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authorjohn stultz <johnstul@us.ibm.com>2006-06-26 00:25:10 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 09:58:21 -0700
commit539eb11e6e904f2cd4f62908cc5e44d724879721 (patch)
treedf18c747c5226b138862fb19fad5b1527055b9c9 /include
parent8d016ef1380a2a9a5ca5742ede04334199868f82 (diff)
[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>
Diffstat (limited to 'include')
-rw-r--r--include/asm-i386/mach-default/mach_timer.h4
-rw-r--r--include/asm-i386/mach-summit/mach_mpparse.h3
-rw-r--r--include/asm-i386/timex.h34
-rw-r--r--include/asm-i386/tsc.h49
4 files changed, 56 insertions, 34 deletions
diff --git a/include/asm-i386/mach-default/mach_timer.h b/include/asm-i386/mach-default/mach_timer.h
index 4b9703bb028..807992fd417 100644
--- a/include/asm-i386/mach-default/mach_timer.h
+++ b/include/asm-i386/mach-default/mach_timer.h
@@ -15,7 +15,9 @@
#ifndef _MACH_TIMER_H
#define _MACH_TIMER_H
-#define CALIBRATE_LATCH (5 * LATCH)
+#define CALIBRATE_TIME_MSEC 30 /* 30 msecs */
+#define CALIBRATE_LATCH \
+ ((CLOCK_TICK_RATE * CALIBRATE_TIME_MSEC + 1000/2)/1000)
static inline void mach_prepare_counter(void)
{
diff --git a/include/asm-i386/mach-summit/mach_mpparse.h b/include/asm-i386/mach-summit/mach_mpparse.h
index 1cce2b924a8..94268399170 100644
--- a/include/asm-i386/mach-summit/mach_mpparse.h
+++ b/include/asm-i386/mach-summit/mach_mpparse.h
@@ -2,6 +2,7 @@
#define __ASM_MACH_MPPARSE_H
#include <mach_apic.h>
+#include <asm/tsc.h>
extern int use_cyclone;
@@ -29,6 +30,7 @@ static inline int mps_oem_check(struct mp_config_table *mpc, char *oem,
(!strncmp(productid, "VIGIL SMP", 9)
|| !strncmp(productid, "EXA", 3)
|| !strncmp(productid, "RUTHLESS SMP", 12))){
+ mark_tsc_unstable();
use_cyclone = 1; /*enable cyclone-timer*/
setup_summit();
return 1;
@@ -42,6 +44,7 @@ static inline int acpi_madt_oem_check(char *oem_id, char *oem_table_id)
if (!strncmp(oem_id, "IBM", 3) &&
(!strncmp(oem_table_id, "SERVIGIL", 8)
|| !strncmp(oem_table_id, "EXA", 3))){
+ mark_tsc_unstable();
use_cyclone = 1; /*enable cyclone-timer*/
setup_summit();
return 1;
diff --git a/include/asm-i386/timex.h b/include/asm-i386/timex.h
index d434984303c..3666044409f 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
diff --git a/include/asm-i386/tsc.h b/include/asm-i386/tsc.h
new file mode 100644
index 00000000000..97b828ce31e
--- /dev/null
+++ b/include/asm-i386/tsc.h
@@ -0,0 +1,49 @@
+/*
+ * linux/include/asm-i386/tsc.h
+ *
+ * i386 TSC related functions
+ */
+#ifndef _ASM_i386_TSC_H
+#define _ASM_i386_TSC_H
+
+#include <linux/config.h>
+#include <asm/processor.h>
+
+/*
+ * 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;
+
+extern unsigned int cpu_khz;
+extern unsigned int tsc_khz;
+
+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 void tsc_init(void);
+extern void mark_tsc_unstable(void);
+
+#endif