[glibc/schwab/ilp32-2.32] aarch64: add bits/struct_mutex.h

[Andreas Schwab <schwab@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=f42a179f4d0f7abd151bd82b7ef0ee13429c5331

commit f42a179f4d0f7abd151bd82b7ef0ee13429c5331
Author: Andreas Schwab <schwab@suse.de>
Date:   Sun Mar 1 15:08:05 2020 +0100

    aarch64: add bits/struct_mutex.h

Diff:
---
 sysdeps/aarch64/nptl/bits/struct_mutex.h | 61 ++++++++++++++++++++++++++++++++
 sysdeps/aarch64/nptl/pthread-offsets.h   |  6 +---
 2 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/sysdeps/aarch64/nptl/bits/struct_mutex.h b/sysdeps/aarch64/nptl/bits/struct_mutex.h
new file mode 100644
index 0000000000..78d72f71a6
--- /dev/null
+++ b/sysdeps/aarch64/nptl/bits/struct_mutex.h
@@ -0,0 +1,61 @@
+/* AArch64 internal mutex struct definitions.
+   Copyright (C) 2019-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#ifndef _THREAD_MUTEX_INTERNAL_H
+#define _THREAD_MUTEX_INTERNAL_H 1
+
+struct __pthread_mutex_s
+{
+  int __lock __LOCK_ALIGNMENT;
+  unsigned int __count;
+  int __owner;
+  unsigned int __nusers;
+  /* KIND must stay at this position in the structure to maintain
+     binary compatibility with static initializers.
+
+     Concurrency notes:
+     The __kind of a mutex is initialized either by the static
+     PTHREAD_MUTEX_INITIALIZER or by a call to pthread_mutex_init.
+
+     After a mutex has been initialized, the __kind of a mutex is usually not
+     changed.  BUT it can be set to -1 in pthread_mutex_destroy or elision can
+     be enabled.  This is done concurrently in the pthread_mutex_*lock
+     functions by using the macro FORCE_ELISION. This macro is only defined
+     for architectures which supports lock elision.
+
+     For elision, there are the flags PTHREAD_MUTEX_ELISION_NP and
+     PTHREAD_MUTEX_NO_ELISION_NP which can be set in addition to the already
+     set type of a mutex.  Before a mutex is initialized, only
+     PTHREAD_MUTEX_NO_ELISION_NP can be set with pthread_mutexattr_settype.
+
+     After a mutex has been initialized, the functions pthread_mutex_*lock can
+     enable elision - if the mutex-type and the machine supports it - by
+     setting the flag PTHREAD_MUTEX_ELISION_NP. This is done concurrently.
+     Afterwards the lock / unlock functions are using specific elision
+     code-paths.  */
+  int __kind;
+  int __spins;
+  __pthread_list_t __list;
+};
+
+#define __PTHREAD_MUTEX_HAVE_PREV      1
+
+#define __PTHREAD_MUTEX_INITIALIZER(__kind) \
+  0, 0, 0, 0, __kind, 0, { 0, 0 }
+
+#endif
diff --git a/sysdeps/aarch64/nptl/pthread-offsets.h b/sysdeps/aarch64/nptl/pthread-offsets.h
index 280d5d5ad2..982b4ac869 100644
--- a/sysdeps/aarch64/nptl/pthread-offsets.h
+++ b/sysdeps/aarch64/nptl/pthread-offsets.h
@@ -1,8 +1,4 @@
-#ifdef __ILP32__
-# define __PTHREAD_MUTEX_KIND_OFFSET		12
-#else
-# define __PTHREAD_MUTEX_KIND_OFFSET		16
-#endif
+#define __PTHREAD_MUTEX_KIND_OFFSET		16
 
 #ifdef  __ILP32__
 # define __PTHREAD_RWLOCK_FLAGS_OFFSET		40