powerpc: Add hwcap/hwcap2/platform data to TCB.

This patch adds a new feature for powerpc.  In order to get faster access to
the HWCAP/HWCAP2 bits and platform number (i.e. for implementing
__builtin_cpu_is () / __builtin_cpu_supports () in GCC) without the overhead of
reading from the auxiliary vector, we now reserve space for them in the TCB.
This is an ABI change for GLIBC 2.23.

A new versioned symbol '__parse_hwcap_and_convert_at_platform' is available to
get the data from the auxiliary vector and parse it, and store it for later use
in the TLS initialization code.  This function is called very early
(in _dl_sysdep_start () via DL_PLATFORM_INFO for the dynamic linking case, and
in __libc_start_main () for the static linking case) to make sure the data is
available at the time of TLS initialization.

	* sysdeps/powerpc/Makefile (sysdep-dl-routines): Add hwcapinfo.
	(sysdep_routines): Likewise.
	(sysdep-rtld-routines): Likewise.
	[$(subdir) = nptl](tests): Add test-get_hwcap and test-get_hwcap-static
	[$(subdir) = nptl](tests-static): test-get_hwcap-static
	* sysdeps/powerpc/Versions: Added new
	__parse_hwcap_and_convert_at_platform symbol to GLIBC-2.23.
	* sysdeps/powerpc/hwcapinfo.c: New file.
	(__tcb_parse_hwcap_and_convert_at_platform): New function to initialize
	and parse hwcap, hwcap2 and platform number information.
	* sysdeps/powerpc/hwcapinfo.h: New file.  Creates global variables
	to store HWCAP+HWCAP2 and platform number.
	* sysdeps/powerpc/nptl/tcb-offsets.sym: Added new offsets
	for HWCAP+HWCAP2 and platform number in the TCB.
	* sysdeps/powerpc/nptl/tls.h: New functionality.  Stores
	the HWCAP, HWCAP2 and platform number in the TCB.
	(dtv): Added new fields for HWCAP+HWCAP2 and platform number.
	(TLS_INIT_TP): Included calls to add the hwcap and
	at_platform values in the TCB in TP initialization.
	(TLS_DEFINE_INIT_TP): Likewise.
	(THREAD_GET_HWCAP): New macro.
	(THREAD_SET_HWCAP): Likewise.
	(THREAD_GET_AT_PLATFORM): Likewise.
	(THREAD_SET_AT_PLATFORM): Likewise.
	* sysdeps/powerpc/powerpc32/dl-machine.h:
	(dl_platform_init): New function that calls
	__parse_hwcap_and_convert_at_platform for the dymanic linking case for
	powerpc32.
	* sysdeps/powerpc/powerpc64/dl-machine.h: Likewise, for powerpc64.
	* sysdeps/powerpc/test-get_hwcap-static.c: New file.  Testcase for
	this functionality, static linking case.
	* sysdeps/powerpc/test-get_hwcap.c: New file.  Likewise, dynamic
	linking case.
	* sysdeps/unix/sysv/linux/powerpc/libc-start.c: Added call to
	__parse_hwcap_and_convert_at_platform for the static linking case.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist:
	Included the new __parse_hwcap_and_convert_at_platform symbol in the
	ABI list for GLIBC 2.23.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist:
	Likewise.

