ARM: 7763/1: kernel: fix __cpu_logical_map default initialization

The __cpu_logical_map array is statically initialized to 0, which is a valid
MPIDR value. To prevent issues with the current impleme

ARM: 7763/1: kernel: fix __cpu_logical_map default initialization

The __cpu_logical_map array is statically initialized to 0, which is a valid
MPIDR value. To prevent issues with the current implementation, this patch
defines an MPIDR_INVALID value, and statically initializes the
__cpu_logical_map[] array to it. Entries in the arm_dt_init_cpu_maps()
tmp_map array used to stash DT reg properties while parsing DT are initialized
with the MPIDR_INVALID value as well for consistency.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: kernel: build MPIDR hash function data structure

On ARM SMP systems, cores are identified by their MPIDR register.
The MPIDR guidelines in the ARM ARM do not provide strict enforcement of
MPIDR

ARM: kernel: build MPIDR hash function data structure

On ARM SMP systems, cores are identified by their MPIDR register.
The MPIDR guidelines in the ARM ARM do not provide strict enforcement of
MPIDR layout, only recommendations that, if followed, split the MPIDR
on ARM 32 bit platforms in three affinity levels. In multi-cluster
systems like big.LITTLE, if the affinity guidelines are followed, the
MPIDR can not be considered an index anymore. This means that the
association between logical CPU in the kernel and the HW CPU identifier
becomes somewhat more complicated requiring methods like hashing to
associate a given MPIDR to a CPU logical index, in order for the look-up
to be carried out in an efficient and scalable way.

This patch provides a function in the kernel that starting from the
cpu_logical_map, implement collision-free hashing of MPIDR values by checking
all significative bits of MPIDR affinity level bitfields. The hashing
can then be carried out through bits shifting and ORing; the resulting
hash algorithm is a collision-free though not minimal hash that can be
executed with few assembly instructions. The mpidr is filtered through a
mpidr mask that is built by checking all bits that toggle in the set of
MPIDRs corresponding to possible CPUs. Bits that do not toggle do not carry
information so they do not contribute to the resulting hash.

Pseudo code:

/* check all bits that toggle, so they are required */
for (i = 1, mpidr_mask = 0; i < num_possible_cpus(); i++)
mpidr_mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));

/*
* Build shifts to be applied to aff0, aff1, aff2 values to hash the mpidr
* fls() returns the last bit set in a word, 0 if none
* ffs() returns the first bit set in a word, 0 if none
*/
fs0 = mpidr_mask[7:0] ? ffs(mpidr_mask[7:0]) - 1 : 0;
fs1 = mpidr_mask[15:8] ? ffs(mpidr_mask[15:8]) - 1 : 0;
fs2 = mpidr_mask[23:16] ? ffs(mpidr_mask[23:16]) - 1 : 0;
ls0 = fls(mpidr_mask[7:0]);
ls1 = fls(mpidr_mask[15:8]);
ls2 = fls(mpidr_mask[23:16]);
bits0 = ls0 - fs0;
bits1 = ls1 - fs1;
bits2 = ls2 - fs2;
aff0_shift = fs0;
aff1_shift = 8 + fs1 - bits0;
aff2_shift = 16 + fs2 - (bits0 + bits1);
u32 hash(u32 mpidr) {
u32 l0, l1, l2;
u32 mpidr_masked = mpidr & mpidr_mask;
l0 = mpidr_masked & 0xff;
l1 = mpidr_masked & 0xff00;
l2 = mpidr_masked & 0xff0000;
return (l0 >> aff0_shift | l1 >> aff1_shift | l2 >> aff2_shift);
}

The hashing algorithm relies on the inherent properties set in the ARM ARM
recommendations for the MPIDR. Exotic configurations, where for instance the
MPIDR values at a given affinity level have large holes, can end up requiring
big hash tables since the compression of values that can be achieved through
shifting is somewhat crippled when holes are present. Kernel warns if
the number of buckets of the resulting hash table exceeds the number of
possible CPUs by a factor of 4, which is a symptom of a very sparse HW
MPIDR configuration.

