ARM/dma-mapping: use dma-direct unconditionally

Use dma-direct unconditionally on arm. It has already been used for
some time for LPAE and nommu configurations.

This mostly changes the streaming mapping implementation and the (simple)
coherent allocator for device that are DMA coherent. The existing
complex allocator for uncached mappings for non-coherent devices is still
used as is using the arch_dma_alloc/arch_dma_free hooks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andre Przywara <andre.przywara@arm.com> [highbank]
Tested-by: Marc Zyngier <maz@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_56.RULE (part 1)

Based on the normalized pattern:

this file is licensed under the terms of the gnu general public
license version 2 this program is licensed as is without any warranty
of any kind whether express or implied

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference.

Reviewed-by: Allison Randal <allison@lohutok.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dma-mapping: split <linux/dma-mapping.h>

Split out all the bits that are purely for dma_map_ops implementations
and related code into a new <linux/dma-map-ops.h> header so that they
don't get pulled into all the drivers. That also means the architecture
specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h>
any more, which leads to a missing includes that were pulled in by the
x86 or arm versions in a few not overly portable drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>

cpu/hotplug: Cleanup state names

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

ARM/mvebu: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153333.503198935@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ARM: mvebu: map PCI I/O regions strongly ordered

In order for HW I/O coherency to work on Cortex-A9 based Marvell SoCs,
all MMIO registers must be mapped strongly ordered. In commit
1c8c3cf0b5239 ("ARM: 8060/1: mm: allow sub-architectures to override PCI
I/O memory type") we implemented a new function,
pci_ioremap_set_mem_type(), that allow sub-architecture code to override
the memory type used to map PCI I/O regions.

In the discussion around this patch series [1], Arnd Bergmann made the
comment that maybe all PCI I/O regions should be mapped
strongly-ordered, which would have made our proposal to add
pci_ioremap_set_mem_type() irrelevant. So, we submitted a patch [2] that
did what Arnd suggested.

However, Russell in the end merged our initial proposal to add
pci_ioremap_set_mem_type(), but it was never used anywhere. Further
discussion with Arnd and other folks on IRC lead to the conclusion that
in fact using strongly-ordered for all platforms was maybe not
desirable, and therefore, using pci_ioremap_set_mem_type() was the most
appropriate solution.

As a consequence, this commit finally adds the
pci_ioremap_set_mem_type() call in the mach-mvebu platform code, which
was originally part of our initial patch series [3] and is necessary for
the whole mechanism to work.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-May/256565.html
[2] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-May/256755.html
[3] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-May/256563.html

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

ARM: mvebu: fix HW I/O coherency related deadlocks

Until now, our understanding for HW I/O coherency to work on the
Cortex-A9 based Marvell SoC was that only the PCIe regions should be
mapped strongly-ordered. However, we were still encountering some
deadlocks, especially when testing the CESA crypto engine. After
checking with the HW designers, it was concluded that all the MMIO
registers should be mapped as strongly ordered for the HW I/O coherency
mechanism to work properly.

This fixes some easy to reproduce deadlocks with the CESA crypto engine
driver (dmcrypt on a sufficiently large disk partition).

Tested-by: Terry Stockert <stockert@inkblotadmirer.me>
Tested-by: Romain Perier <romain.perier@free-electrons.com>
Cc: Terry Stockert <stockert@inkblotadmirer.me>
Cc: Romain Perier <romain.perier@free-electrons.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

ARM: mvebu: mark mvebu_hwcc_pci_nb as __maybe_unused

The coherency notifier block is only used when CONFIG_PCI
is enabled, otherwise we get a warning:

arch/arm/mach-mvebu/coherency.c:110:30: warning: 'mvebu_hwcc_pci_nb' defined but not used [-Wunused-variable]

There is no nice way to use an if(IS_ENABLED()) check here to
let the compiler know that it might be used, so let's mark
the structure as __maybe_unused.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

ARM: mvebu: add support to clear shared L2 bit on Armada XP

For optimal performance, in a HW I/O coherency context such as the one
used on Armada XP, the shared L2 bit of the CPU configuration register
should be cleared.

