platform-msi: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_max() is inclusive. So a -1 has been added when needed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/fd87836efa894aee0ae43e767369c85a2ee7e1ff.1705733916.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

platform-msi: Remove unused interfaces

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

platform-msi: Prepare for real per device domains

Provide functions to create and remove per device MSI domains which replace
the platform-MSI domains. The new model is that each of the devices which
utilize platform-MSI gets now its private MSI domain which is "customized"
in size and with a device specific function to write the MSI message into
the device.

This is the same functionality as platform-MSI but it avoids all the down
sides of platform MSI, i.e. the extra ID book keeping, the special data
structure in the msi descriptor. Further the domains are only created when
the devices are really in use, so the burden is on the usage and not on the
infrastructure.

Fill in the domain template and provide two functions to init/allocate and
remove a per device MSI domain.

Until all users and parent domain providers are converted, the init/alloc
function invokes the original platform-MSI code when the irqdomain which is
associated to the device does not provide MSI parent functionality yet.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240127161753.114685-6-apatel@ventanamicro.com

genirq/msi, platform-msi: Ensure that MSI descriptors are unreferenced

Miquel reported a warning in the MSI core which is triggered when
interrupts are freed via platform_msi_device_domain_free().

This code got reworked to use core functions for freeing the MSI
descriptors, but nothing took care to clear the msi_desc->irq entry, which
then triggers the warning in msi_free_msi_desc() which uses desc->irq to
validate that the descriptor has been torn down. The same issue exists in
msi_domain_populate_irqs().

Up to the point that msi_free_msi_descs() grew a warning for this case,
this went un-noticed.

Provide the counterpart of msi_domain_populate_irqs() and invoke it in
platform_msi_device_domain_free() before freeing the interrupts and MSI
descriptors and also in the error path of msi_domain_populate_irqs().

Fixes: 2f2940d16823 ("genirq/msi: Remove filter from msi_free_descs_free_range()")
Reported-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87mt4wkwnv.ffs@tglx

platform-msi: Switch to the domain id aware MSI interfaces

Switch to the new domain id aware interfaces to phase out the previous
ones. No functional change.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.513924920@linutronix.de

genirq/msi: Remove filter from msi_free_descs_free_range()

When a range of descriptors is freed then all of them are not associated to
a linux interrupt. Remove the filter and add a warning to the free function.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20221111122013.888850936@linutronix.de

platform-msi: Export symbol platform_msi_create_irq_domain()

Allow irqchip drivers using platform MSI to be built as modules.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
[maz: rewrote commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220922161246.20586-2-Frank.Li@nxp.com

platform-msi: Simplify platform device MSI code

The allocation code is overly complex. It tries to have the MSI index space
packed, which is not working when an interrupt is freed. There is no
requirement for this. The only requirement is that the MSI index is unique.

Move the MSI descriptor allocation into msi_domain_populate_irqs() and use
the Linux interrupt number as MSI index which fulfils the unique
requirement.

This requires to lock the MSI descriptors which makes the lock order
reverse to the regular MSI alloc/free functions vs. the domain
mutex. Assign a seperate lockdep class for these MSI device domains.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210748.956731741@linutronix.de

platform-msi: Let core code handle MSI descriptors

Use the core functionality for platform MSI interrupt domains. The platform
device MSI interrupt domains will be converted in a later step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210748.903173257@linutronix.de

platform-msi: Use msi_desc::msi_index

Use the common msi_index member and get rid of the pointless wrapper struct.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221814.413638645@linutronix.de

platform-msi: Store platform private data pointer in msi_device_data

Storing the platform private data in a MSI descriptor is sloppy at
best. The data belongs to the device and not to the descriptor.
Add a pointer to struct msi_device_data and store the pointer there.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221814.287680528@linutronix.de

platform-msi: Rename functions and clarify comments

It's hard to distinguish what platform_msi_domain_alloc() and
platform_msi_domain_alloc_irqs() are about. Make the distinction more
explicit and add comments which explain the use cases properly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221814.228706214@linutronix.de

platform-msi: Let the core code handle sysfs groups

Set the domain info flag and remove the local sysfs code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221814.109408832@linutronix.de

platform-msi: Allocate MSI device data on first use

Allocate the MSI device data on first invocation of the allocation function
for platform MSI private data.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221813.805529729@linutronix.de

device: Move MSI related data into a struct

The only unconditional part of MSI data in struct device is the irqdomain
pointer. Everything else can be allocated on demand. Create a data
structure and move the irqdomain pointer into it. The other MSI specific
parts are going to be removed from struct device in later steps.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20211210221813.617178827@linutronix.de

platform-msi: Add ABI to show msi_irqs of platform devices

PCI devices expose the associated MSI interrupts via sysfs, but platform
devices which utilize MSI interrupts do not. This information is important
for user space tools to optimize affinity settings.

