There is a lot of broken firmware out there that don't really
expose the information the kernel requires when it comes with dealing
with GICv2:

(1) Firmware that only describes the first 4kB of GICv2
(2) Firmware that describe 128kB of CPU interface, while
    the usable portion of the address space is between
    60 and 68kB

So far, we only deal with (2). But we have platforms exhibiting
behaviour (1), resulting in two sub-cases:
(a) The GIC is occupying 8kB, as required by the GICv2 architecture
(b) It is actually spread 128kB, and this is likely to be a version
    of (2)

This patch tries to work around both (a) and (b) by poking at
the outside of the described memory region, and try to work out
what is actually there. This is of course unsafe, and should
only be enabled if there is no way to otherwise fix the DT provided
by the firmware (we provide a "irqchip.gicv2_force_probe" option
to that effect).

Note that for the time being, we restrict ourselves to GICv2
implementations provided by ARM, since there I have no knowledge
of an alternative implementations. This could be relaxed if such
an implementation comes to light on a broken platform.
Reviewed-by: NChristoffer Dall <cdall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Make this const as it is only used in a copy operation.
Done using Coccinelle.
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The GIC driver only targets a single CPU at a time, even if
the notional affinity is wider. Let's inform the core code
about this.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20170818083925.10108-4-marc.zyngier@arm.com

Devices that expose their interrupt status registers via system
registers (e.g. Statistical profiling, CPU PMU, DynamIQ PMU, arch timer,
vgic (although unused by Linux), ...) rely on a context synchronising
operation on the CPU to ensure that the updated status register is
visible to the CPU when handling the interrupt. This usually happens as
a result of taking the IRQ exception in the first place, but there are
two race scenarios where this isn't the case.

For example, let's say we have two peripherals (X and Y), where Y uses a
system register for its interrupt status.

Case 1:
1. CPU takes an IRQ exception as a result of X raising an interrupt
2. Y then raises its interrupt line, but the update to its system
   register is not yet visible to the CPU
3. The GIC decides to expose Y's interrupt number first in the Ack
   register
4. The CPU runs the IRQ handler for Y, but the status register is stale

Case 2:
1. CPU takes an IRQ exception as a result of X raising an interrupt
2. CPU reads the interrupt number for X from the Ack register and runs
   its IRQ handler
3. Y raises its interrupt line and the Ack register is updated, but
   again, the update to its system register is not yet visible to the
   CPU.
4. Since the GIC drivers poll the Ack register, we read Y's interrupt
   number and run its handler without a context synchronisation
   operation, therefore seeing the stale register value.

In either case, we run the risk of missing an IRQ. This patch solves the
problem by ensuring that we execute an ISB in the GIC drivers prior
to invoking the interrupt handler. This is already the case for GICv3
and EOIMode 1 (the usual case for the host).

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

If the GIC cannot map an IRQ via irq_domain_ops->alloc(), it doesn't
return an error code.  This can cause a problem with drivers, where
it thinks it has successfully got an IRQ for the device, but requesting
the same ends up failure with -ENOSYS (as the IRQ's chip is not set).

Fixes: commit 9a1091ef ("irqchip: gic: Support hierarchy irq domain.")
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

It really looks bad without a newline.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

We get 1 warning when building kernel with W=1:
drivers/irqchip/irq-gic.c:917:13: warning: no previous prototype for 'gic_init_physaddr' [-Wmissing-prototypes]

In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
so this patch marks this function with 'static'.
Signed-off-by: NBaoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The BL switcher code manipulates the logical/physical CPU mapping,
forcing a lock to be taken on the IPI path. With an IPI heavy load,
this single lock becomes contended.

But when CONFIG_BL_SWITCHER is not enabled, there is no reason
to take this lock at all since the CPU mapping is immutable.

This patch allows the lock to be entierely removed when BL_SWITCHER
is not enabled (which is the case in most configurations), leading
to a small improvement of "perf bench sched pipe" (measured on
an 8 core AMD Seattle system):

Before: 101370 ops/sec
After:  103680 ops/sec

Take this opportunity to remove a useless lock being taken when
handling an interrupt on a secondary GIC.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

On systems where a single CPU is present, the GIC may not support
having SGIs delivered to a target list. In that case, we use the
self-SGI mechanism to allow the interrupt to be delivered locally.
Tested-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

More or less straightforward, although this driver sports some very
interesting SMP setup code. Regarding the callback ordering, this
deleted comment is interesting:

   ... the GIC needs to be up before the ARM generic timers.

