When processors are about to hit low power states, the assertion of
standbywfi signal, triggered by the wfi instruction, is essential to
entering low power modes. If an IRQ is pending on the processor at the
time wfi is issued, the wfi instruction completes and the processor
restarts execution without asserting the standbywfi signal. Depending
on the platform power controller HW this behaviour can be acceptable or
not; if this behaviour must be prevented software should be provided
with a way to disable the routing of interrupts to the core IRQ pins.

On systems where raw GIC distributor interrupts are connected to the power
controller as wake-up events (hence the power controller still senses
IRQs and can wake up cores upon IRQ pending), the GIC CPU interface can
be disabled on power down, so that the GIC CPU IF output is gated and wfi
cannot complete, thereby preventing the standbywfi issue.

This patch adds a simple function to the GIC driver that allows to
disable the GIC CPU IF from power down procedures.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[rewrote commit log]
Signed-off-by: NOlof Johansson <olof@lixom.net>

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the drivers/clocksource and drivers/irqchip uses of
the __cpuinit macros from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Commit c0114709 (irqchip: gic: Perform the gic_secondary_init() call via
CPU notifier) moves gic_secondary_init() that used to be called in
.smp_secondary_init hook into a notifier call.  But it changes the
system behavior a little bit.  Before the commit, gic_cpu_init()
is called not only when kernel brings up the secondary cores but also
when system resuming procedure hot-plugs the cores back to kernel.
While after the commit, the function will not be called in the latter
case, where the 'action' will not be CPU_STARTING but
CPU_STARTING_FROZEN.  This behavior difference at least causes the
following suspend/resume regression on imx6q.

$ echo mem > /sys/power/state
PM: Syncing filesystems ... done.
PM: Preparing system for mem sleep
mmc1: card e624 removed
Freezing user space processes ... (elapsed 0.01 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
PM: Entering mem sleep
PM: suspend of devices complete after 5.930 msecs
PM: suspend devices took 0.010 seconds
PM: late suspend of devices complete after 0.343 msecs
PM: noirq suspend of devices complete after 0.828 msecs
Disabling non-boot CPUs ...
CPU1: shutdown
CPU2: shutdown
CPU3: shutdown
Enabling non-boot CPUs ...
CPU1: Booted secondary processor
INFO: rcu_sched detected stalls on CPUs/tasks: { 1 2 3} (detected by 0, t=2102 jiffies, g=4294967169, c=4294967168, q=17)
Task dump for CPU 1:
swapper/1       R running      0     0      1 0x00000000
Backtrace:
[<bf895ff4>] (0xbf895ff4) from [<00000000>] (  (null))
Backtrace aborted due to bad frame pointer <8007ccdc>
Task dump for CPU 2:
swapper/2       R running      0     0      1 0x00000000
Backtrace:
[<8075dbdc>] (0x8075dbdc) from [<00000000>] (  (null))
Backtrace aborted due to bad frame pointer <00000002>
Task dump for CPU 3:
swapper/3       R running      0     0      1 0x00000000
Backtrace:
[<8075dbdc>] (0x8075dbdc) from [<00000000>] (  (null))

Fix the regression by checking 'action' being CPU_STARTING_FROZEN to
have gic_cpu_init() called for secondary cores when system resumes.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NJoseph Lo <josephl@nvidia.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Fixes the following errors:
ERROR: do not initialise statics to 0 or NULL
ERROR: space required after that ',' (ctx:VxV)
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

The genirq layer expects a 0 in case that the retrigger function is
not able to resend the irq in hardware, but the code is returning
-ENXIO. Fix it.

