linux_dsm_epyc7002/arch
Suresh Siddha 1e75b31d63 x86, kdump, ioapic: Reset remote-IRR in clear_IO_APIC
In the kdump scenario mentioned below, we can have a case where
the device using level triggered interrupt will not generate any
interrupts in the kdump kernel.

1. IO-APIC sends a level triggered interrupt to the CPU's local APIC.

2. Kernel crashed before the CPU services this interrupt, leaving
   the remote-IRR in the IO-APIC set.

3. kdump kernel boot sequence does clear_IO_APIC() as part of IO-APIC
   initialization. But this fails to reset remote-IRR bit of the
   IO-APIC RTE as the remote-IRR bit is read-only.

4. Device using that level triggered entry can't generate any
   more interrupts because of the remote-IRR bit.

In clear_IO_APIC_pin(), check if the remote-IRR bit is set and if
so do an explicit attempt to clear it (by doing EOI write on
modern io-apic's and changing trigger mode to edge/level on
older io-apic's). Also before doing the explicit EOI to the
io-apic, ensure that the trigger mode is indeed set to level.
This will enable the explicit EOI to the io-apic to reset the
remote-IRR bit.

Tested-by: Leonardo Chiquitto <lchiquitto@novell.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Fixes: https://bugzilla.novell.com/show_bug.cgi?id=701686
Cc: Rafael Wysocki <rjw@novell.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Thomas Renninger <trenn@suse.de>
Cc: jbeulich@novell.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/20110825190657.157502602@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-09-21 10:26:25 +02:00
..
alpha alpha, gpio: GENERIC_GPIO default must be n 2011-09-14 18:09:37 -07:00
arm Merge branch 'fixes' of git://git.linaro.org/people/arnd/arm-soc 2011-09-12 11:51:35 -07:00
avr32 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
blackfin All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
cris All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
frv All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
h8300 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
ia64 iommu: Rename the DMAR and INTR_REMAP config options 2011-09-21 10:22:03 +02:00
m32r All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
m68k All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
microblaze All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
mips All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
mn10300 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
openrisc Add missing DMA ops 2011-09-11 09:50:39 +02:00
parisc remove remaining references to nfsservctl 2011-08-29 16:31:59 -07:00
powerpc Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2011-08-31 08:58:36 -07:00
s390 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
score modules: make arch's use default loader hooks 2011-07-24 22:06:04 +09:30
sh Merge branch 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-3.x 2011-08-29 13:34:48 -07:00
sparc sparc64: Only Panther cheetah+ chips have POPC. 2011-08-29 21:14:29 -07:00
tile Merge branch 'apei-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-08-03 21:53:27 -10:00
um um: fix strrchr() problems 2011-09-14 18:09:37 -07:00
unicore32 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2011-07-29 23:35:05 -07:00
x86 x86, kdump, ioapic: Reset remote-IRR in clear_IO_APIC 2011-09-21 10:26:25 +02:00
xtensa All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
.gitignore
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00