The hash algorithm is quite simple and can easily be implemented in assembly
code, to be used in code paths where the kernel virtual address space is
not set-up (ie cpu_resume) and instruction and data fetches are strongly
ordered so code must be compact and must carry out few data accesses.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Colin Cross <ccross@android.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>

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ARM: elf: add new hwcap for identifying atomic ldrd/strd instructions

CPUs implementing LPAE have atomic ldrd/strd instructions, meaning that
userspace software can avoid having to use the exclusive

ARM: elf: add new hwcap for identifying atomic ldrd/strd instructions

CPUs implementing LPAE have atomic ldrd/strd instructions, meaning that
userspace software can avoid having to use the exclusive variants of
these instructions if they wish.

This patch advertises the atomicity of these instructions via the
hwcaps, so userspace can detect this CPU feature.

Reported-by: Vladimir Danushevsky <vladimir.danushevsky@oracle.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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ARM: Enable selection of SMP operations at boot time

Add a new 'smp_init' hook to machine_desc so platforms can specify a
function to be used to setup smp ops instead of having a statically
defined

ARM: Enable selection of SMP operations at boot time

Add a new 'smp_init' hook to machine_desc so platforms can specify a
function to be used to setup smp ops instead of having a statically
defined value. The hook must return true when smp_ops are initialized.
If false the static mdesc->smp_ops will be used by default.

Add the definition of "bool" by including the linux/types.h file to
asm/mach/arch.h and make it self-contained.

Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

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arm: introduce psci_smp_ops

Rename virt_smp_ops to psci_smp_ops and move them to arch/arm/kernel/psci_smp.c.
Remove mach-virt/platsmp.c, now unused.
Compile psci_smp if CONFIG_ARM_PSCI and CONFIG_SM

arm: introduce psci_smp_ops

Rename virt_smp_ops to psci_smp_ops and move them to arch/arm/kernel/psci_smp.c.
Remove mach-virt/platsmp.c, now unused.
Compile psci_smp if CONFIG_ARM_PSCI and CONFIG_SMP.

Add a cpu_die smp_op based on psci_ops.cpu_off.

Initialize PSCI before setting smp_ops in setup_arch.

If PSCI is available on the platform, prefer psci_smp_ops over the
platform smp_ops.


Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: arnd@arndb.de
CC: marc.zyngier@arm.com
CC: linux@arm.linux.org.uk
CC: nico@linaro.org
CC: rob.herring@calxeda.com

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ARM: 7669/1: keep __my_cpu_offset consistent with generic one

Commit 14318efb(ARM: 7587/1: implement optimized percpu variable access)
introduces arm's __my_cpu_offset to optimize percpu vaiable acc

ARM: 7669/1: keep __my_cpu_offset consistent with generic one

Commit 14318efb(ARM: 7587/1: implement optimized percpu variable access)
introduces arm's __my_cpu_offset to optimize percpu vaiable access,
which really works well on hackbench, but will cause __my_cpu_offset
to return garbage value before it is initialized in cpu_init() called
by setup_arch, so accessing percpu variable before setup_arch may cause
kernel hang. But generic __my_cpu_offset always returns zero before
percpu area is brought up, and won't hang kernel.

So the patch tries to clear __my_cpu_offset on boot CPU early
to avoid boot hang.

At least now percpu variable is accessed by lockdep before
setup_arch(), and enabling CONFIG_LOCK_STAT or CONFIG_DEBUG_LOCKDEP
can trigger kernel hang.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: default machine descriptor for multiplatform

Since we now have default implementations for init_time and init_irq,
the init_machine callback is the only one that is not yet optional,
but since

ARM: default machine descriptor for multiplatform

Since we now have default implementations for init_time and init_irq,
the init_machine callback is the only one that is not yet optional,
but since simple DT based platforms all have the same
of_platform_populate function call in there, we can consolidate them
as well, and then actually boot with a completely empty machine_desc.
Unofortunately we cannot just default to an empty init_machine: We
cannot call of_platform_populate before init_machine because that
does not work in case of auxdata, and we cannot call it after
init_machine either because the machine might need to run code
after adding the devices.

To take the final step, this adds support for booting without defining
any machine_desc whatsoever.

