nptl: Move elision implementations into libc

The elision interfaces are closely aligned between the targets that
implement them, so declare them in the generic <lowlevellock.h>
file.

Empty .c stubs are provided, so that fewer makefile updates
under sysdeps are needed.  Also simplify initialization via
__libc_early_init.

The symbols __lll_clocklock_elision, __lll_lock_elision,
__lll_trylock_elision, __lll_unlock_elision, __pthread_force_elision
move into libc.  For the time being, non-hidden references are used
from libpthread to access them, but once that part of libpthread
is moved into libc, hidden symbols will be used again.  (Hidden
references seem desirable to reduce the likelihood of transactions
aborts.)

12 files changed, 8 insertions, 236 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile
index cc2f804d86..a093cda68b 100644
--- a/sysdeps/unix/sysv/linux/powerpc/Makefile
+++ b/sysdeps/unix/sysv/linux/powerpc/Makefile
@@ -32,7 +32,5 @@ endif
 
 ifeq ($(subdir),nptl)
 libpthread-routines += sysdep
-libpthread-sysdep_routines += elision-lock elision-unlock elision-timed \
-			      elision-trylock
 libpthread-shared-only-routines += sysdep
 endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-conf.c b/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
index 003bc82343..1ecc2a7b8f 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
@@ -51,12 +51,6 @@ struct elision_config __elision_aconf =
     .skip_trylock_internal_abort = 3,
   };
 
-/* Force elision for all new locks.  This is used to decide whether existing
-   DEFAULT locks should be automatically use elision in pthread_mutex_lock().
-   Disabled for suid programs.  Only used when elision is available.  */
-
-int __pthread_force_elision attribute_hidden = 0;
-
 #if HAVE_TUNABLES
 static inline void
 __always_inline
@@ -104,10 +98,8 @@ TUNABLE_CALLBACK_FNDECL (skip_trylock_internal_abort, int32_t);
 
 /* Initialize elision.  */
 
-static void
-elision_init (int argc __attribute__ ((unused)),
-	      char **argv  __attribute__ ((unused)),
-	      char **environ)
+void
+__lll_elision_init (void)
 {
 #if HAVE_TUNABLES
   /* Elision depends on tunables and must be explicitly turned on by setting
@@ -150,17 +142,3 @@ elision_init (int argc __attribute__ ((unused)),
   if (!__pthread_force_elision)
     __elision_aconf.try_tbegin = 0; /* Disable elision on rwlocks.  */
 }
-
-#ifdef SHARED
-# define INIT_SECTION ".init_array"
-# define MAYBE_CONST
-#else
-# define INIT_SECTION ".preinit_array"
-# define MAYBE_CONST const
-#endif
-
-void (*MAYBE_CONST __pthread_init_array []) (int, char **, char **)
-  __attribute__ ((section (INIT_SECTION), aligned (sizeof (void *)))) =
-{
-  &elision_init
-};
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-conf.h b/sysdeps/unix/sysv/linux/powerpc/elision-conf.h
index 8c444d8695..86c677fb7a 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-conf.h
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-conf.h
@@ -22,6 +22,9 @@
 #include <pthread.h>
 #include <time.h>
 
+#define ENABLE_ELISION_SUPPORT 1
+#define ELISION_UNLOCK_NEEDS_ADAPT_COUNT 1
+
 /* Should make sure there is no false sharing on this.  */
 struct elision_config
 {
@@ -34,9 +37,4 @@ struct elision_config
 
 extern struct elision_config __elision_aconf attribute_hidden;
 
-extern int __pthread_force_elision attribute_hidden;
-
-/* Tell the test suite to test elision for this architecture.  */
-#define HAVE_ELISION 1
-
 #endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-lock.c b/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
index 767d439f88..f5fb46df25 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
@@ -23,12 +23,6 @@
 #include <elision-conf.h>
 #include "htm.h"
 
