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* x86, hpet: Introduce x86_msi_ops.setup_hpet_msiJoerg Roedel2013-01-28
| | | | | | | | | | This function pointer can be overwritten by the IRQ remapping code. The irq_remapping_enabled check can be removed from default_setup_hpet_msi. Signed-off-by: Joerg Roedel <joro@8bytes.org> Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* x86: hpet: Fix masking of MSI interruptsJan Beulich2012-11-02
| | | | | | | | | | | | HPET_TN_FSB is not a proper mask bit; it merely toggles between MSI and legacy interrupt delivery. The proper mask bit is HPET_TN_ENABLE, so use both bits when (un)masking the interrupt. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/5093E09002000078000A60E6@nat28.tlf.novell.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: hpet: Fix copy-and-paste mistake in earlier changeJan Beulich2012-05-25
| | | | | | | | | | | This fixes an oversight in 396e2c6fed4ff13b53ce0e573105531cf53b0cad ("x86: Clear HPET configuration registers on startup"), noticed by Thomas Gleixner. Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4FBF7DA902000078000861EE@nat28.tlf.novell.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: Allow multiple values to be specified with "hpet="Jan Beulich2012-05-07
| | | | | | | | | | This is particularly to be able to specify "hpet=force,verbose", as "force" ought to be a primary candidate for also wanting to use "verbose". Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F79D120020000780007C031@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86: Clear HPET configuration registers on startupJan Beulich2012-05-07
| | | | | | | | | | | | | | | | | | | | | While Linux itself has been calling hpet_disable() for quite a while, having e.g. a secondary (kexec) kernel depend on such behavior of the primary (crashed) environment is fragile. It particularly broke until very recently when the primary environment was Xen based, as that hypervisor did not clear any of the HPET settings it may have used. Rather than blindly (and incompletely) clearing certain HPET settings in hpet_disable(), latch the config register settings during boot and restore then here. (Note on the hpet_set_mode() change: Now that we're clearing the level bit upon initialization, there's no need anymore to do so here.) Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/4F79D0BB020000780007C02D@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'driver-core-next' of ↵Linus Torvalds2012-01-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core * 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (73 commits) arm: fix up some samsung merge sysdev conversion problems firmware: Fix an oops on reading fw_priv->fw in sysfs loading file Drivers:hv: Fix a bug in vmbus_driver_unregister() driver core: remove __must_check from device_create_file debugfs: add missing #ifdef HAS_IOMEM arm: time.h: remove device.h #include driver-core: remove sysdev.h usage. clockevents: remove sysdev.h arm: convert sysdev_class to a regular subsystem arm: leds: convert sysdev_class to a regular subsystem kobject: remove kset_find_obj_hinted() m86k: gpio - convert sysdev_class to a regular subsystem mips: txx9_sram - convert sysdev_class to a regular subsystem mips: 7segled - convert sysdev_class to a regular subsystem sh: dma - convert sysdev_class to a regular subsystem sh: intc - convert sysdev_class to a regular subsystem power: suspend - convert sysdev_class to a regular subsystem power: qe_ic - convert sysdev_class to a regular subsystem power: cmm - convert sysdev_class to a regular subsystem s390: time - convert sysdev_class to a regular subsystem ... Fix up conflicts with 'struct sysdev' removal from various platform drivers that got changed: - arch/arm/mach-exynos/cpu.c - arch/arm/mach-exynos/irq-eint.c - arch/arm/mach-s3c64xx/common.c - arch/arm/mach-s3c64xx/cpu.c - arch/arm/mach-s5p64x0/cpu.c - arch/arm/mach-s5pv210/common.c - arch/arm/plat-samsung/include/plat/cpu.h - arch/powerpc/kernel/sysfs.c and fix up cpu_is_hotpluggable() as per Greg in include/linux/cpu.h
| * Merge branch 'driver-core-next' into Linux 3.2Greg Kroah-Hartman2012-01-06
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file, and it fixes the build error in the arch/x86/kernel/microcode_core.c file, that the merge did not catch. The microcode_core.c patch was provided by Stephen Rothwell <sfr@canb.auug.org.au> who was invaluable in the merge issues involved with the large sysdev removal process in the driver-core tree. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| | * driver-core: remove sysdev.h usage.Kay Sievers2011-12-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sysdev.h file should not be needed by any in-kernel code, so remove the .h file from these random files that seem to still want to include it. The sysdev code will be going away soon, so this include needs to be removed no matter what. Cc: Jiandong Zheng <jdzheng@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: David Brown <davidb@codeaurora.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Bryan Huntsman <bryanh@codeaurora.org> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: "Venkatesh Pallipadi Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
* | | Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds2012-01-06
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Use "do { } while(0)" for empty lock_cmos()/unlock_cmos() macros x86: Use "do { } while(0)" for empty flush_tlb_fix_spurious_fault() macro x86, CPU: Drop superfluous get_cpu_cap() prototype arch/x86/mm/pageattr.c: Quiet sparse noise; local functions should be static arch/x86/kernel/ptrace.c: Quiet sparse noise x86: Use kmemdup() in copy_thread(), rather than duplicating its implementation x86: Replace the EVT_TO_HPET_DEV() macro with an inline function
| * | x86: Replace the EVT_TO_HPET_DEV() macro with an inline functionFerenc Wagner2011-12-05
| |/ | | | | | | | | | | | | | | | | | | | | The original macro worked only when applied to variables named 'evt'. While this could have been fixed by simply renaming the macro argument, a more type-safe replacement is preferred. Signed-off-by: Ferenc Wagner <wferi@niif.hu> Cc: Venkatesh Pallipadi \(Venki\) <venki@google.com> Link: http://lkml.kernel.org/r/8ed5c66c02041226e8cf8b4d5d6b41e543d90bd6.1321626272.git.wferi@niif.hu Signed-off-by: Ingo Molnar <mingo@elte.hu>
* / x86, hpet: Immediately disable HPET timer 1 if rtc irq is maskedMark Langsdorf2011-12-08
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | When HPET is operating in RTC mode, the TN_ENABLE bit on timer1 controls whether the HPET or the RTC delivers interrupts to irq8. When the system goes into suspend, the RTC driver sends a signal to the HPET driver so that the HPET releases control of irq8, allowing the RTC to wake the system from suspend. The switchover is accomplished by a write to the HPET configuration registers which currently only occurs while servicing the HPET interrupt. On some systems, I have seen the system suspend before an HPET interrupt occurs, preventing the write to the HPET configuration register and leaving the HPET in control of the irq8. As the HPET is not active during suspend, it does not generate a wake signal and RTC alarms do not work. This patch forces the HPET driver to immediately transfer control of the irq8 channel to the RTC instead of waiting until the next interrupt event. Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com> Link: http://lkml.kernel.org/r/20111118153306.GB16319@alberich.amd.com Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
* x86: Fix files explicitly requiring export.h for EXPORT_SYMBOL/THIS_MODULEPaul Gortmaker2011-10-31
| | | | | | | | | | | | | | | | These files were implicitly getting EXPORT_SYMBOL via device.h which was including module.h, but that will be fixed up shortly. By fixing these now, we can avoid seeing things like: arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’ [ with input from Randy Dunlap <rdunlap@xenotime.net> and also from Stephen Rothwell <sfr@canb.auug.org.au> ] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds2011-07-22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86-64, vdso: Do not allocate memory for the vDSO clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option x86, vdso: Drop now wrong comment Document the vDSO and add a reference parser ia64: Replace clocksource.fsys_mmio with generic arch data x86-64: Move vread_tsc and vread_hpet into the vDSO clocksource: Replace vread with generic arch data x86-64: Add --no-undefined to vDSO build x86-64: Allow alternative patching in the vDSO x86: Make alternative instruction pointers relative x86-64: Improve vsyscall emulation CS and RIP handling x86-64: Emulate legacy vsyscalls x86-64: Fill unused parts of the vsyscall page with 0xcc x86-64: Remove vsyscall number 3 (venosys) x86-64: Map the HPET NX x86-64: Remove kernel.vsyscall64 sysctl x86-64: Give vvars their own page x86-64: Document some of entry_64.S x86-64: Fix alignment of jiffies variable
| * x86-64: Move vread_tsc and vread_hpet into the vDSOAndy Lutomirski2011-07-14
