Unstatic ioapic_write_entry and setup_ioapic_entry functions so that
the Xen code can do its own ioapic routing setup.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Add mp_find_ioapic_pin() to find an IO APIC's specific pin from a GSI,
and use this function within acpi/boot.  Make it non-static so other
code can use it too.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Mainly to get proper type-checking and consistency.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

I was seeing a very odd crash on 64 bit in bind_evtchn_to_cpu because
cpu_from_irq(irq) was coming out as -1. I found this was coming direct
from the mk_ipi_info call.

It's not clear to me that this isn't a compiler bug (implicit
initialisation to zero of unsigned shorts in a struct not handled
correctly?).

On the other hand is it true that all event channels start of bound to
CPU 0? If not then -1 might be correct and the various other functions
should cope with this.
Signed-off-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Make sure that irq_enter()/irq_exit() wrap the entire event processing
loop, rather than each individual event invokation.  This makes sure
that softirq processing is deferred until the end of event processing,
rather than in the middle with interrupts disabled.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

There should be no need for us to maintain our own bind count for
irqs, since the surrounding irq system should keep track of shared
irqs for us.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Put all irq info into one struct.  Also, use a union to keep
event channel type-specific information, rather than overloading the
index field.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Rather than overloading vectors for event channels, take full
responsibility for mapping an event channel to irq directly.  With
this patch Xen has its own irq allocator.

When the kernel gets an event channel upcall, it maps the event
channel number to an irq and injects it into the normal interrupt
path.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/mach-voyager/voyager_smp.c

By default, the irq_chip.disable operation is a no-op.  Explicitly set
it to disable the Xen event channel.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

With the differences in interrupt handling hoisted into handle_irq(),
do_IRQ is more or less identical between 32 and 64 bit, so unify it.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Xen uses a different interrupt path, so introduce handle_irq() to
allow interrupts to be inserted into the normal interrupt path.  This
is handled slightly differently on 32 and 64-bit.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: find right nr_irqs_gsi on some systems.

One test-system has gap between gsi's:

[    0.000000] ACPI: IOAPIC (id[0x04] address[0xfec00000] gsi_base[0])
[    0.000000] IOAPIC[0]: apic_id 4, version 0, address 0xfec00000, GSI 0-23
[    0.000000] ACPI: IOAPIC (id[0x05] address[0xfeafd000] gsi_base[48])
[    0.000000] IOAPIC[1]: apic_id 5, version 0, address 0xfeafd000, GSI 48-54
[    0.000000] ACPI: IOAPIC (id[0x06] address[0xfeafc000] gsi_base[56])
[    0.000000] IOAPIC[2]: apic_id 6, version 0, address 0xfeafc000, GSI 56-62
...
[    0.000000] nr_irqs_gsi: 38

So nr_irqs_gsi is not right. some irq for MSI will overwrite with io_apic.

need to get that with acpi_probe_gsi when acpi io_apic is used
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: make check-timer more robust potentially solve boot fragility

For edge trigger io-apic routing, we already unmasked the pin via
setup_IO_APIC_irq(), so don't unmask it again.

Also call local_irq_disable() between timer_irq_works(), because it
calls local_irq_enable() inside.

Also remove not needed apic version reading for 64-bit
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

also could kill platform_legacy_irq
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: make nr_irqs depend more on cards used in a system

depend on nr_irq_gsi more, and have a ratio for MSI.

v2: make nr_irqs less than NR_VECTORS * nr_cpu_ids
    aka if only one cpu, we only can support nr_irqs = NR_VECTORS
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

- Consistent alignment of help text
- Use the ---help--- keyword everywhere consistently as a visual separator
- fix whitespace mismatches
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Also move xquad_portio over to where it's allocated.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/mach-default/setup.c

Semantic merge:
	arch/x86/kernel/irqinit_32.c
Signed-off-by: Ingo Molnar <mingo@elte.hu>

