perf,x86: fix link failure for non-Intel configs

commit 6c4d3bc99b3341067775efd4d9d13cc8e655fd7c upstream.

Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") introduces a link failure since
perf_restore_debug_store() is only defined for CONFIG_CPU_SUP_INTEL:

	arch/x86/power/built-in.o: In function `restore_processor_state':
	(.text+0x45c): undefined reference to `perf_restore_debug_store'

Fix it by defining the dummy function appropriately.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 4dfbf87..9b9b2aa 100644 (file)
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1146,7 +1146,6 @@ extern void perf_swevent_put_recursion_context(int rctx);
 extern void perf_event_enable(struct perf_event *event);
 extern void perf_event_disable(struct perf_event *event);
 extern void perf_event_task_tick(void);
-extern void perf_restore_debug_store(void);
 #else
 static inline void
 perf_event_task_sched_in(struct task_struct *prev,
@@ -1185,6 +1184,11 @@ static inline void perf_swevent_put_recursion_context(int rctx)          { }
 static inline void perf_event_enable(struct perf_event *event)         { }
 static inline void perf_event_disable(struct perf_event *event)                { }
 static inline void perf_event_task_tick(void)                          { }
+#endif
+
+#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
+extern void perf_restore_debug_store(void);
+#else
 static inline void perf_restore_debug_store(void)                      { }
 #endif