-#if !defined(LLL_LOCK) && !defined(EXTRAARG)
-/* Make sure the configuration code is always linked in for static
-   libraries.  */
-#include "elision-conf.c"
-#endif
-
 #ifndef EXTRAARG
 # define EXTRAARG
 #endif
@@ -84,3 +78,4 @@ __lll_lock_elision (int *lock, short *adapt_count, EXTRAARG int pshared)
 use_lock:
   return LLL_LOCK ((*lock), pshared);
 }
+libc_hidden_def (__lll_lock_elision)
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c b/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
index ab92f4d72f..5ebbced427 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
@@ -67,3 +67,4 @@ __lll_trylock_elision (int *futex, short *adapt_count)
 use_lock:
   return lll_trylock (*futex);
 }
+libc_hidden_def (__lll_trylock_elision)
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c b/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
index 35044af40b..5aa87521c5 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
@@ -41,3 +41,4 @@ __lll_unlock_elision (int *lock, short *adapt_count, int pshared)
     }
   return 0;
 }
+libc_hidden_def (__lll_unlock_elision)
diff --git a/sysdeps/unix/sysv/linux/powerpc/force-elision.h b/sysdeps/unix/sysv/linux/powerpc/force-elision.h
deleted file mode 100644
index d1fa611c52..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/force-elision.h
+++ /dev/null
@@ -1,62 +0,0 @@
-/* force-elision.h: Automatic enabling of elision for mutexes
-   Copyright (C) 2015-2021 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
-   <https://www.gnu.org/licenses/>.  */
-
-/* Automatically enable elision for existing user lock kinds.  */
-#define FORCE_ELISION(m, s)						\
-  if (__pthread_force_elision)						\
-    {									\
-      /* See concurrency notes regarding __kind in			\
-	 struct __pthread_mutex_s in					\
-	 sysdeps/nptl/bits/thread-shared-types.h.			\
-									\
-	 There are the following cases for the kind of a mutex		\
-	 (The mask PTHREAD_MUTEX_ELISION_FLAGS_NP covers the flags	\
-	 PTHREAD_MUTEX_ELISION_NP and PTHREAD_MUTEX_NO_ELISION_NP where	\
-	 only one of both flags can be set):				\
-	 - both flags are not set:					\
-	 This is the first lock operation for this mutex.  Enable	\
-	 elision as it is not enabled so far.				\
-	 Note: It can happen that multiple threads are calling e.g.	\
-	 pthread_mutex_lock at the same time as the first lock		\
-	 operation for this mutex.  Then elision is enabled for this	\
-	 mutex by multiple threads.  Storing with relaxed MO is enough	\
-	 as all threads will store the same new value for the kind of	\
-	 the mutex.  But we have to ensure that we always use the	\
-	 elision path regardless if this thread has enabled elision or	\
-	 another one.							\
-									\
-	 - PTHREAD_MUTEX_ELISION_NP flag is set:			\
-	 Elision was already enabled for this mutex by a previous lock	\
-	 operation.  See case above.  Just use the elision path.	\
-									\
-	 - PTHREAD_MUTEX_NO_ELISION_NP flag is set:			\
-	 Elision was explicitly disabled by pthread_mutexattr_settype.	\
-	 Do not use the elision path.					\
-	 Note: The flag PTHREAD_MUTEX_NO_ELISION_NP will never be	\
-	 changed after mutex initialization.  */			\
-      int mutex_kind = atomic_load_relaxed (&((m)->__data.__kind));	\
-      if ((mutex_kind & PTHREAD_MUTEX_ELISION_FLAGS_NP) == 0)		\
-	{								\
-	  mutex_kind |= PTHREAD_MUTEX_ELISION_NP;			\
-	  atomic_store_relaxed (&((m)->__data.__kind), mutex_kind);	\
-	}								\
-      if ((mutex_kind & PTHREAD_MUTEX_ELISION_NP) != 0)			\
-	{								\
-	  s;								\
-	}								\
-    }
diff --git a/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h b/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
deleted file mode 100644
index 65962020c6..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
+++ /dev/null
@@ -1,49 +0,0 @@
-/* PowerPC specific lock definitions.
-   Copyright (C) 2015-2021 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
-   <https://www.gnu.org/licenses/>.  */
-
-#ifndef _POWERPC_LOWLEVELLOCK_H
-#define _POWERPC_LOWLEVELLOCK_H 1
-
-#include <sysdeps/nptl/lowlevellock.h>
-
-/* Transactional lock elision definitions.  */
-extern int __lll_clocklock_elision
-  (int *futex, short *adapt_count,
-   clockid_t clockid, const struct __timespec64 *timeout, int private)
-  attribute_hidden;
-
-#define lll_clocklock_elision(futex, adapt_count, clockid, timeout, private) \
-  __lll_clocklock_elision (&(futex), &(adapt_count), clockid, timeout, private)
-
-extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
-  attribute_hidden;
-
-extern int __lll_unlock_elision (int *lock, short *adapt_count, int private)
-  attribute_hidden;
-
-extern int __lll_trylock_elision(int *lock, short *adapt_count)
-  attribute_hidden;
-
-#define lll_lock_elision(futex, adapt_count, private) \
-  __lll_lock_elision (&(futex), &(adapt_count), private)
-#define lll_unlock_elision(futex, adapt_count, private) \
-  __lll_unlock_elision (&(futex), &(adapt_count), private)
-#define lll_trylock_elision(futex, adapt_count) \
-  __lll_trylock_elision (&(futex), &(adapt_count))
-
-#endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_cond_lock.c b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_cond_lock.c
deleted file mode 100644
index f33bac7ca1..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_cond_lock.c
+++ /dev/null
@@ -1,22 +0,0 @@
-/* Copyright (C) 2015-2021 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
-   <https://www.gnu.org/licenses/>.  */
-
-/* The cond lock is not actually elided yet, but we still need to handle
-   already elided locks.  */
-#include <elision-conf.h>
-
-#include <nptl/pthread_mutex_cond_lock.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_lock.c b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_lock.c
deleted file mode 100644
index 110a6bf47b..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_lock.c
+++ /dev/null
@@ -1,22 +0,0 @@
-/* Elided version of pthread_mutex_lock.
-   Copyright (C) 2015-2021 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <elision-conf.h>
-#include <force-elision.h>
-
-#include <nptl/pthread_mutex_lock.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_timedlock.c b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_timedlock.c
deleted file mode 100644
index 6f8b06d459..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_timedlock.c
+++ /dev/null
@@ -1,22 +0,0 @@
-/* Elided version of pthread_mutex_timedlock.
-   Copyright (C) 2015-2021 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <elision-conf.h>
-#include <force-elision.h>
-
-#include <nptl/pthread_mutex_timedlock.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_trylock.c b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_trylock.c
deleted file mode 100644
index ee9fe1d186..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_trylock.c
+++ /dev/null
@@ -1,22 +0,0 @@
-/* Elided version of pthread_mutex_trylock.
-   Copyright (C) 2015-2021 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <elision-conf.h>
-#include <force-elision.h>
-
-#include <nptl/pthread_mutex_trylock.c>