[PATCH 2/2] S390: Use generic spinlock code.

[Stefan Liebler <stli@linux.vnet.ibm.com>]

This patch removes the s390 specific implementation of spinlock code
and is now using the generic one.

For pthread_spin_trylock an explicit load and test before executing
compare and swap instruction is done as it is an interlock update even
if the lock is already acquired.

ChangeLog:

	* sysdeps/s390/nptl/pthread_spin_init.c: Delete File.
	* sysdeps/s390/nptl/pthread_spin_unlock.c: Likewise.
	* sysdeps/s390/nptl/pthread_spin_lock.c:
	(SPIN_LOCK_READS_BETWEEN_CMPXCHG): New define.
	Use generic spinlock code.
	* sysdeps/s390/nptl/pthread_spin_trylock.c:
	(SPIN_TRYLOCK_USE_CMPXCHG_INSTEAD_OF_XCHG): New define.
	Use generic spinlock code.
---
 sysdeps/s390/nptl/pthread_spin_init.c    | 19 -------------------
 sysdeps/s390/nptl/pthread_spin_lock.c    | 18 +++++-------------
 sysdeps/s390/nptl/pthread_spin_trylock.c | 18 +++++-------------
 sysdeps/s390/nptl/pthread_spin_unlock.c  | 32 --------------------------------
 4 files changed, 10 insertions(+), 77 deletions(-)
 delete mode 100644 sysdeps/s390/nptl/pthread_spin_init.c
 delete mode 100644 sysdeps/s390/nptl/pthread_spin_unlock.c

diff --git a/sysdeps/s390/nptl/pthread_spin_init.c b/sysdeps/s390/nptl/pthread_spin_init.c
deleted file mode 100644
index 7d3568f..0000000
--- a/sysdeps/s390/nptl/pthread_spin_init.c
+++ /dev/null
@@ -1,19 +0,0 @@
-/* Copyright (C) 2003-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-/* Not needed.  pthread_spin_init is an alias for pthread_spin_unlock.  */
diff --git a/sysdeps/s390/nptl/pthread_spin_lock.c b/sysdeps/s390/nptl/pthread_spin_lock.c
index def6a24..d99cd81 100644
--- a/sysdeps/s390/nptl/pthread_spin_lock.c
+++ b/sysdeps/s390/nptl/pthread_spin_lock.c
@@ -16,17 +16,9 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include "pthreadP.h"
+#define SPIN_LOCK_READS_BETWEEN_CMPXCHG 1000
 
-int
-pthread_spin_lock (pthread_spinlock_t *lock)
-{
-  int oldval;
-
-  __asm__ __volatile__ ("0: lhi %0,0\n"
-			"   cs  %0,%2,%1\n"
-			"   jl  0b"
-			: "=&d" (oldval), "=Q" (*lock)
-			: "d" (1), "m" (*lock) : "cc" );
-  return 0;
-}
+/* We can't use the normal "#include <nptl/pthread_spin_lock.c>" because
+   it will resolve to this very file.  Using "sysdeps/.." as reference to the
+   top level directory does the job.  */
+#include <sysdeps/../nptl/pthread_spin_lock.c>
diff --git a/sysdeps/s390/nptl/pthread_spin_trylock.c b/sysdeps/s390/nptl/pthread_spin_trylock.c
index 4c00e08..d7a2089 100644
--- a/sysdeps/s390/nptl/pthread_spin_trylock.c
+++ b/sysdeps/s390/nptl/pthread_spin_trylock.c
@@ -16,17 +16,9 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include "pthreadP.h"
+#define SPIN_TRYLOCK_USE_CMPXCHG_INSTEAD_OF_XCHG 1
 
-int
-pthread_spin_trylock (pthread_spinlock_t *lock)
-{
-  int old;
-
-  __asm__ __volatile__ ("cs %0,%3,%1"
-			: "=d" (old), "=Q" (*lock)
-			: "0" (0), "d" (1), "m" (*lock) : "cc" );
-
-  return old != 0 ? EBUSY : 0;
-}
+/* We can't use the normal "#include <nptl/pthread_spin_trylock.c>" because
+   it will resolve to this very file.  Using "sysdeps/.." as reference to the
+   top level directory does the job.  */
+#include <sysdeps/../nptl/pthread_spin_trylock.c>
diff --git a/sysdeps/s390/nptl/pthread_spin_unlock.c b/sysdeps/s390/nptl/pthread_spin_unlock.c
deleted file mode 100644
index 0dcc2d0..0000000
--- a/sysdeps/s390/nptl/pthread_spin_unlock.c
+++ /dev/null
@@ -1,32 +0,0 @@
-/* Copyright (C) 2003-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-/* Ugly hack to avoid the declaration of pthread_spin_init.  */
-#define pthread_spin_init pthread_spin_init_XXX
-#include "pthreadP.h"
-#undef pthread_spin_init
-
-int
-pthread_spin_unlock (pthread_spinlock_t *lock)
-{
-  __asm__ __volatile__ ("   xc  %O0(4,%R0),%0\n"
-			"   bcr 15,0"
-			: "=Q" (*lock) : "m" (*lock) : "cc" );
-  return 0;
-}
-strong_alias (pthread_spin_unlock, pthread_spin_init)
-- 
2.3.0