b20367a6c2
If the HPET timer is enabled, the clock can drift by ~3 seconds a day. This is due to the HPET timer not being initialized with the correct setting (still using PIT count). If HZ changes, this drift can become even more pronounced. HPET patch initializes tick_nsec with correct tick_nsec settings for HPET timer. Vojtech comments: "It's not entirely correct (it assumes the HPET ticks totally exactly), but it's significantly better than assuming the PIT error there." Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
115 lines
3.2 KiB
C
115 lines
3.2 KiB
C
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#ifndef _I386_HPET_H
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#define _I386_HPET_H
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#ifdef CONFIG_HPET_TIMER
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <asm/io.h>
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#include <asm/smp.h>
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#include <asm/irq.h>
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#include <asm/msr.h>
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#include <asm/delay.h>
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#include <asm/mpspec.h>
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#include <asm/uaccess.h>
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#include <asm/processor.h>
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#include <linux/timex.h>
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#include <linux/config.h>
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#include <asm/fixmap.h>
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/*
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* Documentation on HPET can be found at:
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* http://www.intel.com/ial/home/sp/pcmmspec.htm
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* ftp://download.intel.com/ial/home/sp/mmts098.pdf
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*/
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#define HPET_MMAP_SIZE 1024
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#define HPET_ID 0x000
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#define HPET_PERIOD 0x004
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#define HPET_CFG 0x010
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#define HPET_STATUS 0x020
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#define HPET_COUNTER 0x0f0
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#define HPET_T0_CFG 0x100
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#define HPET_T0_CMP 0x108
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#define HPET_T0_ROUTE 0x110
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#define HPET_T1_CFG 0x120
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#define HPET_T1_CMP 0x128
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#define HPET_T1_ROUTE 0x130
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#define HPET_T2_CFG 0x140
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#define HPET_T2_CMP 0x148
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#define HPET_T2_ROUTE 0x150
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#define HPET_ID_LEGSUP 0x00008000
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#define HPET_ID_NUMBER 0x00001f00
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#define HPET_ID_REV 0x000000ff
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#define HPET_ID_NUMBER_SHIFT 8
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#define HPET_CFG_ENABLE 0x001
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#define HPET_CFG_LEGACY 0x002
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#define HPET_LEGACY_8254 2
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#define HPET_LEGACY_RTC 8
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#define HPET_TN_ENABLE 0x004
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#define HPET_TN_PERIODIC 0x008
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#define HPET_TN_PERIODIC_CAP 0x010
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#define HPET_TN_SETVAL 0x040
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#define HPET_TN_32BIT 0x100
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/* Use our own asm for 64 bit multiply/divide */
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#define ASM_MUL64_REG(eax_out,edx_out,reg_in,eax_in) \
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__asm__ __volatile__("mull %2" \
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:"=a" (eax_out), "=d" (edx_out) \
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:"r" (reg_in), "0" (eax_in))
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#define ASM_DIV64_REG(eax_out,edx_out,reg_in,eax_in,edx_in) \
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__asm__ __volatile__("divl %2" \
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:"=a" (eax_out), "=d" (edx_out) \
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:"r" (reg_in), "0" (eax_in), "1" (edx_in))
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#define KERNEL_TICK_USEC (1000000UL/HZ) /* tick value in microsec */
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/* Max HPET Period is 10^8 femto sec as in HPET spec */
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#define HPET_MAX_PERIOD (100000000UL)
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/*
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* Min HPET period is 10^5 femto sec just for safety. If it is less than this,
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* then 32 bit HPET counter wrapsaround in less than 0.5 sec.
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*/
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#define HPET_MIN_PERIOD (100000UL)
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#define HPET_TICK_RATE (HZ * 100000UL)
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extern unsigned long hpet_tick; /* hpet clks count per tick */
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extern unsigned long hpet_address; /* hpet memory map physical address */
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extern int hpet_use_timer;
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extern int hpet_rtc_timer_init(void);
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extern int hpet_enable(void);
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extern int hpet_reenable(void);
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extern int is_hpet_enabled(void);
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extern int is_hpet_capable(void);
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extern int hpet_readl(unsigned long a);
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#ifdef CONFIG_HPET_EMULATE_RTC
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extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
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extern int hpet_set_rtc_irq_bit(unsigned long bit_mask);
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extern int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec);
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extern int hpet_set_periodic_freq(unsigned long freq);
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extern int hpet_rtc_dropped_irq(void);
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extern int hpet_rtc_timer_init(void);
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extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs);
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#endif /* CONFIG_HPET_EMULATE_RTC */
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#endif /* CONFIG_HPET_TIMER */
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#endif /* _I386_HPET_H */
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