[PATCH] Time: i386 Conversion - part 2: Rework TSC Support

As part of the i386 conversion to the generic timekeeping infrastructure, this
introduces a new tsc.c file.  The code in this file replaces the TSC
initialization, management and access code currently in timer_tsc.c (which
will be removed) that we want to preserve.

The code also introduces the following functionality:

o tsc_khz: like cpu_khz but stores the TSC frequency on systems that do not
  change TSC frequency w/ CPU frequency

o check/mark_tsc_unstable: accessor/modifier flag for TSC timekeeping
  usability

o minor cleanups to calibration math.

This patch also includes a one line __cpuinitdata fix from Zwane Mwaikambo.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 33 deletions

diff --git a/include/asm-i386/timex.h b/include/asm-i386/timex.h
index d434984303ca..3666044409f0 100644
--- a/include/asm-i386/timex.h
+++ b/include/asm-i386/timex.h
@@ -7,6 +7,7 @@
 #define _ASMi386_TIMEX_H
 
 #include <asm/processor.h>
+#include <asm/tsc.h>
 
 #ifdef CONFIG_X86_ELAN
 #  define CLOCK_TICK_RATE 1189200 /* AMD Elan has different frequency! */
@@ -15,39 +16,6 @@
 #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 int cpu_khz;
-
 extern int read_current_timer(unsigned long *timer_value);
 #define ARCH_HAS_READ_CURRENT_TIMER     1