This commit adjusts the coherency fabric code used by Marvell EBU
processors to clear this bit on Armada XP. Since it's a per-CPU
register, it's cleared in set_cpu_coherent() for the boot CPU, and
through a CPU notifier for the non-boot CPUs.

[gregory.clement@free-electrons.com: rebasd on 4.3-rc1]

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

ARM: mvebu: prepare set_cpu_coherent() for future extension

This patch prepares the set_cpu_coherent() function in coherency.c to
be extended to support other SoCs than Armada XP. It will be needed on
Armada 38x to re-enable the coherency after exiting from suspend to
RAM.

This preparation simply moves the function further down in coherency.c
so that it can use coherency_type(), and uses that function to only do
the Armada XP specific work if we are on Armada XP.

Signed-off-by: Nadav Haklai <nadavh@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

ARM: make of_device_ids const

of_device_ids (i.e. compatible strings and the respective data) are not
supposed to change at runtime. All functions working with of_device_ids
provided by <linux/of.h> work with const of_device_ids. So mark the
non-const structs in arch/arm as const, too.

While at it also add some __initconst annotations.

Acked-by: Jason Cooper <jason@lakedameon.net>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: mvebu: don't set the PL310 in I/O coherency mode when I/O coherency is disabled

Since commit f2c3c67f00 (merge commit that adds commit "ARM: mvebu:
completely disable hardware I/O coherency"), we disable I/O coherency
on Armada EBU platforms.

However, we continue to initialize the coherency fabric, because this
coherency fabric is needed on Armada XP for inter-CPU
coherency. Unfortunately, due to this, we also continued to execute
the coherency fabric initialization code for Armada 375/38x, which
switched the PL310 into I/O coherent mode. This has the effect of
disabling the outer cache sync operation: this is needed when I/O
coherency is enabled to work around a PCIe/L2 deadlock. But obviously,
when I/O coherency is disabled, having the outer cache sync operation
is crucial.

Therefore, this commit fixes the armada_375_380_coherency_init() so
that the PL310 is switched to I/O coherent mode only if I/O coherency
is enabled.

Without this fix, all devices using DMA are broken on Armada 375/38x.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: <stable@vger.kernel.org> # v3.8+

ARM: mvebu: use arm_coherent_dma_ops and re-enable hardware I/O coherency

Now that we have enabled automatic I/O synchronization barriers, we no
longer need any explicit barriers. We can therefore simplify
arch/arm/mach-mvebu/coherency.c by using the existing
arm_coherent_dma_ops instead of our custom mvebu_hwcc_dma_ops, and
re-enable hardware I/O coherency support.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[Andrew Lunn <andrew@lunn.ch>: Remove forgotten comment]
Signed-off-by: Andrew Lunn <andrew@lunn.ch>

Merge tag 'mvebu-fixes-3.19-3' of git://git.infradead.org/linux-mvebu into fixes

Merge " mvebu fixes for 3.19-rc (part #3)" from Andrew Lunn:

mvebu: completely disable hardware I/O coherency

* tag 'mvebu-fixes-3.19-3' of git://git.infradead.org/linux-mvebu:
ARM: mvebu: completely disable hardware I/O coherency

Signed-off-by: Olof Johansson <olof@lixom.net>

ARM: mvebu: completely disable hardware I/O coherency

The current hardware I/O coherency is known to cause problems with DMA
coherent buffers, as it still requires explicit I/O synchronization
barriers, which is not compatible with the semantics expected by the
Linux DMA coherent buffers API.

So, in order to have enough time to validate a new solution based on
automatic I/O synchronization barriers, this commit disables hardware
I/O coherency entirely. Future patches will re-enable it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: <stable@vger.kernel.org> # v3.8+
Signed-off-by: Andrew Lunn <andrew@lunn.ch>

ARM: mvebu: Clean-up the Armada XP support

This patch removes the unneeded include of the armada-370-xp.h header.

It also moves some declarations from this file into more accurate
places.

Finally, it also adds a comment explaining that we can't remove yet the
smp field in the dt machine struct due to backward compatibly of the
device tree.

