Commit graph

59 commits

Author SHA1 Message Date
Thomas Gleixner
507fa3a3d8 x86: hpet: Mark per cpu interrupts IRQF_TIMER to prevent resume failure
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
2009-06-14 18:24:29 +02:00
Andreas Herrmann
7a6f9cbb37 x86: hpet: fix periodic mode programming on AMD 81xx
(See http://bugzilla.kernel.org/show_bug.cgi?id=12961)

It partially reverts commit c23e253e67
(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>
2009-04-22 15:53:40 +02:00
Magnus Damm
8e19608e8b clocksource: pass clocksource to read() callback
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>
2009-04-21 13:41:47 -07:00
Andreas Herrmann
c23e253e67 x86: hpet: stop HPET_COUNTER when programming periodic mode
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>
2009-02-22 18:01:18 +01:00
Andreas Herrmann
8d6f0c8214 x86: hpet: provide separate functions to stop and start the counter
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>
2009-02-22 18:01:17 +01:00
Andreas Herrmann
b98103a559 x86: hpet: print HPET registers during setup (if hpet=verbose is used)
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>
2009-02-22 18:01:14 +01:00
Linus Torvalds
35010334aa Merge branch 'x86-fixes-for-linus' of 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
2009-02-17 14:27:39 -08:00
john stultz
b13e24644c x86, hpet: fix for LS21 + HPET = boot hang
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 b8ce335906, 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>
2009-02-13 09:15:46 +01:00
Pavel Emelyanov
ff08f76d73 x86: clean up hpet timer reinit
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>
2009-02-06 15:07:13 +01:00
Pavel Emelyanov
a6a95406c6 x86: fix hpet timer reinit for x86_64
There's a small problem with hpet_rtc_reinit function - it checks
for the:

	hpet_readl(HPET_COUNTER) - hpet_t1_cmp > 0

to continue increasing both the HPET_T1_CMP (register) and the
hpet_t1_cmp (variable).

But since the HPET_COUNTER is always 32-bit, if the hpet_t1_cmp
is 64-bit this condition will always be FALSE once the latter hits
the 32-bit boundary, and we can have a situation, when we don't
increase the HPET_T1_CMP register high enough.

The result - timer stops ticking, since HPET_T1_CMP becomes less,
than the COUNTER and never increased again.

The solution is (based on Linus's suggestion) to not compare 64-bits
(on 64-bit x86), but to do the comparison on 32-bit signed
integers.

Reported-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05 01:04:16 +01:00
Thomas Gleixner
336f6c322d debugobjects: add and use INIT_WORK_ON_STACK
Impact: Fix debugobjects warning

debugobject enabled kernels spit out a warning in hpet code due to a
workqueue which is initialized on stack.

Add INIT_WORK_ON_STACK() which calls init_timer_on_stack() and use it
in hpet.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-01-22 10:02:07 +01:00
Linus Torvalds
b840d79631 Merge branch 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
  x86: export vector_used_by_percpu_irq
  x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
  sched: nominate preferred wakeup cpu, fix
  x86: fix lguest used_vectors breakage, -v2
  x86: fix warning in arch/x86/kernel/io_apic.c
  sched: fix warning in kernel/sched.c
  sched: move test_sd_parent() to an SMP section of sched.h
  sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
  sched: activate active load balancing in new idle cpus
  sched: bias task wakeups to preferred semi-idle packages
  sched: nominate preferred wakeup cpu
  sched: favour lower logical cpu number for sched_mc balance
  sched: framework for sched_mc/smt_power_savings=N
  sched: convert BALANCE_FOR_xx_POWER to inline functions
  x86: use possible_cpus=NUM to extend the possible cpus allowed
  x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
  x86: update io_apic.c to the new cpumask code
  x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
  x86: xen: use smp_call_function_many()
  x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
  ...

