[v2,3/3] PowerPC: abort transaction in syscalls
diff mbox

Message ID 5491C9B4.3080302@linux.vnet.ibm.com
State New
Headers show

Commit Message

Adhemerval Zanella Dec. 17, 2014, 6:21 p.m. UTC
Linux kernel powerpc documentation states issuing a syscall inside a
transaction is not recommended and may lead to undefined behavior. It
also states syscalls does not abort transactoin neither they run in
transactional state.

To avoid side-effects being visible outside transactions, GLIBC with
lock elision enable will issue a transaction abort instruction just
before all syscalls if hardware supports hardware transactions

Tested on powerpc64 and powercp32.

Changed from previous version:
- Cosmetics fixes from Will Schmidt


--

	* sysdeps/powerpc/nptl/tls.h (tcbhead_t): Add tm_capable field.
	(TLS_INIT_TP): Add tm_capable initialization.
	(TLS_DEFINE_INIT_TP): Likewise.
	(THREAD_GET_TM_CAPABLE): New file: get tm_capable field value from
	TCB.
	(THREAD_SET_TM_CAPABLE): New file: set tm_capable field value in TCB.
	* sysdeps/powerpc/nptl/tcb-offsets.sym (TM_CAPABLE): Add field offset
	calculation.
	* sysdeps/powerpc/powerpc32/sysdep.h (DO_CALL): Abort hardware
	transactoion is lock elision is built and TCB tm_capable is set.
	* sysdeps/powerpc/powerpc64/sysdep.h (DO_CALL): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
	(INTERNAL_SYSCALL_NCS): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
	(INTERNAL_SYSCALL_NCS): Likewise.
	* sysdeps/powerpc/sysdep.h (ABORT_TRANSACTION): New define.

--

Patch
diff mbox

diff --git a/ChangeLog b/ChangeLog
index 4be48d0..7529299 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,32 @@ 
+2014-12-16  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
+
+	* sysdeps/unix/sysv/linux/powerpc/Makefile [nptl]
+	(sysdep_routines): Add lock elision objects.
+	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
+	[pthread_mutex_t] (__spins): Rework to add lock elision field.
+	[pthread_mutex_t] (__elision): Add field.
+	[__PTHREAD_SPINS]: Adjust to init lock elision field.
+	* sysdeps/unix/sysv/linux/powerpc/elision-conf.c: New file: lock
+	elision definitions for powerpc.
+	* sysdeps/unix/sysv/linux/powerpc/elision-lock.c: New file:
+	implementation of lock elision for powerpc.
+	* sysdeps/unix/sysv/linux/powerpc/elision-timed.c: New file:
+	implementation of timed lock elision for powerpc.
+	* sysdeps/unix/sysv/linux/powerpc/elision-trylock.c: New file:
+	implementation of trylock with lock elision for powerpc.
+	* sysdeps/unix/sysv/linux/powerpc/elision-unlock.c: New file:
+	implementaion of unlock for lock elision for powerpc.
+	* sysdeps/unix/sysv/linux/powerpc/force-elision.h: New file:
+	automatic enable lock elision for mutexes.
+	* sysdeps/unix/sysv/linux/powerpc/htm.h: New file: hardware
+	transaction execution definitions for powerpc.
+	* sysdeps/unix/sysv/linux/powerpc/lowlevellock.h: New file: add TLE
+	definitions.
+	* sysdeps/unix/sysv/linux/powerpc/pthread_mutex_cond_lock.c: New file.
+	* sysdeps/unix/sysv/linux/powerpc/pthread_mutex_lock.c: Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/pthread_mutex_timedlock.c: Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/pthread_mutex_trylock.c: Likewise.
+
 2014-12-16  Roland McGrath  <roland@hack.frob.com>
 
