEX_NOT_ACQUIRED         (acpi_thread_id) 0
 
 /* Table for the global mutexes */
 
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 3f853cabbd41..1cb51bf96ece 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -59,6 +59,7 @@
 #include <asm/acpi.h>
 #include <linux/slab.h>
 #include <linux/spinlock_types.h>
+#include <asm/current.h>
 
 /* Host-dependent types and defines */
 
@@ -100,8 +101,8 @@
 
 #define acpi_cpu_flags unsigned long
 
-#define acpi_thread_id u32
+#define acpi_thread_id struct task_struct *
 
-static inline acpi_thread_id acpi_os_get_thread_id(void) { return 0; }
+static inline acpi_thread_id acpi_os_get_thread_id(void) { return current; }
 
 #endif                          /* __ACLINUX_H__ */