[ tglx: Reworked comment and changelog ]
Signed-off-by: NAbhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1363734349-32635-1-git-send-email-sboyd@codeaurora.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

All the calls to gic_secondary_init() pass 0 as the first argument.
Since this function is called on each CPU when starting, it can be done
in a platform-independent way via a CPU notifier registered by the GIC
code.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Tested-by: NSimon Horman <horms+renesas@verge.net.au>
Acked-by: NSrinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Tested-by: NDinh Nguyen <dinguyen@altera.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: David Brown <davidb@codeaurora.org>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Barry Song <baohua.song@csr.com>

Previously, the gic_handle_cascade_irq() function was calling the
ARM-specific do_bad_IRQ() function which calls handle_bad_irq() after
acquiring the desk->lock. Locking the cascaded IRQ desc is not needed
for error reporting, so just call handle_bad_irq() directly.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <rob.herring@calxeda.com>

These functions have been introduced by commit 10a8c383 (irq: introduce
entry and exit functions for chained handlers) in asm/mach/irq.h. This
patch moves them to linux/irqchip/chained_irq.h so that generic irqchip
drivers do not rely on architecture specific header files.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <rob.herring@calxeda.com>

In b1cffebf (ARM: GIC: remove direct use of gic_raise_softirq)
gic_raise_softirq() was moved inside arch/arm/common/gic.c but in the
process it reverted by mistake a change to that function made by
384a2902 (ARM: gic: use a private mapping for CPU target interfaces).
This breaks multicluster systems on ARM.

This patch fixes the typo.
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Now that we have GIC moved to drivers/irqchip and all GIC DT init for
platforms using irqchip_init, move gic.h and update the remaining
includes.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Anton Vorontsov <avorontsov@mvista.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>

Now that we have drivers/irqchip, move GIC irqchip to drivers/irqchip. This
is necessary to share the GIC with arm and arm64.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>

Now that the GIC initialization sets up the handle_arch_irq pointer, we
can remove it for all machines and make it static.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Anton Vorontsov <avorontsov@mvista.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Acked-by: NStephen Warren <swarren@nvidia.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Set handle_arch_irq to gic_handle_irq. Only the first GIC initialized can
setup the handler.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NOlof Johansson <olof@lixom.net>

In preparation of moving gic code to drivers/irqchip, remove the direct
platform dependencies on gic_raise_softirq. Move the setup of
smp_cross_call into the gic code and use arch_send_wakeup_ipi_mask
function to trigger wake-up IPIs.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Acked-by: NStephen Warren <swarren@nvidia.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Acked-by: NOlof Johansson <olof@lixom.net>

The GIC interface numbering does not necessarily follow the logical
CPU numbering, especially for complex topologies such as multi-cluster
systems.

Fortunately we can easily probe the GIC to create a mapping as the
Interrupt Processor Targets Registers for the first 32 interrupts are
read-only, and each field returns a value that always corresponds to
the processor reading the register.

Initially all mappings target all CPUs in case an IPI is required to
boot secondary CPUs.  It is refined as those CPUs discover what their
actual mapping is.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>

The irq_start and hwirq_base assignment code is fairly hairy and ended
up being difficult to read following a conflict resolution for 3.2.

This patch rearranges the code slightly to make it easier to read.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Mark Salter <msalter@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

This patch removes the simplistic implementation of irq_domains and enables
the powerpc infrastructure for all irq_domain users.  The powerpc
infrastructure includes support for complex mappings between Linux and
hardware irq numbers, and can manage allocation of irq_descs.

This patch also converts the few users of irq_domain_add()/irq_domain_del()
to call irq_domain_add_legacy() instead.

v3: Fix bug that set up too many irqs in translation range.
v2: Fix removal of irq_alloc_descs() call in gic driver
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: NOlof Johansson <olof@lixom.net>

Part of the series to unify the irq remapping mechanisms in the
kernel.  A follow up patch will copy the powerpc implementation into
kernel/irq/irqdomain.c, which will be a lot easier if the structures
are identical.

Where they differ, I've chose to use the powerpc names since there is
a lot more code using those names.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: NOlof Johansson <olof@lixom.net>

It turns out that the logical CPU mapping is useful even when !CONFIG_SMP
for manipulation of devices like interrupt and power controllers when
running a UP kernel on a CPU other than 0. This can happen when kexecing
a UP image from an SMP kernel.

