From 6e6a6ef0ed1fc9652e98fcd9990959fb73e94d80 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@gmx.de>
Date: Mon, 6 May 2013 19:13:33 +0000
Subject: [PATCH] --- yaml --- r: 374271 b: refs/heads/master c:
 f21dda025ab00da197ac30b6c6690c380d838683 h: refs/heads/master i:   374269:
 6eb0789c86c76e75958a33d681c81fec7df05f46   374267:
 896fcda4b7b3e1186e8dea46293df77760f45052   374263:
 fb1a54b7a34adacde325510ba9d7ee9ddd927e63   374255:
 59af2cdbe70207b58fcf2da173d415cc0f2a5ba8   374239:
 8a2a100f5c01ac4cfcbb7a6b5262de66e8637876   374207:
 72b2e4dc9c9ac02298aa2c8de8e81d6af82c64f9   374143:
 dbcdd992a48298898b02480fc198eb6590456958   374015:
 4bed1b954c11681a6c097d64c3e4208618317756   373759:
 aff92e1d6f8b32509fe6b4ff7c165de325f62478 v: v3

---
 [refs]                                 |  2 +-
 trunk/arch/parisc/Kconfig              |  1 +
 trunk/arch/parisc/include/asm/atomic.h | 23 +++++++++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 3ae70e83f61e..9724d6160c1c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bbbfde782084b4f0d85ddffb88f1cf4650ff40e4
+refs/heads/master: f21dda025ab00da197ac30b6c6690c380d838683
diff --git a/trunk/arch/parisc/Kconfig b/trunk/arch/parisc/Kconfig
index 433e75a2ee9a..fe4afb0f152f 100644
--- a/trunk/arch/parisc/Kconfig
+++ b/trunk/arch/parisc/Kconfig
@@ -13,6 +13,7 @@ config PARISC
 	select BUG
 	select HAVE_PERF_EVENTS
 	select GENERIC_ATOMIC64 if !64BIT
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_GENERIC_HARDIRQS
 	select BROKEN_RODATA
 	select GENERIC_IRQ_PROBE
diff --git a/trunk/arch/parisc/include/asm/atomic.h b/trunk/arch/parisc/include/asm/atomic.h
index f38e1984b242..472886ceab1d 100644
--- a/trunk/arch/parisc/include/asm/atomic.h
+++ b/trunk/arch/parisc/include/asm/atomic.h
@@ -229,6 +229,29 @@ static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 
 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 
+/*
+ * atomic64_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.
+ */
+static inline long atomic64_dec_if_positive(atomic64_t *v)
+{
+	long c, old, dec;
+	c = atomic64_read(v);
+	for (;;) {
+		dec = c - 1;
+		if (unlikely(dec < 0))
+			break;
+		old = atomic64_cmpxchg((v), c, dec);
+		if (likely(old == c))
+			break;
+		c = old;
+	}
+	return dec;
+}
+
 #endif /* !CONFIG_64BIT */