Fixed up trivial conflict in kernel/time/tick-sched.c manually
2009-01-02 11:44:09 -08:00
Linus Torvalds
bb758e9637 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimers: fix warning in kernel/hrtimer.c
  x86: make sure we really have an hpet mapping before using it
  x86: enable HPET on Fujitsu u9200
  linux/timex.h: cleanup for userspace
  posix-timers: simplify de_thread()->exit_itimers() path
  posix-timers: check ->it_signal instead of ->it_pid to validate the timer
  posix-timers: use "struct pid*" instead of "struct task_struct*"
  nohz: suppress needless timer reprogramming
  clocksource, acpi_pm.c: put acpi_pm_read_slow() under CONFIG_PCI
  nohz: no softirq pending warnings for offline cpus
  hrtimer: removing all ur callback modes, fix
  hrtimer: removing all ur callback modes, fix hotplug
  hrtimer: removing all ur callback modes
  x86: correct link to HPET timer specification
  rtc-cmos: export second NVRAM bank

Fixed up conflicts in sound/drivers/pcsp/pcsp.c and sound/core/hrtimer.c
manually.
2008-12-30 16:16:21 -08:00
Jeremy Fitzhardinge
39c04b5524 x86: make sure we really have an hpet mapping before using it
Impact: prepare the hpet code for Xen dom0 booting

When booting in Xen dom0, the hpet isn't really accessible, so make
sure the mapping is non-NULL before use.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 22:01:46 +01:00
Janne Kulmala
bacbe99945 x86: enable HPET on Fujitsu u9200
Impact: auto-enable HPET on Fujitsu u9200

HPET timer is listed in the ACPI table, but needs a quirk entry in order to
work. Unfortunately, the quirk code runs after first HPET hpet_enable() which
has already determined that the timer doesn't work (reads 0xFFFFFFFF). This
patch allows hpet_enable() to be called again after running the quirk code.

Signed-off-by: Janne Kulmala <janne.t.kulmala@tut.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 20:36:44 +01:00
Rusty Russell
320ab2b0b1 cpumask: convert struct clock_event_device to cpumask pointers.
Impact: change calling convention of existing clock_event APIs

struct clock_event_timer's cpumask field gets changed to take pointer,
as does the ->broadcast function.

Another single-patch change.  For safety, we BUG_ON() in
clockevents_register_device() if it's not set.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
2008-12-13 21:20:26 +10:30
Rusty Russell
0de26520c7 cpumask: make irq_set_affinity() take a const struct cpumask
Impact: change existing irq_chip API

Not much point with gentle transition here: the struct irq_chip's
setaffinity method signature needs to change.

Fortunately, not widely used code, but hits a few architectures.

Note: In irq_select_affinity() I save a temporary in by mangling
irq_desc[irq].affinity directly.  Ingo, does this break anything?

(Folded in fix from KOSAKI Motohiro)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Acked-by: Ingo Molnar <mingo@redhat.com>
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: jeremy@xensource.com
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
2008-12-13 21:20:26 +10:30
Ingo Molnar
e951e4af2e x86: fix unused variable warning in arch/x86/kernel/hpet.c
Impact: fix build warning

this warning:

  arch/x86/kernel/hpet.c:36: warning: ‘hpet_num_timers’ defined but not used

Triggers because hpet_num_timers is unused in the !CONFIG_PCI_MSI case.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-25 09:03:43 +01:00
Hannes Eder
3b71e9e307 x86: HPET: fix sparse warning
Impact: make global variable static

Fix this sparse warning:

 arch/x86/kernel/hpet.c:36:18: warning: symbol 'hpet_num_timers' was
 not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 20:23:37 +01:00
Matt Fleming
5ceb1a0418 x86: HPET: enter hpet_interrupt_handler with interrupts disabled
Some functions that may be called from this handler require that
interrupts are disabled. Also, combining IRQF_DISABLED and
IRQF_SHARED does not reliably disable interrupts in a handler, so
remove IRQF_SHARED from the irq flags (this irq is not shared anyway).

Signed-off-by: Matt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Cc: "Will Newton" <will.newton@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-11-10 17:38:07 +01:00
Matt Fleming
89d77a1eb6 x86: HPET: read from HPET_Tn_CMP() not HPET_T0_CMP
In hpet_next_event() we check that the value we just wrote to
HPET_Tn_CMP(timer) has reached the chip. Currently, we're checking that
the value we wrote to HPET_Tn_CMP(timer) is in HPET_T0_CMP, which, if
timer is anything other than timer 0, is likely to fail.

Signed-off-by: Matt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-11-10 17:38:07 +01:00
Matt Fleming
1de5b08546 x86: HPET: convert WARN_ON to WARN_ON_ONCE
It is possible to flood the console with call traces if the WARN_ON
condition is true because of the frequency with which this function is
called.

