The ARM SMP booting code allocates a temporary set of page tables
containing an identity mapping of the kernel image and provides this
to secondary CPUs for initial booting.

In reality, we only need to include the __turn_mmu_on function in the
identity mapping since the rest of the kernel is executing from virtual
addresses after this point.

This patch adds __turn_mmu_on to the .idmap.text section, allowing the
SMP booting code to use the idmap_pgd directly and not have to populate
its own set of page table.

As a result of this patch, we can make the identity_mapping_add function
static (since it is only used within mm/idmap.c) and also remove the
identity_mapping_del function. The identity map population is moved to
an early initcall so that it is setup in time for secondary CPU bringup.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

__create_page_tables identity maps the region of memory from
__enable_mmu to the end of __turn_mmu_on.

In preparation for including __turn_mmu_on in the .idmap.text section,
this patch modifies the identity mapping so that it only includes the
__turn_mmu_on code.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

For soft-rebooting a system, it is necessary to map the MMU-off code
with an identity mapping so that execution can continue safely once the
MMU has been switched off.

Currently, switch_mm_for_reboot takes out a 1:1 mapping from 0x0 to
TASK_SIZE during reboot in the hope that the reset code lives at a
physical address corresponding to a userspace virtual address.

This patch modifies the code so that we switch to the idmap_pgd tables,
which contain a 1:1 mapping of the cpu_reset code. This has the
advantage of only remapping the code that we need and also means we
don't need to worry about allocating a pgd from an atomic context in the
case that the physical address of the cpu_reset code aliases with the
virtual space used by the kernel.
Acked-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

The CPU reset functions disable the MMU and therefore must be executed
with an identity mapping in place.

This patch places the CPU reset functions into the .idmap.text section,
causing the idmap code to include them as part of the identity mapping.
Acked-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

The ARM CPU suspend code requires cpu_resume_mmu to be identity mapped
in order to re-enable the MMU when coming out of suspend. Currently,
this is accomplished by maintaining a suspend_pgd with the relevant
mapping put in place at init time.

This patch replaces the use of suspend_pgd with the new idmap_pgd.
cpu_resume_mmu is placed in the .idmap.text section so that it is
included in the identity map.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Dave Martin <dave.martin@linaro.org>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

When disabling and re-enabling the MMU, it is necessary to take out an
identity mapping for the code that manipulates the SCTLR in order to
avoid it disappearing from under our feet. This is useful when soft
rebooting and returning from CPU suspend.

This patch allocates a set of page tables during boot and populates them
with an identity mapping for the .idmap.text section. This means that
users of the identity map do not need to manage their own pgd and can
instead annotate their functions with __idmap or, in the case of assembly
code, place them in the correct section.
Acked-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Fix the below build break by including common.h

arch/arm/mach-omap2/cpuidle34xx.c: In function 'omap3_enter_idle':
arch/arm/mach-omap2/cpuidle34xx.c:117: error: implicit declaration of function 'omap_irq_pending'
make[1]: *** [arch/arm/mach-omap2/cpuidle34xx.o] Error 1
make: *** [arch/arm/mach-omap2] Error 2
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Fix the build break by adding the necessary irq functions to
common header.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Merge branch 'irqchip-consolidation' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into devel-stable

Trivial fix to fix below build error:

  CC      arch/arm/mach-exynos/mach-universal_c210.o
arch/arm/mach-exynos/mach-universal_c210.c:24: error: expected identifier or '(' before '<' token
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Fix below build error:
  CC      arch/arm/mach-exynos/cpu.o
arch/arm/mach-exynos/cpu.c: In function 'exynos4_init_irq':
arch/arm/mach-exynos/cpu.c:245: error: 'gic_bank_offset' undeclared (first use in this function)
arch/arm/mach-exynos/cpu.c:245: error: (Each undeclared identifier is reported only once
arch/arm/mach-exynos/cpu.c:245: error: for each function it appears in.)
arch/arm/mach-exynos/cpu.c:243: warning: unused variable 'bank_offset'
make[1]: *** [arch/arm/mach-exynos/cpu.o] Error 1
make: *** [arch/arm/mach-exynos] Error 2
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Merge branch 'irqchip-consolidation' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into devel-stable

Conflicts:
	arch/arm/mach-omap2/board-4430sdp.c
	arch/arm/mach-omap2/board-omap4panda.c
	arch/arm/mach-omap2/include/mach/omap4-common.h
	arch/arm/plat-omap/include/plat/irqs.h

The changes to omap4-common.h were moved to arch/arm/mach-omap2/common.h
and the other trivial conflicts resolved.  The now empty ifdef in irqs.h
was also eliminated.

The poodle restart handler was added in 74617fb6 (3593/1: Add reboot
and shutdown handlers for Zaurus handhelds), and at that time it was
necessary to deal with the RCSR register.  This commit also forced all
restarts to use the 'hard' restart method.

