[tip:locking/core] locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h

[tip-bot for Boqun Feng]

Commit-ID:  84567995612258c23bc55795575babe7ef605dd9
Gitweb:     http://git.kernel.org/tip/84567995612258c23bc55795575babe7ef605dd9
Author:     Boqun Feng <boqun.feng@xxxxxxxxx>
AuthorDate: Wed, 26 Aug 2015 19:52:46 +0800
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 13 Sep 2015 10:35:46 +0200

locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h

After commit:

  654672d4ba1a ("locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations")

Architectures may only provide {cmp,}xchg_relaxed definitions in
asm/cmpxchg.h. Other variants, such as {cmp,}xchg, may be built in
linux/atomic.h, which means simply including asm/cmpxchg.h may not get
the definitions of all the{cmp,}xchg variants.

Therefore, we should privatize the inclusions of asm/cmpxchg.h to
keep it only included in arch/* and replace the inclusions outside
with linux/atomic.h

Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Aybuke Ozdemir <aybuke.147@xxxxxxxxx>
Cc: Chris Brannon <chris@xxxxxxxxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Kirk Reiser <kirk@xxxxxxxxxx>
Cc: Kishon Vijay Abraham I <kishon@xxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
Cc: Shradha Shah <sshah@xxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: William Hubbs <w.d.hubbs@xxxxxxxxx>
Cc: devel@xxxxxxxxxxxxxxxxxxxx
Cc: linux-net-drivers@xxxxxxxxxxxxxx
Cc: speakup@xxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1440589966-26280-1-git-send-email-boqun.feng@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 Documentation/atomic_ops.txt        | 4 ++++
 drivers/net/ethernet/sfc/mcdi.c     | 2 +-
 drivers/phy/phy-rcar-gen2.c         | 3 +--
 drivers/staging/speakup/selection.c | 2 +-
 4 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Documentation/atomic_ops.txt b/Documentation/atomic_ops.txt
index b19fc34..c9d1cac 100644
--- a/Documentation/atomic_ops.txt
+++ b/Documentation/atomic_ops.txt
@@ -542,6 +542,10 @@ The routines xchg() and cmpxchg() must provide the same exact
 memory-barrier semantics as the atomic and bit operations returning
 values.
 
+Note: If someone wants to use xchg(), cmpxchg() and their variants,
+linux/atomic.h should be included rather than asm/cmpxchg.h, unless
+the code is in arch/* and can take care of itself.
+
 Spinlocks and rwlocks have memory barrier expectations as well.
 The rule to follow is simple:
 
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 98d172b..a9b9460 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -9,7 +9,7 @@
 
 #include <linux/delay.h>
 #include <linux/moduleparam.h>
-#include <asm/cmpxchg.h>
+#include <linux/atomic.h>
 #include "net_driver.h"
 #include "nic.h"
 #include "io.h"
diff --git a/drivers/phy/phy-rcar-gen2.c b/drivers/phy/phy-rcar-gen2.c
index 6e0d9fa..c7a0599 100644
--- a/drivers/phy/phy-rcar-gen2.c
+++ b/drivers/phy/phy-rcar-gen2.c
@@ -17,8 +17,7 @@
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
-
-#include <asm/cmpxchg.h>
+#include <linux/atomic.h>
 
 #define USBHS_LPSTS			0x02
 #define USBHS_UGCTRL			0x80
diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c
index 98af3b1..aa5ab6c 100644
--- a/drivers/staging/speakup/selection.c
+++ b/drivers/staging/speakup/selection.c
@@ -7,7 +7,7 @@
 #include <linux/workqueue.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
-#include <asm/cmpxchg.h>
+#include <linux/atomic.h>
 
 #include "speakup.h"
 
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