 	* sysdeps/gnu/unwind-resume.c: #include <sysdep.h>.
diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile
index e660736..dd5d3bc 100644
--- a/sysdeps/unix/sysv/linux/powerpc/Makefile
+++ b/sysdeps/unix/sysv/linux/powerpc/Makefile
@@ -32,4 +32,6 @@  endif
 
 ifeq ($(subdir),nptl)
 libpthread-routines += sysdep
+libpthread-sysdep_routines += elision-lock elision-unlock elision-timed \
+			      elision-trylock
 endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h b/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
index 4e9c518..396a3d9 100644
--- a/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
@@ -90,14 +90,23 @@  typedef union
        binary compatibility.  */
     int __kind;
 #if __WORDSIZE == 64
-    int __spins;
+    short __spins;
+    short __elision;
     __pthread_list_t __list;
 # define __PTHREAD_MUTEX_HAVE_PREV	1
+# define __PTHREAD_SPINS             0, 0
 #else
     unsigned int __nusers;
     __extension__ union
     {
-      int __spins;
+      struct
+      {
+	short __espins;
+	short __elision;
+# define __spins __elision_data.__espins
+# define __elision __elision_data.__elision
+# define __PTHREAD_SPINS         { 0, 0 }
+      } __elision_data;
       __pthread_slist_t __list;
     };
 #endif
@@ -106,9 +115,6 @@  typedef union
   long int __align;
 } pthread_mutex_t;
 
