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authorDaniel Vetter <daniel.vetter@ffwll.ch>2013-05-21 09:52:16 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2013-05-21 09:52:16 +0200
commite1b73cba13a0cc68dd4f746eced15bd6bb24cda4 (patch)
treeb1c9e10730724024a700031ad56c20419dabb500 /include/linux/preempt.h
parent98304ad186296dc1e655399e28d5973c21db6a73 (diff)
parentc7788792a5e7b0d5d7f96d0766b4cb6112d47d75 (diff)
Merge tag 'v3.10-rc2' into drm-intel-next-queued
Backmerge Linux 3.10-rc2 since the various (rather trivial) conflicts grew a bit out of hand. intel_dp.c has the only real functional conflict since the logic changed while dev_priv->edp.bpp was moved around. Also squash in a whitespace fixup from Ben Widawsky for i915_gem_gtt.c, git seems to do something pretty strange in there (which I don't fully understand tbh). Conflicts: drivers/gpu/drm/i915/i915_reg.h drivers/gpu/drm/i915/intel_dp.c Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'include/linux/preempt.h')
-rw-r--r--include/linux/preempt.h22
1 files changed, 14 insertions, 8 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 5a710b9c578e..87a03c746f17 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -93,14 +93,20 @@ do { \
#else /* !CONFIG_PREEMPT_COUNT */
-#define preempt_disable() do { } while (0)
-#define sched_preempt_enable_no_resched() do { } while (0)
-#define preempt_enable_no_resched() do { } while (0)
-#define preempt_enable() do { } while (0)
-
-#define preempt_disable_notrace() do { } while (0)
-#define preempt_enable_no_resched_notrace() do { } while (0)
-#define preempt_enable_notrace() do { } while (0)
+/*
+ * Even if we don't have any preemption, we need preempt disable/enable
+ * to be barriers, so that we don't have things like get_user/put_user
+ * that can cause faults and scheduling migrate into our preempt-protected
+ * region.
+ */
+#define preempt_disable() barrier()
+#define sched_preempt_enable_no_resched() barrier()
+#define preempt_enable_no_resched() barrier()
+#define preempt_enable() barrier()
+
+#define preempt_disable_notrace() barrier()
+#define preempt_enable_no_resched_notrace() barrier()
+#define preempt_enable_notrace() barrier()
#endif /* CONFIG_PREEMPT_COUNT */