Utilize the generic MSI sysfs facility to expose this information for
platform MSI.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210813035628.6844-3-21cnbao@gmail.com

platform-msi: fix kernel-doc warnings

remove make W=1 warnings

drivers/base/platform-msi.c:336: warning:
Function parameter or member 'is_tree' not described in
'__platform_msi_create_device_domain'

drivers/base/platform-msi.c:336: warning:
expecting prototype for platform_msi_create_device_domain(). Prototype
was for __platform_msi_create_device_domain() instead

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210331232614.304591-7-pierre-louis.bossart@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

platform-msi: Track shared domain allocation

We have two flavours of platform-MSI:

- MSIs generated by devices for themselves (the usual case)

- MSIs generated on behalf of other devices, as the generating
device is some form of bridge (either a wire-to-MSI bridge,
or even a non-transparent PCI bridge that repaints the PCI
requester ID).

In the latter case, the underlying interrupt architecture may need
to track this in order to keep the mapping alive even when no MSI
are currently being generated.

Add a set of flags to the generic msi_alloc_info_t structure, as
well as the MSI_ALLOC_FLAGS_PROXY_DEVICE flag that will get
advertized by the platform-MSI code when allocating an irqdomain
for a device.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20201129135208.680293-2-maz@kernel.org

platform-msi: Fix typos in comment

Fix up one typos @nev -> @nr_irqs.

Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1589770859-19340-1-git-send-email-zhangshaokun@hisilicon.com

platform-msi: Free descriptors in platform_msi_domain_free()

Since the addition of platform MSI support, there were two helpers
supposed to allocate/free IRQs for a device:

platform_msi_domain_alloc_irqs()
platform_msi_domain_free_irqs()

In these helpers, IRQ descriptors are allocated in the "alloc" routine
while they are freed in the "free" one.

Later, two other helpers have been added to handle IRQ domains on top
of MSI domains:

platform_msi_domain_alloc()
platform_msi_domain_free()

Seen from the outside, the logic is pretty close with the former
helpers and people used it with the same logic as before: a
platform_msi_domain_alloc() call should be balanced with a
platform_msi_domain_free() call. While this is probably what was
intended to do, the platform_msi_domain_free() does not remove/free
the IRQ descriptor(s) created/inserted in
platform_msi_domain_alloc().

One effect of such situation is that removing a module that requested
an IRQ will let one orphaned IRQ descriptor (with an allocated MSI
entry) in the device descriptors list. Next time the module will be
inserted back, one will observe that the allocation will happen twice
in the MSI domain, one time for the remaining descriptor, one time for
the new one. It also has the side effect to quickly overshoot the
maximum number of allocated MSI and then prevent any module requesting
an interrupt in the same domain to be inserted anymore.

This situation has been met with loops of insertion/removal of the
mvpp2.ko module (requesting 15 MSIs each time).

Fixes: 552c494a7666 ("platform-msi: Allow creation of a MSI-based stacked irq domain")
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

genirq/msi: Allow creation of a tree-based irqdomain for platform-msi

platform_msi_create_device_domain() always creates a revmap-based
irqdomain, which has the drawback of requiring the number of MSIs
that can be allocated ahead of time. This is not always possible,
and we sometimes need to use a tree-based irqdomain instead.

Add a new platform_msi_create_device_tree_domain() helper to
that effect.

Reported-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

genirq/msi: Limit level-triggered MSI to platform devices

Nobody would be insane enough to try and use level triggered
MSIs on PCI, but let's make sure it doesn't happen. Also,
let's mandate that the irqchip backing the platform MSI domain
is providing the IRQCHIP_SUPPORTS_LEVEL_MSI flag.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lkml.kernel.org/r/20180508121438.11301-3-marc.zyngier@arm.com

driver core: Remove redundant license text

Now that the SPDX tag is in all driver core files, that identifies the
license in a specific and legally-defined manner. So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: add SPDX identifiers to all driver core files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

irqchip/MSI: Use irq_domain_update_bus_token instead of an open coded access

Now that we have irq_domain_update_bus_token(), switch everyone over
to it. The debugfs code thanks you for your continued support.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

platform-msi: Make platform_msi_create_device_domain() ACPI aware

The irqdomain creation that is carried out in:

platform_msi_create_device_domain()

relies on the fwnode_handle interrupt controller token to associate the
interrupt controller with a specific irqdomain. Current code relies on
the OF layer to retrieve a fwnode_handle for the device representing the
interrupt controller from its device->of_node pointer. This makes
platform_msi_create_device_domain() DT specific whilst it really is not
because after the merge of commit f94277af03ea ("of/platform: Initialise
dev->fwnode appropriately") the fwnode_handle can easily be retrieved
from the dev->fwnode pointer in a firmware agnostic way.

Update platform_msi_create_device_domain() to retrieve the interrupt
controller fwnode_handle from the dev->fwnode pointer so that it can
be used seamlessly in ACPI and DT systems.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Ming Lei <ming.lei@canonical.com>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irq/platform-msi: Fix comment about maximal MSIs

Commit aff5e06b0dda ("irq/platform-MSI: Increase the maximum MSIs the MSI
framework can support") increased the maximum MSIs to 2048.