| | | | | | | | | | | | | | | | | | The vsyscall page now consists entirely of trap instructions. Cc: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/637648f303f2ef93af93bae25186e9a1bea093f5.1310639973.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * clocksource: Replace vread with generic arch dataAndy Lutomirski2011-07-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vread field was bloating struct clocksource everywhere except x86_64, and I want to change the way this works on x86_64, so let's split it out into per-arch data. Cc: x86@kernel.org Cc: Clemens Ladisch <clemens@ladisch.de> Cc: linux-ia64@vger.kernel.org Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/3ae5ec76a168eaaae63f08a2a1060b91aa0b7759.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * x86-64: Map the HPET NXAndy Lutomirski2011-06-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the HPET mapping is a user-accessible syscall instruction at a fixed address some of the time. A sufficiently determined hacker might be able to guess when. Signed-off-by: Andy Lutomirski <luto@mit.edu> Cc: Jesper Juhl <jj@chaosbits.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Jan Beulich <JBeulich@novell.com> Cc: richard -rw- weinberger <richard.weinberger@gmail.com> Cc: Mikael Pettersson <mikpe@it.uu.se> Cc: Andi Kleen <andi@firstfloor.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Louis Rilling <Louis.Rilling@kerlabs.com> Cc: Valdis.Kletnieks@vt.edu Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/ab41b525a4ca346b1ca1145d16fb8d181861a8aa.1307292171.git.luto@mit.edu Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86: i8253: Consolidate definitions of global_clock_eventRalf Baechle2011-06-09
| | | | | | | | | | | | | | | | | | | | | | | | There are multiple declarations of global_clock_event in header files specific to particular clock event implementations. Consolidate them in <asm/time.h> and make sure all users include that header. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Venkatesh Pallipadi (Venki) <venki@google.com> Link: http://lkml.kernel.org/r/20110601180610.762763451@duck.linux-mips.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | i8253: Create linux/i8253.h and use it in all 8253 related filesRalf Baechle2011-06-09
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Link: http://lkml.kernel.org/r/20110601180610.054254048@duck.linux-mips.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de> arch/arm/mach-footbridge/isa-timer.c | 2 +- arch/mips/cobalt/time.c | 2 +- arch/mips/jazz/irq.c | 2 +- arch/mips/kernel/i8253.c | 2 +- arch/mips/mti-malta/malta-time.c | 2 +- arch/mips/sgi-ip22/ip22-time.c | 2 +- arch/mips/sni/time.c | 2 +- arch/x86/kernel/apic/apic.c | 2 +- arch/x86/kernel/apm_32.c | 2 +- arch/x86/kernel/hpet.c | 2 +- arch/x86/kernel/i8253.c | 2 +- arch/x86/kernel/time.c | 2 +- drivers/block/hd.c | 2 +- drivers/clocksource/i8253.c | 2 +- drivers/input/gameport/gameport.c | 2 +- drivers/input/joystick/analog.c | 2 +- drivers/input/misc/pcspkr.c | 2 +- include/linux/i8253.h | 11 +++++++++++ sound/drivers/pcsp/pcsp.h | 2 +- 19 files changed, 29 insertions(+), 18 deletions(-)
* x86: hpet: Cleanup the clockevents init and register codeThomas Gleixner2011-05-19
| | | | | | | | | | | No need to recalculate the frequency and the conversion factors over and over. Calculate the frequency once and use the new config/register interface and let the core code do the math. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Reviewed-by: Ingo Molnar <mingo@elte.hu> Link: http://lkml.kernel.org/r/%3C20110518210136.646482357%40linutronix.de%3E
* x86: Cleanup the genirq name spaceThomas Gleixner2011-03-12
| | | | | | | genirq is switching to a consistent name space for the irq related functions. Convert x86. Conversion was done with coccinelle. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: HPET: Chose a paranoid safe value for the ETIME checkThomas Gleixner2010-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 995bd3bb5 (x86: Hpet: Avoid the comparator readback penalty) chose 8 HPET cycles as a safe value for the ETIME check, as we had the confirmation that the posted write to the comparator register is delayed by two HPET clock cycles on Intel chipsets which showed readback problems. After that patch hit mainline we got reports from machines with newer AMD chipsets which seem to have an even longer delay. See http://thread.gmane.org/gmane.linux.kernel/1054283 and http://thread.gmane.org/gmane.linux.kernel/1069458 for further information. Boris tried to come up with an ACPI based selection of the minimum HPET cycles, but this failed on a couple of test machines. And of course we did not get any useful information from the hardware folks. For now our only option is to chose a paranoid high and safe value for the minimum HPET cycles used by the ETIME check. Adjust the minimum ns value for the HPET clockevent accordingly. Reported-Bistected-and-Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <alpine.LFD.2.00.1012131222420.2653@localhost6.localdomain6> Cc: Simon Kirby <sim@hostway.ca> Cc: Borislav Petkov <bp@alien8.de> Cc: Andreas Herrmann <Andreas.Herrmann3@amd.com> Cc: John Stultz <johnstul@us.ibm.com>
* workqueues: s/ON_STACK/ONSTACK/Andrew Morton2010-10-26
| | | | | | | | | | | | | | | Silly though it is, completions and wait_queue_heads use foo_ONSTACK (COMPLETION_INITIALIZER_ONSTACK, DECLARE_COMPLETION_ONSTACK, __WAIT_QUEUE_HEAD_INIT_ONSTACK and DECLARE_WAIT_QUEUE_HEAD_ONSTACK) so I guess workqueues should do the same thing. s/INIT_WORK_ON_STACK/INIT_WORK_ONSTACK/ s/INIT_DELAYED_WORK_ON_STACK/INIT_DELAYED_WORK_ONSTACK/ Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds2010-10-22
