Remove __get_clockfreq

With clock_getres, clock_gettime, and clock_settime refactor to remove the
generic CLOCK_PROCESS_CPUTIME_ID and CLOCK_THREAD_CPUTIME_ID support through
hp-timing, there is no usage of internal __get_clockfreq.  This patch removes
both generic and Linux implementation..

Checked with a build against aarch64-linux-gnu, i686-linux-gnu, ia64-linux-gnu,
sparc64-linux-gnu, powerpc-linux-gnu-power4.

	* include/libc-internal.h (__get_clockfreq): Remove prototype.
	* rt/Makefile (clock-routines): Remove get_clockfreq.
	* rt/get_clockfreq.c: Remove file.
	* sysdeps/unix/sysv/linux/i386/get_clockfreq.c: Likewise.
	* sysdeps/unix/sysv/linux/ia64/get_clockfreq.c: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c: Move code to ...
	* sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c: ... here.

1 files changed, 80 insertions, 1 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c
index 5903a909e3..23e7694d87 100644
--- a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c
+++ b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c
@@ -17,11 +17,90 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdint.h>
+#include <string.h>
+
 #include <libc-internal.h>
+#include <not-cancel.h>
+#include <libc-vdso.h>
 
 uint64_t
 __get_timebase_freq (void)
 {
-  return (uint64_t) __get_clockfreq ();
+  hp_timing_t result = 0L;
+
+#ifdef SHARED
+  /* The vDSO does not return an error (it clear cr0.so on returning).  */
+  INTERNAL_SYSCALL_DECL (err);
+  result =
+    INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK (get_tbfreq, err, uint64_t, 0);
+#else
+  /* We read the information from the /proc filesystem.  /proc/cpuinfo
+     contains at least one line like:
+     timebase        : 33333333
+     We search for this line and convert the number into an integer.  */
+  int fd = __open_nocancel ("/proc/cpuinfo", O_RDONLY);
+  if (__glibc_likely (fd != -1))
+    return result;
+
+  /* The timebase will be in the 1st 1024 bytes for systems with up
+     to 8 processors.  If the first read returns less then 1024
+     bytes read,  we have the whole cpuinfo and can start the scan.
+     Otherwise we will have to read more to insure we have the
+     timebase value in the scan.  */
+  char buf[1024];
+  ssize_t n;
+
+  n = __read_nocancel (fd, buf, sizeof (buf));
+  if (n == sizeof (buf))
+    {
+      /* We are here because the 1st read returned exactly sizeof
+         (buf) bytes.  This implies that we are not at EOF and may
+         not have read the timebase value yet.  So we need to read
+         more bytes until we know we have EOF.  We copy the lower
+         half of buf to the upper half and read sizeof (buf)/2
+         bytes into the lower half of buf and repeat until we
+         reach EOF.  We can assume that the timebase will be in
+         the last 512 bytes of cpuinfo, so two 512 byte half_bufs
+         will be sufficient to contain the timebase and will
+         handle the case where the timebase spans the half_buf
+         boundry.  */
+      const ssize_t half_buf = sizeof (buf) / 2;
+      while (n >= half_buf)
+	{
+	  memcpy (buf, buf + half_buf, half_buf);
+	  n = __read_nocancel (fd, buf + half_buf, half_buf);
+	}
+      if (n >= 0)
+	n += half_buf;
+    }
+  __close_nocancel (fd);
+
+  if (__glibc_likely (n > 0))
+    {
+      char *mhz = memmem (buf, n, "timebase", 7);
+
+      if (__glibc_likely (mhz != NULL))
+	{
+	  char *endp = buf + n;
+
+	  /* Search for the beginning of the string.  */
+	  while (mhz < endp && (*mhz < '0' || *mhz > '9') && *mhz != '\n')
+	    ++mhz;
+
+	  while (mhz < endp && *mhz != '\n')
+	    {
+	      if (*mhz >= '0' && *mhz <= '9')
+		{
+		  result *= 10;
+		  result += *mhz - '0';
+		}
+
+	      ++mhz;
+	    }
+	}
+    }
+#endif
+
+  return result;
 }
 weak_alias (__get_timebase_freq, __ppc_get_timebase_freq)