Ingo Molnar reported that read_apic is buggy novadays:

[    0.000000] Using APIC driver default
[    0.000000] SMP: Allowing 1 CPUs, 0 hotplug CPUs
[    0.000000] Local APIC disabled by BIOS -- you can enable it with "lapic"
[    0.000000] APIC: disable apic facility
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at arch/x86/kernel/apic/apic.c:254 native_apic_read_dummy+0x2d/0x3b()
[    0.000000] Hardware name: HP OmniBook PC

Indeed we still rely on apic->read operation for SMP compiled
kernel. And instead of disfigure the SMP code with #ifdef we
allow to call apic->read. To capture any unexpected results
we check for apic->read being called for sane reason via
WARN_ON_ONCE but(!) instead of OR we should use AND logical
operation (thanks Yinghai for spotting the root of the problem).

Along with that we could be have bad MP table and we are
to fix it that way no SMP started and no complains about
BIOS bug if apic was just disabled via command line.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090607124840.GD4547@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

lapic_resume forgets to restore interrupts on fail paths.
Fix that.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <1243497289-18591-1-git-send-email-jirislaby@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>

Ed found that on 32-bit, boot_cpu_physical_apicid is not read right,
when the mptable is broken.

Interestingly, actually three paths use/set it:

 1. acpi: at that time that is already read from reg
 2. mptable: only read from mptable
 3. no madt, and no mptable, that use default apic id 0 for 64-bit, -1 for 32-bit

so we could read the apic id for the 2/3 path. We trust the hardware
register more than we trust a BIOS data structure (the mptable).

We can also avoid the double set_fixmap() when acpi_lapic
is used, and also need to move cpu_has_apic earlier and
call apic_disable().

Also when need to update the apic id, we'd better read and
set the apic version as well - so that quirks are applied precisely.

v2: make path 3 with 64bit, use -1 as apic id, so could read it later.
v3: fix whitespace problem pointed out by Ed Swierk
v5: fix boot crash

[ Impact: get correct apic id for bsp other than acpi path ]
Reported-by: NEd Swierk <eswierk@aristanetworks.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <49FC85A9.2070702@kernel.org>
[ v4: sanity-check in the ACPI case too ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In case if apic were disabled by boot option
we still need read_apic operation. So fixmap
a fake apic area if needed.

[ Impact: fix boot crash ]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: yinghai@kernel.org
Cc: eswierk@aristanetworks.com
LKML-Reference: <20090511134140.GH4624@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Both print_local_APIC (used when apic=debug kernel param is set) and
cpu_debug code missed support for some extended APIC registers that
I'd like to see.

This adds support to show:

 - extended APIC feature register
 - extended APIC control register
 - extended LVT registers

[ Impact: print more debug info ]
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090508162350.GO29045@alberich.amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ed found that on 32-bit, boot_cpu_physical_apicid is not read right,
when the mptable is broken.

Interestingly, actually three paths use/set it:

 1. acpi: at that time that is already read from reg
 2. mptable: only read from mptable
 3. no madt, and no mptable, that use default apic id 0 for 64-bit, -1 for 32-bit

so we could read the apic id for the 2/3 path. We trust the hardware
register more than we trust a BIOS data structure (the mptable).

We can also avoid the double set_fixmap() when acpi_lapic
is used, and also need to move cpu_has_apic earlier and
call apic_disable().

Also when need to update the apic id, we'd better read and
set the apic version as well - so that quirks are applied precisely.

v2: make path 3 with 64bit, use -1 as apic id, so could read it later.
v3: fix whitespace problem pointed out by Ed Swierk

[ Impact: get correct apic id for bsp other than acpi path ]
Reported-by: NEd Swierk <eswierk@aristanetworks.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <49FC85A9.2070702@kernel.org>
[ v4: sanity-check in the ACPI case too ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Replace recenly appeared printk with pr_ macro
(the file already use a lot of them).

[ Impact: cleanup ]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090501195425.GB4633@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We will have systems with 2 and more sockets 8cores/2thread,
but we treat them as multi chassis - while they could have
a stable TSC domain.

Use DMI check instead.

[ Impact: do not turn possibly stable TSCs off incorrectly ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
LKML-Reference: <49F5532A.5000802@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When interrupt-remapping is enabled, we are relying on
setup_IO_APIC_irqs() to configure remapped entries in the
IO-APIC, which comes little bit later after enabling
interrupt-remapping.

Meanwhile, restoration of old io-apic entries after enabling
interrupt-remapping will not make the interrupts through
io-apic functional anyway.

So remove the unnecessary reinit_intr_remapped_IO_APIC() step.

The longer story:

When interrupt-remapping is enabled, IO-APIC entries need to be
setup in the re-mappable format (pointing to
interrupt-remapping table entries setup by the OS). This
remapping configuration is happening in the same place where we
traditionally configure IO-APIC (i.e., in
setup_IO_APIC_irqs()).