|\ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Hpet: Avoid the comparator readback penalty
| * x86: Hpet: Avoid the comparator readback penaltyThomas Gleixner2010-09-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to the overly intelligent design of HPETs, we need to workaround the problem that the compare value which we write is already behind the actual counter value at the point where the value hits the real compare register. This happens for two reasons: 1) We read out the counter, add the delta and write the result to the compare register. When a NMI or SMI hits between the read out and the write then the counter can be ahead of the event already 2) The write to the compare register is delayed by up to two HPET cycles in certain chipsets. We worked around this by reading back the compare register to make sure that the written value has hit the hardware. For certain ICH9+ chipsets this can require two readouts, as the first one can return the previous compare register value. That's bad performance wise for the normal case where the event is far enough in the future. As we already know that the write can be delayed by up to two cycles we can avoid the read back of the compare register completely if we make the decision whether the delta has elapsed already or not based on the following calculation: cmp = event - actual_count; If cmp is less than 8 HPET clock cycles, then we decide that the event has happened already and return -ETIME. That covers the above #1 and #2 problems which would cause a wait for HPET wraparound (~306 seconds). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Nix <nix@esperi.org.uk> Tested-by: Artur Skawina <art.08.09@gmail.com> Cc: Damien Wyart <damien.wyart@free.fr> Tested-by: John Drescher <drescherjm@gmail.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Tested-by: Borislav Petkov <borislav.petkov@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <alpine.LFD.2.00.1009151500060.2416@localhost6.localdomain6>
* | x86: ioapic/hpet: Convert to new chip functionsThomas Gleixner2010-10-12
| | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
* | x86, hpet: Fix bogus error check in hpet_assign_irq()Thomas Gleixner2010-09-30
|/ | | | | | | | | | | | | create_irq() returns -1 if the interrupt allocation failed, but the code checks for irq == 0. Use create_irq_nr() instead. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Venkatesh Pallipadi <venki@google.com> LKML-Reference: <alpine.LFD.2.00.1009282310360.2416@localhost6.localdomain6> Cc: stable@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: hpet: Work around hardware stupidityThomas Gleixner2010-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This more or less reverts commits 08be979 (x86: Force HPET readback_cmp for all ATI chipsets) and 30a564be (x86, hpet: Restrict read back to affected ATI chipsets) to the status of commit 8da854c (x86, hpet: Erratum workaround for read after write of HPET comparator). The delta to commit 8da854c is mostly comments and the change from WARN_ONCE to printk_once as we know the call path of this function already. This needs really in depth explanation: First of all the HPET design is a complete failure. Having a counter compare register which generates an interrupt on matching values forces the software to do at least one superfluous readback of the counter register. While it is nice in theory to program "absolute" time events it is practically useless because the timer runs at some absurd frequency which can never be matched to real world units. So we are forced to calculate a relative delta and this forces a readout of the actual counter value, adding the delta and programming the compare register. When the delta is small enough we run into the danger that we program a compare value which is already in the past. Due to the compare for equal nature of HPET we need to read back the counter value after writing the compare rehgister (btw. this is necessary for absolute timeouts as well) to make sure that we did not miss the timer event. We try to work around that by setting the minimum delta to a value which is larger than the theoretical time which elapses between the counter readout and the compare register write, but that's only true in theory. A NMI or SMI which hits between the readout and the write can easily push us beyond that limit. This would result in waiting for the next HPET timer interrupt until the 32bit wraparound of the counter happens which takes about 306 seconds. So we designed the next event function to look like: match = read_cnt() + delta; write_compare_ref(match); return read_cnt() < match ? 