Jiang Liu cffe0a2b5a x86, irq: Keep balance of IOAPIC pin reference count
To keep balance of IOAPIC pin reference count, we need to protect
pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable()
from reentrance. There are two cases which will cause reentrance.

The first case is caused by suspend/hibernation. If pcibios_disable_irq
is called during suspending/hibernating, we don't release the assigned
IRQ number, otherwise it may break the suspend/hibernation. So late when
pcibios_enable_irq is called during resume, we shouldn't allocate IRQ
number again.

The second case is that function acpi_pci_irq_enable() may be called
twice for PCI devices present at boot time as below:
1) pci_acpi_init()
	--> acpi_pci_irq_enable() if pci_routeirq is true
2) pci_enable_device()
	--> pcibios_enable_device()
		--> acpi_pci_irq_enable()
We can't kill kernel parameter pci_routeirq yet because it's still
needed for debugging purpose.

So flag irq_managed is introduced to track whether IRQ number is
assigned by OS and to protect pirq_enable_irq(), acpi_pci_irq_enable()
and intel_mid_pci_irq_enable() from reentrance.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/1414387308-27148-13-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-12-16 14:08:15 +01:00
..
2014-12-08 21:19:19 -08:00
2014-11-23 14:29:44 -05:00
2014-12-09 14:48:22 -08:00
2014-12-09 17:25:00 -08:00
2014-12-09 14:48:22 -08:00
2014-11-25 16:18:56 +00:00
2014-12-08 20:02:54 -08:00
2014-12-08 20:02:54 -08:00
2014-12-08 20:02:54 -08:00
2014-12-08 20:02:54 -08:00
2014-12-09 14:18:35 -08:00
2014-11-02 14:45:52 -08:00
2014-12-16 14:08:14 +01:00
2014-12-09 14:38:28 -08:00
2014-10-21 08:17:43 -07:00
2014-12-08 20:42:41 -08:00
2014-12-04 16:57:36 +01:00
2014-12-09 14:48:22 -08:00
2014-12-09 14:57:37 -08:00
2014-12-09 13:12:47 -08:00