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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2018-03-05 14:46:24 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2018-03-07 17:39:44 -0300
commite921c89e01389161c036ec09112da6e18aeaa688 (patch)
tree99d6527bc95f91501d92565021031e03c820da1a /sysdeps/unix/sysv/linux/powerpc
parent3dc214977beccc95f0df3b90fa4ca2557fe1bdd2 (diff)
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powerpc: Fix TLE build for SPE (BZ #22926)
Some SPE opcodes clashes with some recent PowerISA opcodes and
until recently gas did not complain about it.  However binutils
recently changed it and now VLE configured gas does not support to
assembler some instruction that might class with VLE (HTM for
instance).  It also does not help that glibc build hardware lock
elision support as default (regardless of assembler support).

Although runtime will not actually enables TLE on SPE hardware
(since kernel will not advertise it), I see little advantage on
adding HTM support on SPE built glibc.  SPE uses an incompatible
ABI which does not allow share the same build with default
powerpc and HTM code slows down SPE without any benefict.

This patch fixes it by only building HTM when SPE configuration
is not used.

Checked with a powerpc-linux-gnuspe build. I also did some sniff
tests on a e500 hardware without any issue.

	[BZ #22926]
	* sysdeps/powerpc/powerpc32/sysdep.h (ABORT_TRANSACTION_IMPL): Define
	empty for __SPE__.
	* sysdeps/powerpc/sysdep.h (ABORT_TRANSACTION): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/elision-lock.c (__lll_lock_elision):
	Do not build hardware transactional code for __SPE__.
	* sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
	(__lll_trylock_elision): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
	(__lll_unlock_elision): Likewise.
Diffstat (limited to 'sysdeps/unix/sysv/linux/powerpc')
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/elision-lock.c2
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/elision-trylock.c2
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/elision-unlock.c4
3 files changed, 8 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-lock.c b/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
index b7093feab9..98a23f0dd2 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-lock.c
@@ -45,6 +45,7 @@
 int
 __lll_lock_elision (int *lock, short *adapt_count, EXTRAARG int pshared)
 {
+#ifndef __SPE__
   /* adapt_count is accessed concurrently but is just a hint.  Thus,
      use atomic accesses but relaxed MO is sufficient.  */
   if (atomic_load_relaxed (adapt_count) > 0)
@@ -82,5 +83,6 @@ __lll_lock_elision (int *lock, short *adapt_count, EXTRAARG int pshared)
 			  aconf.skip_lock_out_of_tbegin_retries);
 
 use_lock:
+#endif
   return LLL_LOCK ((*lock), pshared);
 }
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c b/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
index b74a810648..fabb03b2c4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-trylock.c
@@ -30,6 +30,7 @@
 int
 __lll_trylock_elision (int *futex, short *adapt_count)
 {
+#ifndef __SPE__
   /* Implement POSIX semantics by forbiding nesting elided trylocks.  */
   __libc_tabort (_ABORT_NESTED_TRYLOCK);
 
@@ -65,5 +66,6 @@ __lll_trylock_elision (int *futex, short *adapt_count)
     }
 
 use_lock:
+#endif
   return lll_trylock (*futex);
 }
diff --git a/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c b/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
index dcfab199d7..14e0680ee9 100644
--- a/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
+++ b/sysdeps/unix/sysv/linux/powerpc/elision-unlock.c
@@ -23,6 +23,7 @@
 int
 __lll_unlock_elision (int *lock, short *adapt_count, int pshared)
 {
+#ifndef __SPE__
   /* When the lock was free we're in a transaction.  */
   if (*lock == 0)
     __libc_tend (0);
@@ -39,5 +40,8 @@ __lll_unlock_elision (int *lock, short *adapt_count, int pshared)
 
       lll_unlock ((*lock), pshared);
     }
+#else
+  lll_unlock ((*lock), pshared);
+#endif
   return 0;
 }