In dc38e2ad (pxa: Fix RCSR handling), the RCSR handling was removed,
leaving just the forcing to use a 'hard' restart.  As hard restarts are
the default (in the absense of a reboot= command line argument), this
seems pointless.  In any case, Richard Purdie says:

> From what I remember that hardware either always reboots or always
> halts. I think the option was therefore left hardcoded to make it clear
> it wasn't expected to work. Later Zaurii models could do either but
> required some manual poking of registers to make it happen iirc.
>
> Regardless, you can probably clean this up as you suggest now.

So, lets remove the unnecessary interception and rely on the default
restart mode.
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Rather than having separate extern declarations in nuc9*.h, provide
a common header file containing these definitions.
Tested-by: Wan Zongshun <mcuos.com@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

We only need to set the system up for a soft-restart if we're going to
be doing a soft-restart.  Provide a new function (soft_restart()) which
does the setup and final call for this, and make platforms use it.
Eliminate the call to setup_restart() from the default handler.

This means that platforms arch_reset() function is no longer called with
the page tables prepared for a soft-restart, and caches will still be
enabled.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Krzysztof Ha■asa <khc@pm.waw.pl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The separate files for clps711x which contain maybe one or two data
structures or functions is an inefficient use of files, and encourages
further small files as other changes happen.  Collapse down these into
a single core.c file.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

As suggested by Russell King - ARM Linux <linux@arm.linux.org.uk>,
there's no need to keep local prototypes in non-local headers.

Add mach-omap1/common.h and mach-omap2/common.h and move the
local prototypes there from plat/common.h and mach/omap4-common.h.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

IRQs are already disabled by the time arch_reset() is called, so these
calls to local_irq_disable() instead arch_reset() are redundant.  Remove
them.
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Now that all platforms are converted to MULTI_IRQ_HANDLER, remove the
legacy support.
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for picoxcell to help building multi platform kernels.
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for samsung to help building multi platform kernels.

Cc: Kukjin Kim <kgene.kim@samsung.com>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for versatile to help building multi platform kernels.

Cc: Russell King <linux@arm.linux.org.uk>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for u300 to help building multi platform kernels.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for spear to help building multi platform kernels.
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for s3c64xx to help building multi platform kernels.

Cc: Ben Dooks <ben-linux@fluff.org>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for nomadik to help building multi platform kernels.

Cc: Alessandro Rubini <rubini@unipv.it>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: STEricsson <STEricsson_nomadik_linux@list.st.com>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for netx to help building multi platform kernels.
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Now that there is a generic IRQ handler for multiple VIC devices use it
for ep93xx to help building multi platform kernels.

Cc: Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Add a handler for the VIC that is suitable for MULTI_IRQ_HANDLER
platforms.  This can replace the ASM entry macros for platforms that use
the VIC.

v4:	- rebase ontop of move __exception and friends to
	  asm/exception.h
	- rework polling loop to handle as many irqs as possible in one go
v3:	- simplify irq handling loop as suggested by Grant
	- service interrupts from msb->lsb order
v2:	- allow the handler be used for !CONFIG_OF
	- use irq_domain_to_irq()

Cc: Rob Herring <robherring2@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

This adds a device tree binding for the VIC based on the of_irq_init()
support.  This adds an irqdomain to the vic and always registers all
vics in the static vic array rather than for pm only to keep track of
the irq domain.  struct irq_data::hwirq is used where appropriate rather
than runtime masking.

v3:	- include linux/export.h for THIS_MODULE
v2:	- use irq_domain_simple_ops
	- remove stub implementation of vic_of_init for !CONFIG_OF
	- Make VIC select IRQ_DOMAIN
Reviewed-by: Rob Herring <robherring2@gmail.com>
Reviewed-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>

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: Marc Zyngier <marc.zyngier@arm.com>

After the MULTI_IRQ_HANDLER conversion, a couple of global
variables can be removed.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Convert the omap2plus platforms to be using CONFIG_MULTI_IRQ_HANDLER.
Each machine is modified to provide either omap2_intc_handle_irq(),
omap3_intc_handle_irq() or gic_handle_irq().

This allows for a major cleanup, removing the MULTI_OMAP setup
from the interrupt path.

Tested on both Panda and IGEPv2 (single kernel image)
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Provide the OMAP2/3 IRQ code with low level handlers that can be used
by platforms using CONFIG_MULTI_IRQ_HANDLER. Though the handlers are
written in C, the compiled code looks very similar to its assembly
counterpart (at least with my gcc 4.4.1).
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Convert the zynq platform to be using the gic_handle_irq
function as its primary interrupt handler.
Acked-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Convert the cns3xxx platform to be using the gic_handle_irq
function as its primary interrupt handler.
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Convert the SMP shmobile platforms to use gic_handle_irq() instead
of the assembly macro.

Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Convert the ux500 platforms to be using the gic_handle_irq
function as their primary interrupt handler.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Convert the tegra2 platforms to be using the gic_handle_irq
function as their primary interrupt handler.

Tested on harmony.

Cc: Colin Cross <ccross@android.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>