Signed-off-by: Matt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-11-10 17:38:07 +01:00
Venki Pallipadi
5f79f2f2ad hpet: clean up warning
Fix the below compile warnings due to recent HPET MSI changes

arch/x86/kernel/hpet.c:48: warning: 'hpet_devs' defined but not used
arch/x86/kernel/hpet.c:50: warning: 'per_cpu__cpu_hpet_dev' defined but not used

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:12 +02:00
Yinghai Lu
c81bba49a1 x86: print out irq nr for msi/ht, v3
v2: fix hpet compiling error
v3: Bjorn want to use dev_printk instead

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:12 +02:00
Steven Noonan
ba374c9bae x86: fix HPET compiler error when not using CONFIG_PCI_MSI
Added dummy function for hpet_setup_msi_irq().

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:09 +02:00
Venki Pallipadi
f0ed4e695f x86: using HPET in MSI mode and setting up per CPU HPET timers, fix
On Sat, Sep 06, 2008 at 06:03:53AM -0700, Ingo Molnar wrote:
>
> it crashes two testsystems, the fault on a NULL pointer in hpet init,
> with:
>
> initcall print_all_ICs+0x0/0x520 returned 0 after 26 msecs
> calling  hpet_late_init+0x0/0x1c0
> BUG: unable to handle kernel NULL pointer dereference at 000000000000008c
> IP: [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0
> PGD 0
> Oops: 0000 [1] SMP
> CPU 0
> Modules linked in:
> Pid: 1, comm: swapper Not tainted 2.6.27-rc5 #29725
> RIP: 0010:[<ffffffff80d228be>]  [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0
> RSP: 0018:ffff88003fa07dd0  EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
> RDX: ffffc20000000160 RSI: 0000000000000000 RDI: 0000000000000003
> RBP: ffff88003fa07e90 R08: 0000000000000000 R09: ffff88003fa07dd0
> R10: 0000000000000001 R11: 0000000000000000 R12: ffff88003fa07dd0
> R13: 0000000000000002 R14: ffffc20000000000 R15: 000000006f57e511
> FS:  0000000000000000(0000) GS:ffffffff80cf6a80(0000) knlGS:0000000000000000
> CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
> CR2: 000000000000008c CR3: 0000000000201000 CR4: 00000000000006e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process swapper (pid: 1, threadinfo ffff88003fa06000, task ffff88003fa08000)
> Stack:  00000000fed00000 ffffc20000000000 0000000100000003 0000000800000002
>  0000000000000000 0000000000000000 0000000000000000 0000000000000000
>  0000000000000000 0000000000000000 0000000000000000 0000000000000000
> Call Trace:
>  [<ffffffff80d227c0>] ? hpet_late_init+0x0/0x1c0
>  [<ffffffff80209045>] do_one_initcall+0x45/0x190
>  [<ffffffff80296f39>] ? register_irq_proc+0x19/0xe0
>  [<ffffffff80d0d140>] ? early_idt_handler+0x0/0x73
>  [<ffffffff80d0dabc>] kernel_init+0x14c/0x1b0
>  [<ffffffff80942ac1>] ? trace_hardirqs_on_thunk+0x3a/0x3f
>  [<ffffffff8020dbd9>] child_rip+0xa/0x11
>  [<ffffffff8020ceee>] ? restore_args+0x0/0x30
>  [<ffffffff80d0d970>] ? kernel_init+0x0/0x1b0
>  [<ffffffff8020dbcf>] ? child_rip+0x0/0x11
> Code: 20 48 83 c1 01 48 39 f1 75 e3 44 89 e8 4c 8b 05 29 29 22 00 31 f6 48 8d 78 01 66 66 90 89 f0 48 8d 04 80 48 c1 e0 05 4a 8d 0c 00 <f6> 81 8c 00 00 00 08 74 26 8b 81 80 00 00 00 8b 91 88 00 00 00
> RIP  [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0
>  RSP <ffff88003fa07dd0>
> CR2: 000000000000008c
> Kernel panic - not syncing: Fatal exception

There was one code path, with CONFIG_PCI_MSI disabled, where we were accessing
hpet_devs without initialization. That resulted in the above crash. The change
below adds a check for hpet_devs.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:09 +02:00
venkatesh.pallipadi@intel.com
26afe5f2fb x86: HPET_MSI Initialise per-cpu HPET timers
Initialize a per CPU HPET MSI timer when possible. We retain the HPET
timer 0 (IRQ 0) and timer 1 (IRQ 8) as is when legacy mode is being used. We
setup the remaining HPET timers as per CPU MSI based timers. This per CPU
timer will eliminate the need for timer broadcasting with IRQ 0 when there
is non-functional LAPIC timer across CPU deep C-states.

