Fix stupid thinko on the path freeing the interrupts, where only
the first interrupt would get reset, and none of the others.

This should only affect multi-MSI allocations.
Reported-by: NWuyun Wu (Abel) <wuyun.wu@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Robert Richter <robert.richter@caviumnetworks.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Commit

  853a33ce irqchip: gic-v2m: Add support for ARM GICv2m MSI(-X) doorbell

Introduced a series of warnings when building ARM multi_v7_defconfig:

  include/linux/irqchip/arm-gic.h:109:53: warning: its scope is only this definition or declaration, which is probably not what you want
  In file included from arch/arm/mach-ux500/pm.c:13:0:
  include/linux/irqchip/arm-gic.h:109:53: warning: 'struct irq_domain' declared inside parameter list
   int gicv2m_of_init(struct device_node *node, struct irq_domain *parent);
                                                       ^

Fix this by adding the proper include.
Signed-off-by: NJason Cooper <jason@lakedaemon.net>
[ jac merged much more correct version from Marc into this patch ]
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/1417170975-1163-1-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Update the GIC DT bindings to support GICv2m.
Signed-off-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
[maz: split DT patch from main driver, updated changelog]
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416941243-7181-3-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

ARM GICv2m specification extends GICv2 to support MSI(-X) with
a new register frame. This allows a GICv2 based system to support
MSI with minimal changes.
Signed-off-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
[maz: converted the driver to use stacked irq domains,
      updated changelog]
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416941243-7181-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Add binding documentation for Mediatek SoC SYSIRQ.
Signed-off-by: NYingjoe Chen <yingjoe.chen@mediatek.com>
Link: https://lkml.kernel.org/r/1416902662-19281-5-git-send-email-yingjoe.chen@mediatek.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Mediatek SoCs have interrupt polarity support in sysirq which
allows to invert polarity for given interrupt. Add this support
using hierarchy irq domain.
Signed-off-by: NYingjoe Chen <yingjoe.chen@mediatek.com>
Link: https://lkml.kernel.org/r/1416902662-19281-3-git-send-email-yingjoe.chen@mediatek.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Add support to use gic as a parent for stacked irq domain.
Signed-off-by: NYingjoe Chen <yingjoe.chen@mediatek.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416902662-19281-2-git-send-email-yingjoe.chen@mediatek.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Add the documentation for the bindings describing the GICv3 ITS.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-14-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Get the show on the road...
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-13-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

As the ITS is always a subsystem if GICv3, its probing/init is
driven by the main GICv3 code.

Plug that code in (guarded by a config option).
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-12-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Add the code that probes the ITS from the device tree,
and initialize it.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-11-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

Now, the bit of code that allow us to use the ITS as a MSI controller.
Both MSI and MSI-X are supported.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-10-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The ITS has a notion of "device" that can write to it in order to
generate an interrupt.

Conversly, the driver maintains a per-ITS list of devices, together
with their configuration information, and uses this to configure
the HW.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-9-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The interrupt translation is driven by a set of tables (device,
ITT, and collection) to be in the end delivered to a CPU. Also,
the redistributors rely on a couple of tables (configuration, and
pending) to deliver the interrupts to the CPUs.

This patch adds the required allocators for these tables.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-8-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

LPIs are the type of interrupts that are used by the ITS. Given
the size of the namespace (anywhere between 16 and 32bit), interrupt
IDs are allocated in chunks of 32.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-7-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The usual methods that are used to present an irqchip to the rest
of the kernel
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-6-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The ITS is configured through a number commands that the driver
issues to the HW using a memory-based circular buffer.

This patch implements the subset of commands that are required
for Linux.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-5-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

The basic GICv3 driver has almost no use for the redistributor
(other than the basic per-CPU interrupts), but the ITS needs
a lot more from them.

As such, rework the set of data structures. The behaviour of the
GICv3 driver is otherwise unaffected.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-4-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

In order to start supporting stacked domains, convert the GICv3
code base to the new domain hierarchy framework, which mostly
amounts to supporting the new alloc/free callbacks.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-3-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

In order to support CONFIG_GENERIC_MSI_IRQ_DOMAIN, we need to
define msi_alloc_info_t. As the generic version exposed in
asm-generic/msi.h is perfectly convenient, import this file
as asm/msi.h.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

With the new stacked irq domains, it becomes pretty tempting to
allocate an MSI domain per PCI bus, which would remove the requirement
of either relying on arch-specific code, or a default PCI MSI domain.

By allowing the msi_controller structure to carry a pointer to an
irq_domain, we can easily use this in pci_msi_setup_msi_irqs.  The
existing code can still be used as a fallback if the MSI driver does
not populate the domain field.

Tested on arm64 with the GICv3 ITS driver.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1416048553-29289-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Provide mechanism to directly alloc/free MSI/MSIX interrupt from
irqdomain, which will be used to replace arch_setup_msi_irq()/
arch_setup_msi_irqs()/arch_teardown_msi_irq()/arch_teardown_msi_irqs().

To kill weak functions, this patch introduce a new weak function
arch_get_pci_msi_domain(), which is to retrieve the MSI irqdomain
for a PCI device. This weak function could be killed once we get
a common way to associate MSI domain with PCI device.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/1416061447-9472-10-git-send-email-jiang.liu@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Enhance PCI MSI core to support hierarchy irqdomain, so the common
code can be shared across architectures.

[ tglx: Extracted and combined from several patches ]
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Required to support non PCI based MSI.

