x86, build, pci: Fix PCI_MSI build on !SMP

Commit ebd97be635 ('PCI: remove ARCH_SUPPORTS_MSI kconfig option')
removed the ARCH_SUPPORTS_MSI option which architectures could select
to indicate that they support MSI. Now, all architectures are supposed
to build fine when MSI support is enabled: instead of having the
architecture tell *when* MSI support can be used, it's up to the
architecture code to ensure that MSI support can be enabled.

On x86, commit ebd97be635 removed the following line:

  select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)

Which meant that MSI support was only available when the local APIC
and I/O APIC were enabled. While this is always true on SMP or x86-64,
it is not necessarily the case on i386 !SMP.

The below patch makes sure that the local APIC and I/O APIC support is
always enabled when MSI support is enabled. To do so, it:

 * Ensures the X86_UP_APIC option is not visible when PCI_MSI is
   enabled. This is the option that allows, on UP machines, to enable
   or not the APIC support. It is already not visible on SMP systems,
   or x86-64 systems, for example. We're simply also making it
   invisible on i386 MSI systems.

 * Ensures that the X86_LOCAL_APIC and X86_IO_APIC options are 'y'
   when PCI_MSI is enabled.

Notice that this change requires a change in drivers/iommu/Kconfig to
avoid a recursive Kconfig dependencey. The AMD_IOMMU option selects
PCI_MSI, but was depending on X86_IO_APIC. This dependency is no
longer needed: as soon as PCI_MSI is selected, the presence of
X86_IO_APIC is guaranteed. Moreover, the AMD_IOMMU already depended on
X86_64, which already guaranteed that X86_IO_APIC was enabled, so this
dependency was anyway redundant.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: http://lkml.kernel.org/r/1380794354-9079-1-git-send-email-thomas.petazzoni@free-electrons.com
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/reboot: Add reboot quirk for Dell Latitude E5410

Dell Latitude E5410 needs reboot=pci to actually reboot.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://lkml.kernel.org/r/1380888964-14517-1-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
compiler/gcc4: Add quirk for 'asm goto' miscompilation bug

Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down
a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto'
constructs, as outlined here:

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

Implement a workaround suggested by Jakub Jelinek.

Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc"

ARCompact TRAP_S insn used for breakpoints, commits before exception is
taken (updating architectural PC). So ptregs->ret contains next-PC and
not the breakpoint PC itself. This is different from other restartable
exceptions such as TLB Miss where ptregs->ret has exact faulting PC.
gdb needs to know exact-PC hence ARC ptrace GETREGSET provides for
@stop_pc which returns ptregs->ret vs. EFA depending on the
situation.

However, writing stop_pc (SETREGSET request), which updates ptregs->ret
doesn't makes sense stop_pc doesn't always correspond to that reg as
described above.

This was not an issue so far since user_regs->ret / user_regs->stop_pc
had same value and both writing to ptregs->ret was OK, needless, but NOT
broken, hence not observed.

With gdb "jump", they diverge, and user_regs->ret updating ptregs is
overwritten immediately with stop_pc, which this patch fixes.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Merge tag 'arc-fixes-for-3.12-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC fix from Vineet Gupta:
 "Fix for broken gdb 'jump'"

* tag 'arc-fixes-for-3.12-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc"
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "A build fix and a reboot quirk"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/reboot: Add reboot quirk for Dell Latitude E5410
  x86, build, pci: Fix PCI_MSI build on !SMP
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull gcc "asm goto" miscompilation workaround from Ingo Molnar:
 "This is the fix for the GCC miscompilation discussed in the following
  lkml thread:

    [x86] BUG: unable to handle kernel paging request at 00740060

  The bug in GCC has been fixed by Jakub and the fix will be part of the
  GCC 4.8.2 release expected to be released next week - so the quirk's
  version test checks for <= 4.8.1.

  The quirk is only added to compiler-gcc4.h and not to the higher level
  compiler.h because all asm goto uses are behind a feature check"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  compiler/gcc4: Add quirk for 'asm goto' miscompilation bug