If there are more CPUs than number of available timers, CPUs that do not
find any timer to use will continue using LAPIC and IRQ 0 broadcast.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:08 +02:00
Ingo Molnar
4588c1f035 x86: HPET_MSI Basic HPET_MSI setup code, cleanups
small style cleanups.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:07 +02:00
venkatesh.pallipadi@intel.com
58ac1e76ce x86: HPET_MSI Basic HPET_MSI setup code
Basic HPET MSI setup code. Routines to perform basic MSI read write
in HPET memory map and setting up irq_chip for HPET MSI.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:07 +02:00
venkatesh.pallipadi@intel.com
b40d575bf0 x86: HPET_MSI Refactor code in preparation for HPET_MSI
Preparatory patch before the actual HPET MSI changes. Sets up hpet_set_mode
and hpet_next_event for the MSI related changes. Just the code
refactoring and should be zero functional change.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:07 +02:00
Ingo Molnar
83bd6998b0 Merge commit 'v2.6.27-rc6' into timers/hpet 2008-09-14 18:24:00 +02:00
Thomas Gleixner
72d43d9bc9 x86: HPET: read back compare register before reading counter
After fixing the u32 thinko I sill had occasional hickups on ATI chipsets
with small deltas. There seems to be a delay between writing the compare
register and the transffer to the internal register which triggers the
interrupt. Reading back the value makes sure, that it hit the internal
match register befor we compare against the counter value.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-06 07:21:17 +02:00
Thomas Gleixner
f7676254f1 x86: HPET fix moronic 32/64bit thinko
We use the HPET only in 32bit mode because:
1) some HPETs are 32bit only
2) on i386 there is no way to read/write the HPET atomic 64bit wide

The HPET code unification done by the "moron of the year" did
not take into account that unsigned long is different on 32 and
64 bit.

This thinko results in a possible endless loop in the clockevents
code, when the return comparison fails due to the 64bit/332bit
unawareness. 

unsigned long cnt = (u32) hpet_read() + delta can wrap over 32bit.
but the final compare will fail and return -ETIME causing endless
loops.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-06 07:21:17 +02:00
Thomas Gleixner
7cfb043533 HPET: make minimum reprogramming delta useful
The minimum reprogramming delta was hardcoded in HPET ticks,
which is stupid as it does not work with faster running HPETs.
The C1E idle patches made this prominent on AMD/RS690 chipsets,
where the HPET runs with 25MHz. Set it to 5us which seems to be
a reasonable value and fixes the problems on the bug reporters
machines. We have a further sanity check now in the clock events,
which increases the delta when it is not sufficient.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Tested-by: Dmitry Nezhevenko <dion@inhex.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 11:11:54 +02:00
Thomas Gleixner
a6825f1c1f x86: hpet: workaround SB700 BIOS
AMD SB700 based systems with spread spectrum enabled use a SMM based
HPET emulation to provide proper frequency setting. The SMM code is
initialized with the first HPET register access and takes some time to
complete. During this time the config register reads 0xffffffff. We
check for max. 1000 loops whether the config register reads a non
0xffffffff value to make sure that HPET is up and running before we go
further. A counting loop is safe, as the HPET access takes thousands
of CPU cycles. On non SB700 based machines this check is only done
once and has no side effects.

Based on a quirk patch from: crane cai <crane.cai@amd.com>

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-08-14 13:23:45 +02:00
David Brownell
64a76f667d hpet: /dev/hpet - fixes and cleanup
Minor /dev/hpet updates and bugfixes:

  * Remove dead code, mostly remnants of an incomplete/unusable
    kernel interface ... noted when addressing "sparse" warnings:
      + hpet_unregister() and a routine it calls
      + hpet_task and all references, including hpet_task_lock
      + hpet_data.hd_flags (and HPET_DATA_PLATFORM)

  * Correct and improve boot message:
      + displays *counter* (shared between comparators) bit width,
        not *timer* bit widths (which are often mixed)
      + relabel "timers" as "comparators"; this is less confusing,
        they are not independent like normal timers are (sigh)
      + display MHz not Hz; it's never less than 10 MHz.