This function should be provided on UP too.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

only leave _default_ipi_xx etc in .h

Beyond the cleanup factor, this saves a bit of code size as well:

    text	   data	    bss	    dec	            hex	filename
 7281931	1630144	1463304	10375379	 9e50d3	vmlinux.before
 7281753	1630144	1463304	10375201	 9e5021	vmlinux.after
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

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

Due to recurring issues with DMAR support on certain platforms.
There's a number of filesystem corruption incidents reported:

  https://bugzilla.redhat.com/show_bug.cgi?id=479996
  http://bugzilla.kernel.org/show_bug.cgi?id=12578

Provide a Kconfig option to change whether it is enabled by
default.

If disabled, it can still be reenabled by passing intel_iommu=on to the
kernel. Keep the .config option off by default.
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

On an x86 system which doesn't support global mappings,
__supported_pte_mask has _PAGE_GLOBAL clear, to make sure it never
appears in the PTE.  pfn_pte() and so on will enforce it with:

static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
{
	return __pte((((phys_addr_t)page_nr << PAGE_SHIFT) |
		      pgprot_val(pgprot)) & __supported_pte_mask);
}

However, we overload _PAGE_GLOBAL with _PAGE_PROTNONE on non-present
ptes to distinguish them from swap entries.  However, applying
__supported_pte_mask indiscriminately will clear the bit and corrupt the
pte.

I guess the best fix is to only apply __supported_pte_mask to present
ptes.  This seems like the right solution to me, as it means we can
completely ignore the issue of overlaps between the present pte bits and
the non-present pte-as-swap entry use of the bits.

__supported_pte_mask contains the set of flags we support on the
current hardware.  We also use bits in the pte for things like
logically present ptes with no permissions, and swap entries for
swapped out pages.  We should only apply __supported_pte_mask to
present ptes, because otherwise we may destroy other information being
stored in the ptes.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Enable the use of the direct vcpu-access operations on 64-bit.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Now that x86-64 has directly accessible percpu variables, it can also
implement the direct versions of these operations, which operate on a
vcpu_info structure directly embedded in the percpu area.

In fact, the 64-bit versions are more or less identical, and so can be
shared.  The only two differences are:
 1. xen_restore_fl_direct takes its argument in eax on 32-bit, and rdi on 64-bit.
    Unfortunately it isn't possible to directly refer to the 2nd lsb of rdi directly
    (as you can with %ah), so the code isn't quite as dense.
 2. check_events needs to variants to save different registers.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

We need to access percpu data fairly early, so set up the percpu
registers as soon as possible.  We only need to load the appropriate
segment register.  We already have a GDT, but its hard to change it
early because we need to manipulate the pagetable to do so, and that
hasn't been set up yet.

Also, set the kernel stack when bringing up secondary CPUs.  If we
don't they all end up sharing the same stack...
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Moving the mmu code from enlighten.c to mmu.c inadvertently broke the
32-bit build.  Fix it.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Fix user-visible grammo.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: cleanup

Some lines exceed the 80 char width making them unreadable.
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

This patch echoes what we already do on 32-bit since
90f7d25c, and prints the DMI
product name in show_regs, so that system specific problems can be
easily identified.
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Ingo 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: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Impact: Fix race condition

xen_mc_batch has a small preempt race where it takes the address of a
percpu variable immediately before disabling interrupts, thereby
leaving a small window in which we may migrate to another cpu and save
the flags in the wrong percpu variable.  Disable interrupts before
saving the old flags in a percpu.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Impact: Bug fix

A hunk went missing in the original patch, and callee-save callsites were
not marked as returning the upper 32-bit of result, causing Badness.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Impact: Documentation only

There is an email alias as well to reach the x86 maintainers: x86@kernel.org.
Document it.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Impact: Fixes dumpstack and KDB on 64 bits

This re-adds the old stack pointer to the top of the irqstack to help
with unwinding.  It was removed in commit d99015b1
as part of the save_args out-of-line work.

Both dumpstack and KDB require this information.
Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>