-/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER.  */
-#define __PTHREAD_SPINS 0
-
 typedef union
 {
   char __size[__SIZEOF_PTHREAD_MUTEXATTR_T];
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-conf.c b/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
new file mode 100644
index 0000000..1d962e1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-conf.c
@@ -0,0 +1,80 @@ 
+/* elision-conf.c: Lock elision tunable parameters.
+   Copyright (C) 2014 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/>.  */
+
+#include "config.h"
+#include <pthreadP.h>
+#include <elision-conf.h>
+#include <unistd.h>
+#include <dl-procinfo.h>
+
+/* Reasonable initial tuning values, may be revised in the future.
+   This is a conservative initial value.  */
+
+struct elision_config __elision_aconf =
+  {
+    /* How many times to use a non-transactional lock after a transactional
+       failure has occurred because the lock is already acquired.  Expressed
+       in number of lock acquisition attempts.  */
+    .skip_lock_busy = 3,
+    /* How often to not attempt to use elision if a transaction aborted due
+       to reasons other than other threads' memory accesses.  Expressed in
+       number of lock acquisition attempts.  */
+    .skip_lock_internal_abort = 3,
+    /* How often to not attempt to use elision if a lock used up all retries
+       without success.  Expressed in number of lock acquisition attempts.  */
+    .skip_lock_out_of_tbegin_retries = 3,
+    /* How often we retry using elision if there is chance for the transaction
+       to finish execution (e.g., it wasn't aborted due to the lock being
+       already acquired.  */
+    .try_tbegin = 3,
+    /* Same as SKIP_LOCK_INTERNAL_ABORT but for trylock.  */
+    .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;
+
+/* Initialize elision.  */
+
+static void
+elision_init (int argc __attribute__ ((unused)),
+	      char **argv  __attribute__ ((unused)),
+	      char **environ)
+{
+#ifdef ENABLE_LOCK_ELISION
+  int elision_available = (GLRO (dl_hwcap2) & PPC_FEATURE2_HAS_HTM) ? 1 : 0;
+  __pthread_force_elision = __libc_enable_secure ? 0 : elision_available;
+#endif
+}
+
+#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
new file mode 100644
index 0000000..fc9994d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-conf.h
@@ -0,0 +1,42 @@ 
+/* elision-conf.h: Lock elision tunable parameters.
+   Copyright (C) 2014 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 _ELISION_CONF_H
+#define _ELISION_CONF_H 1
+
+#include <pthread.h>
+#include <time.h>
+
+/* Should make sure there is no false sharing on this.  */
+struct elision_config
+{
+  int skip_lock_busy;
+  int skip_lock_internal_abort;
+  int skip_lock_out_of_tbegin_retries;
+  int try_tbegin;
+  int skip_trylock_internal_abort;
+} __attribute__ ((__aligned__ (128)));
+
+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
new file mode 100644
index 0000000..712ac47
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
@@ -0,0 +1,107 @@ 
+/* elision-lock.c: Elided pthread mutex lock.
+   Copyright (C) 2014 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/>.  */
+
+#include <stdio.h>
+#include <pthread.h>
+#include <pthreadP.h>
+#include <lowlevellock.h>
+#include <elision-conf.h>
+#include "htm.h"
+
+/* PowerISA 2.0.7 Section B.5.5 defines isync to be insufficient to memory
+   barrier in acquire mechanism for HTM operations, a strong 'sync' is
+   required.  */
+#undef __arch_compare_and_exchange_val_32_acq
+#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval)           \
+  ({                                                                          \
+      __typeof (*(mem)) __tmp;                                                \
+      __typeof (mem)  __memp = (mem);                                         \
+      __asm __volatile (                                                      \
+                        "1:     lwarx   %0,0,%1" MUTEX_HINT_ACQ "\n"          \
+                        "       cmpw    %0,%2\n"                              \
+                        "       bne     2f\n"                                 \
+                        "       stwcx.  %3,0,%1\n"                            \
+                        "       bne-    1b\n"                                 \
+                        "2:     sync"                                         \
+                        : "=&r" (__tmp)                                       \
+                        : "b" (__memp), "r" (oldval), "r" (newval)            \
+                        : "cr0", "memory");                                   \
+      __tmp;                                                                  \
+  })
+
+#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
+#ifndef LLL_LOCK
+# define LLL_LOCK(a,b) lll_lock(a,b), 0
+#endif
+
+#define aconf __elision_aconf
+
+/* Adaptive lock using transactions.
+   By default the lock region is run as a transaction, and when it
+   aborts or the lock is busy the lock adapts itself.  */
+
+int
+__lll_lock_elision (int *lock, short *adapt_count, EXTRAARG int pshared)
+{
+  if (*adapt_count > 0)