0 : -ETIME; At some point we got into trouble with certain ATI chipsets. Even the above "safe" procedure failed. The reason was that the write to the compare register was delayed probably for performance reasons. The theory was that they wanted to avoid the synchronization of the write with the HPET clock, which is understandable. So the write does not hit the compare register directly instead it goes to some intermediate register which is copied to the real compare register in sync with the HPET clock. That opens another window for hitting the dreaded "wait for a wraparound" problem. To work around that "optimization" we added a read back of the compare register which either enforced the update of the just written value or just delayed the readout of the counter enough to avoid the issue. We unfortunately never got any affirmative info from ATI/AMD about this. One thing is sure, that we nuked the performance "optimization" that way completely and I'm pretty sure that the result is worse than before some HW folks came up with those. Just for paranoia reasons I added a check whether the read back compare register value was the same as the value we wrote right before. That paranoia check triggered a couple of years after it was added on an Intel ICH9 chipset. Venki added a workaround (commit 8da854c) which was reading the compare register twice when the first check failed. We considered this to be a penalty in general and restricted the readback (thus the wasted CPU cycles) to the known to be affected ATI chipsets. This turned out to be a utterly wrong decision. 2.6.35 testers experienced massive problems and finally one of them bisected it down to commit 30a564be which spured some further investigation. Finally we got confirmation that the write to the compare register can be delayed by up to two HPET clock cycles which explains the problems nicely. All we can do about this is to go back to Venki's initial workaround in a slightly modified version. Just for the record I need to say, that all of this could have been avoided if hardware designers and of course the HPET committee would have thought about the consequences for a split second. It's out of my comprehension why designing a working timer is so hard. There are two ways to achieve it: 1) Use a counter wrap around aware compare_reg <= counter_reg implementation instead of the easy compare_reg == counter_reg Downsides: - It needs more silicon. - It needs a readout of the counter to apply a relative timeout. This is necessary as the counter does not run in any useful (and adjustable) frequency and there is no guarantee that the counter which is used for timer events is the same which is used for reading the actual time (and therefor for calculating the delta) Upsides: - None 2) Use a simple down counter for relative timer events Downsides: - Absolute timeouts are not possible, which is not a problem at all in the context of an OS and the expected max. latencies/jitter (also see Downsides of #1) Upsides: - It needs less or equal silicon. - It works ALWAYS - It is way faster than a compare register based solution (One write versus one write plus at least one and up to four reads) I would not be so grumpy about all of this, if I would not have been ignored for many years when pointing out these flaws to various hardware folks. I really hate timers (at least those which seem to be designed by janitors). Though finally we got a reasonable explanation plus a solution and I want to thank all the folks involved in chasing it down and providing valuable input to this. Bisected-by: Nix <nix@esperi.org.uk> Reported-by: Artur Skawina <art.08.09@gmail.com> Reported-by: Damien Wyart <damien.wyart@free.fr> Reported-by: John Drescher <drescherjm@gmail.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: stable@kernel.org Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86/hpet: Use the FSEC_PER_SEC constant for femto-second periodsChris Wilson2010-08-12
| | | | | | | | | | | | | | | | | The current computation, introduced with f12a15be63, of FSEC_PER_SEC using the multiplication of (FSEC_PER_NSEC * NSEC_PER_SEC) is performed only with 32bit integers on small machines, resulting in an overflow and a *very* short intervals being programmed. An interrupt storm follows. Note that we also have to specify FSEC_PER_SEC as being long long to overcome the same limitations. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: Convert common clocksources to use clocksource_register_hz/khzJohn Stultz2010-07-27
| | | | | | | | | This converts the most common of the x86 clocksources over to use clocksource_register_hz/khz. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-11-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: Do not try to disable hpet if it hasn't been initialized beforeStefano Stabellini2010-07-23