In a few releases, when the old device tree will be obsolete, we will be
able to remove the smp field and then the armada-370-xp.h header.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1414669184-16785-2-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: update comments in coherency.c

The coherency.c top-level comment mentions that it supports the
coherency fabric for Armada 370 and XP, but it also supports the
coherency fabric on Armada 375 and 38x, so this commit updates the
comment accordingly.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1415871540-20302-6-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: remove Armada 375 Z1 workaround for I/O coherency

This reverts commit 5ab5afd8ba83 ("ARM: mvebu: implement Armada 375
coherency workaround"), since we are removing the support for the very
early Z1 revision of the Armada 375 SoC.

This commit is an exact revert, with two exceptions:

- minor adaptations needed due to other changes that have taken place
in coherency.c since the original commit

- keep the definition of pr_fmt. This shouldn't originally have been
part of the Armada 375 Z1 workaround commit since it had nothing to
do with it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1415871540-20302-5-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: remove unused register offset definition

Since commit b21dcafea36d ("arm: mvebu: remove dependency of SMP init
on static I/O mapping"), the COHERENCY_FABRIC_CFG_OFFSET register
offset definition is no longer used, so this commit removes it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1415871540-20302-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: disable I/O coherency on non-SMP situations on Armada 370/375/38x/XP

Enabling the hardware I/O coherency on Armada 370, Armada 375, Armada
38x and Armada XP requires a certain number of conditions:

- On Armada 370, the cache policy must be set to write-allocate.

- On Armada 375, 38x and XP, the cache policy must be set to
write-allocate, the pages must be mapped with the shareable
attribute, and the SMP bit must be set

Currently, on Armada XP, when CONFIG_SMP is enabled, those conditions
are met. However, when Armada XP is used in a !CONFIG_SMP kernel, none
of these conditions are met. With Armada 370, the situation is worse:
since the processor is single core, regardless of whether CONFIG_SMP
or !CONFIG_SMP is used, the cache policy will be set to write-back by
the kernel and not write-allocate.

Since solving this problem turns out to be quite complicated, and we
don't want to let users with a mainline kernel known to have
infrequent but existing data corruptions, this commit proposes to
simply disable hardware I/O coherency in situations where it is known
not to work.

And basically, the is_smp() function of the kernel tells us whether it
is OK to enable hardware I/O coherency or not, so this commit slightly
refactors the coherency_type() function to return
COHERENCY_FABRIC_TYPE_NONE when is_smp() is false, or the appropriate
type of the coherency fabric in the other case.

Thanks to this, the I/O coherency fabric will no longer be used at all
in !CONFIG_SMP configurations. It will continue to be used in
CONFIG_SMP configurations on Armada XP, Armada 375 and Armada 38x
(which are multiple cores processors), but will no longer be used on
Armada 370 (which is a single core processor).

In the process, it simplifies the implementation of the
coherency_type() function, and adds a missing call to of_node_put().

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Fixes: e60304f8cb7bb545e79fe62d9b9762460c254ec2 ("arm: mvebu: Add hardware I/O Coherency support")
Cc: <stable@vger.kernel.org> # v3.8+
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1415871540-20302-3-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: add missing of_node_put() call in coherency.c

There is a missing of_node_put() to decrement the device_node
reference counter after a of_find_matching_node() in coherency_init().

Fixes: 501f928e0097 ("ARM: mvebu: add a coherency_available() call")
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1414423955-5933-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: Fix coherency bus notifiers by using separate notifiers

Currently, the coherency fabric support registers two bus notifiers;
one for platform, one for pci bus types, with the same notifier block.
However, this is illegal and can cause serious issues: the notifier
block is also a link in the notifier list and cannot be inserted twice.

This commit fixes this by using different notifier blocks (with the same
notifier callback) to set the platform and pci bus types notifiers.

Fixes: b0063aad5dd8 ("ARM: mvebu: use hardware I/O coherency also for PCI devices")
Reported-by: Paolo Pisati <p.pisati@gmail.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Link: https://lkml.kernel.org/r/1404826657-6977-1-git-send-email-ezequiel.garcia@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: coherency: fix registration of PCI bus notifier when !PCI

Commit b0063aad5dd8 ("ARM: mvebu: use hardware I/O coherency also for
PCI devices") added a reference to the pci_bus_type variable, but this
variable is only available when CONFIG_PCI is enabled. Therefore,
there is now a build failure in !CONFIG_PCI situations.

