From d66bea57e779cd592657cca6e61345ae899b78d9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 16 Feb 2007 01:27:57 -0800 Subject: [PATCH] [PATCH] Allow early access to the power management timer Allow early access to the power management timer by exposing the verified read function and providing a helper function which checks the pmtmr_ioport variable and returns either the pm timer readout or 0 in case the pm timer is not available. Create a new header file and replace also the ifdef'ed extern definition in arch/i386/kernel/acpi/boot.c This is a preperatory patch for the rework of the local apic timer calibration. No functional changes. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: john stultz Cc: Roman Zippel Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/acpi/boot.c | 5 +---- drivers/clocksource/acpi_pm.c | 17 ++++++++-------- include/linux/acpi_pmtmr.h | 38 +++++++++++++++++++++++++++++++++++ 3 files changed, 48 insertions(+), 12 deletions(-) create mode 100644 include/linux/acpi_pmtmr.h diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c index e94aff6888c..56818cf5bc4 100644 --- a/arch/i386/kernel/acpi/boot.c +++ b/arch/i386/kernel/acpi/boot.c @@ -25,6 +25,7 @@ #include #include +#include #include #include #include @@ -676,10 +677,6 @@ static int __init acpi_parse_hpet(struct acpi_table_header *table) #define acpi_parse_hpet NULL #endif -#ifdef CONFIG_X86_PM_TIMER -extern u32 pmtmr_ioport; -#endif - static int __init acpi_parse_fadt(struct acpi_table_header *table) { diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c index c7276a61695..ccaa6a39cb4 100644 --- a/drivers/clocksource/acpi_pm.c +++ b/drivers/clocksource/acpi_pm.c @@ -16,15 +16,13 @@ * This file is licensed under the GPL v2. */ +#include #include #include #include #include #include -/* Number of PMTMR ticks expected during calibration run */ -#define PMTMR_TICKS_PER_SEC 3579545 - /* * The I/O port the PMTMR resides at. * The location is detected during setup_arch(), @@ -32,15 +30,13 @@ */ u32 pmtmr_ioport __read_mostly; -#define ACPI_PM_MASK CLOCKSOURCE_MASK(24) /* limit it to 24 bits */ - static inline u32 read_pmtmr(void) { /* mask the output to 24 bits */ return inl(pmtmr_ioport) & ACPI_PM_MASK; } -static cycle_t acpi_pm_read_verified(void) +u32 acpi_pm_read_verified(void) { u32 v1 = 0, v2 = 0, v3 = 0; @@ -57,7 +53,12 @@ static cycle_t acpi_pm_read_verified(void) } while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2))); - return (cycle_t)v2; + return v2; +} + +static cycle_t acpi_pm_read_slow(void) +{ + return (cycle_t)acpi_pm_read_verified(); } static cycle_t acpi_pm_read(void) @@ -88,7 +89,7 @@ __setup("acpi_pm_good", acpi_pm_good_setup); static inline void acpi_pm_need_workaround(void) { - clocksource_acpi_pm.read = acpi_pm_read_verified; + clocksource_acpi_pm.read = acpi_pm_read_slow; clocksource_acpi_pm.rating = 110; } diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h new file mode 100644 index 00000000000..1d0ef1ae803 --- /dev/null +++ b/include/linux/acpi_pmtmr.h @@ -0,0 +1,38 @@ +#ifndef _ACPI_PMTMR_H_ +#define _ACPI_PMTMR_H_ + +#include + +/* Number of PMTMR ticks expected during calibration run */ +#define PMTMR_TICKS_PER_SEC 3579545 + +/* limit it to 24 bits */ +#define ACPI_PM_MASK CLOCKSOURCE_MASK(24) + +/* Overrun value */ +#define ACPI_PM_OVRRUN (1<<24) + +#ifdef CONFIG_X86_PM_TIMER + +extern u32 acpi_pm_read_verified(void); +extern u32 pmtmr_ioport; + +static inline u32 acpi_pm_read_early(void) +{ + if (!pmtmr_ioport) + return 0; + /* mask the output to 24 bits */ + return acpi_pm_read_verified() & ACPI_PM_MASK; +} + +#else + +static inline u32 acpi_pm_read_early(void) +{ + return 0; +} + +#endif + +#endif + -- 2.41.1