+    {
+      (*adapt_count)--;
+      goto use_lock;
+    }
+
+  int try_begin = aconf.try_tbegin;
+  while (1)
+    {
+      if (__builtin_tbegin (0))
+	{
+	  if (*lock == 0)
+	    return 0;
+	  /* Lock was busy.  Fall back to normal locking.  */
+	  __builtin_tabort (_ABORT_LOCK_BUSY);
+	}
+      else
+	{
+	  /* A persistent failure indicates that a retry will probably
+	     result in another failure.  Use normal locking now and
+	     for the next couple of calls.  */
+	  if (try_begin-- <= 0
+	      || _TEXASRU_FAILURE_PERSISTENT (__builtin_get_texasru ()))
+	    {
+	      if (aconf.skip_lock_internal_abort > 0)
+		*adapt_count = aconf.skip_lock_internal_abort;
+	      goto use_lock;
+	    }
+	  /* Same logic as above, but for for a number of temporary failures
+	     in a row.  */
+	  else if (aconf.skip_lock_out_of_tbegin_retries > 0
+                   && aconf.try_tbegin > 0)
+	    *adapt_count = aconf.skip_lock_out_of_tbegin_retries;
+	}
+     }
+
+use_lock:
+  return LLL_LOCK ((*lock), pshared);
+}
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-timed.c b/sysdeps/unix/sysv/linux/powerpc/elision-timed.c
new file mode 100644
index 0000000..7d5de9b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-timed.c
@@ -0,0 +1,28 @@ 
+/* elision-timed.c: Lock elision timed lock.
+   Copyright (C) 2014 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/>.  */
+
+#include <time.h>
+#include <elision-conf.h>
+#include "lowlevellock.h"
+
+#define __lll_lock_elision __lll_timedlock_elision
+#define EXTRAARG const struct timespec *t,
+#undef LLL_LOCK
+#define LLL_LOCK(a, b) lll_timedlock(a, t, b)
+
+#include "elision-lock.c"
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c b/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
new file mode 100644
index 0000000..4a310d5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
@@ -0,0 +1,68 @@ 
+/* elision-trylock.c: Lock eliding trylock for pthreads.
+   Copyright (C) 2014 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/>.  */
+
+#include <pthread.h>
+#include <pthreadP.h>
+#include <lowlevellock.h>
+#include <elision-conf.h>
+#include "htm.h"
+
+#define aconf __elision_aconf
+
+/* Try to elide a futex trylock.  FUTEX is the futex variable.  ADAPT_COUNT is
+   the adaptation counter in the mutex.  */
+
+int
+__lll_trylock_elision (int *futex, short *adapt_count)
+{
+  /* Implement POSIX semantics by forbiding nesting elided trylocks.  */
+  __builtin_tabort (_ABORT_NESTED_TRYLOCK);
+
+  /* Only try a transaction if it's worth it.  */
+  if (*adapt_count > 0)
+    {
+      (*adapt_count)--;
+      goto use_lock;
+    }
+
+  if (__builtin_tbegin (0))
+    {
+      if (*futex == 0)
+	return 0;
+
+      /* Lock was busy.  Fall back to normal locking.  */
+      __builtin_tabort (_ABORT_LOCK_BUSY);
+    }
+  else
+    {
+      if (_TEXASRU_FAILURE_PERSISTENT (__builtin_get_texasru ()))
+	{
+	  /* A persistent failure indicates that a retry will probably
+	     result in another failure.  Use normal locking now and
+	     for the next couple of calls.  */
+	  if (aconf.skip_trylock_internal_abort > 0)
+	    *adapt_count = aconf.skip_trylock_internal_abort;
+	}
+
+	if (aconf.skip_lock_busy > 0)
+	  *adapt_count = aconf.skip_lock_busy;
+    }
+
+use_lock:
+  return lll_trylock (*futex);
+}
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c b/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
new file mode 100644
index 0000000..59d46bb
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
@@ -0,0 +1,32 @@ 
+/* elision-unlock.c: Commit an elided pthread lock.
+   Copyright (C) 2014 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/>.  */
+
+#include "pthreadP.h"
+#include "lowlevellock.h"
+#include "htm.h"
+
+int
+__lll_unlock_elision(int *lock, int pshared)
+{
+  /* When the lock was free we're in a transaction.  */
+  if (*lock == 0)
+    __builtin_tend (0);
+  else
+    lll_unlock ((*lock), pshared);
+  return 0;
+}
diff --git a/sysdeps/unix/sysv/linux/powerpc/force-elision.h b/sysdeps/unix/sysv/linux/powerpc/force-elision.h
new file mode 100644
index 0000000..3da576b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/force-elision.h
@@ -0,0 +1,28 @@ 
+/* force-elision.h: Automatic enabling of elision for mutexes
+   Copyright (C) 2014 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/>.  */
+
+#ifdef ENABLE_LOCK_ELISION
+/* Automatically enable elision for existing user lock kinds.  */
+#define FORCE_ELISION(m, s)						\
+  if (__pthread_force_elision						\
+      && (m->__data.__kind & PTHREAD_MUTEX_ELISION_FLAGS_NP) == 0)	\
+    {									\
+      mutex->__data.__kind |= PTHREAD_MUTEX_ELISION_NP;			\
+      s;								\
+    }
+#endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/htm.h b/sysdeps/unix/sysv/linux/powerpc/htm.h
new file mode 100644
index 0000000..4e8fb6b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/htm.h
@@ -0,0 +1,138 @@ 
+/* Shared HTM header.  Emulate transactional execution facility intrinsics for
+   compilers and assemblers that do not support the intrinsics and instructions
+   yet.
+
+   Copyright (C) 2014 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 _HTM_H