That comment is half baken as the same requirement is true for perf.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153333.069777215@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add a platform driver to support non-root GICs that require runtime
power-management. Currently, only non-root GICs are supported because
the functions, smp_cross_call() and set_handle_irq(), that need to
be called for a root controller are located in the __init section and
so cannot be called by the platform driver.

The GIC platform driver re-uses many functions from the existing GIC
driver including some functions to save and restore the GIC context
during power transitions. The functions for saving and restoring the
GIC context are currently only defined if CONFIG_CPU_PM is enabled and
to ensure that these functions are always defined when the platform
driver is enabled, a dependency on CONFIG_ARM_GIC_PM (which selects the
platform driver) has been added.

In order to re-use the private GIC initialisation code, a new public
function, gic_of_init_child(), has been added which calls various
private functions to initialise the GIC. This is different from the
existing gic_of_init() because it only supports non-root GICs (ie. does
not call smp_cross_call() is set_handle_irq()) and is not located in
the __init section (so can be used by platform drivers). Furthermore,
gic_of_init_child() dynamically allocates memory for the GIC chip data
which is also different from gic_of_init().

There is no specific suspend handling for GICs registered as platform
devices. Non-wakeup interrupts will be disabled by the kernel during
late suspend, however, this alone will not power down the GIC if
interrupts have been requested and not freed. Therefore, requestors of
non-wakeup interrupts will need to free them on entering suspend in
order to power-down the GIC.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

To support GICs that require runtime power management, it is necessary
to add a platform driver, so that the probing of the chip can be
deferred if resources, such as a power-domain, is not yet available.

To prepare for adding a platform driver:
 1. Drop the __init section from the gic_dist_config() so this can be
    re-used by the platform driver.
 2. Add prototypes for functions required by the platform driver to the
    GIC header file so they can be re-used.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

For GICs that require runtime power-management it is necessary to
populate the 'parent_device' member of the irqchip structure. In
preparation for supporting such GICs, move the code that initialises
the irqchip structure for a GIC into its own function called
gic_init_chip() where the parent device pointer is also set.

Instead of calling gic_init_chip() from within gic_init_bases(), move
the calls to outside of this function, so that in the future we can
avoid having to pass additional parameters to gic_init_bases() in order
set the parent device pointer or set the name to a specific string.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

To re-use the code that initialises the GIC (found in
__gic_init_bases()), from within a platform driver, it is necessary to
move the code from the __init section so that it is always present and
not removed. Unfortunately, it is not possible to simply drop the __init
from the function declaration for __gic_init_bases() because it contains
calls to set_smp_cross_call() and set_handle_irq() which are both
located in the __init section. Fortunately, these calls are only
required for the root controller and because the initial platform driver
will only support non-root controllers that can be initialised later in
the boot process, we can move these calls to another function.

Move the bulk of the code from __gic_init_bases() to a new function
called gic_init_bases() which is not located in the __init section and
can be used by the platform driver. Update __gic_init_bases() to call
gic_init_bases() and if necessary, set_smp_cross_call() and
set_handle_irq().
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the code that sets-up a GIC via device-tree into it's own
function and add a generic function for GIC teardown that can be used
for both device-tree and ACPI to unmap the GIC memory.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Store the GIC configuration parameters in the GIC chip data structure.
This will allow us to simplify the code by reducing the number of
parameters passed between functions.

Update the __gic_init_bases() function so that we only need to pass a
pointer to the GIC chip data structure and no longer need to pass the
GIC index in order to look-up the chip data.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Instead of passing the GIC index to the save/restore functions pass a
pointer to the GIC chip data. This will allow these save/restore
functions to be re-used by a platform driver where the GIC chip data
structure is allocated dynamically and so there is no applicable index
for identifying the GIC.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

If the GIC initialisation fails, then currently we do not return an error
or clean-up afterwards. Although for root controllers, this failure may be
fatal anyway, for secondary controllers, it may not be fatal and so return
an error on failure and clean-up.