| | | | | | | | | | | | | | | hpet_disable is called unconditionally on machine reboot if hpet support is compiled in the kernel. hpet_disable only checks if the machine is hpet capable but doesn't make sure that hpet has been initialized. [ tglx: Made it a one liner and removed the redundant hpet_address check ] Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Venkatesh Pallipadi <venki@google.com> LKML-Reference: <alpine.DEB.2.00.1007211726240.22235@kaball-desktop> Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86, hpet: Restrict read back to affected ATI chipsetsThomas Gleixner2010-04-28
| | | | | | | | | | | | | | | | After programming the HPET, we do a readback as a workaround for ATI/SBx00 chipsets as a synchronization. Unfortunately this triggers an erratum in newer ICH chipsets (ICH9+) where reading the comparator immediately after the write returns the old value. Furthermore, as always, I/O reads are bad for performance. Therefore, restrict the readback to the chipsets that need it, or, for debugging purposes, when we are running with hpet=verbose. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Venkatesh Pallipadi <venki@google.com> LKML-Reference: <20100225185348.GA9674@linux-os.sc.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2010-04-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip: x86: Fix double enable_IR_x2apic() call on SMP kernel on !SMP boards x86: Increase CONFIG_NODES_SHIFT max to 10 ibft, x86: Change reserve_ibft_region() to find_ibft_region() x86, hpet: Fix bug in RTC emulation x86, hpet: Erratum workaround for read after write of HPET comparator bootmem, x86: Fix 32bit numa system without RAM on node 0 nobootmem, x86: Fix 32bit numa system without RAM on node 0 x86: Handle overlapping mptables x86: Make e820_remove_range to handle all covered case x86-32, resume: do a global tlb flush in S4 resume
| * x86, hpet: Fix bug in RTC emulationAlok Kataria2010-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We think there exists a bug in the HPET code that emulates the RTC. In the normal case, when the RTC frequency is set, the rtc driver tells the hpet code about it here: int hpet_set_periodic_freq(unsigned long freq) { uint64_t clc; if (!is_hpet_enabled()) return 0; if (freq <= DEFAULT_RTC_INT_FREQ) hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq; else { clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC; do_div(clc, freq); clc >>= hpet_clockevent.shift; hpet_pie_delta = (unsigned long) clc; } return 1; } If freq is set to 64Hz (DEFAULT_RTC_INT_FREQ) or lower, then hpet_pie_limit (a static) is set to non-zero. Then, on every one-shot HPET interrupt, hpet_rtc_timer_reinit is called to compute the next timeout. Well, that function has this logic: if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit) delta = hpet_default_delta; else delta = hpet_pie_delta; Since hpet_pie_limit is not 0, hpet_default_delta is used. That corresponds to 64Hz. Now, if you set a different rtc frequency, you'll take the else path through hpet_set_periodic_freq, but unfortunately no one resets hpet_pie_limit back to 0. Boom....now you are stuck with 64Hz RTC interrupts forever. The patch below just resets the hpet_pie_limit value when requested freq is greater than DEFAULT_RTC_INT_FREQ, which we think fixes this problem. Signed-off-by: Alok N Kataria <akataria@vmware.com> LKML-Reference: <201003112200.o2BM0Hre012875@imap1.linux-foundation.org> Signed-off-by: Daniel Hecht <dhecht@vmware.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * x86, hpet: Erratum workaround for read after write of HPET comparatorPallipadi, Venkatesh2010-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Wed, Feb 24, 2010 at 03:37:04PM -0800, Justin Piszcz wrote: > Hello, > > Again, on the Intel DP55KG board: > > # uname -a > Linux host 2.6.33 #1 SMP Wed Feb 24 18:31:00 EST 2010 x86_64 GNU/Linux > > [ 1.237600] ------------[ cut here ]------------ > [ 1.237890] WARNING: at arch/x86/kernel/hpet.c:404 hpet_next_event+0x70/0x80() > [ 1.238221] Hardware name: > [ 1.238504] hpet: compare register read back failed. > [ 1.238793] Modules linked in: > [ 1.239315] Pid: 0, comm: swapper Not tainted 2.6.33 #1 > [ 1.239605] Call Trace: > [ 1.239886] <IRQ> [<ffffffff81056c13>] ? warn_slowpath_common+0x73/0xb0 > [ 1.240409] [<ffffffff81079608>] ? tick_dev_program_event+0x38/0xc0 > [ 1.240699] [<ffffffff81056cb0>] ? warn_slowpath_fmt+0x40/0x50 > [ 1.240992] [<ffffffff81079608>] ? tick_dev_program_event+0x38/0xc0 > [ 1.241281] [<ffffffff81041ad0>] ? hpet_next_event+0x70/0x80 > [ 1.241573] [<ffffffff81079608>] ? tick_dev_program_event+0x38/0xc0 > [ 1.241859] [<ffffffff81078e32>] ? tick_handle_oneshot_broadcast+0xe2/0x100 > [ 1.246533] [<ffffffff8102a67a>] ? timer_interrupt+0x1a/0x30 > [ 1.246826] [<ffffffff81085499>] ? handle_IRQ_event+0x39/0xd0 > [ 1.247118] [<ffffffff81087368>] ? handle_edge_irq+0xb8/0x160 > [ 1.247407] [<ffffffff81029f55>] ? handle_irq+0x15/0x20 > [ 1.247689] [<ffffffff810294a2>] ? do_IRQ+0x62/0xe0 > [ 1.247976] [<ffffffff8146be53>] ? ret_from_intr+0x0/0xa > [ 1.248262] <EOI> [<ffffffff8102f277>] ? mwait_idle+0x57/0x80 > [ 1.248796] [<ffffffff8102645c>] ? cpu_idle+0x5c/0xb0 > [ 1.249080] ---[ end trace db7f668fb6fef4e1 ]--- > > Is this something Intel has to fix or is it a bug in the kernel? This is a chipset erratum. Thomas: You mentioned we can retain this check only for known-buggy and hpet debug kind of options. But here is the simple workaround patch for this particular erratum. Some chipsets have a erratum due to which read immediately following a write of HPET comparator returns old comparator value instead of most recently written value. Erratum 15 in "Intel I/O Controller Hub 9 (ICH9) Family Specification Update" (http://www.intel.com/assets/pdf/specupdate/316973.pdf) Workaround for the errata is to read the comparator twice if the first one fails. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> LKML-Reference: <20100225185348.GA9674@linux-os.sc.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@gmail.com> Cc: <stable@kernel.org>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-30
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* clocksource: add argument to resume callbackMagnus Damm2010-02-05
| | | | | | | | | | | | Pass the clocksource as an argument to the clocksource resume callback. Needed so we can point out which CMT channel the sh_cmt.c driver shall resume. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: john stultz <johnstul@us.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: Disable HPET MSI on ATI SB700/SB800Pallipadi, Venkatesh2010-01-23
| | | | | | | | | | | | | | | | | | | HPET MSI on platforms with ATI SB700/SB800 as they seem to have some side-effects on floppy DMA. Do not use HPET MSI on such platforms. Original problem report from Mark Hounschell http://lkml.indiana.edu/hypermail/linux/kernel/0912.2/01118.html [ This patch needs to go to stable as well. But, there are some conflicts that prevents the patch from going as is. I can rebase/resubmit to stable once the patch goes upstream. hpa: still Cc:'ing stable@ as an FYI. ] Tested-by: Mark Hounschell <markh@compro.net> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: <stable@kernel.org> LKML-Reference: <20100121190952.GA32523@linux-os.sc.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86: hpet: Make WARN_ON understandableThomas Gleixner2009-11-27
| | | | | | | | | | | | Andrew complained rightly that the WARN_ON in hpet_next_event() is confusing and the code comment not really helpful. Change it to WARN_ONCE and print the reason in clear text. Change the comment to explain what kind of hardware wreckage we deal with. Pointed-out-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
* x86: arch specific support for remapping HPET MSIsSuresh Siddha2009-08-27
| | | | | | | | | | | | | x86 arch support for remapping HPET MSI's by associating the HPET timer block with the interrupt-remapping HW unit and setting up appropriate irq_chip Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Jay Fenlason <fenlason@redhat.com> LKML-Reference: <20090804190729.630510000@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86, hpet: Simplify the HPET codeJan Beulich2009-08-21
| | | | | | | | | | | | | | | On 64-bits, using unsigned long when unsigned int suffices needlessly creates larger code (due to the need for REX prefixes), and most of the logic in hpet.c really doesn't need 64-bit operations. At once this avoids the need for a couple of type casts. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> LKML-Reference: <4A8BC9780200007800010832@vpn.id2.novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, hpet: Disable per-cpu hpet timer if ARAT is supportedShaohua Li2009-08-12
| | | | | | | | | | | | | If CPU support always running local APIC timer, per-cpu hpet timer could be disabled, which is useless and wasteful in such case. Let's leave the timers to others. The effect is that we reserve less timers. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: venkatesh.pallipadi@intel.com LKML-Reference: <20090812031612.GA10062@sli10-desk.sh.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: hpet: Mark per cpu interrupts IRQF_TIMER to prevent resume failureThomas Gleixner2009-06-14
| | | | | | | | | | | | | | | | | | | timer interrupts are excluded from being disabled during suspend. The clock events code manages the disabling of clock events on its own because the timer interrupt needs to be functional before the resume code reenables the device interrupts. The hpet per cpu timers request their interrupt without setting the IRQF_TIMER flag so suspend_device_irqs() disables them as well which results in a fatal resume failure on the boot CPU. Adding IRQF_TIMER to the interupt flags when requesting the hpet per cpu timer interrupts solves the problem. Reported-by: Benjamin S. <sbenni@gmx.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Benjamin S. <sbenni@gmx.de> Cc: stable@kernel.org
