linux_dsm_epyc7002/arch/x86/kernel/apic
Yinghai Lu fd19dce7ac x86: Fix x2apic preenabled system with kexec
Found one x2apic system kexec loop test failed
when CONFIG_NMI_WATCHDOG=y (old) or CONFIG_LOCKUP_DETECTOR=y (current tip)

first kernel can kexec second kernel, but second kernel can not kexec third one.

it can be duplicated on another system with BIOS preenabled x2apic.
First kernel can not kexec second kernel.

It turns out, when kernel boot with pre-enabled x2apic, it will not execute
disable_local_APIC on shutdown path.

when init_apic_mappings() is called in setup_arch, it will skip setting of
apic_phys when x2apic_mode is set. ( x2apic_mode is much early check_x2apic())
Then later, disable_local_APIC() will bail out early because !apic_phys.

So check !x2apic_mode in x2apic_mode in disable_local_APIC with !apic_phys.

another solution could be updating init_apic_mappings() to set apic_phys even
for preenabled x2apic system. Actually even for x2apic system, that lapic
address is mapped already in early stage.

BTW: is there any x2apic preenabled system with apicid of boot cpu > 255?

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C3EB22B.3000701@kernel.org>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: stable@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-16 16:49:41 -07:00
..
apic_flat_64.c arch/x86/kernel/apic/apic_flat_64.c: Make comment match the code 2010-02-04 11:55:47 +01:00
apic_noop.c x86: Fix bogus warning in apic_noop.apic_write() 2009-12-07 13:16:37 +01:00
apic.c x86: Fix x2apic preenabled system with kexec 2010-07-16 16:49:41 -07:00
bigsmp_32.c x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system 2009-12-17 22:03:06 -08:00
es7000_32.c x86, irq: Kill io_apic_renumber_irq 2010-05-04 13:35:20 -07:00
io_apic.c x86, irq: Rename gsi_end gsi_top, and fix off by one errors 2010-06-09 13:34:06 -07:00
ipi.c Merge commit 'v2.6.31-rc7' into x86/cleanups 2009-08-24 12:25:54 +02:00
Makefile x86, apic: Introduce the NOOP apic driver 2009-10-14 09:17:00 +02:00
nmi.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
numaq_32.c Merge branch 'x86-mrst-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-07 15:59:39 -08:00
probe_32.c x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs 2010-02-09 20:51:11 -08:00
probe_64.c x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs 2010-02-09 20:51:11 -08:00
summit_32.c x86: apic: Do not use stacked physid_mask_t 2009-11-10 05:52:07 +01:00
x2apic_cluster.c x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system 2009-12-17 22:03:06 -08:00
x2apic_phys.c x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system 2009-12-17 22:03:06 -08:00
x2apic_uv_x.c Merge branch 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 09:46:35 -07:00