powerpc/eeh: Cleanup on eeh_subsystem_enabled

The patch cleans up variable eeh_subsystem_enabled so that we needn't
refer the variable directly from external. Instead, we will use
function eeh_enabled() and eeh_set_enable() to operate the variable.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index 9e39ceb..d4dd41f 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h
@@ -172,10 +172,20 @@
 };
 
 extern struct eeh_ops *eeh_ops;
-extern int eeh_subsystem_enabled;
+extern bool eeh_subsystem_enabled;
 extern raw_spinlock_t confirm_error_lock;
 extern int eeh_probe_mode;
 
+static inline bool eeh_enabled(void)
+{
+	return eeh_subsystem_enabled;
+}
+
+static inline void eeh_set_enable(bool mode)
+{
+	eeh_subsystem_enabled = mode;
+}
+
 #define EEH_PROBE_MODE_DEV	(1<<0)	/* From PCI device	*/
 #define EEH_PROBE_MODE_DEVTREE	(1<<1)	/* From device tree	*/
 
@@ -246,7 +256,7 @@
  * If this macro yields TRUE, the caller relays to eeh_check_failure()
  * which does further tests out of line.
  */
-#define EEH_POSSIBLE_ERROR(val, type)	((val) == (type)~0 && eeh_subsystem_enabled)
+#define EEH_POSSIBLE_ERROR(val, type)	((val) == (type)~0 && eeh_enabled())
 
 /*
  * Reads from a device which has been isolated by EEH will return
@@ -257,6 +267,13 @@
 
 #else /* !CONFIG_EEH */
 
+static inline bool eeh_enabled(void)
+{
+        return false;
+}
+
+static inline void eeh_set_enable(bool mode) { }
+
 static inline int eeh_init(void)
 {
 	return 0;