The first cpu in irq cfg->domain is likely to be CPU 0 and may not be available
when CPU 0 is offline. Instead of using CPU 0 to handle retriggered irq, we use
first available CPU which is online and in this irq's domain.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-13-git-send-email-fenghua.yu@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Posting this patch to fix an issue concerning sparse irq's that
I raised a while back.  There was discussion about adding
refcounting to sparse irqs (to fix other potential race
conditions), but that does not appear to have been addressed
yet.  This covers the only issue of this type that I've
encountered in this area.

A NULL pointer dereference can occur in
smp_irq_move_cleanup_interrupt() if we haven't yet setup the
irq_cfg pointer in the irq_desc.irq_data.chip_data.

In create_irq_nr() there is a window where we have set
vector_irq in __assign_irq_vector(), but not yet called
irq_set_chip_data() to set the irq_cfg pointer.

Should an IRQ_MOVE_CLEANUP_VECTOR hit the cpu in question during
this time, smp_irq_move_cleanup_interrupt() will attempt to
process the aforementioned irq, but panic when accessing
irq_cfg.

Only continue processing the irq if irq_cfg is non-NULL.
Signed-off-by: NDimitri Sivanich <sivanich@sgi.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20121016125021.GA22935@sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Recent commit 332afa65 cleaned up
a workaround that updates irq_cfg domain for legacy irq's that
are handled by the IO-APIC. This was assuming that the recent
changes in assign_irq_vector() were sufficient to remove the workaround.

But this broke couple of AMD platforms. One of them seems to be
sending interrupts to the offline cpu's, resulting in spurious
"No irq handler for vector xx (irq -1)" messages when those cpu's come online.
And the other platform seems to always send the interrupt to the last logical
CPU (cpu-7). Recent changes had an unintended side effect of using only logical
cpu-0 in the IO-APIC RTE (during boot for the legacy interrupts) and this
broke the legacy interrupts not getting routed to the cpu-7 on the AMD
platform, resulting in a boot hang.

For now, reintroduce the removed workaround, (essentially not allowing the
vector to change for legacy irq's when io-apic starts to handle the irq. Which
also addressed the uninteded sife effect of just specifying cpu-0 in the
IO-APIC RTE for those irq's during boot).
Reported-and-tested-by: NRobert Richter <robert.richter@amd.com>
Reported-and-tested-by: NBorislav Petkov <bp@amd64.org>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1344453412.29170.5.camel@sbsiddha-desk.sc.intel.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

In the current kernel, percpu variable `vector_irq' is not always
cleared when a CPU is offlined. If the CPU that has the disabled
irqs in vector_irq is hotplugged again, __setup_vector_irq()
hits invalid irq vector and may crash.

This bug can be reproduced as following;

 # echo 0 > /sys/devices/system/cpu/cpu7/online
 # modprobe -r some_driver_using_interrupts     # vector_irq@cpu7 uncleared
 # echo 1 > /sys/devices/system/cpu/cpu7/online # kernel may crash

To fix this problem, this patch clears vector_irq in
__fixup_irqs() when the CPU is offlined.

This also reverts commit f6175f5b, which partially fixes
this bug by clearing vector in __clear_irq_vector(). But in
environments with IOMMU IRQ remapper, it could fail because
cfg->domain doesn't contain offlined CPUs. With this patch, the
fix in __clear_irq_vector() can be reverted because every
vector_irq is already cleared in __fixup_irqs() on offlined CPUs.
Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120726104732.2889.19144.stgit@kvmdevSigned-off-by: NIngo Molnar <mingo@kernel.org>

For the x2apic cluster mode, vector for an interrupt is
currently reserved on all the cpu's that are part of the x2apic
cluster. But the interrupts will be routed only to the cluster
(derived from the first cpu in the mask) members specified in
the mask. So there is no need to reserve the vector in the
unused cluster members.

Modify __assign_irq_vector() to reserve the vectors based on the
user specified irq destination mask. If the new mask is a proper
subset of the currently used mask, cleanup the vector allocation
on the unused cpu members.

