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authorDaniel Vetter <daniel.vetter@ffwll.ch>2012-10-22 14:34:51 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2012-10-22 14:34:51 +0200
commitc2fb7916927e989ea424e61ce5fe617e54878827 (patch)
tree02f9d5482075f8931637d82bb697a6470270136a /include/linux/atomic.h
parent29de6ce574870a0d3fd157afdbf51c0282e2bf63 (diff)
parent6f0c0580b70c89094b3422ba81118c7b959c7556 (diff)
Merge tag 'v3.7-rc2' into drm-intel-next-queued
Linux 3.7-rc2 Backmerge to solve two ugly conflicts: - uapi. We've already added new ioctl definitions for -next. Do I need to say more? - wc support gtt ptes. We've had to revert this for snb+ for 3.7 and also fix a few other things in the code. Now we know how to make it work on snb+, but to avoid losing the other fixes do the backmerge first before re-enabling wc gtt ptes on snb+. And a few other minor things, among them git getting confused in intel_dp.c and seemingly causing a conflict out of nothing ... Conflicts: drivers/gpu/drm/i915/i915_reg.h drivers/gpu/drm/i915/intel_display.c drivers/gpu/drm/i915/intel_dp.c drivers/gpu/drm/i915/intel_modes.c include/drm/i915_drm.h Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'include/linux/atomic.h')
-rw-r--r--include/linux/atomic.h25
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index 70cfcb2d63c4..5b08a8540ecf 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -86,6 +86,31 @@ static inline int atomic_dec_unless_positive(atomic_t *p)
}
#endif
+/*
+ * atomic_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
+ */
+#ifndef atomic_dec_if_positive
+static inline int atomic_dec_if_positive(atomic_t *v)
+{
+ int c, old, dec;
+ c = atomic_read(v);
+ for (;;) {
+ dec = c - 1;
+ if (unlikely(dec < 0))
+ break;
+ old = atomic_cmpxchg((v), c, dec);
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+ return dec;
+}
+#endif
+
#ifndef CONFIG_ARCH_HAS_ATOMIC_OR
static inline void atomic_or(int i, atomic_t *v)
{