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authorUlrich Drepper <drepper@redhat.com>2005-11-01 02:13:41 +0000
committerUlrich Drepper <drepper@redhat.com>2005-11-01 02:13:41 +0000
commit7006f757e6d6f110b88f6a5a7759d1e118870489 (patch)
tree7630af90063c8630ff668bcfb06972db2f5ecdef /sysdeps/unix/sysv/linux
parentcb07f6f67db0ef4ccbf3bedfb7c9c4f140773d2c (diff)
* sysdeps/powerpc/powerpc64/Makefile
(sysdep_routines, elide-routines.os): Add hp-timing. * sysdeps/powerpc/powerpc64/hp-timing.c: New file. * sysdeps/powerpc/powerpc64/hp-timing.h: New file. * sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c: New file.
Diffstat (limited to 'sysdeps/unix/sysv/linux')
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
new file mode 100644
index 0000000000..ddaff303c5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
@@ -0,0 +1,105 @@
+/* Get frequency of the system processor. powerpc/Linux version.
+ Copyright (C) 2000, 2001, 2005 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <ctype.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <libc-internal.h>
+
+
+hp_timing_t
+__get_clockfreq (void)
+{
+ /* 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. */
+ static hp_timing_t timebase_freq;
+ hp_timing_t result = 0L;
+
+ /* If this function was called before, we know the result. */
+ if (timebase_freq != 0)
+ return timebase_freq;
+
+ int fd = open ("/proc/cpuinfo", O_RDONLY);
+ if (__builtin_expect (fd != -1, 1))
+ {
+ /* 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 (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 (fd, buf + half_buf, half_buf);
+ }
+ if (n >= 0)
+ n += half_buf;
+ }
+
+ if (__builtin_expect (n, 1) > 0)
+ {
+ char *mhz = memmem (buf, n, "timebase", 7);
+
+ if (__builtin_expect (mhz != NULL, 1))
+ {
+ 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;
+ }
+ }
+ timebase_freq = result;
+ }
+ close (fd);
+ }
+
+ return timebase_freq;
+}