Also, allow the apic driver to tune the vector domain based on
the affinity mask (which in most cases is the user-specified
mask).
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NAlexander Gordeev <agordeev@redhat.com>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/1340656709-11423-3-git-send-email-suresh.b.siddha@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently __assign_irq_vector() goes through each cpu in the
specified mask until it finds a free vector in all the cpu's
that are part of the same interrupt domain. We visit all the
interrupt domain sibling cpus to reserve the free vector. So,
when we fail to find a free vector in an interrupt domain, it is
safe to continue our search with a cpu belonging to a new
interrupt domain. No need to go through each cpu, if the domain
containing that cpu is already visited.

Use the irq_cfg's old_domain to track the visited domains and
optimize the cpu traversal while finding a free vector in the
given cpumask.

NOTE: We can also optimize the search by using for_each_cpu() and
skip the current cpu, if it is not the first cpu in the mask
returned by the vector_allocation_domain(). But re-using the
cfg->old_domain to track the visited domains will be slightly
faster.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NAlexander Gordeev <agordeev@redhat.com>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/1340656709-11423-2-git-send-email-suresh.b.siddha@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Move the ->irq_set_affinity() routines out of the #ifdef CONFIG_SMP
sections and use config_enabled(CONFIG_SMP) checks inside those
routines. Thus making those routines simple null stubs for
!CONFIG_SMP and retaining those routines with no additional
runtime overhead for CONFIG_SMP kernels.

Cleans up the ifdef CONFIG_SMP in and around routines related to
irq_set_affinity in io_apic and irq_remapping subsystems.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: torvalds@linux-foundation.org
Cc: joerg.roedel@amd.com
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1339723729.3475.63.camel@sbsiddha-desk.sc.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Since there are only two locations where cpu_mask_to_apicid() is
called from, remove the operation and use only
cpu_mask_to_apicid_and() instead.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Suggested-and-acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120614074935.GE3383@dhcp-26-207.brq.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Current cpu_mask_to_apicid() and cpu_mask_to_apicid_and()
implementations have few shortcomings:

1. A value returned by cpu_mask_to_apicid() is written to
hardware registers unconditionally. Should BAD_APICID get ever
returned it will be written to a hardware too. But the value of
BAD_APICID is not universal across all hardware in all modes and
might cause unexpected results, i.e. interrupts might get routed
to CPUs that are not configured to receive it.

2. Because the value of BAD_APICID is not universal it is
counter- intuitive to return it for a hardware where it does not
make sense (i.e. x2apic).

3. cpu_mask_to_apicid_and() operation is thought as an
complement to cpu_mask_to_apicid() that only applies a AND mask
on top of a cpumask being passed. Yet, as consequence of 18374d89
commit the two operations are inconsistent in that of:
  cpu_mask_to_apicid() should not get a offline CPU with the cpumask
  cpu_mask_to_apicid_and() should not fail and return BAD_APICID
These limitations are impossible to realize just from looking at
the operations prototypes.

Most of these shortcomings are resolved by returning a error
code instead of BAD_APICID. As the result, faults are reported
back early rather than possibilities to cause a unexpected
behaviour exist (in case of [1]).

The only exception is setup_timer_IRQ0_pin() routine. Although
obviously controversial to this fix, its existing behaviour is
preserved to not break the fragile check_timer() and would
better addressed in a separate fix.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131559.GF4759@dhcp-26-207.brq.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In case of static vector allocation domains (i.e. flat) if all
vector numbers are exhausted, an attempt to assign a new vector
will lead to useless scans through all CPUs in the cpumask, even
though it is known that each new pass would fail. Make this
corner case less painful by letting report whether the vector
allocation domain depends on passed arguments or not and stop
scanning early.

The same could have been achived by introducing a static flag to
the apic operations. But let's allow vector_allocation_domain()
have more intelligence here and decide dynamically, in case we
would need it in the future.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131542.GE4759@dhcp-26-207.brq.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When assigning a new vector it is primarially done by adding 8
to the previously given out vector number. Hence, two
consequently allocated vector numbers would likely fall into the
same priority level. Try to spread vector numbers to different
priority levels better by changing the step from 8 to 16.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131514.GD4759@dhcp-26-207.brq.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In current Linux, percpu variable `vector_irq' is not cleared on
offlined cpus while disabling devices' irqs. If the cpu that has
the disabled irqs in vector_irq is hotplugged,
__setup_vector_irq() hits invalid irq vector and may crash.