Update the functions gic_cpu_init() and gic_pm_init() to return an error
instead of calling BUG() and perform any necessary clean-up.

For non-banked GIC controllers, make sure that we free any memory
allocated if we fail to initialise the IRQ domain. Please note that
free_percpu() only frees memory if the pointer passed to it is not NULL
and so it is unnecessary to check if both pointers are valid or not.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

There are only 3 differences (not including the name) in the definitions
of the gic_chip and gic_eoimode1_chip structures. Instead of statically
defining the gic_eoimode1_chip structure, remove it and populate the
eoimode1 functions dynamically for the appropriate GIC irqchips.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

If we fail to map the address space for the GIC distributor or CPU
interface, then don't attempt to initialise the chip, just WARN and
return.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

When an IPI is generated by a CPU, the pattern looks roughly like:

  <write shared data>
  smp_wmb();
  <write to GIC to signal SGI>

On the receiving CPU we rely on the fact that, once we've taken the
interrupt, then the freshly written shared data must be visible to us.
Put another way, the CPU isn't going to speculate taking an interrupt.

Unfortunately, this assumption turns out to be broken.

Consider that CPUx wants to send an IPI to CPUy, which will cause CPUy
to read some shared_data. Before CPUx has done anything, a random
peripheral raises an IRQ to the GIC and the IRQ line on CPUy is raised.
CPUy then takes the IRQ and starts executing the entry code, heading
towards gic_handle_irq. Furthermore, let's assume that a bunch of the
previous interrupts handled by CPUy were SGIs, so the branch predictor
kicks in and speculates that irqnr will be <16 and we're likely to
head into handle_IPI. The prefetcher then grabs a speculative copy of
shared_data which contains a stale value.

Meanwhile, CPUx gets round to updating shared_data and asking the GIC
to send an SGI to CPUy. Internally, the GIC decides that the SGI is
more important than the peripheral interrupt (which hasn't yet been
ACKed) but doesn't need to do anything to CPUy, because the IRQ line
is already raised.

CPUy then reads the ACK register on the GIC, sees the SGI value which
confirms the branch prediction and we end up with a stale shared_data
value.

This patch fixes the problem by adding an smp_rmb() to the IPI entry
code in gic_handle_irq. As it turns out, the combination of a control
dependency and an ISB instruction from the EOI in the GICv3 driver is
enough to provide the ordering we need, so we add a comment there
justifying the absence of an explicit smp_rmb().

Cc: stable@vger.kernel.org
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

For now, the firmware tables are parsed 2 times: once in the GIC
drivers, the other timer when initializing the vGIC. It means code
duplication and make more tedious to add the support for another
firmware table (like ACPI).

Introduce a new structure and set of helpers to get/set the virtual GIC
information. Also fill up the structure for GICv2.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

The ACPI code requires to use global variables in order to collect
information from the tables.

For now, a single global variable is used, but more will be added in a
subsequent patch. To make clear they are ACPI specific, gather all the
information in a single structure.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NChristofer Dall <christoffer.dall@linaro.org>
Acked-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

When introducing the whole CPU feature detection framework,
we lost the capability to detect a mismatched GIC configuration
(using the GICv2 MMIO interface, but having the system register
interface enabled).

In order to solve this, use the new this_cpu_has_cap() helper.
Also move the check to the CPU interface path in order to catch
systems where the first CPU has been correctly configured,
but the secondaries are not.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Moving an SPI around doesn't require any extra work from the rest
of the stack, and specially not for MSI-generated SPIs.

It is then worth returning IRQ_SET_MASK_OK_DONE instead of
IRQ_SET_MASK_OK, and simplify the other irqchips that rely on
this behaviour (GICv2m and Marvell's ODMI controller).
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1455894029-17270-1-git-send-email-marc.zyngier@arm.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

EOImode1 is only used for the root controller and hence only the root
controller uses the eoimode1 functions for handling interrupts. However,
if the root controller supports EOImode1, then the EOImodeNS bit will be
set for all GICs, enabling EOImode1. This is not what we want and this
causes interrupts on non-root GICs to only be dropped in priority but
never deactivated. Therefore, only set the EOImodeNS bit for the root
controller.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Setting the affinity of an IRQ, it only applicable for the root
interrupt controller and so only populate this operator for the root
controller.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

