From 1122b134bcd6e77c5a4117952b8cbc55c8d018bc Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 30 Jan 2008 13:30:27 +0100 Subject: [PATCH] x86: share rtc code Remove the rtc code from time_64.c and add the extra bits to the i386 path. The ACPI century check is probably valid for i386 as well, but this is material for a separate patch. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/Makefile_64 | 2 +- arch/x86/kernel/rtc.c | 96 ++++++++++++++-------- arch/x86/kernel/time_64.c | 157 ------------------------------------ 3 files changed, 64 insertions(+), 191 deletions(-) diff --git a/arch/x86/kernel/Makefile_64 b/arch/x86/kernel/Makefile_64 index 9cb3df27c413..ae95d21ea885 100644 --- a/arch/x86/kernel/Makefile_64 +++ b/arch/x86/kernel/Makefile_64 @@ -11,7 +11,7 @@ obj-y := process_64.o signal_64.o entry_64.o traps_64.o irq_64.o \ x8664_ksyms_64.o i387_64.o syscall_64.o vsyscall_64.o \ setup64.o bootflag.o e820_64.o reboot_64.o quirks.o i8237.o \ pci-dma_64.o pci-nommu_64.o alternative.o hpet.o tsc_64.o bugs_64.o \ - i8253.o io_delay.o + i8253.o io_delay.o rtc.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += cpu/ diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 45bf54d9f4c5..d040840ff1b6 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -1,11 +1,32 @@ /* * RTC related functions */ +#include #include #include #include +#ifdef CONFIG_X86_32 +# define CMOS_YEARS_OFFS 1900 +/* + * This is a special lock that is owned by the CPU and holds the index + * register we are working with. It is required for NMI access to the + * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details. + */ +volatile unsigned long cmos_lock = 0; +EXPORT_SYMBOL(cmos_lock); +#else +/* + * x86-64 systems only exists since 2002. + * This will work up to Dec 31, 2100 + */ +# define CMOS_YEARS_OFFS 2000 +#endif + +DEFINE_SPINLOCK(rtc_lock); +EXPORT_SYMBOL(rtc_lock); + /* * In order to set the CMOS clock precisely, set_rtc_mmss has to be * called 500 ms after the second nowtime has started, because when @@ -22,10 +43,12 @@ int mach_set_rtc_mmss(unsigned long nowtime) int real_seconds, real_minutes, cmos_minutes; unsigned char save_control, save_freq_select; - save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */ + /* tell the clock it's being set */ + save_control = CMOS_READ(RTC_CONTROL); CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); - save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */ + /* stop and reset prescaler */ + save_freq_select = CMOS_READ(RTC_FREQ_SELECT); CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); cmos_minutes = CMOS_READ(RTC_MINUTES); @@ -40,8 +63,9 @@ int mach_set_rtc_mmss(unsigned long nowtime) */ real_seconds = nowtime % 60; real_minutes = nowtime / 60; + /* correct for half hour time zone */ if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) - real_minutes += 30; /* correct for half hour time zone */ + real_minutes += 30; real_minutes %= 60; if (abs(real_minutes - cmos_minutes) < 30) { @@ -73,18 +97,32 @@ int mach_set_rtc_mmss(unsigned long nowtime) unsigned long mach_get_cmos_time(void) { - unsigned int year, mon, day, hour, min, sec; - - do { - sec = CMOS_READ(RTC_SECONDS); - min = CMOS_READ(RTC_MINUTES); - hour = CMOS_READ(RTC_HOURS); - day = CMOS_READ(RTC_DAY_OF_MONTH); - mon = CMOS_READ(RTC_MONTH); - year = CMOS_READ(RTC_YEAR); - } while (sec != CMOS_READ(RTC_SECONDS)); - - if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { + unsigned int year, mon, day, hour, min, sec, century = 0; + + /* + * If UIP is clear, then we have >= 244 microseconds before + * RTC registers will be updated. Spec sheet says that this + * is the reliable way