  * Tighten and correct the userspace interface code
      + don't accidentally program comparators in 64-bit mode using
        32-bit values ... always force comparators into 32-bit mode
      + provide the correct bit definition flagging comparators with
        periodic capability ... the ABI is unchanged

  * Update Documentation/hpet.txt
      + be more correct and current
      + expand description a bit
      + don't mention that now-gone kernel interface

Plus, add a FIXME comment for something that could cause big trouble
on systems with more capable HPETs than at least Intel seems to ship.

It seems that few folk use this userspace interface; it's not very
usable given the general lack of HPET IRQ routing.  I'm told that
the only real point of it any more is to mmap for fast timestamps;
IMO that's handled better through the gettimeofday() vsyscall.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-31 18:45:41 +02:00
David Brownell
7e2a31da85 rtc-cmos: avoid spurious irqs
This fixes kernel http://bugzilla.kernel.org/show_bug.cgi?id=11112 (bogus
RTC update IRQs reported) for rtc-cmos, in two ways:

  - When HPET is stealing the IRQs, use the first IRQ to grab
    the seconds counter which will be monitored (instead of
    using whatever was previously in that memory);

  - In sane IRQ handling modes, scrub out old IRQ status before
    enabling IRQs.

That latter is done by tightening up IRQ handling for rtc-cmos everywhere,
also ensuring that when HPET is used it's the only thing triggering IRQ
reports to userspace; net object shrink.

Also fix a bogus HPET message related to its RTC emulation.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Report-by: W Unruh <unruh@physics.ubc.ca>
Cc: Andrew Victor <avictor.za@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:34 -07:00
Yinghai Lu
2387ce57a8 x86: make 64bit hpet_set_mapping to use ioremap too, v2
keep the one for VSYSCALL_HPET

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-14 09:24:17 +02:00
Carlos R. Mafra
6fd592daae x86: clean up computation of HPET .mult variables
While reading through the HPET code I realized that the
computation of .mult variables could be done with less
lines of code, resulting in a 1.6% text size saving
for hpet.o

So I propose the following patch, which applies against
today's Linus -git tree.

>From 0c6507e400e9ca5f7f14331e18f8c12baf75a9d3 Mon Sep 17 00:00:00 2001
From: Carlos R. Mafra <crmafra@ift.unesp.br>
Date: Mon, 5 May 2008 19:38:53 -0300

The computation of clocksource_hpet.mult

       tmp = (u64)hpet_period << HPET_SHIFT;
       do_div(tmp, FSEC_PER_NSEC);
       clocksource_hpet.mult = (u32)tmp;

can be streamlined if we note that it is equal to

       clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);

Furthermore, the computation of hpet_clockevent.mult

       uint64_t hpet_freq;

       hpet_freq = 1000000000000000ULL;
       do_div(hpet_freq, hpet_period);
       hpet_clockevent.mult = div_sc((unsigned long) hpet_freq,
                                     NSEC_PER_SEC, hpet_clockevent.shift);

can also be streamlined with the observation that hpet_period and hpet_freq are
inverse to each other (in proper units).

So instead of computing hpet_freq and using (schematically)
div_sc(hpet_freq, 10^9, shift) we use the trick of calling with the
arguments in reverse order, div_sc(10^6, hpet_period, shift).

The different power of ten is due to frequency being in Hertz (1/sec)
and the period being in units of femtosecond. Explicitly,

mult = (hpet_freq * 2^shift)/10^9    (before)
mult = (10^6 * 2^shift)/hpet_period  (after)

because hpet_freq = 10^15/hpet_period.

The comments in the code are also updated to reflect the changes.

As a result,

   text    data     bss     dec     hex filename
   2957     425      92    3474     d92 arch/x86/kernel/hpet.o
   3006     425      92    3523     dc3 arch/x86/kernel/hpet.o.old

a 1.6% reduction in text size.

Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 21:27:54 +02:00
Ingo Molnar
fc3fbc4509 hpet: fix
Al Viro pointed out that there's a missing readl() of timer->hpet_config,
found by Sparse.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-30 23:15:34 +02:00
Akinobu Mita
877084fb1c x86: cleanup div_sc() usage
Remove the magic number in the third argment of div_sc().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-26 17:35:47 +02:00
Thomas Gleixner
5761d64b27 x86: revert assign IRQs to hpet timer
The commits:

commit 37a47db8d7
Author: Balaji Rao <balajirrao@gmail.com>
Date:   Wed Jan 30 13:30:03 2008 +0100

    x86: assign IRQs to HPET timers, fix

and

commit e3f37a54f6
Author: Balaji Rao <balajirrao@gmail.com>
Date:   Wed Jan 30 13:30:03 2008 +0100

    x86: assign IRQs to HPET timers

have been identified to cause a regression on some platforms due to
the assignement of legacy IRQs which makes the legacy devices
connected to those IRQs disfunctional.