This bug can be reproduced as following;

  # echo 0 > /sys/devices/system/cpu/cpu7/online
  # modprobe -r some_driver_using_interrupts      # vector_irq@cpu7 uncleared
  # echo 1 > /sys/devices/system/cpu/cpu7/online  # kernel may crash

This patch fixes this bug by clearing vector_irq in
__clear_irq_vector() even if the cpu is offlined.
Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: ltc-kernel@ml.yrl.intra.hitachi.co.jp
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/4FC340BE.7080101@hitachi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120605112310.GA11443@dhcp-26-207.brq.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Until now, irq_cfg domain is mostly static. Either all CPU's
(used by flat mode) or one CPU (first CPU in the irq afffinity
mask) to which irq is being migrated (this is used by the rest
of apic modes).

Upcoming x2apic cluster mode optimization patch allows the irq
to be sent to any CPU in the x2apic cluster (if supported by the
HW). So irq_cfg domain changes on the fly (depending on which
CPU in the x2apic cluster is online).

Instead of checking for any intersection between the new irq
affinity mask and the current irq_cfg domain, check if the new
irq affinity mask is a subset of the current irq_cfg domain.
Otherwise proceed with updating the irq_cfg domain aswell as
assigning vector's on all the CPUs specified in the new mask.

This also cleans up a workaround in updating irq_cfg domain for
legacy irq's that are handled by the IO-APIC.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: yinghai@kernel.org
Cc: gorcunov@openvz.org
Cc: agordeev@redhat.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337644682-19854-1-git-send-email-suresh.b.siddha@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Use a more current logging style:

 - Bare printks should have a KERN_<LEVEL> for consistency's sake
 - Add pr_fmt where appropriate
 - Neaten some macro definitions
 - Convert some Ok output to OK
 - Use "%s: ", __func__ in pr_fmt for summit
 - Convert some printks to pr_<level>

Message output is not identical in all cases.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: levinsasha928@gmail.com
Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop
[ merged two similar patches, tidied up the changelog ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The interrupt chip irq_set_affinity() functions copy the affinity mask
to irq_data->affinity but return 0, i.e. IRQ_SET_MASK_OK.
IRQ_SET_MASK_OK causes the core code to do another redundant copy.

Return IRQ_SET_MASK_OK_NOCOPY to avoid this.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Cliff Wickman <cpw@sgi.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Keping Chen <chenkeping@huawei.com>
Link: http://lkml.kernel.org/r/1333120296-13563-4-git-send-email-jiang.liu@huawei.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Hardware with MCA bus is limited to 386 and 486 class machines
that are now 20+ years old and typically with less than 32MB
of memory.  A quick search on the internet, and you see that
even the MCA hobbyist/enthusiast community has lost interest
in the early 2000 era and never really even moved ahead from
the 2.4 kernels to the 2.6 series.

This deletes anything remaining related to CONFIG_MCA from core
kernel code and from the x86 architecture.  There is no point in
carrying this any further into the future.

One complication to watch for is inadvertently scooping up
stuff relating to machine check, since there is overlap in
the TLA name space (e.g. arch/x86/boot/mca.c).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: x86@kernel.org
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

The local function io_apic_level_ack_pending() is only called
from io_apic_level_ack_pending(). The later function is only
compiled if CONFIG_GENERIC_PENDING_IRQ is defined. Move the
io_apic_level_ack_pending() to the existing #ifdef
CONFIG_GENERIC_PENDING_IRQ code block.

This will remove the following warning message during compiling
without CONFIG_GENERIC_PENDING_IRQ defined:

 * arch/x86/kernel/apic/io_apic.c:382: warning: ‘io_apic_level_ack_pending’ defined but not used
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Link: http://lkml.kernel.org/r/1336461860.2296.3.camel@sbsiddha-mobl2Signed-off-by: NIngo Molnar <mingo@kernel.org>

Make the file names consistent with the naming conventions of irq subsystem.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Make the code consistent with the naming conventions of irq subsystem.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Remove the Intel specific interfaces from dmar.h and remove
asm/irq_remapping.h which is only used for io_apic.c anyway.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

This patch introduces remapping-ops for setting ups MSI
interrupts.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

The operation for releasing a remapping entry is iommu
specific too.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

The function to set interrupt affinity with interrupt
remapping enabled is Intel specific too. So move it to the
irq_remap_ops too.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

The IOAPIC setup routine for interrupt remapping is VT-d
specific. Move it to the irq_remap_ops and add a call helper
function.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