to read RTC - registers. If UIP is set + * then the register access might be invalid. + */ + while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)) + cpu_relax(); + + sec = CMOS_READ(RTC_SECONDS); + min = CMOS_READ(RTC_MINUTES); + hour = CMOS_READ(RTC_HOURS); + day = CMOS_READ(RTC_DAY_OF_MONTH); + mon = CMOS_READ(RTC_MONTH); + year = CMOS_READ(RTC_YEAR); + +#if defined(CONFIG_ACPI) && defined(CONFIG_X86_64) + /* CHECKME: Is this really 64bit only ??? */ + if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && + acpi_gbl_FADT.century) + century = CMOS_READ(acpi_gbl_FADT.century); +#endif + + if (RTC_ALWAYS_BCD || !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)) { BCD_TO_BIN(sec); BCD_TO_BIN(min); BCD_TO_BIN(hour); @@ -93,24 +131,19 @@ unsigned long mach_get_cmos_time(void) BCD_TO_BIN(year); } - year += 1900; - if (year < 1970) - year += 100; + if (century) { + BCD_TO_BIN(century); + year += century * 100; + printk(KERN_INFO "Extended CMOS year: %d\n", century * 100); + } else { + year += CMOS_YEARS_OFFS; + if (year < 1970) + year += 100; + } return mktime(year, mon, day, hour, min, sec); } -DEFINE_SPINLOCK(rtc_lock); -EXPORT_SYMBOL(rtc_lock); - -/* - * This is a special lock that is owned by the CPU and holds the index - * register we are working with. It is required for NMI access to the - * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details. - */ -volatile unsigned long cmos_lock = 0; -EXPORT_SYMBOL(cmos_lock); - /* Routines for accessing the CMOS RAM/RTC. */ unsigned char rtc_cmos_read(unsigned char addr) { @@ -138,8 +171,6 @@ static int set_rtc_mmss(unsigned long nowtime) int retval; unsigned long flags; - /* gets recalled with irq locally disabled */ - /* XXX - does irqsave resolve this? -johnstul */ spin_lock_irqsave(&rtc_lock, flags); retval = set_wallclock(nowtime); spin_unlock_irqrestore(&rtc_lock, flags); @@ -150,8 +181,7 @@ static int set_rtc_mmss(unsigned long nowtime) /* not static: needed by APM */ unsigned long read_persistent_clock(void) { - unsigned long retval; - unsigned long flags; + unsigned long retval, flags; spin_lock_irqsave(&rtc_lock, flags); retval = get_wallclock(); diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c index 0a01504586a5..64cd03ed9bfc 100644 --- a/arch/x86/kernel/time_64.c +++ b/arch/x86/kernel/time_64.c @@ -46,9 +46,6 @@ #include #include -DEFINE_SPINLOCK(rtc_lock); -EXPORT_SYMBOL(rtc_lock); - volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; unsigned long profile_pc(struct pt_regs *regs) @@ -69,103 +66,6 @@ unsigned long profile_pc(struct pt_regs *regs) } EXPORT_SYMBOL(profile_pc); -/* Routines for accessing the CMOS RAM/RTC. */ -unsigned char rtc_cmos_read(unsigned char addr) -{ - unsigned char val; - lock_cmos_prefix(addr); - outb_p(addr, RTC_PORT(0)); - val = inb_p(RTC_PORT(1)); - lock_cmos_suffix(addr); - return val; -} -EXPORT_SYMBOL(rtc_cmos_read); - -void rtc_cmos_write(unsigned char val, unsigned char addr) -{ - lock_cmos_prefix(addr); - outb_p(addr, RTC_PORT(0)); - outb_p(val, RTC_PORT(1)); - lock_cmos_suffix(addr); -} -EXPORT_SYMBOL(rtc_cmos_write); - -/* - * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500 - * ms after the second nowtime has started, because when nowtime is written - * into the registers of the CMOS clock, it will jump to the next second - * precisely 500 ms later. Check the Motorola MC146818A or Dallas DS12887 data - * sheet for details. - */ - -static int set_rtc_mmss(unsigned long nowtime) -{ - int retval = 0; - int real_seconds, real_minutes, cmos_minutes; - unsigned char control, freq_select; - unsigned long flags; - -/* - * set_rtc_mmss is called when irqs are enabled, so