linux/arch/x86
Vitaly Kuznetsov 8c058b0b9c x86/irq: Probe for PIC presence before allocating descs for legacy IRQs
Commit d32932d02e ("x86/irq: Convert IOAPIC to use hierarchical irqdomain
interfaces") brought a regression for Hyper-V Gen2 instances. These
instances don't have i8259 legacy PIC but they use legacy IRQs for serial
port, rtc, and acpi. With this commit included we end up with these IRQs
not initialized. Earlier, there was a special workaround for legacy IRQs
in mp_map_pin_to_irq() doing mp_irqdomain_map() without looking at
nr_legacy_irqs() and now we fail in __irq_domain_alloc_irqs() when
irq_domain_alloc_descs() returns -EEXIST.

The essence of the issue seems to be that early_irq_init() calls
arch_probe_nr_irqs() to figure out the number of legacy IRQs before
we probe for i8259 and gets 16. Later when init_8259A() is called we switch
to NULL legacy PIC and nr_legacy_irqs() starts to return 0 but we already
have 16 descs allocated.

Solve the issue by separating i8259 probe from init and calling it in
arch_probe_nr_irqs() before we actually use nr_legacy_irqs() information.

Fixes: d32932d02e ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1446543614-3621-1-git-send-email-vkuznets@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-11-07 10:37:37 +01:00
..
boot * Make the EFI System Resource Table (ESRT) driver explicitly 2015-10-14 16:51:34 +02:00
configs Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-09-04 15:49:32 -07:00
crypto Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 20:50:26 -08:00
entry Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:23:56 -08:00
ia32 Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:05:40 -08:00
include x86/irq: Probe for PIC presence before allocating descs for legacy IRQs 2015-11-07 10:37:37 +01:00
kernel x86/irq: Probe for PIC presence before allocating descs for legacy IRQs 2015-11-07 10:37:37 +01:00
kvm Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 20:50:26 -08:00
lguest genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
lib Linux 4.3-rc1 2015-09-13 11:25:35 +02:00
math-emu Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:05:40 -08:00
mm Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:23:56 -08:00
net bpf: Make the bpf_prog_array_map more generic 2015-08-09 22:50:05 -07:00
oprofile
pci PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code" 2015-09-15 13:18:04 -05:00
platform Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:33:18 -08:00
power x86/ldt: Make modify_ldt synchronous 2015-07-31 10:23:23 +02:00
purgatory
ras x86/ras/mce_amd_inj: Inject bank 4 errors on the NBC 2015-10-12 16:15:48 +02:00
realmode
tools
um Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:59:10 -08:00
video
xen x86/vdso: Remove runtime 32-bit vDSO selection 2015-10-07 11:34:08 +02:00
.gitignore
Kbuild x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/ 2015-06-03 18:51:37 +02:00
Kconfig Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:59:10 -08:00
Kconfig.cpu x86/Kconfig/cpus: Fix/complete CPU type help texts 2015-10-21 11:12:56 +02:00
Kconfig.debug x86/mm: Warn on W^X mappings 2015-10-06 11:11:48 +02:00
Makefile x86/asm: Re-add parts of the manual CFI infrastructure 2015-10-09 09:41:05 +02:00
Makefile_32.cpu
Makefile.um