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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-i386/timex.h
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Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-i386/timex.h')
-rw-r--r--include/asm-i386/timex.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/include/asm-i386/timex.h b/include/asm-i386/timex.h
new file mode 100644
index 00000000000..b41e484c344
--- /dev/null
+++ b/include/asm-i386/timex.h
@@ -0,0 +1,52 @@
+/*
+ * linux/include/asm-i386/timex.h
+ *
+ * i386 architecture timex specifications
+ */
+#ifndef _ASMi386_TIMEX_H
+#define _ASMi386_TIMEX_H
+
+#include <linux/config.h>
+#include <asm/processor.h>
+
+#ifdef CONFIG_X86_ELAN
+# define CLOCK_TICK_RATE 1189200 /* AMD Elan has different frequency! */
+#else
+# define CLOCK_TICK_RATE 1193182 /* Underlying HZ */
+#endif
+
+
+/*
+ * Standard way to access the cycle counter on i586+ CPUs.
+ * Currently only used on SMP.
+ *
+ * If you really have a SMP machine with i486 chips or older,
+ * compile for that, and this will just always return zero.
+ * That's ok, it just means that the nicer scheduling heuristics
+ * won't work for you.
+ *
+ * We only use the low 32 bits, and we'd simply better make sure
+ * that we reschedule before that wraps. Scheduling at least every
+ * four billion cycles just basically sounds like a good idea,
+ * regardless of how fast the machine is.
+ */
+typedef unsigned long long cycles_t;
+
+static inline cycles_t get_cycles (void)
+{
+ unsigned long long ret=0;
+
+#ifndef CONFIG_X86_TSC
+ if (!cpu_has_tsc)
+ return 0;
+#endif
+
+#if defined(CONFIG_X86_GENERIC) || defined(CONFIG_X86_TSC)
+ rdtscll(ret);
+#endif
+ return ret;
+}
+
+extern unsigned long cpu_khz;
+
+#endif