This patch introduces irq_remap_ops to hold implementation
specific function pointer to handle interrupt remapping. As
the first part the initialization functions for VT-d are
converted to these ops.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Which makes the code fit within the rest of the x86_ops functions.
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
[v1: Changed x86_apic -> x86_ioapic per Yinghai Lu <yinghai@kernel.org> suggestion]
[v2: Rebased on tip/x86/urgent and redid to match Ingo's syntax style]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Xen dom0 needs to paravirtualize IO operations to the IO APIC,
so add a io_apic_ops for it to intercept.  Do this as ops
structure because there's at least some chance that another
paravirtualized environment may want to intercept these.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: jwboyer@redhat.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/1332385090-18056-2-git-send-email-konrad.wilk@oracle.com
[ Made all the affected code easier on the eyes ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This patch removes dead code from certain .config variations.

When CONFIG_GENERIC_PENDING_IRQ=n irq move and reenable code is
never get executed, nor do_unmask_irq variable updates its init
value. Move the code under CONFIG_GENERIC_PENDING_IRQ macro.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120320141935.GA24806@dhcp-26-207.brq.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

With the recent changes to clear_IO_APIC_pin() which tries to
clear remoteIRR bit explicitly, some of the users started to see
"Unable to reset IRR for apic .." messages.

Close look shows that these are related to bogus IO-APIC entries
which return's all 1's for their io-apic registers. And the
above mentioned error messages are benign. But kernel should
have ignored such io-apic's in the first place.

Check if register 0, 1, 2 of the listed io-apic are all 1's and
ignore such io-apic.
Reported-by: NÁlvaro Castillo <midgoon@gmail.com>
Tested-by: NJon Dufresne <jon@jondufresne.org>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: yinghai@kernel.org
Cc: kernel-team@fedoraproject.org
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1331577393.31585.94.camel@sbsiddha-desk.sc.intel.com
[ Performed minor cleanup of affected code. ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We use MP IRQs for SFI presented timer interrupts, we should
also set mp_bus_not_pci for MP_ISA_BUS so that pin_2_irq mapping
is correct.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Link: http://lkml.kernel.org/n/tip-8h3rc1igpp8ir94aas69qmhk@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

Using compile time NR_LEGACY_IRQS causes the wrong gsi-irq
mapping on non-PC platforms, such as Moorestown. This patch uses
legacy_pic abstraction to set the correct number of legacy
interrupts at runtime. For Moorestown, nr_legacy_irqs = 0. We
have 1:1 mapping for gsi-irq even within the legacy irq range.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Link: http://lkml.kernel.org/n/tip-kzvj4xp9tmicuoqoh2w05iay@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

On some of the recent Intel SNB platforms, by default bios is pre-enabling
x2apic mode in the cpu with out setting up interrupt-remapping.
This case was resulting in the kernel to panic as the cpu is already in
x2apic mode but the OS was not able to enable interrupt-remapping (which
is a pre-req for using x2apic capability).

On these platforms all the apic-ids are < 255 and the kernel can fallback to
xapic mode if the bios has not enabled interrupt-remapping (which is
mostly the case if the bios has not exported interrupt-remapping tables to the
OS).
Reported-by: NBerck E. Nash <flyboy@gmail.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20111222014632.600418637@sbsiddha-desk.sc.intel.comSigned-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Interrupts notify the idle exit state before calling irq_enter().
But the notifier code calls rcu_read_lock() and this is not
allowed while rcu is in an extended quiescent state. We need
to wait for irq_enter() -> rcu_idle_exit() to be called before
doing so otherwise this results in a grumpy RCU:

