From 35b61edb41ffee58711850e76215b852386ddb10 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 6 Mar 2013 11:18:37 +0000 Subject: x86: Use tick broadcast expired check Avoid going back into deep idle if the tick broadcast IPI is about to fire. Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Arjan van de Veen Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20130306111537.702278273@linutronix.de --- arch/x86/kernel/process.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/x86') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 14ae10031ff0..aa524da03bba 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -336,6 +336,18 @@ void cpu_idle(void) local_touch_nmi(); local_irq_disable(); + /* + * We detected in the wakeup path that the + * tick broadcast device expired for us, but + * we raced with the other CPU and came back + * here before it was able to fire the IPI. + * No point in going idle. + */ + if (tick_check_broadcast_expired()) { + local_irq_enable(); + continue; + } + enter_idle(); /* Don't trace irqs off for idle */ -- cgit v1.2.3 From 3195ef59cb42cda3aeeb24a7fd2ba1b900c4a3cc Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Thu, 14 Feb 2013 12:02:54 -0500 Subject: x86: Do full rtc synchronization with ntp Every 11 minutes ntp attempts to update the x86 rtc with the current system time. Currently, the x86 code only updates the rtc if the system time is within +/-15 minutes of the current value of the rtc. This was done originally to avoid setting the RTC if the RTC was in localtime mode (common with Windows dualbooting). Other architectures do a full synchronization and now that we have better infrastructure to detect when the RTC is in localtime, there is no reason that x86 should be software limited to a 30 minute window. This patch changes the behavior of the kernel to do a full synchronization (year, month, day, hour, minute, and second) of the rtc when ntp requests a synchronization between the system time and the rtc. I've used the RTC library functions in this patchset as they do all the required bounds checking. Cc: Thomas Gleixner Cc: John Stultz Cc: x86@kernel.org Cc: Matt Fleming Cc: David Vrabel Cc: Andrew Morton Cc: Andi Kleen Cc: linux-efi@vger.kernel.org Signed-off-by: Prarit Bhargava [jstultz: Tweak commit message, fold in build fix found by fengguang Also add select RTC_LIB to X86, per new dependency, as found by prarit] Signed-off-by: John Stultz --- arch/x86/Kconfig | 1 + arch/x86/kernel/rtc.c | 69 ++++++++----------------------------------- arch/x86/platform/efi/efi.c | 24 ++++++++++----- arch/x86/platform/mrst/vrtc.c | 44 ++++++++++++++++----------- 4 files changed, 55 insertions(+), 83 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index a4f24f5b1218..26bd79261532 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -120,6 +120,7 @@ config X86 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION select OLD_SIGACTION if X86_32 select COMPAT_OLD_SIGACTION if IA32_EMULATION + select RTC_LIB config INSTRUCTION_DECODER def_bool y diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 2e8f3d3b5641..198eb201ed3b 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -13,6 +13,7 @@ #include #include #include +#include #ifdef CONFIG_X86_32 /* @@ -36,70 +37,24 @@ EXPORT_SYMBOL(rtc_lock); * 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. - * - * BUG: This routine does not handle hour overflow properly; it just - * sets the minutes. Usually you'll only notice that after reboot! */ int mach_set_rtc_mmss(unsigned long nowtime) { - int real_seconds, real_minutes, cmos_minutes; - unsigned char save_control, save_freq_select; - unsigned long flags; + struct rtc_time tm; int retval = 0; - spin_lock_irqsave(&rtc_lock, flags); - - /* tell the clock it's being set */ - save_control = CMOS_READ(RTC_CONTROL); - CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); - - /* 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); - if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) - cmos_minutes = bcd2bin(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 - */ - 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; - real_minutes %= 60; - - if (abs(real_minutes - cmos_minutes) < 30) { - if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { - real_seconds = bin2bcd(real_seconds); - real_minutes = bin2bcd(real_minutes); - } - CMOS_WRITE(real_seconds, RTC_SECONDS); - CMOS_WRITE(real_minutes, RTC_MINUTES); + rtc_time_to_tm(nowtime, &tm); + if (!rtc_valid_tm(&tm)) { + retval = set_rtc_time(&tm); + if (retval) + printk(KERN_ERR "%s: RTC write failed with error %d\n", + __FUNCTION__, retval); } else { - printk_once(KERN_NOTICE - "set_rtc_mmss: can't update from %d to %d\n", - cmos_minutes, real_minutes); - retval = -1; + printk(KERN_ERR + "%s: Invalid RTC value: write of %lx to RTC failed\n", + __FUNCTION__, nowtime); + retval = -EINVAL; } - - /* 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(save_control, RTC_CONTROL); - CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); - - spin_unlock_irqrestore(&rtc_lock, flags); - return retval; } diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 5f2ecaf3f9d8..28d9efacc9b6 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -48,6 +48,7 @@ #include #include #include +#include #define EFI_DEBUG 1 @@ -258,10 +259,10 @@ static efi_status_t __init phys_efi_get_time(efi_time_t *tm, int efi_set_rtc_mmss(unsigned long nowtime) { - int