For the case that CONFIG_MULTIPLATFORM is enabled, it adds a
global machine descriptor that never matches any machine but is
used as a fallback if nothing else matches. We assume that without
CONFIG_MULTIPLATFORM, we only want to boot on the systems that the kernel
is built for, so we still retain the build-time warning for missing
machine descriptors and the run-time warning when the platform does not
match in that case.

In the case that we run on a multiplatform kernel and the machine
provides a fully populated device tree, we attempt to keep booting,
hoping that no machine specific callbacks are necessary.

Finally, this also removes the misguided "select ARCH_VEXPRESS" that
was only added to avoid a build error for allnoconfig kernels.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Cc: "Russell King - ARM Linux" <linux@arm.linux.org.uk>
Cc: Rob Herring <robherring2@gmail.com>

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ARM: 7700/2: Make cpu_init() notrace

On resume from CPU power down any trace hooks enabled in cpu_init()
will get called before that function has done set_my_cpu_offset(),
so any use of per-cpu vari

ARM: 7700/2: Make cpu_init() notrace

On resume from CPU power down any trace hooks enabled in cpu_init()
will get called before that function has done set_my_cpu_offset(),
so any use of per-cpu variables by trace hook code will cause bad
things to happen. Prevent this by marking the function notrace.

This fixes lockups/crashes seen when enabling function tracer on TC2
with the not yet mainlined cpuidle driver.

Signed-off-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: Add base support for ARMv7-M

This patch adds the base support for the ARMv7-M
architecture. It consists of the corresponding arch/arm/mm/ files and
various #ifdef's around the kernel. Exception

ARM: Add base support for ARMv7-M

This patch adds the base support for the ARMv7-M
architecture. It consists of the corresponding arch/arm/mm/ files and
various #ifdef's around the kernel. Exception handling is implemented by
a subsequent patch.

[ukleinek: squash in some changes originating from commit

b5717ba (Cortex-M3: Add support for the Microcontroller Prototyping System)

from the v2.6.33-arm1 patch stack, port to post 3.6, drop zImage
support, drop reorganisation of pt_regs, assert CONFIG_CPU_V7M doesn't
leak into installed headers and a few cosmetic changes]

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Jonathan Austin <jonathan.austin@arm.com>
Tested-by: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

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ARM: 7694/1: ARM, TCM: initialize TCM in paging_init(), instead of setup_arch()

tcm_init() call iotable_init() and it use early_alloc variants which
do memblock allocation. Directly using memblock a

ARM: 7694/1: ARM, TCM: initialize TCM in paging_init(), instead of setup_arch()

tcm_init() call iotable_init() and it use early_alloc variants which
do memblock allocation. Directly using memblock allocation after
initializing bootmem should not permitted, because bootmem can't know
where are additinally reserved.
So move tcm_init() to a safe place before initalizing bootmem.

(On the U300)

Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: 7690/1: mm: fix CONFIG_LPAE typos

CONFIG_LPAE doesn't exist: the correct option is CONFIG_ARM_LPAE, so fix
up the two typos under arch/arm/.

The fix to head.S is slightly scary, but this is ju

ARM: 7690/1: mm: fix CONFIG_LPAE typos

CONFIG_LPAE doesn't exist: the correct option is CONFIG_ARM_LPAE, so fix
up the two typos under arch/arm/.

The fix to head.S is slightly scary, but this is just for setting up
an early io-mapping for the serial port when running on a big-endian,
LPAE system. Since these systems don't exist in the wild (at least, I
have no access to one outside of kvmtool, which doesn't provide a serial
port suitable for earlyprintk), then we can revisit the code later if it
causes any problems.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: 7680/1: Detect support for SDIV/UDIV from ISAR0 register

The ISAR0 register indicates support for the SDIV and UDIV
instructions in both the Thumb and ARM instruction set. Read the
register to

ARM: 7680/1: Detect support for SDIV/UDIV from ISAR0 register

The ISAR0 register indicates support for the SDIV and UDIV
instructions in both the Thumb and ARM instruction set. Read the
register to detect the supported instructions and update the
elf_hwcap mask as appropriate. This is better than adding more
and more cpuid checks in proc-v7.S for each new cpu variant that
supports these instructions.

Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: 7679/1: Clear IDIVT hwcap if CONFIG_ARM_THUMB=n

Don't advertise support for the SDIV/UDIV thumb instructions if
the kernel is not compiled with support for thumb userspace. This
is in line with

ARM: 7679/1: Clear IDIVT hwcap if CONFIG_ARM_THUMB=n

Don't advertise support for the SDIV/UDIV thumb instructions if
the kernel is not compiled with support for thumb userspace. This
is in line with how we remove the THUMB hwcap in these
configurations.

Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: use read_cpuid_id() instead of read_cpuid(CPUID_ID)

Both calls are identical currently. This patch prepares to deprecate
read_cpuid on machines without cp15.

Also move an unconditional usage o

ARM: use read_cpuid_id() instead of read_cpuid(CPUID_ID)

Both calls are identical currently. This patch prepares to deprecate
read_cpuid on machines without cp15.

Also move an unconditional usage of read_cpuid_cachetype to a more local
scope as read_cpuid_cachetype uses read_cpuid, too.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1359646587-1788-1-git-send-email-u.kleine-koenig@pengutronix.de

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ARM: 7602/1: Pass real "__machine_arch_type" variable to setup_machine_tags() procedure

This modification is needed to proper boot the custom machines with
the IDs that are not described in the mach

ARM: 7602/1: Pass real "__machine_arch_type" variable to setup_machine_tags() procedure

This modification is needed to proper boot the custom machines with
the IDs that are not described in the mach-types.h table.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: 7587/1: implement optimized percpu variable access

Use the previously unused TPIDRPRW register to store percpu offsets.
TPIDRPRW is only accessible in PL1, so it can only be used in the kernel.

ARM: 7587/1: implement optimized percpu variable access

Use the previously unused TPIDRPRW register to store percpu offsets.
TPIDRPRW is only accessible in PL1, so it can only be used in the kernel.

This replaces 2 loads with a mrc instruction for each percpu variable
access. With hackbench, the performance improvement is 1.4% on Cortex-A9
(highbank). Taking an average of 30 runs of "hackbench -l 1000" yields:

Before: 6.2191
After: 6.1348

Will Deacon reported similar delta on v6 with 11MPCore.

The asm "memory clobber" are needed here to ensure the percpu offset
gets reloaded. Testing by Will found that this would not happen in
__schedule() which is a bit of a special case as preemption is disabled
but the execution can move cores.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: kernel: add cpu logical map DT init in setup_arch

As soon as the device tree is unflattened the cpu logical to physical
mapping is carried out in setup_arch to build a proper array of MPIDR and

ARM: kernel: add cpu logical map DT init in setup_arch

As soon as the device tree is unflattened the cpu logical to physical
mapping is carried out in setup_arch to build a proper array of MPIDR and
corresponding logical indexes.

The mapping could have been carried out using the flattened DT blob and
related primitives, but since the mapping is not needed by early boot
code it can safely be executed when the device tree has been uncompressed to
its tree data structure.

This patch adds the arm_dt_init_cpu maps() function call in setup_arch().

If the kernel is not compiled with DT support the function is empty and
no logical mapping takes place through it; the mapping carried out in
smp_setup_processor_id() is left unchanged.
If DT is supported the mapping created in smp_setup_processor_id() is overriden.
The DT mapping also sets the possible cpus mask, hence platform
code need not set it again in the respective smp_init_cpus() functions.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>

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ARM: kernel: smp_setup_processor_id() updates

This patch applies some basic changes to the smp_setup_processor_id()
ARM implementation to make the code that builds cpu_logical_map more
uniform acros

ARM: kernel: smp_setup_processor_id() updates

This patch applies some basic changes to the smp_setup_processor_id()
ARM implementation to make the code that builds cpu_logical_map more
uniform across the kernel.