In the future, multi-cluster systems running AMP configurations will
require something similar for mapping cluster IDs, so it makes sense to
decouple this logic in preparation for this support.
Acked-by: NYang Bai <hamo.by@gmail.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Reported-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit 4294f8ba ("ARM: gic: add irq_domain support") defines irq_start
as irq_start = (irq_start & ~31) + 16; On a platform with a GIC and a
CPU without PPIs, this results in irq_start being off by 16.

This patch fixes gic_init so that we only carve out a PPI space when
PPIs exist for the GIC being initialised.

Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When multiple GICs exist on a platform (RealView PB1176/11MP),
we must make sure the PM notifier block is only registered
once, otherwise we end up corrupting the PM notifier list.

The fix is to only register the notifier when initializing
the first GIC, as the power management functions seem
to iterate over all the registered GICs.

Tested on PB11MP and PB1176.
Reported-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
Cc: Colin Cross <ccross@android.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Now that MULTI_IRQ_HANDLER is selected by all the in-tree
GIC users, make it mandatory and remove the unused macros.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Provide the GIC code with a low level handler that can be used
by platforms using CONFIG_MULTI_IRQ_HANDLER.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The GIC support code is heavily using the fact that hardware
implementations are exposing banked registers. Unfortunately, it
looks like at least one GIC implementation (EXYNOS) offers both
the distributor and the CPU interfaces at different addresses,
depending on the CPU.

This problem is solved by allowing the distributor and CPU interface
addresses to be per-cpu variables for the platforms that require it.
The EXYNOS code is updated not to mess with the GIC internals while
handling interrupts, and struct gic_chip_data is back to being private.
The DT binding for the gic is updated to allow an optional "cpu-offset"
value, which is used to compute the various base addresses.

Finally, a new config option (GIC_NON_BANKED) is used to control this
feature, so the overhead is only present on kernels compiled with
support for EXYNOS.

Tested on Origen (EXYNOS4) and Panda (OMAP4).

Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The module.h cleanup series is not merged at this point, so use the
older header file for now, to make it build either way.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Commit "ARM: gic: add irq_domain support" (b49b6ff) breaks SPARSE_IRQ
on platforms with GIC. When SPARSE_IRQ is enabled, all NR_IRQS or
mach_desc->nr_irqs will be allocated by arch_probe_nr_irqs(). This caused
irq_alloc_descs to allocate irq_descs after the pre-allocated space.

Make irq_alloc_descs search for an exact irq range and assume it has
been pre-allocated on failure. For DT probing dynamic allocation is used.
DT enabled platforms should set their nr_irqs to NR_IRQ_LEGACY and have all
irq_chips allocate their irq_descs with irq_alloc_descs if SPARSE_IRQ is
enabled.

gic_init irq_start param is changed to be signed with negative meaning do
dynamic Linux irq assigment.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>

This adds ARM gic interrupt controller initialization using device tree
data.

The initialization function is intended to be called by of_irq_init
function like this:

const static struct of_device_id irq_match[] = {
	{ .compatible = "arm,cortex-a9-gic", .data = gic_of_init, },
	{}
};

static void __init init_irqs(void)
{
	of_irq_init(irq_match);
}
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Reviewed-by: NJamie Iles <jamie@jamieiles.com>
Tested-by: NThomas Abraham <thomas.abraham@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

Convert the gic interrupt controller to use irq domains in preparation
for device-tree binding and MULTI_IRQ. This allows for translation between
GIC interrupt IDs and Linux irq numbers.

The meaning of irq_offset has changed. It now is just the number of skipped
GIC interrupt IDs for the controller. It will be 16 for primary GIC and 32
for secondary GICs.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NJamie Iles <jamie@jamieiles.com>
Tested-by: NThomas Abraham <thomas.abraham@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

This patch remove the hardcoded link between local timers and PPIs,
and convert the PPI users (TWD, MCT and MSM timers) to the new
*_percpu_irq interface. Also some collateral cleanup
(local_timer_ack() is gone, and the interrupt handler is strictly
private to each driver).

PPIs are now useable for more than just the local timers.

Additional testing by David Brown (msm8250 and msm8660) and
Shawn Guo (imx6q).