[ tglx: Extracted from Jiangs patch series ]
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Extend struct msi_domain_info and provide default callbacks for
msi_domain_ops.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/1416061447-9472-8-git-send-email-jiang.liu@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Introduce msi_domain_{alloc|free}_irqs() to alloc/free interrupts
from generic MSI irqdomain.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/1416061447-9472-7-git-send-email-jiang.liu@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

To support MSI irq domains we want a generic data structure for
allocation, but we need the option to provide an architecture specific
version of it. So instead of playing #ifdef games in linux/msi.h we
add a generic header file and let architectures decide whether to
include it or to provide their own implementation and provide the
required typedef.

I know that typedefs are not really nice, but in this case there are no
forward declarations required and it's the simplest solution.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Alexander Gordeev <agordeev@redhat.com>

Implement the basic functions for MSI interrupt support with
hierarchical interrupt domains.

[ tglx: Extracted and combined from several patches ]
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Introduce callback irq_chip.irq_write_msi_msg, so we can share common
code among MSI alike interrupt controllers, such as HPET and DMAR.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

With the introduction of stacked domains, we have the issue that,
depending on where in the stack this is called, __irq_set_handler
will succeed or fail: If this is called from the inner irqchip,
__irq_set_handler() will fail, as it will look at the outer domain
as the (desc->irq_data.chip == &no_irq_chip) test fails (we haven't
set the top level yet).

This patch implements the following: "If there is at least one
valid irqchip in the domain, it will probably sort itself out".
This is clearly not ideal, but it is far less confusing then
crashing because the top-level domain is not up yet.

[ tglx: Added comment and a protection against chained interrupts in
  	that context ]
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1416048553-29289-3-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Introduce helper function irq_domain_add_hierarchy(), which creates
a linear irqdomain if parameter 'size' is not zero, otherwise creates
a tree irqdomain.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Link: http://lkml.kernel.org/r/1416061447-9472-5-git-send-email-jiang.liu@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Add a flags to irq_domain.flags to control whether the irqdomain core
should automatically call parent irqdomain's alloc/free callbacks. It
help to reduce hierarchy irqdomains users' code size.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Link: http://lkml.kernel.org/r/1416061447-9472-4-git-send-email-jiang.liu@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Required to avoid circular include dependencies.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add IRQ_SET_MASK_OK_DONE in addition to IRQ_SET_MASK_OK and
IRQ_SET_MASK_OK_NOCOPY to support stacked irqchip. IRQ_SET_MASK_OK_DONE
is the same as IRQ_SET_MASK_OK to irq core. To stacked irqchip, it means
that ascendant irqchips have done all the work and no more handling
needed in descendant irqchips.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add callback irq_compose_msi_msg to struct irq_chip, which will be used
to support stacked irqchip.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add more helper function for stacked irq_chip to just call parent's
function.
Signed-off-by: NYingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Gran Likely <grant.likely@linaro.org>
Cc: Boris BREZILLON <boris.brezillon@free-electrons.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: <srv_heupstream@mediatek.com>
Cc: <yingjoe.chen@gmail.com>
Cc: <hc.yen@mediatek.com>
Cc: <eddie.huang@mediatek.com>
Cc: <nathan.chung@mediatek.com>
Cc: <yh.chen@mediatek.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1415893029-2971-3-git-send-email-yingjoe.chen@mediatek.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Now we already support hierarchy irq_data, so introduce several helpers
to support stacked irq_chips.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

It is possible to call irq_create_of_mapping to create/translate the
same IRQ from DT for multiple times. Perform irq_find_mapping check
and set_type for hierarchy irqdomain in irq_create_of_mapping() to
avoid duplicate these functionality in all outer most irqdomain.
Signed-off-by: NYingjoe Chen <yingjoe.chen@mediatek.com>
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We plan to use hierarchy irqdomain to suppport CPU vector assignment,
interrupt remapping controller, IO-APIC controller, MSI interrupt
and hypertransport interrupt etc on x86 platforms. So extend irqdomain
interfaces to support hierarchy irqdomain.

There are already many clients of current irqdomain interfaces.
To minimize the changes, we choose to introduce new version 2 interfaces
to support hierarchy instead of extending existing irqdomain interfaces.

According to Thomas's suggestion, the most important design decision is
to build hierarchy struct irq_data to support hierarchy irqdomain, so
hierarchy irqdomain related data could be saved in struct irq_data.
With support of hierarchy irq_data, we could also support stacked
irq_chips. This is most useful in case of set_affinity().

The new hierarchy irqdomain introduces following interfaces:
1) irq_domain_alloc_irqs()/irq_domain_free_irqs(): allocate/release IRQ
   and related resources.
2) __irq_domain_alloc_irqs(): a special version to support legacy IRQs.
3) irq_domain_activate_irq()/irq_domain_deactivate_irq(): program
   interrupt controllers to activate/deactivate interrupt.

There are also several help functions to ease irqdomain implemenations:
1) irq_domain_get_irq_data(): get irq_data associated with a specific
   irqdomain.
2) irq_domain_set_hwirq_and_chip(): save irqdomain specific data into
   irq_data.
3) irq_domain_alloc_irqs_parent()/irq_domain_free_irqs_parent(): invoke
   parent irqdomain's alloc/free callbacks.

We also changed irq_startup()/irq_shutdown() to invoke
irq_domain_activate_irq()/irq_domain_deactivate_irq() to program
interrupt controller when start/stop interrupts.

[ tglx: Folded parts of the later patch series in ]
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>