This patch introduces gicv2m_acpi_init(), which uses information
in MADT GIC MSI frames structure to initialize GICv2m driver.
It also exposes gicv2m_init() function, which simplifies callers
to a single GICv2m init function.
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Tested-by: NDuc Dang <dhdang@apm.com>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Since there will be several places checking if fwnode.type
is equal FWNODE_IRQCHIP, this patch adds a convenient function
for this purpose.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

There is currently a hack in the GIC driver making it possible
to pass the number of GIC instances from the platform-specific
include files and thus override the variable MAX_GIC_NR.

With multiplatform deployments, this will not work as we need
to get rid of the platform-specific include files.

It turns out that this feature is only used by the RealView
platform which has a cascaded GIC. So move the configuration
to Kconfig and bump to 2 instances if we're building for the
RealView. The include file hacks can then be removed.

Tested on the ARM PB11MPCore with its cascaded GIC.
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The GIC has no such thing as interrupt 1020: the last valid ID is
1019, and the range 1020-1023 is reserved - 1023 indicating that
no interrupt is pending. So let's make sure we don't try to handle
this ID.

This bug has been in since the initial GIC code was introduced in
8ad68bbf ("[ARM] Add support for ARM RealView board").
Reported-by: NEric Auger <eric.auger@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Instead of having the irqchip being a static struct, make it part
of the per-instance data so we can assign it a dynamic name. This
has the usable side effect of displaying the GIC with an instance
number as GIC0, GIC1 ... GICn in /proc/interrupts, which is helpful
when debugging cascaded GICs, such as on the ARM PB11MPCore.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The ARM RealView PB11MPCore reference design has some special
bits in a system controller register to set up the GIC in one
of three modes: legacy, new with DCC, new without DCC. The
register is also used to enable FIQ.

Since the platform will not boot unless this register is set
up to "new with DCC" mode, we need a special quirk to be
compiled-in for the RealView platforms.

If we find the right compatible string on the GIC TestChip,
we enable this quirk by looking up the system controller and
enabling the special bits.

We depend on the CONFIG_REALVIEW_DT Kconfig symbol as the old
boardfile code has the same fix hardcoded, and this is only
needed for the attempts to modernize the RealView code using
device tree.

After fixing this, the PB11MPCore boots with device tree
only.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

When using EOImode==1, we may mark interrupts as being forwarded
to a virtual machine. In that case, the interrupt is left active
while being passed to the VM.

If we suspend the system before the VM has deactivated the interrupt,
the active state will be lost (which may be very annoying, as this
may result in spurious interrupts and a confused guest).

To avoid this, save and restore the active state together with the
rest of the GIC registers.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Russell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/1447701208-18150-5-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

When restoring the GIC state (after a suspend/resume cycle,
for example), the driver directly writes the 'enabled' state
it has saved by accessing GICD_ISENABLERn, which performs
an OR operation between the value present in the register
and the value we write.

If whatever code that has run before we reentered the kernel
has enabled an interrupt that was previously disabled, we won't
restore that disabled state.

Making sure we first clear the register (by writting to
GICD_ICENABLERn) before restoring the enabled state.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Russell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/1447701208-18150-4-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

We are now left with only two use models for the GIC driver:
- Via a firmware interface, which mandates a hierarchical domain,
  and the use of the 'translate' method
- The legacy platforms, which assume irq==hwirq, hence not using
  the 'xlate' method.

The logical conclusion is that we can now nuke the 'xlate' method
altogether.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-and-tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Tested-by: NLorenzo 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/1444737105-31573-14-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Now that the basic ACPI GSI code is irq domain aware, make sure
that the ACPI support in the GIC doesn't pointlessly deviate from
the DT path.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-and-tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Tested-by: NLorenzo 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/1444737105-31573-13-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Since nobody is using gic_init_bases anymore outside of the GIC
driver itself, let's do a bit of housekeeping and remove the now
useless entry point.

Only gic_init() is now exposed to the rest of the kernel for the
benefit of legacy systems.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-and-tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Tested-by: NLorenzo 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/1444737105-31573-12-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>