[    0.099991] WARNING: at include/linux/rcupdate.h:194 __atomic_notifier_call_chain+0xd2/0x110()
[    0.099991] Hardware name: AMD690VM-FMH
[    0.099991] Modules linked in:
[    0.099991] Pid: 0, comm: swapper Not tainted 3.0.0-rc6+ #255
[    0.099991] Call Trace:
[    0.099991]  <IRQ>  [<ffffffff81051c8a>] warn_slowpath_common+0x7a/0xb0
[    0.099991]  [<ffffffff81051cd5>] warn_slowpath_null+0x15/0x20
[    0.099991]  [<ffffffff817d6fa2>] __atomic_notifier_call_chain+0xd2/0x110
[    0.099991]  [<ffffffff817d6ff1>] atomic_notifier_call_chain+0x11/0x20
[    0.099991]  [<ffffffff81001873>] exit_idle+0x43/0x50
[    0.099991]  [<ffffffff81020439>] smp_apic_timer_interrupt+0x39/0xa0
[    0.099991]  [<ffffffff817da253>] apic_timer_interrupt+0x13/0x20
[    0.099991]  <EOI>  [<ffffffff8100ae67>] ? default_idle+0xa7/0x350
[    0.099991]  [<ffffffff8100ae65>] ? default_idle+0xa5/0x350
[    0.099991]  [<ffffffff8100b19b>] amd_e400_idle+0x8b/0x110
[    0.099991]  [<ffffffff810cb01f>] ? rcu_enter_nohz+0x8f/0x160
[    0.099991]  [<ffffffff810019a0>] cpu_idle+0xb0/0x110
[    0.099991]  [<ffffffff817a7505>] rest_init+0xe5/0x140
[    0.099991]  [<ffffffff817a7468>] ? rest_init+0x48/0x140
[    0.099991]  [<ffffffff81cc5ca3>] start_kernel+0x3d1/0x3dc
[    0.099991]  [<ffffffff81cc5321>] x86_64_start_reservations+0x131/0x135
[    0.099991]  [<ffffffff81cc5412>] x86_64_start_kernel+0xed/0xf4
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Henroid <andrew.d.henroid@intel.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

with "apic=verbose" the print_IO_APIC() function tries to print
IRQ to pin mappings for every active irq. It assumes chip_data
is of type irq_cfg and may cause an oops if not.

As the print_IO_APIC() is called from a late_initcall other
chained irq chips may already be registered with custom
chip_data information, causing an oops. This is the case with
intel MID SoC devices with gpio demuxers registered as irq_chips.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
[ -v2: fixed build failure ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

nr_legacy_irqs is set in probe_nr_irqs_gsi, we should not clear
it after that. Otherwise, the result is that MSI irqs will be
allocated from the wrong range for the systems without legacy
PIC.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Sparseirq got introduced in v2.6.28 and Thomas did a huge cleanup
around v2.6.38 that eliminated basically all disadvantages
of it.

So we can remove non-sparseirq support now and simplify
our IRQ degrees of freedom a bit.
Suggested-and-acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/4E95E21D.6090200@oracle.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

While looking at the code, apic_id sometime is referred to index
of ioapic, but sometime is used for phys apic id. and some even
use apic for real apic id. It is very confusing.

So try to limit apic_id or ioapic_id to be real apic id for
ioapic, and use ioapic_idx for ioapic index in the array.

-v2: Suggested by Ingo, use ioapic_idx consistently, instead of ioapic
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/4E9542DC.3090509@oracle.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

It is getting too big after the interrupt remaping entries debug
print out was added.

Original print_IO_APIC() becomes print_IO_APICs().
New print_IO_APIC() will only print one ioapic's registers

As a side-effect this clean-up also made checkpatch.pl happier.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/4E9542D3.5000008@oracle.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

While checking irte dump in dmesg, the print out is confusing
ioapic index with real io apic id:

IOAPIC[0]: Set routing entry (1-1 -> 0x31 -> IRQ 1 Mode:0
Active:0 Dest:1) IOAPIC[1]: Set IRTE entry (P:1 FPD:0 Dst_Mode:1
Redir_hint:1 Trig_Mode:0 Dlvry_Mode:1 Avail:0 Vector:31
Dest:00000001 SID:00FF SQ:0 SVT:1) IOAPIC[0]: Set routing entry
(1-2 -> 0x30 -> IRQ 0 Mode:0 Active:0 Dest:1) IOAPIC[1]: Set IRTE entry (P:1 FPD:0 Dst_Mode:1 Redir_hint:1 Trig_Mode:0 Dlvry_Mode:1 Avail:0 Vector:30 Dest:00000001 SID:00FF SQ:0 SVT:1)

The system's first ioapic id is 1.

This commit:

| commit 3040db92
| Author: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
| Date:   Tue Jul 12 21:17:41 2011 +0000
|
|    x86, ioapic: Print IRTE when IR is enabled

Confused apic_id with the ioapic ID - fix it.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/4E9542C8.8040209@oracle.comSigned-off-by: NIngo Molnar <mingo@elte.hu>