real_seconds, real_minutes; efi_status_t status; efi_time_t eft; efi_time_cap_t cap; + struct rtc_time tm; status = efi.get_time(&eft, &cap); if (status != EFI_SUCCESS) { @@ -269,13 +270,20 @@ int efi_set_rtc_mmss(unsigned long nowtime) return -1; } - real_seconds = nowtime % 60; - real_minutes = nowtime / 60; - if (((abs(real_minutes - eft.minute) + 15)/30) & 1) - real_minutes += 30; - real_minutes %= 60; - eft.minute = real_minutes; - eft.second = real_seconds; + rtc_time_to_tm(nowtime, &tm); + if (!rtc_valid_tm(&tm)) { + eft.year = tm.tm_year + 1900; + eft.month = tm.tm_mon + 1; + eft.day = tm.tm_mday; + eft.minute = tm.tm_min; + eft.second = tm.tm_sec; + eft.nanosecond = 0; + } else { + printk(KERN_ERR + "%s: Invalid EFI RTC value: write of %lx to EFI RTC failed\n", + __FUNCTION__, nowtime); + return -1; + } status = efi.set_time(&eft); if (status != EFI_SUCCESS) { diff --git a/arch/x86/platform/mrst/vrtc.c b/arch/x86/platform/mrst/vrtc.c index 225bd0f0f675..d62b0a3b5c14 100644 --- a/arch/x86/platform/mrst/vrtc.c +++ b/arch/x86/platform/mrst/vrtc.c @@ -85,27 +85,35 @@ unsigned long vrtc_get_time(void) return mktime(year, mon, mday, hour, min, sec); } -/* Only care about the minutes and seconds */ int vrtc_set_mmss(unsigned long nowtime) { - int real_sec, real_min; unsigned long flags; - int vrtc_min; - - spin_lock_irqsave(&rtc_lock, flags); - vrtc_min = vrtc_cmos_read(RTC_MINUTES); - - real_sec = nowtime % 60; - real_min = nowtime / 60; - if (((abs(real_min - vrtc_min) + 15)/30) & 1) - real_min += 30; - real_min %= 60; - - vrtc_cmos_write(real_sec, RTC_SECONDS); - vrtc_cmos_write(real_min, RTC_MINUTES); - spin_unlock_irqrestore(&rtc_lock, flags); - - return 0; + struct rtc_time tm; + int year; + int retval = 0; + + rtc_time_to_tm(nowtime, &tm); + if (!rtc_valid_tm(&tm) && tm.tm_year >= 72) { + /* + * tm.year is the number of years since 1900, and the + * vrtc need the years since 1972. + */ + year = tm.tm_year - 72; + spin_lock_irqsave(&rtc_lock, flags); + vrtc_cmos_write(year, RTC_YEAR); + vrtc_cmos_write(tm.tm_mon, RTC_MONTH); + vrtc_cmos_write(tm.tm_mday, RTC_DAY_OF_MONTH); + vrtc_cmos_write(tm.tm_hour, RTC_HOURS); + vrtc_cmos_write(tm.tm_min, RTC_MINUTES); + vrtc_cmos_write(tm.tm_sec, RTC_SECONDS); + spin_unlock_irqrestore(&rtc_lock, flags); + } else { + printk(KERN_ERR + "%s: Invalid vRTC value: write of %lx to vRTC failed\n", + __FUNCTION__, nowtime); + retval = -EINVAL; + } + return retval; } void __init mrst_rtc_init(void) -- cgit v1.2.3 From c54fdbb2823d96b842d00c548e14dbc0dd37831d Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Tue, 12 Mar 2013 11:56:45 +0800 Subject: x86: Add cpu capability flag X86_FEATURE_NONSTOP_TSC_S3 On some new Intel Atom processors (Penwell and Cloverview), there is a feature that the TSC won't stop in S3 state, say the TSC value won't be reset to 0 after resume. This feature makes TSC a more reliable clocksource and could benefit the timekeeping code during system suspend/resume cycle, so add a flag for it. Signed-off-by: Feng Tang [jstultz: Fix checkpatch warning] Signed-off-by: John Stultz --- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/intel.c | 12 ++++++++++++ 2 files changed, 13 insertions(+) (limited to 'arch/x86') diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 93fe929d1cee..a8466f203e62 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -100,6 +100,7 @@ #define X86_FEATURE_AMD_DCM (3*32+27) /* multi-node processor */ #define X86_FEATURE_APERFMPERF (3*32+28) /* APERFMPERF */ #define X86_FEATURE_EAGER_FPU (3*32+29) /* "eagerfpu" Non lazy FPU restore */ +#define X86_FEATURE_NONSTOP_TSC_S3 (3*32+30) /* TSC doesn't stop in S3 state */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* "pni" SSE-3 */ diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 1905ce98bee0..e7ae0d89e7e0 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -96,6 +96,18 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) sched_clock_stable = 1; } + /* Penwell and Cloverview have the TSC which doesn't sleep on S3 */ + if (c->x86 == 6) { + switch (c->x86_model) { + case 0x27: /* Penwell */ + case 0x35: /* Cloverview */ + set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3); + break; + default: + break; + } + } + /* * There is a known erratum on Pentium III and Core Solo * and Core Duo CPUs. -- cgit v1.2.3 From 82f9c080b22a5b859ae2b50822dfb6b812898fdb Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Tue, 12 Mar 2013 11:56:47 +0800 Subject: x86: tsc: Add support for new S3_NONSTOP feature Add support for new S3_NONSTOP feature Signed-off-by: Feng Tang Signed-off-by: John Stultz --- arch/x86/kernel/tsc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 4b9ea101fe3b..098b3cfda72e 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -768,7 +768,8 @@ static cycle_t read_tsc(struct clocksource *cs) static void resume_tsc(struct clocksource *cs) { - clocksource_tsc.cycle_last = 0; + if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3)) + clocksource_tsc.cycle_last = 0; } static struct clocksource clocksource_tsc = { @@ -939,6 +940,9 @@ static int __init init_tsc_clocksource(void) clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS; } + if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3)) + clocksource_tsc.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP; + /* * Trust the results of the earlier calibration on systems * exporting a reliable TSC. -- cgit v1.2.3