+#define _HTM_H 1
+
+#ifdef __ASSEMBLER__
+
+/* tbegin.  */
+.macro TBEGIN
+	.long 0x7c00051d
+.endm
+
+/* tend. 0  */
+.macro TEND
+	.long 0x7c00055d
+.endm
+
+/* tabort. code  */
+.macro TABORT code
+	.byte 0x7c
+	.byte \code
+	.byte 0x07
+	.byte 0x1d
+.endm
+
+/*"TEXASR - Transaction EXception And Summary Register"
+   mfspr %dst,130  */
+.macro TEXASR dst
+	mfspr \dst,130
+.endm
+
+#else
+
+#include <endian.h>
+
+/* Official HTM intrinsics interface matching GCC, but works
+   on older GCC compatible compilers and binutils.
+   We should somehow detect if the compiler supports it, because
+   it may be able to generate slightly better code.  */
+
+#define TBEGIN ".long 0x7c00051d"
+#define TEND   ".long 0x7c00055d"
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+# define TABORT ".byte 0x1d,0x07,%1,0x1d"
+#else
+# define TABORT ".byte 0x7c,%1,0x07,0x1d"
+#endif
+
+#define __force_inline        inline __attribute__((__always_inline__))
+
+#ifndef __HTM__
+
+#define _TEXASRU_EXTRACT_BITS(TEXASR,BITNUM,SIZE) \
+  (((TEXASR) >> (31-(BITNUM))) & ((1<<(SIZE))-1))
+#define _TEXASRU_FAILURE_PERSISTENT(TEXASRU) \
+  _TEXASRU_EXTRACT_BITS(TEXASRU, 7, 1)
+
+#define _tbegin()			\
+  ({ unsigned int __ret;		\
+     asm volatile (			\
+       TBEGIN "\t\n"			\
+       "mfcr   %0\t\n"			\
+       "rlwinm %0,%0,3,1\t\n"		\
+       "xori %0,%0,1\t\n"		\
+       : "=r" (__ret) :			\
+       : "cr0", "memory");		\
+     __ret;				\
+  })
+
+#define _tend()				\
+  ({ unsigned int __ret;		\
+     asm volatile (			\
+       TEND "\t\n"			\
+       "mfcr   %0\t\n"			\
+       "rlwinm %0,%0,3,1\t\n"		\
+       "xori %0,%0,1\t\n"		\
+       : "=r" (__ret) :			\
+       : "cr0", "memory");		\
+     __ret;				\
+  })
+
+#define _tabort(__code)			\
+  ({ unsigned int __ret;		\
+     asm volatile (			\
+       TABORT "\t\n"			\
+       "mfcr   %0\t\n"			\
+       "rlwinm %0,%0,3,1\t\n"		\
+       "xori %0,%0,1\t\n"		\
+       : "=r" (__ret) : "r" (__code)	\
+       : "cr0", "memory");		\
+     __ret;				\
+  })
+
+#define _texasru()			\
+  ({ unsigned long __ret;		\
+     asm volatile (			\
+       "mfspr %0,131\t\n"		\
+       : "=r" (__ret));			\
+     __ret;				\
+  })
+
+#define __builtin_tbegin(tdb)       _tbegin ()
+#define __builtin_tend(nested)      _tend ()
+#define __builtin_tabort(abortcode) _tabort (abortcode)
+#define __builtin_get_texasru()     _texasru ()
+
+#else
+# include <htmintrin.h>
+#endif /* __HTM__  */
+
+#endif /* __ASSEMBLER__ */
+
+/* Definitions used for TEXASR Failure code (bits 0:6), they need to be even
+   because tabort. always sets the first bit.  */
+#define _ABORT_LOCK_BUSY       0x3f   /* Lock already used.  */
+#define _ABORT_NESTED_TRYLOCK  0x3e   /* Write operation in trylock.  */
+#define _ABORT_SYSCALL         0x3d   /* Syscall issued.  */
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h b/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
new file mode 100644
index 0000000..36c8ade
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
@@ -0,0 +1,48 @@ 
+/* PowerPC specific lock definitions.
+   Copyright (C) 2014 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 _POWERPC_LOWLEVELLOCK_H
+#define _POWERPC_LOWLEVELLOCK_H 1
+
+#include <sysdeps/nptl/lowlevellock.h>
+
+/* Transactional lock elision definitions.  */
+extern int __lll_timedlock_elision
+  (int *futex, short *adapt_count, const struct timespec *timeout, int private)
+  attribute_hidden;
+
+#define lll_timedlock_elision(futex, adapt_count, timeout, private)	      \
+  __lll_timedlock_elision(&(futex), &(adapt_count), timeout, private)
+
+extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
+  attribute_hidden;
+
+extern int __lll_unlock_elision(int *lock, 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, private) \
+  __lll_unlock_elision (&(futex), 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
new file mode 100644
index 0000000..aa6cf9a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_cond_lock.c
@@ -0,0 +1,22 @@ 
+/* Copyright (C) 2014 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/>.  */
+
+/* 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
new file mode 100644
index 0000000..6fd6a98
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_lock.c
@@ -0,0 +1,22 @@ 
+/* Elided version of pthread_mutex_lock.
+   Copyright (C) 2014 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/>.  */
+
+#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
new file mode 100644
index 0000000..d0e6537
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_timedlock.c
@@ -0,0 +1,22 @@ 
+/* Elided version of pthread_mutex_timedlock.
+   Copyright (C) 2014 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/>.  */
+
+#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
new file mode 100644
index 0000000..ea8a8ff
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/pthread_mutex_trylock.c
@@ -0,0 +1,22 @@ 
+/* Elided version of pthread_mutex_trylock.
+   Copyright (C) 2014 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/>.  */
+
+#include <elision-conf.h>
+#include <force-elision.h>
+
+#include <nptl/pthread_mutex_trylock.c>