So when we enable interrupt-remapping successfully, there is no
need to restore old io-apic RTE entries before we actually do a
complete configuration shortly in setup_IO_APIC_irqs(). Old
IO-APIC RTE's may be in traditional format (non re-mappable) or
in re-mappable format pointing to interrupt-remapping table
entries setup by BIOS. Restoring both of these will not make
IO-APIC functional. We have to rely on setup_IO_APIC_irqs() for
proper configuration by OS.

So I am removing this unnecessary and broken step.

[ Impact: remove unnecessary/broken IO-APIC setup step ]
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NWeidong Han <weidong.han@intel.com>
Cc: dwmw2@infradead.org
LKML-Reference: <20090420200450.552359000@linux-os.sc.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Instead of panic() ignore the "nox2apic" boot option when BIOS
has already enabled x2apic prior to OS handover.

[ Impact: printk warning instead of panic() when BIOS has enabled x2apic already ]
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: dwmw2@infradead.org
Cc: Weidong Han <weidong.han@intel.com>
LKML-Reference: <20090420200450.425091000@linux-os.sc.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add x2apic_supported() to clean up CONFIG_X86_X2APIC checks.

Fix CONFIG_INTR_REMAP checks.

[ Impact: cleanup ]
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: dwmw2@infradead.org
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Weidong Han <weidong.han@intel.com>
LKML-Reference: <20090420200450.128993000@linux-os.sc.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Interrupt remapping was decoupled from x2apic. Shouldn't check
x2apic before resume interrupt remapping. Otherwise, interrupt
remapping won't be resumed when x2apic is not enabled.

[ Impact: fix potential intr-remap resume hang on !x2apic ]
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Acked-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: allen.m.kay@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1239957736-6161-6-git-send-email-weidong.han@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Currently, when x2apic is not enabled, interrupt remapping
will be enabled in init_dmars(), where it is too late to remap
ioapic interrupts, that is, ioapic interrupts are really in
compatibility mode, not remappable mode.

This patch always enables interrupt remapping before ioapic
setup, it guarantees all interrupts will be remapped when
interrupt remapping is enabled. Thus it doesn't need to set
the compatibility interrupt bit.

[ Impact: refactor intr-remap init sequence, enable fuller remap mode ]
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Acked-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: allen.m.kay@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1239957736-6161-4-git-send-email-weidong.han@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The patch "introduce imcr_ helpers" introduced good comments, but
also a few new compile warnings. This fixes the function definitions
to have a 'void' return type.
Signed-off-by: NAlexander van Heukelum <heukelum@fastmail.fm>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090413153924.GA20287@mailshack.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: refactor, speed up and robustize code

In case if apic was disabled by kernel option
or by hardware limits we can use dummy operations
in apic->write to simplify the ack_APIC_irq() code.

At the lame time the patch fixes the missed EOI in
do_IRQ function (which has place if kernel is compiled
as X86-32 and interrupt without handler happens where
apic was not asked to be disabled via kernel option).

Note that native_apic_write_dummy() consists of
WARN_ON_ONCE to catch any buggy writes on enabled
APICs. Could be removed after some time of testing.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090412165058.724788431@openvz.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

Distinguish port writting magic into helpers with comments.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090412165058.535921550@openvz.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add support for Always Running APIC timer, CPUID_0x6_EAX_Bit2.
This bit means the APIC timer continues to run even when CPU is
in deep C-states.

The advantage is that we can use LAPIC timer on these CPUs
always, and there is no need for "slow to read and program"
external timers (HPET/PIT) and the timer broadcast logic
and related code in C-state entry and exit.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

This patch enables suspend/resume for interrupt remapping. During suspend,
interrupt remapping is disabled. When resume, interrupt remapping is enabled
again.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Impact: fix possible race

save_mask_IO_APIC_setup() was using non atomic memory allocation while getting
called with interrupts disabled. Fix this by splitting this into two different
function. Allocation part save_IO_APIC_setup() now happens before
disabling interrupts.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: cleanup, paranoia

We were not clearing the local APIC in clear_local_APIC() in the
presence of x2apic. Fix it.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: cleanup

Make x86_quirks support more transparent. The highlevel
methods are now named:

  extern void x86_quirk_pre_intr_init(void);
  extern void x86_quirk_intr_init(void);

  extern void x86_quirk_trap_init(void);

  extern void x86_quirk_pre_time_init(void);
  extern void x86_quirk_time_init(void);

This makes it clear that if some platform extension has to
do something here that it is considered ... weird, and is
discouraged.

Also remove arch_hooks.h and move it into setup.h (and other
header files where appropriate).
Signed-off-by: NIngo Molnar <mingo@elte.hu>

If BIOS hands over the control to OS in legacy xapic mode, select
legacy xapic related ops in the early apic probe and shift to x2apic
ops later in the boot sequence, only after enabling x2apic mode.