Fix the comment to reflect that.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Cc: gregkh@linuxfoundation.org
Cc: majun258@huawei.com
Link: http://lkml.kernel.org/r/1484592500-15400-1-git-send-email-mbrugger@suse.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

genirq/msi: Add cpumask allocation to alloc_msi_entry

For irq spreading want to store affinity masks in the msi_entry. Add the
infrastructure for it.

We allocate an array of cpumasks with an array size of the number of used
vectors in the entry, so we can hand in the information per linux interrupt
later.

As we hand in the number of used vectors, we assign them right
away. Convert all the call sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/1473862739-15032-2-git-send-email-hch@lst.de

base: Export platform_msi_domain_[alloc,free]_irqs

The new function platform_msi_domain_{alloc,free}_irqs are meant to be
used in platform drivers, which can be built as modules. Therefore, it
makes sense to export them to be used from kernel modules.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1453816347-32720-4-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irq/platform-MSI: Increase the maximum MSIs the MSI framework can support

The current MSI framework can only support 256 platform MSIs. But on Hisilicon
platform, some network related devices has about 500 wired interrupts.

To support these devices and align with MSI-X increase the maximum to 2048
devices.

Signed-off-by: Ma Jun <majun258@huawei.com>
Cc: <Catalin.Marinas@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <Will.Deacon@arm.com>
Cc: <mark.rutland@arm.com>
Cc: <marc.zyngier@arm.com>
Cc: <jason@lakedaemon.net>
Cc: <lizefan@huawei.com>
Cc: <huxinwei@huawei.com>
Cc: <dingtianhong@huawei.com>
Cc: <liguozhu@hisilicon.com>
Cc: <guohanjun@huawei.com>
Link: http://lkml.kernel.org/r/1450752442-9392-1-git-send-email-majun258@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

platform-msi: Allow creation of a MSI-based stacked irq domain

We almost have all the needed bits requiredable to create a irq domain
on top of a MSI domain.

For this, we enable a few things:
- the virq is stored in the msi_desc
- device, msi_alloc_info and domain-specific data
are stored in the platform_priv_data structure
- we introduce a new API for platform-msi:

/* Create a MSI-based domain */
struct irq_domain *
platform_msi_create_device_domain(struct device *dev,
unsigned int nvec,
irq_write_msi_msg_t write_msi_msg,
const struct irq_domain_ops *ops,
void *host_data);

/* Allocate MSIs in an MSI domain */
int platform_msi_domain_alloc(struct irq_domain *domain,
unsigned int virq,
unsigned int nr_irqs);

/* Free MSIs from an MSI domain */
void platform_msi_domain_free(struct irq_domain *domain,
unsigned int virq,
unsigned int nvec);

/* Obtain the host data passed to platform_msi_create_device_domain */
void *platform_msi_get_host_data(struct irq_domain *domain);

platform_msi_create_device_domain() is a hybrid of irqdomain creation
and interrupt allocation, creating a domain backed by the MSIs associated
to a device. IRQs can then be allocated in that domain using
platform_msi_domain_alloc().

This now allows a wired irq to MSI bridge to be created.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

platform-msi: Factor out allocation/free of private data

As we're going to have multiple paths to allocate/free the
platform-msi private data, factor this out into separate
utility functions.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

platform-msi: Allow MSIs to be allocated in chunks

MSIs for a given device are normally all allocated in one go.
Make sure the internal code can allocate them one at a time
if required.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqdomain/msi: Use fwnode instead of of_node

As we continue to push of_node towards the outskirts of irq domains,
let's start tackling the case of msi_create_irq_domain and its little
friends.

This has limited impact in both PCI/MSI, platform MSI, and a few
drivers.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Graeme Gregory <graeme@xora.org.uk>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/1444737105-31573-17-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

platform-msi: Do not cache msi_desc in handler_data

The current implementation of platform MSI caches the msi_desc
pointer in irq_data::handler_data. This is a bit silly, as
we also have irq_data::msi_desc, which is perfectly valid.

Remove the useless assignment and simplify the whole flow.

Reported-by: Ma Jun <majun258@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1442147824-20971-1-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/base: Add MSI domain support for non-PCI devices

With the msi_list and the msi_domain properties now being at the
generic device level, it is starting to be relatively easy to offer
a generic way of providing non-PCI MSIs.

The two major hurdles with this idea are:

- Lack of global ID that identifies a device: this is worked around by
having a global ID allocator for each device that gets enrolled in
the platform MSI subsystem

- Lack of standard way to write the message in the generating device.
This is solved by mandating driver code to provide a write_msg
callback, so that everyone can have their own square wheel

Apart from that, the API is fairly straightforward:

- platform_msi_create_irq_domain creates an MSI domain that gets
tagged with DOMAIN_BUS_PLATFORM_MSI

- platform_msi_domain_alloc_irqs allocate MSIs for a given device,
populating the msi_list

- platform_msi_domain_free_irqs does what is written on the tin

[ tglx: Created a seperate struct platform_msi_desc and added
kerneldoc entries ]

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-10-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>