This commit fixes that by enclosing the entire initcall into a
IS_ENABLED(CONFIG_PCI) condition.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1400598783-706-1-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: implement L2/PCIe deadlock workaround

The Marvell Armada 375 and Armada 38x SOCs, which use the Cortex-A9
CPU core, the PL310 cache and the Marvell PCIe hardware block are
affected a L2/PCIe deadlock caused by a system erratum when hardware
I/O coherency is used.

This deadlock can be avoided by mapping the PCIe memory areas as
strongly-ordered (note: MT_UNCACHED is strongly-ordered), and by
removing the outer cache sync done in software. This is implemented in
this patch by:

* Registering a custom arch_ioremap_caller function that allows to
make sure PCI memory regions are mapped MT_UNCACHED.

* Adding at runtime the 'arm,io-coherent' property to the PL310 cache
controller. This cannot be done permanently in the DT, because the
hardware I/O coherency can only be enabled when CONFIG_SMP is
enabled, in the current kernel situation.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1400165974-9059-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: use hardware I/O coherency also for PCI devices

Since the beginning of the introduction of hardware I/O coherency
support for Armada 370 and Armada XP, the special DMA operations
should have applied to all DMA capable devices. Unfortunately, while
the original code properly took into account platform devices, it
didn't take into account PCI devices, which can also be DMA masters.

This commit fixes that by registering a bus notifier on pci_bus_type,
to register our custom DMA operations, like is already done for
platform devices. While doing this, we also rename
mvebu_hwcc_platform_notifier() to mvebu_hwcc_notifier() and
mvebu_hwcc_platform_nb to mvebu_hwcc_nb because they are no longer
specific to platform devices.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1399997070-11434-1-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: conditionalize Armada 375 coherency workaround

The Armada 375 coherency workaround only needs to be applied to the Z1
revision of the SoC. The A0 and later revisions have been fixed, and
no longer need this workaround.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1399302326-6917-6-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: Split low level functions to manipulate HW coherency

Actually enabling coherency and adding a CPU on a SMP group are two
different operations which can be done separately. This patch splits
this in two functions.

Moreover as they use common pattern, this patch also creates local low
level functions (ll_get_coherency_base and ll_get_cpuid) to be used by
the exposed functions (ll_add_cpu_to_smp_group and
ll_enable_coherency)

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-6-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: Remove the unused argument of set_cpu_coherent()

set_cpu_coherent() took the SMP group ID as parameter. But this
parameter was never used, and the CPU always uses the SMP group 0. So
we can remove this parameter.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-5-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: ll_set_cpu_coherent always uses the current CPU

ll_set_cpu_coherent is always used on the current CPU, so instead of
passing the CPU id as argument, ll_set_cpu_coherent() can find it by
itself.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-4-git-send-email-gregory.clement@free-electrons.com
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: remove the address parameter for ll_set_cpu_coherent

In order to be able to deal with the MMU enabled and the MMU disabled
cases, the base address of the coherency registers was passed to the
function. The address by itself was not interesting as it can't change
for a given SoC, the only thing we need is to have a distinction
between the physical or the virtual address.

This patch add a check of the MMU bit to choose the accurate address,
then the calling function doesn't have to pass this information.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-3-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: add Armada 38x support to the coherency code

The Armada 38x has a coherency unit that is similar to the one of the
Armada 375 SoC, except that it does not have the bug of the Armada 375
coherency unit that requires the XOR based workaround.

This commit therefore extends the Marvell EBU coherency code with a
new compatible string to support the Armada 38x coherency unit.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483228-25625-9-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: implement Armada 375 coherency workaround

The early revisions of Armada 375 SOCs (Z1 stepping) have a bug in the
I/O coherency unit that prevents using the normal method for the I/O
coherency barrier. The recommended workaround is to use a XOR memset
transfer to act as the I/O coherency barrier.