If BIOS hands over the control in x2apic mode, select x2apic related
ops in the early apic probe.

This fixes the early boot panic, where we were selecting x2apic ops,
while the cpu is still in legacy xapic mode.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/ is getting a bit crowded, and the APIC
drivers are scattered into various different files.

Move them to arch/x86/kernel/apic/*, and also remove
the 'gen' prefix from those which had it.

Also move APIC related functionality: the IO-APIC driver,
the NMI and the IPI code.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

Remove genapic.h and remove all references to it.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

make it simpler, don't need have one extra struct.

v2: fix the sgi_uv build
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

so could deselect x2apic
and INTR_REMAP will select x2apic
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

1. move localise_nmi_watchdog() later
2. change setup_boot_APIC_clock() to setup_boot_clock() for 64-bit
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

So we remove some #ifdefs.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

disable_ioapic_setup() in init/main.c is ugly as the function is
x86-specific. The #ifdef inline prototype there is ugly too.

Replace it with a generic arch_disable_smp_support() function - which
has a weak alias for non-x86 architectures and for non-ioapic x86 builds.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix to enable APIC for AMD Fam10h on chipsets with a missing/b0rked
	ACPI MP table (MADT)

Booting a 32bit kernel on an AMD Fam10h CPU running on chipsets with
missing/b0rked MP table leads to a hang pretty early in the boot process
due to the APIC not being initialized. Fix that by falling back to the
default APIC base address in 32bit code, as it is done in the 64bit
codepath.
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Move the spurious vector sanity check to the place where it's
defined - out of a .c file.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: Cleans up printk formatting

When LOCAL APIC was calibrated, the debug message is displayed as follows.

	CPU0: Intel(R) Xeon(R) CPU            5110  @ 1.60GHz stepping 06
	Using local APIC timer interrupts.
	calibrating APIC timer ...
	... lapic delta = 3773131
	... PM timer delta = 812434
	APIC calibration not consistent with PM Timer: 226ms instead of 100ms
	APIC delta adjusted to PM-Timer: 1662420 (3773131)
	TSC delta adjusted to PM-Timer: 159592409 (362220564)
	..... delta 1662420
	..... mult: 71411249
	..... calibration result: 265987
	..... CPU clock speed is 1595.0924 MHz.
	..... host bus clock speed is 265.0987 MHz.

There are three type of PM-Timer (PM-Timer, PM Timer, and PM timer),
in this message. This patch unifies those messages to PM-Timer.
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: Fixes incorrect printk

LOCAL APIC is corrected by PM-Timer, when SMI occurred while LOCAL APIC is calibrated.
In this case, LOCAL APIC debug message(Boot with apic=debug) is displayed correctly,
however, CPU clock speed debug message is displayed wrongly .

When SMI occured on my machine, which has 1.6GHz CPU, CPU clock speed is displayed
3622.0205 MHz as follow.

	CPU0: Intel(R) Xeon(R) CPU            5110  @ 1.60GHz stepping 06
	Using local APIC timer interrupts.
	calibrating APIC timer ...
	... lapic delta = 3773130
	... PM timer delta = 812434
	APIC calibration not consistent with PM Timer: 226ms instead of 100ms
	APIC delta adjusted to PM-Timer: 1662420 (3773130)
	..... delta 1662420
	..... mult: 71411249
	..... calibration result: 265987
	..... CPU clock speed is 3622.0205 MHz.  =====>  here
	..... host bus clock speed is 265.0987 MHz.

This patch fixes to displaying CPU clock speed correctly as follow.

	CPU0: Intel(R) Xeon(R) CPU            5110  @ 1.60GHz stepping 06
	Using local APIC timer interrupts.
	calibrating APIC timer ...
	... lapic delta = 3773131
	... PM timer delta = 812434
	APIC calibration not consistent with PM Timer: 226ms instead of 100ms
	APIC delta adjusted to PM-Timer: 1662420 (3773131)
	TSC delta adjusted to PM-Timer: 159592409 (362220564)
	..... delta 1662420
	..... mult: 71411249
	..... calibration result: 265987
	..... CPU clock speed is 1595.0924 MHz.
	..... host bus clock speed is 265.0987 MHz.
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The x86/Voyager subarch used to have this distinction between
 'x86 SMP support' and 'Voyager SMP support':

 config X86_SMP
	bool
	depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)

This is a pointless distinction - Voyager can (and already does) use
smp_ops to implement various SMP quirks it has - and it can be extended
more to cover all the specialities of Voyager.

So remove this complication in the Kconfig space.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move mach_ipi.h definitions into genapic.h.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Spread mach_apic.h definitions into genapic.h. (with some knock-on effects
on smp.h and apic.h.)
Signed-off-by: NIngo Molnar <mingo@elte.hu>