Cc: David Brown <davidb@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NDavid Brown <davidb@codeaurora.org>
Tested-by: NDavid Brown <davidb@codeaurora.org>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

PPI handling is a bit of an odd beast. It uses its own low level
handling code and is hardwired to the local timers (hence lacking
a registration interface).

Instead, switch the low handling to the normal SPI handling code.
PPIs are handled by the handle_percpu_devid_irq flow.

This also allows the removal of some duplicated code.

Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NDavid Brown <davidb@codeaurora.org>
Tested-by: NDavid Brown <davidb@codeaurora.org>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The GIC driver must convert logical CPU numbers passed in from Linux
into physical CPU numbers that are understood by the hardware.

This patch uses the new cpu_logical_map macro for performing the
conversion inside the GIC driver.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Tegra can benefit from the IRQCHIP_MASK_ON_SUSPEND flag, allow it
to be passed to the gic irq chip.
Signed-off-by: NColin Cross <ccross@android.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-and-Acked-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>

When the cpu is powered down in a low power mode, the gic cpu
interface may be reset, and when the cpu cluster is powered
down, the gic distributor may also be reset.

This patch uses CPU_PM_ENTER and CPU_PM_EXIT notifiers to save
and restore the gic cpu interface registers, and the
CPU_CLUSTER_PM_ENTER and CPU_CLUSTER_PM_EXIT notifiers to save
and restore the gic distributor registers.

Original-author: Gary King <gking@nvidia.com>
Signed-off-by: NColin Cross <ccross@android.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-and-Acked-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>

Annotate the low level hardware locks which must not be preempted.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The irq_set_affinity() method can be called with masks which include
offline CPUs.  This allows offline CPUs to have interrupts routed to
them by writing to /proc/irq/*/smp_affinity after hotplug has taken
a CPU offline.  Fix this by ensuring that we select a target CPU
present in both the required affinity and the online CPU mask.

Ensure that we return IRQ_SET_MASK_OK (which happens to be 0) on
success to ensure generic code copies the new mask into the irq_data
structure.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

irqdesc's node member is supposed to mark the numa node number for the
interrupt.  Our use of it is non-standard.  Remove this, replacing the
functionality with a test of the affinity mask.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Since Samsung EXYNOS4210 cannot support register banking in GIC,
so needs to update CPU interface base address.
The 'gic_chip_data' is used for it, this patch moves gic_chip_data
structure declaraton to arch/arm/include/asm/hardware/gic.h to use
it.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NChanghwan Youn <chaos.youn@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

The GIC register accesses today make use of readl()/writel()
which prove to be very expensive when used along with mandatory
barriers. This mandatory barriers also introduces an un-necessary
and expensive l2x0_sync() operation. On Cortex-A9 MP cores, GIC
IO accesses from CPU are direct and doesn't go through L2X0 write
buffer.

A DSB before writel_relaxed() in gic_raise_softirq() is added to be
compliant with the Barrier Litmus document - the mailbox scenario.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>

Currently, the gic uses handle_level_irq for handling SPIs (Shared
Peripheral Interrupts), requiring active interrupts to be masked at
the distributor level during IRQ handling.

On a virtualised system, only the CPU interfaces are virtualised in
hardware. Accesses to the distributor must be trapped by the
hypervisor, adding latency to the critical interrupt path in Linux.

This patch modifies the GIC code to use handle_fasteoi_irq for handling
interrupts, which only requires us to signal EOI to the CPU interface
when handling is complete. Cascaded IRQ handling is also updated to use
the chained IRQ enter/exit functions to honour the flow control of the
parent chip.

Note that commit 846afbd1 ("GIC: Dont disable INT in ack callback")
broke cascading interrupts by forgetting to add IRQ masking. This is
no longer an issue because the unmask call is now unnecessary.

Tested on Versatile Express and Realview EB (1176 w/ cascaded GICs).
Tested-and-reviewed-by: NAbhijeet Dharmapurikar <adharmap@codeaurora.org>
Tested-and-acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>