Add __ppc_get_timebase_freq to ppc.h.

ChangeLog

@@ -1,3 +1,23 @@
+2012-09-25  Tulio Magno Quites Machado Filho  <tuliom@linux.vnet.ibm.com>
+
+	* manual/platform.texi (PowerPC): Document __ppc_get_timebase_freq.
+	* sysdeps/powerpc/sys/platform/ppc.h: Include the operating
+	system header.
+	* sysdeps/unix/sysv/linux/powerpc/Makefile (sysdep_headers):
+	Likewise.
+	(sydep_routines): Add the new and the internal functions.
+	* sysdeps/unix/sysv/linux/powerpc/bits/ppc.h: New file.
+	* sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c: Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/powerpc32/Versions
+	(GLIBC_2.17): Add the new function.
+	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/libc.abilist
+	(GLIBC_2.17): Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/powerpc64/Versions
+	(GLIBC_2.17): Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libc.abilist
+	(GLIBC_2.17): Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/test-gettimebasefreq.c: New file.
+
 2012-09-25  Alan Modra  <amodra@gmail.com>
 
 	* sysdeps/unix/sysv/linux/powerpc/pthread_once.c (__pthread_once):

manual/platform.texi

@@ -26,3 +26,11 @@ different from the processor frequency.  More information is available in
 without requiring assistance from the operating system, so it is very
 efficient.
 @end deftypefun
+
+@deftypefun {uint64_t} __ppc_get_timebase_freq (void)
+Read the current frequency at which the Time Base Register is updated.
+
+This frequency is not related to the processor clock or the bus clock.
+It is also possible that this frequency is not constant.  More information is
+available in @cite{Power ISA 2.06b - Book II - Section 5.2}.
+@end deftypefun

sysdeps/powerpc/sys/platform/ppc.h

@@ -20,6 +20,7 @@
 #define _SYS_PLATFORM_PPC_H	1
 
 #include <stdint.h>
+#include <bits/ppc.h>
 
 /* Read the Time Base Register.   */
 static inline uint64_t

sysdeps/unix/sysv/linux/powerpc/Makefile

@@ -16,3 +16,9 @@ endif
 ifeq ($(subdir),elf)
 sysdep_routines += dl-vdso
 endif
+
+ifeq ($(subdir),misc)
+sysdep_headers += bits/ppc.h
+sysdep_routines += get_clockfreq get_timebase_freq
+tests += test-gettimebasefreq
+endif

sysdeps/unix/sysv/linux/powerpc/bits/ppc.h

@@ -0,0 +1,33 @@
+/* Facilities specific to the PowerPC architecture on Linux
+   Copyright (C) 2012 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 _BITS_PPC_H
+#define _BITS_PPC_H
+
+#ifndef _SYS_PLATFORM_PPC_H
+# error "Never include this file directly; use <sys/platform/ppc.h> instead."
+#endif
+
+__BEGIN_DECLS
+
+/* Read the time base frequency.   */
+extern uint64_t __ppc_get_timebase_freq (void);
+
+__END_DECLS
+
+#endif

sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c

@@ -0,0 +1,26 @@
+/* Get the frequency of the time base.
+   Copyright (C) 2012 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 <libc-internal.h>
+
+uint64_t
+__get_timebase_freq (void)
+{
+  return (uint64_t) __get_clockfreq ();
+}
+weak_alias (__get_timebase_freq, __ppc_get_timebase_freq)

sysdeps/unix/sysv/linux/powerpc/powerpc32/Versions

@@ -30,4 +30,7 @@ libc {
   GLIBC_2.11 {
     fallocate64;
   }
+  GLIBC_2.17 {
+    __ppc_get_timebase_freq;
+  }
 }

sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/libc.abilist

@@ -1775,6 +1775,7 @@ GLIBC_2.16
 GLIBC_2.17
  GLIBC_2.17 A
  secure_getenv F
+ __ppc_get_timebase_freq F
 GLIBC_2.2
  GLIBC_2.2 A
  _IO_adjust_wcolumn F

sysdeps/unix/sysv/linux/powerpc/powerpc64/Versions

@@ -19,4 +19,7 @@ libc {
     setcontext; 
     swapcontext;
   }
+  GLIBC_2.17 {
+    __ppc_get_timebase_freq;
+  }
 }

sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/libc.abilist

@@ -81,6 +81,7 @@ GLIBC_2.16
 GLIBC_2.17
  GLIBC_2.17 A
  secure_getenv F
+ __ppc_get_timebase_freq F
 GLIBC_2.3
  GLIBC_2.3 A
  _Exit F

sysdeps/unix/sysv/linux/powerpc/test-gettimebasefreq.c

@@ -0,0 +1,62 @@
+/* Check __ppc_get_timebase_freq() for architecture changes
+   Copyright (C) 2012 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/>.  */
+
+/* Test if __ppc_get_timebase_freq() works and is different from zero.  A read
+   failure might indicate a Linux Kernel change.
+   This test also use the frequency to compute the real elapsed time.  */
+
+#include <inttypes.h>
+#include <stdio.h>
+
+#include <sys/platform/ppc.h>
+
+/* Maximum value of the Time Base Register: 2^60 - 1.  */
+#define MAX_TB 0xFFFFFFFFFFFFFFF
+
+static int
+do_test (void)
+{
+  uint64_t t1, t2, f, diff;
+
+  t1 = __ppc_get_timebase ();
+  printf ("t1 = %"PRIu64"\n", t1);
+
+  f = __ppc_get_timebase_freq ();
+  printf ("Time Base frequency = %"PRIu64" Hz\n", f);
+
+  if (f == 0) {
+      printf ("Fail: The time base frequency can't be zero.");
+      return 1;
+  }
+
+  t2 = __ppc_get_timebase ();
+  printf ("t2 = %"PRIu64"\n", t2);
+
+  if (t2 > t1) {
+    diff = t2 - t1;
+  } else {
+    diff = (MAX_TB - t2) + t1;
+  }
+
+  printf ("Elapsed time  = %1.2f usecs\n", (double) diff * 1000000 / f );
+
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"