* x86: hpet: fix periodic mode programming on AMD 81xxAndreas Herrmann2009-04-22
| | | | | | | | | | | | | | | | | | | | | | | (See http://bugzilla.kernel.org/show_bug.cgi?id=12961) It partially reverts commit c23e253e67c9d8a91a0ffa33c1f571a17f0a2403 (x86: hpet: stop HPET_COUNTER when programming periodic mode) HPET on AMD 81xx chipset needs a second write (with HPET_TN_SETVAL cleared) to T0_CMP register to set the period in periodic mode. With this patch HPET_COUNTER is still stopped but not reset when HPET is programmed in periodic mode. This should help to avoid races when HPET is programmed in periodic mode and fixes a boot time hang that I've observed on a machine when using 1000HZ. [ Impact: fix boot time hang on machines with AMD 81xx chipset ] Reported-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Tested-by: Jeff Mahoney <jeffm@suse.com> LKML-Reference: <20090421180037.GA2763@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* clocksource: pass clocksource to read() callbackMagnus Damm2009-04-21
| | | | | | | | | | | | | | Pass clocksource pointer to the read() callback for clocksources. This allows us to share the callback between multiple instances. [hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods] [akpm@linux-foundation.org: cleanup] Signed-off-by: Magnus Damm <damm@igel.co.jp> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: hpet: stop HPET_COUNTER when programming periodic modeAndreas Herrmann2009-02-22
| | | | | | | | | | | | | | | | | | Impact: fix system hang on some systems operating with HZ_1000 On a system that stalled with HZ_1000, the first value written to T0_CMP (when the main counter was not stopped) did not trigger an interrupt. Instead after the main counter wrapped around (after several minutes) an interrupt was triggered and afterwards the periodic interrupt took effect. This can be fixed by implementing HPET spec recommendation for programming the periodic mode (i.e. stopping the main counter). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Mark Hounschell <markh@compro.net> Cc: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: hpet: provide separate functions to stop and start the counterAndreas Herrmann2009-02-22
| | | | | | | | | By splitting up existing hpet_start_counter function. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Mark Hounschell <markh@compro.net> Cc: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: hpet: print HPET registers during setup (if hpet=verbose is used)Andreas Herrmann2009-02-22
| | | | | | | Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Mark Hounschell <markh@compro.net> Cc: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-02-17
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, vm86: fix preemption bug x86, olpc: fix model detection without OFW x86, hpet: fix for LS21 + HPET = boot hang x86: CPA avoid repeated lazy mmu flush x86: warn if arch_flush_lazy_mmu_cpu is called in preemptible context x86/paravirt: make arch_flush_lazy_mmu/cpu disable preemption x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem x86/cpa: make sure cpa is safe to call in lazy mmu mode x86, ptrace, mm: fix double-free on race
| * x86, hpet: fix for LS21 + HPET = boot hangjohn stultz2009-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Between 2.6.23 and 2.6.24-rc1 a change was made that broke IBM LS21 systems that had the HPET enabled in the BIOS, resulting in boot hangs for x86_64. Specifically commit b8ce33590687888ebb900d09557b8807c4539022, which merges the i386 and x86_64 HPET code. Prior to this commit, when we setup the HPET timers in x86_64, we did the following: hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL | HPET_TN_32BIT, HPET_T0_CFG); However after the i386/x86_64 HPET merge, we do the following: cfg = hpet_readl(HPET_Tn_CFG(timer)); cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL | HPET_TN_32BIT; hpet_writel(cfg, HPET_Tn_CFG(timer)); However on LS21s with HPET enabled in the BIOS, the HPET_T0_CFG register boots with Level triggered interrupts (HPET_TN_LEVEL) enabled. This causes the periodic interrupt to be not so periodic, and that results in the boot time hang I reported earlier in the delay calibration. My fix: Always disable HPET_TN_LEVEL when setting up periodic mode. Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86: clean up hpet timer reinitPavel Emelyanov2009-02-06
| | | | | | | | | | | | | | | | | | | | | | Implement Linus's suggestion: introduce the hpet_cnt_ahead() helper function to compare hpet time values - like other wrapping counter comparisons are abstracted away elsewhere. (jiffies, ktime_t, etc.) Reported-by: Kirill Korotaev <dev@openvz.org> Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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