disable irqs here - */ - spin_lock_irqsave(&rtc_lock, flags); -/* - * Tell the clock it's being set and stop it. - */ - control = CMOS_READ(RTC_CONTROL); - CMOS_WRITE(control | RTC_SET, RTC_CONTROL); - - freq_select = CMOS_READ(RTC_FREQ_SELECT); - CMOS_WRITE(freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT); - - cmos_minutes = CMOS_READ(RTC_MINUTES); - BCD_TO_BIN(cmos_minutes); - -/* - * since we're only adjusting minutes and seconds, don't interfere with hour - * overflow. This avoids messing with unknown time zones but requires your RTC - * not to be off by more than 15 minutes. Since we're calling it only when - * our clock is externally synchronized using NTP, this shouldn't be a problem. - */ - - real_seconds = nowtime % 60; - real_minutes = nowtime / 60; - if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1) - real_minutes += 30; /* correct for half hour time zone */ - real_minutes %= 60; - - if (abs(real_minutes - cmos_minutes) >= 30) { - printk(KERN_WARNING "time.c: can't update CMOS clock " - "from %d to %d\n", cmos_minutes, real_minutes); - retval = -1; - } else { - BIN_TO_BCD(real_seconds); - BIN_TO_BCD(real_minutes); - CMOS_WRITE(real_seconds, RTC_SECONDS); - CMOS_WRITE(real_minutes, RTC_MINUTES); - } - -/* - * The following flags have to be released exactly in this order, otherwise the - * DS12887 (popular MC146818A clone with integrated battery and quartz) will - * not reset the oscillator and will not update precisely 500 ms later. You - * won't find this mentioned in the Dallas Semiconductor data sheets, but who - * believes data sheets anyway ... -- Markus Kuhn - */ - - CMOS_WRITE(control, RTC_CONTROL); - CMOS_WRITE(freq_select, RTC_FREQ_SELECT); - - spin_unlock_irqrestore(&rtc_lock, flags); - - return retval; -} - -int update_persistent_clock(struct timespec now) -{ - return set_rtc_mmss(now.tv_sec); -} - static irqreturn_t timer_event_interrupt(int irq, void *dev_id) { add_pda(irq0_irqs, 1); @@ -175,63 +75,6 @@ static irqreturn_t timer_event_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -unsigned long read_persistent_clock(void) -{ - unsigned int year, mon, day, hour, min, sec; - unsigned long flags; - unsigned century = 0; - - spin_lock_irqsave(&rtc_lock, flags); - /* - * if UIP is clear, then we have >= 244 microseconds before RTC - * registers will be updated. Spec sheet says that this is the - * reliable way to read RTC - registers invalid (off bus) during update - */ - while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)) - cpu_relax(); - - - /* now read all RTC registers while stable with interrupts disabled */ - sec = CMOS_READ(RTC_SECONDS); - min = CMOS_READ(RTC_MINUTES); - hour = CMOS_READ(RTC_HOURS); - day = CMOS_READ(RTC_DAY_OF_MONTH); - mon = CMOS_READ(RTC_MONTH); - year = CMOS_READ(RTC_YEAR); -#ifdef CONFIG_ACPI - if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && - acpi_gbl_FADT.century) - century = CMOS_READ(acpi_gbl_FADT.century); -#endif - spin_unlock_irqrestore(&rtc_lock, flags); - - /* - * We know that x86-64 always uses BCD format, no need to check the - * config register. - */ - - BCD_TO_BIN(sec); - BCD_TO_BIN(min); - BCD_TO_BIN(hour); - BCD_TO_BIN(day); - BCD_TO_BIN(mon); - BCD_TO_BIN(year); - - if (century) { - BCD_TO_BIN(century); - year += century * 100; - printk(KERN_INFO "Extended CMOS year: %d\n", century * 100); - } else { - /* - * x86-64 systems only exists since 2002. - * This will work up to Dec 31, 2100 - */ - year += 2000; - } - - return mktime(year, mon, day, hour, min, sec); -} - /* calibrate_cpu is used on systems with fixed rate TSCs to determine * processor frequency */ #define TICK_COUNT 100000000 -- 2.20.1