1 files changed, 188 insertions, 0 deletions

diff --git a/sysdeps/powerpc/test-get_hwcap.c b/sysdeps/powerpc/test-get_hwcap.c
new file mode 100644
index 0000000000..11aa8409e2
--- /dev/null
+++ b/sysdeps/powerpc/test-get_hwcap.c
@@ -0,0 +1,188 @@
+/* Check __ppc_get_hwcap() and __ppc_get_at_plaftorm() functionality.
+   Copyright (C) 2015 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/>.  */
+
+/* Tests if the hwcap, hwcap2 and platform data are stored in the TCB.  */
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <pthread.h>
+
+#include <sys/auxv.h>
+
+#include <dl-procinfo.h>
+
+#ifndef STATIC_TST_HWCAP
+#undef PROCINFO_DECL
+#include <dl-procinfo.c>
+#endif
+
+/* Offsets copied from tcb-offsets.h.  */
+
+#ifdef __powerpc64__
+# define __TPREG     "r13"
+# define __HWCAPOFF -28776
+# define __ATPLATOFF -28764
+#else
+# define __TPREG     "r2"
+# define __HWCAPOFF -28736
+# define __HWCAP2OFF -28732
+# define __ATPLATOFF -28724
+#endif
+
+uint64_t check_tcbhwcap (long tid)
+{
+
+  uint32_t tcb_at_platform, at_platform;
+  uint64_t hwcap, hwcap2, tcb_hwcap;
+  const char *at_platform_string;
+
+  /* Testing if the hwcap/hwcap2 data is correctly initialized by
+     TLS_TP_INIT.  */
+
+  register unsigned long __tp __asm__ (__TPREG);
+
+#ifdef __powerpc64__
+  __asm__  ("ld %0,%1(%2)\n"
+	    : "=r" (tcb_hwcap)
+	    : "i" (__HWCAPOFF), "b" (__tp));
+#else
+  uint64_t h1, h2;
+
+  __asm__ ("lwz %0,%1(%2)\n"
+      : "=r" (h1)
+      : "i" (__HWCAPOFF), "b" (__tp));
+  __asm__ ("lwz %0,%1(%2)\n"
+      : "=r" (h2)
+      : "i" (__HWCAP2OFF), "b" (__tp));
+  tcb_hwcap = (h1 >> 32) << 32 | (h2 >> 32);
+#endif
+
+  hwcap = getauxval (AT_HWCAP);
+  hwcap2 = getauxval (AT_HWCAP2);
+
+  /* hwcap contains only the latest supported ISA, the code checks which is
+     and fills the previous supported ones.  This is necessary because the
+     same is done in hwcapinfo.c when setting the values that are copied to
+     the TCB.  */
+
+  if (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+    hwcap |= PPC_FEATURE_ARCH_2_06
+	  | PPC_FEATURE_ARCH_2_05
+	  | PPC_FEATURE_POWER5_PLUS
+	  | PPC_FEATURE_POWER5
+	  | PPC_FEATURE_POWER4;
+  else if (hwcap & PPC_FEATURE_ARCH_2_06)
+    hwcap |= PPC_FEATURE_ARCH_2_05
+	  | PPC_FEATURE_POWER5_PLUS
+	  | PPC_FEATURE_POWER5
+	  | PPC_FEATURE_POWER4;
+  else if (hwcap & PPC_FEATURE_ARCH_2_05)
+    hwcap |= PPC_FEATURE_POWER5_PLUS
+	  | PPC_FEATURE_POWER5
+	  | PPC_FEATURE_POWER4;
+  else if (hwcap & PPC_FEATURE_POWER5_PLUS)
+    hwcap |= PPC_FEATURE_POWER5
+	  | PPC_FEATURE_POWER4;
+  else if (hwcap & PPC_FEATURE_POWER5)
+    hwcap |= PPC_FEATURE_POWER4;
+
+  hwcap = (hwcap << 32) + hwcap2;
+
+  if ( tcb_hwcap != hwcap )
+    {
+      printf ("FAIL: __ppc_get_hwcap() - HWCAP is %" PRIx64 ". Should be %"
+	      PRIx64 " for thread %ld.\n", tcb_hwcap, hwcap, tid);
+      return 1;
+    }
+
+  /* Same test for the platform number.  */
+  __asm__  ("lwz %0,%1(%2)\n"
+	    : "=r" (tcb_at_platform)
+	    : "i" (__ATPLATOFF), "b" (__tp));
+
+  at_platform_string = (const char *) getauxval (AT_PLATFORM);
+  at_platform = _dl_string_platform (at_platform_string);
+
+  if ( tcb_at_platform != at_platform )
+    {
+      printf ("FAIL: __ppc_get_at_platform() - AT_PLATFORM is %x. Should be %x"
+	     " for thread %ld\n", tcb_at_platform, at_platform, tid);
+      return 1;
+    }
+
+  return 0;
+}
+
+void *t1 (void *tid)
+{
+  if (check_tcbhwcap ((long) tid))
+    {
+      pthread_exit (tid);
+    }
+
+  pthread_exit (NULL);
+
+}
+
+static int
+do_test (void)
+{
+
+  pthread_t threads[2];
+  pthread_attr_t attr;
+  pthread_attr_init (&attr);
+  pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_JOINABLE);
+  void *status;
+
+  long i = 0;
+
+  /* Check for main.  */
+  if (check_tcbhwcap (i))
+    {
+      return 1;
+    }
+
+  /* Check for other thread.  */
+  i++;
+  if (pthread_create (&threads[i], &attr, t1, (void *)i))
+    {
+      printf ("FAIL: error creating thread %ld.\n", i);
+      return 1;
+    }
+
+  pthread_attr_destroy (&attr);
+  if (pthread_join (threads[i], &status))
+    {
+      printf ("FAIL: error joining thread %ld.\n", i);
+      return 1;
+    }
+  if (status)
+    {
+      return 1;
+    }
+
+  printf("PASS: HWCAP, HWCAP2 and AT_PLATFORM are correctly set in the TCB for"
+	 " all threads.\n");
+
+  pthread_exit (NULL);
+
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"