diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2007-02-16 01:27:57 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-16 08:13:58 -0800 |
commit | d66bea57e779cd592657cca6e61345ae899b78d9 (patch) | |
tree | 70fe41bf930ac96a59d594ba5a37272a3df775e0 | |
parent | 169a0abbe32813af4904cc1605c0f7ea0534f77b (diff) | |
download | linux-d66bea57e779cd592657cca6e61345ae899b78d9.tar.gz linux-d66bea57e779cd592657cca6e61345ae899b78d9.tar.bz2 linux-d66bea57e779cd592657cca6e61345ae899b78d9.zip |
[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 <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | arch/i386/kernel/acpi/boot.c | 5 | ||||
-rw-r--r-- | drivers/clocksource/acpi_pm.c | 17 | ||||
-rw-r--r-- | include/linux/acpi_pmtmr.h | 38 |
3 files changed, 48 insertions, 12 deletions
diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c index e94aff6888ca..56818cf5bc40 100644 --- a/arch/i386/kernel/acpi/boot.c +++ b/arch/i386/kernel/acpi/boot.c @@ -25,6 +25,7 @@ #include <linux/init.h> #include <linux/acpi.h> +#include <linux/acpi_pmtmr.h> #include <linux/efi.h> #include <linux/cpumask.h> #include <linux/module.h> @@ -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 c7276a61695b..ccaa6a39cb4b 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 <linux/acpi_pmtmr.h> #include <linux/clocksource.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/pci.h> #include <asm/io.h> -/* 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 000000000000..1d0ef1ae8036 --- /dev/null +++ b/include/linux/acpi_pmtmr.h @@ -0,0 +1,38 @@ +#ifndef _ACPI_PMTMR_H_ +#define _ACPI_PMTMR_H_ + +#include <linux/clocksource.h> + +/* 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 + |