From 37f8173dd84936ea78000ed1cad24f8b18d48ebb Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 24 Jan 2020 22:13:03 +0100
Subject: locking/atomics: Flip fallbacks and instrumentation

Currently instrumentation of atomic primitives is done at the architecture
level, while composites or fallbacks are provided at the generic level.

The result is that there are no uninstrumented variants of the
fallbacks. Since there is now need of such variants to isolate text poke
from any form of instrumentation invert this ordering.

Doing this means moving the instrumentation into the generic code as
well as having (for now) two variants of the fallbacks.

Notes:

 - the various *cond_read* primitives are not proper fallbacks
   and got moved into linux/atomic.c. No arch_ variants are
   generated because the base primitives smp_cond_load*()
   are instrumented.

 - once all architectures are moved over to arch_atomic_ one of the
   fallback variants can be removed and some 2300 lines reclaimed.

 - atomic_{read,set}*() are no longer double-instrumented

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20200505134058.769149955@linutronix.de
---
 scripts/atomic/fallbacks/inc_unless_negative | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'scripts/atomic/fallbacks/inc_unless_negative')

diff --git a/scripts/atomic/fallbacks/inc_unless_negative b/scripts/atomic/fallbacks/inc_unless_negative
index 177a7cb51eda..87629e0d4a80 100755
--- a/scripts/atomic/fallbacks/inc_unless_negative
+++ b/scripts/atomic/fallbacks/inc_unless_negative
@@ -1,13 +1,13 @@
 cat <<EOF
 static __always_inline bool
-${atomic}_inc_unless_negative(${atomic}_t *v)
+${arch}${atomic}_inc_unless_negative(${atomic}_t *v)
 {
-	${int} c = ${atomic}_read(v);
+	${int} c = ${arch}${atomic}_read(v);
 
 	do {
 		if (unlikely(c < 0))
 			return false;
-	} while (!${atomic}_try_cmpxchg(v, &c, c + 1));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, c + 1));
 
 	return true;
 }
-- 
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