Revert them.

This fixes http://bugzilla.kernel.org/show_bug.cgi?id=10382

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-04 18:36:49 +02:00
Pavel Machek
b02a7f22f3 x86: hpet fix docbook comment
Signed-off-by: Pavel Machek <Pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-26 12:55:50 +01:00
Bernhard Walle
f8f76481bc rtc: use the IRQ callback interface in (old) RTC driver
the previous patch in the old RTC driver.  It also removes the direct
rtc_interrupt() call from arch/x86/kernel/hpetc.c so that there's finally no
(code) dependency to CONFIG_RTC in arch/x86/kernel/hpet.c.

Because of this, it's possible to compile the drivers/char/rtc.ko driver as
module and still use the HPET emulation functionality.  This is also expressed
in Kconfig.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Robert Picco <Robert.Picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:31 +01:00
Bernhard Walle
1bdbdaacf7 x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules
enabled, then interrupts don't work for the rtc-cmos driver which results in
RTC_AIE*, RTC_PIE* and RTC_ALM being unusable.  This affects hwclock from
util-linux-ng at least on i386 since that uses RTC_PIE_ON.  (For x86-64, a
polling method is used for unknown reasons.)

This patch series now

  1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc
     driver uses to work around that problem,

  2. makes it possible to compile the old rtc driver as module, while still
     having CONFIG_HPET_EMULATE_RTC enabled and

  3. makes use of the exported functions in (1) in the new rtc-cmos driver.

This patch:

This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable
for kernel modules. It

  - exports the functions (EXPORT_SYMBOL_GPL()),
  - adds an interface to register the interrupt callback function
    instead of using only a fixed callback function and
  - replaces the rtc_get_rtc_time() function which depends on
    CONFIG_RTC with a call to get_rtc_time() which is defined in
    include/asm-generic/rtc.h.

The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is
removed by the next patch. After this, there's no (code) dependency of
this functions to CONFIG_RTC=y any more.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Robert Picco <Robert.Picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:28 +01:00
Lucas Woods
201c19948b x86: remove duplicate includes
Signed-off-by: Lucas Woods <woodzy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:32 +01:00
Balaji Rao
37a47db8d7 x86: assign IRQs to HPET timers, fix
Looks like IRQ 31 is assigned to timer 3, even without the patch!
I wonder who wrote the number 31. But the manual says that it is
zero by default.

I think we should check whether the timer has been allocated an IRQ before
proceeding to assign one to it.  Here is a patch that does this.

Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Tested-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:03 +01:00
Balaji Rao
e3f37a54f6 x86: assign IRQs to HPET timers
The userspace API for the HPET (see Documentation/hpet.txt) did not work. The
HPET_IE_ON ioctl was failing as there was no IRQ assigned to the timer
device. This patch fixes it by allocating IRQs to timer blocks in the HPET.

arch/x86/kernel/hpet.c |   13 +++++--------
drivers/char/hpet.c    |   45 ++++++++++++++++++++++++++++++++++++++-------
include/linux/hpet.h   |    2 +-
3 files changed, 44 insertions(+), 16 deletions(-)

Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:03 +01:00
Pavel Machek
b10db7f0d2 time: more timer related cleanups
I was confused by FSEC = 10^15 NSEC statement, plus small whitespace
fixes. When there's copyright, there should be GPL.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:00 +01:00
Bernhard Walle
8ee291f87c x86: fix RTC_AIE with CONFIG_HPET_EMULATE_RTC
In the current code, RTC_AIE doesn't work if the RTC relies on
CONFIG_HPET_EMULATE_RTC because the code sets the RTC_AIE flag in
hpet_set_rtc_irq_bit().  The interrupt handles does accidentally check
for RTC_PIE and not RTC_AIE when comparing the time which was set in
hpet_set_alarm_time().

I now verified on a test system here that without the patch applied,
the attached test program fails on a system that has HPET with
2.6.24-rc7-default. That's not critical since I guess the problem has
been there for several kernel releases, but as the fix is quite
obvious.

Configuration is CONFIG_RTC=y and CONFIG_HPET_EMULATE_RTC=y.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-15 16:44:38 +01:00