d66bea57e7
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>
39 lines
635 B
C
39 lines
635 B
C
#ifndef _ACPI_PMTMR_H_
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#define _ACPI_PMTMR_H_
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#include <linux/clocksource.h>
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/* Number of PMTMR ticks expected during calibration run */
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#define PMTMR_TICKS_PER_SEC 3579545
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/* limit it to 24 bits */
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#define ACPI_PM_MASK CLOCKSOURCE_MASK(24)
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/* Overrun value */
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#define ACPI_PM_OVRRUN (1<<24)
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#ifdef CONFIG_X86_PM_TIMER
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extern u32 acpi_pm_read_verified(void);
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extern u32 pmtmr_ioport;
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static inline u32 acpi_pm_read_early(void)
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{
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if (!pmtmr_ioport)
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return 0;
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/* mask the output to 24 bits */
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return acpi_pm_read_verified() & ACPI_PM_MASK;
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}
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#else
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static inline u32 acpi_pm_read_early(void)
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{
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return 0;
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}
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#endif
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#endif
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