The function now prints the full extent of the boot CPU MPIDR[23:0] and
initializes the cpu_logical_map for CPUs up to nr_cpu_ids.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>

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ARM: kernel: update cpuinfo to print all online CPUs features

Currently, reading /proc/cpuinfo provides userspace with CPU ID of
the CPU carrying out the read from the file. This is fine as long as

ARM: kernel: update cpuinfo to print all online CPUs features

Currently, reading /proc/cpuinfo provides userspace with CPU ID of
the CPU carrying out the read from the file. This is fine as long as all
CPUs in the system are the same. With the advent of big.LITTLE and
heterogenous ARM systems this approach provides user space with incorrect
bits of information since CPU ids in the system might differ from the one
provided by the CPU reading the file.

This patch updates the cpuinfo show function so that a read from
/proc/cpuinfo prints HW information for all online CPUs at once, mirroring
x86 behaviour.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>

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ARM: virt: Add boot-time diagnostics

In order to easily detect pathological cases, print some diagnostics
when the kernel boots.

This also provides helpers to detect that HYP mode is actually avail

ARM: virt: Add boot-time diagnostics

In order to easily detect pathological cases, print some diagnostics
when the kernel boots.

This also provides helpers to detect that HYP mode is actually available,
which can be used by other subsystems to enable HYP specific features.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

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ARM: SoC: add per-platform SMP operations

This adds a 'struct smp_operations' to abstract the CPU initialization
and hot plugging functions on SMP systems, which otherwise conflict
in a multiplatfor

ARM: SoC: add per-platform SMP operations

This adds a 'struct smp_operations' to abstract the CPU initialization
and hot plugging functions on SMP systems, which otherwise conflict
in a multiplatform kernel. This also helps shmobile and potentially
others that have more than one method to do these.

To allow the kernel to continue building, the platform hooks are
defined as weak symbols which are overrided by the platform code.
Once all platforms are converted, the "weak" attribute will be
removed and the function made static.

Unlike the original version from Marc, this new version from Arnd
does not use a generalized abstraction for per-soc data structures
but only tries to solve the problem for the SMP operations. This
way, we can collapse the previous four data structures into a
single struct, which is less systematic but also easier to follow
as a causal reader.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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ARM: 7505/1: split out ATAGS parsing

Make ATAGS parsing into a source file of its own, namely atags_parse.c.
Also rename compat.c to atags_compat.c to make it clearer what it is
about. Same for ata

ARM: 7505/1: split out ATAGS parsing

Make ATAGS parsing into a source file of its own, namely atags_parse.c.
Also rename compat.c to atags_compat.c to make it clearer what it is
about. Same for atags.c which is now atags_proc.c. Gather all the atags
function declarations into a common atags.h.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option

The memory regions which are passed to arm_add_memory() from
device tree blobs via early_init_dt_add_memory_arch() can

ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option

The memory regions which are passed to arm_add_memory() from
device tree blobs via early_init_dt_add_memory_arch() can
have sizes which are larger than will fit in a 32 bit integer,
so switch to using a phys_addr_t to hold them, to avoid
silently dropping the top 32 bits of the size. Similarly, use
phys_addr_t in early_mem() so that mem=size@start command line
options specifying more than 4GB behave sensibly.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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ARM: integrate CMA with DMA-mapping subsystem

This patch adds support for CMA to dma-mapping subsystem for ARM
architecture. By default a global CMA area is used, but specific devices
are allowed to

ARM: integrate CMA with DMA-mapping subsystem

This patch adds support for CMA to dma-mapping subsystem for ARM
architecture. By default a global CMA area is used, but specific devices
are allowed to have their private memory areas if required (they can be
created with dma_declare_contiguous() function during board
initialisation).

Contiguous memory areas reserved for DMA are remapped with 2-level page
tables on boot. Once a buffer is requested, a low memory kernel mapping
is updated to to match requested memory access type.

GFP_ATOMIC allocations are performed from special pool which is created
early during boot. This way remapping page attributes is not needed on
allocation time.

CMA has been enabled unconditionally for ARMv6+ systems.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>

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ARM: provide a late_initcall hook for platform initialization

This allows platforms to set up things that need to be done at
late_initcall time.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Test

ARM: provide a late_initcall hook for platform initialization

This allows platforms to set up things that need to be done at
late_initcall time.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Robert Lee <rob.lee@linaro.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>

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