From: John Stultz <johnstul@us.ibm.com>
To: lkml <linux-kernel@vger.kernel.org>
Cc: John Stultz <johnstul@us.ibm.com>, Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 2/3] Convert common x86 clocksources to use clocksource_register_hz/khz
Date: Fri, 30 Apr 2010 18:36:24 -0700 [thread overview]
Message-ID: <1272677785-23881-2-git-send-email-johnstul@us.ibm.com> (raw)
In-Reply-To: <1272677785-23881-1-git-send-email-johnstul@us.ibm.com>
This converts the most common of the x86 clocksources over to use
clocksource_register_hz/khz.
I've tested this on my system, and would probably be fine for 2.6.35.
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
---
arch/x86/kernel/hpet.c | 13 +++++++++----
arch/x86/kernel/tsc.c | 6 ++----
drivers/clocksource/acpi_pm.c | 9 ++-------
3 files changed, 13 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 23b4ecd..bfd1e6f 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -16,7 +16,6 @@
#include <asm/hpet.h>
#define HPET_MASK CLOCKSOURCE_MASK(32)
-#define HPET_SHIFT 22
/* FSEC = 10^-15
NSEC = 10^-9 */
@@ -782,7 +781,6 @@ static struct clocksource clocksource_hpet = {
.rating = 250,
.read = read_hpet,
.mask = HPET_MASK,
- .shift = HPET_SHIFT,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.resume = hpet_resume_counter,
#ifdef CONFIG_X86_64
@@ -793,6 +791,7 @@ static struct clocksource clocksource_hpet = {
static int hpet_clocksource_register(void)
{
u64 start, now;
+ u64 hpet_freq;
cycle_t t1;
/* Start the counter */
@@ -827,9 +826,15 @@ static int hpet_clocksource_register(void)
* mult = (hpet_period * 2^shift)/10^6
* mult = (hpet_period << shift)/FSEC_PER_NSEC
*/
- clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);
- clocksource_register(&clocksource_hpet);
+ /* Need to convert hpet_period (fsec/cyc) to cyc/sec:
+ *
+ * cyc/sec = FSEC_PER_SEC/hpet_period(fsec/cyc)
+ * cyc/sec = (FSEC_PER_NSEC * NSEC_PER_SEC)/hpet_period
+ */
+ hpet_freq = FSEC_PER_NSEC * NSEC_PER_SEC;
+ do_div(hpet_freq, hpet_period);
+ clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq);
return 0;
}
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 9faf91a..5ca6370 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -751,7 +751,6 @@ static struct clocksource clocksource_tsc = {
.read = read_tsc,
.resume = resume_tsc,
.mask = CLOCKSOURCE_MASK(64),
- .shift = 22,
.flags = CLOCK_SOURCE_IS_CONTINUOUS |
CLOCK_SOURCE_MUST_VERIFY,
#ifdef CONFIG_X86_64
@@ -845,8 +844,6 @@ __cpuinit int unsynchronized_tsc(void)
static void __init init_tsc_clocksource(void)
{
- clocksource_tsc.mult = clocksource_khz2mult(tsc_khz,
- clocksource_tsc.shift);
if (tsc_clocksource_reliable)
clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
/* lower the rating if we already know its unstable: */
@@ -854,7 +851,8 @@ static void __init init_tsc_clocksource(void)
clocksource_tsc.rating = 0;
clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
}
- clocksource_register(&clocksource_tsc);
+
+ clocksource_register_khz(&clocksource_tsc, tsc_khz);
}
#ifdef CONFIG_X86_64
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 72a633a..cfb0f52 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -68,10 +68,7 @@ static struct clocksource clocksource_acpi_pm = {
.rating = 200,
.read = acpi_pm_read,
.mask = (cycle_t)ACPI_PM_MASK,
- .mult = 0, /*to be calculated*/
- .shift = 22,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
-
};
@@ -190,9 +187,6 @@ static int __init init_acpi_pm_clocksource(void)
if (!pmtmr_ioport)
return -ENODEV;
- clocksource_acpi_pm.mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC,
- clocksource_acpi_pm.shift);
-
/* "verify" this timing source: */
for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
udelay(100 * j);
@@ -220,7 +214,8 @@ static int __init init_acpi_pm_clocksource(void)
if (verify_pmtmr_rate() != 0)
return -ENODEV;
- return clocksource_register(&clocksource_acpi_pm);
+ return clocksource_register_hz(&clocksource_acpi_pm,
+ PMTMR_TICKS_PER_SEC);
}
/* We use fs_initcall because we want the PCI fixups to have run
--
1.6.0.4
next prev parent reply other threads:[~2010-05-01 1:36 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-01 1:36 [PATCH 1/3] Add clocksource_register_hz/khz interface John Stultz
2010-05-01 1:36 ` John Stultz [this message]
2010-05-01 1:36 ` [RFC][PATCH 3/3] Try to convert non-trivial clocksources to clocksource_register_hz John Stultz
2010-05-10 15:53 ` Martin Schwidefsky
2010-05-10 19:19 ` john stultz
2010-05-11 6:20 ` Martin Schwidefsky
2010-05-10 21:33 ` Jim Cromie
2010-05-11 0:04 ` john stultz
2010-05-11 1:51 ` Jim Cromie
2010-05-11 0:37 ` john stultz
2010-05-12 16:43 ` Julien Ridoux
2010-05-01 8:45 ` [PATCH 1/3] Add clocksource_register_hz/khz interface Thomas Gleixner
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