This involves "borrowing" a XOR engine, which gets disabled in the
Device Tree so the normal XOR driver doesn't use it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483228-25625-8-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: add Armada 375 support to the coherency code

The Armada 375, like the Armada 370 and Armada XP, has a coherency
unit. However, unlike the coherency unit of 370/XP which does both CPU
and I/O coherency, the one on Armada 735 only does I/O
coherency. Therefore, instead of having two sets of registers (the
first one being used mainly to register each CPU in the coherency
fabric, the second one being used for the I/O coherency barrier), it
has only one set of register (for the I/O coherency barrier).

This commit adds a new "marvell,armada-375-coherency-fabric"
compatible string for this variant of the coherency fabric. The custom
DMA operations, and the way of triggering an I/O barrier is the same
as Armada 370/XP, so the code changes are minimal. However, the
set_cpu_coherent() function is not needed on Armada 375 and will not
work.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483228-25625-7-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: ARM: mvebu: use of_find_matching_node_and_match() in coherency.c

In the mach-mvebu coherency code, instead of using
of_find_matching_node() and then of_match_node(), directly use the
of_find_matching_node_and_match() which does both at once.

We take this opportunity to also simplify the initialization of the
"type" variable.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483228-25625-5-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: add a coherency_available() call

This commit extends the coherency fabric code to provide a
coherency_available()function that the SoC code can call to be told
whether coherency support is available or not. On Armada 370/XP,
coherency support is available as soon as the relevant DT node is
present. On some upcoming SoCs, the DT node needs to be present *and*
the system running with CONFIG_SMP enabled.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483228-25625-3-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: prepare coherency code to support more SOCs

The code that handles the coherency fabric of Armada 370 and Armada XP
in arch/arm/mach-mvebu/coherency.c made the assumption that there was
only one type of coherency fabric. Unfortunately, it turns out that
upcoming SoCs have a slightly different coherency unit.

In preparation to the introduction of the coherency support for more
SoCs, this commit:

* Introduces a data associated to the compatible string in the
compatible string match table, so that the code can differantiate
the variant of coherency unit being used.

* Separates the coherency unit initialization code into its own
function.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483228-25625-2-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: fix some sparse warnings

This patch fixes conflicting types for 'set_cpu_coherent' and fixes the
following sparse warnings.

arch/arm/mach-mvebu/system-controller.c:42:38:
warning: symbol 'armada_370_xp_system_controller' was not declared. Should it be static?
arch/arm/mach-mvebu/system-controller.c:49:38:
warning: symbol 'orion_system_controller' was not declared. Should it be static?
arch/arm/mach-mvebu/system-controller.c:67:6:
warning: symbol 'mvebu_restart' was not declared. Should it be static?
arch/arm/mach-mvebu/coherency.c:31:15:
warning: symbol 'coherency_phys_base' was not declared. Should it be static?
arch/arm/mach-mvebu/coherency.c:48:5:
warning: symbol 'set_cpu_coherent' was not declared. Should it be static?
arch/arm/mach-mvebu/coherency.c:123:12:
warning: symbol 'coherency_init' was not declared. Should it be static?
arch/arm/mach-mvebu/pmsu.c:38:5: warning:
symbol 'armada_xp_boot_cpu' was not declared. Should it be static?
arch/arm/mach-mvebu/pmsu.c:61:12: warning:
symbol 'armada_370_xp_pmsu_init' was not declared. Should it be static?
arch/arm/mach-mvebu/platsmp.c:49:13: warning:
symbol 'set_secondary_cpus_clock' was not declared. Should it be static?
arch/arm/mach-mvebu/platsmp.c:97:13: warning:
symbol 'armada_xp_smp_prepare_cpus' was not declared. Should it be static?
arch/arm/mach-mvebu/hotplug.c:24:12: warning:
symbol 'armada_xp_cpu_die' was not declared. Should it be static?

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: add missing of_node_put() to fix reference leak

Add of_node_put to properly decrement the refcount when we are
done using a given node.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Reviewed-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

Conflicts:
arch/arm/mach-mvebu/armada-370-xp.c
arch/arm/mach-mvebu/platsmp.c

arm: delete __cpuinit/__CPUINIT usage from all ARM users

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 5e427ec2d0 ("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.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings. In any case, they are temporary and harmless.

This removes all the ARM uses of the __cpuinit macros from C code,
and all __CPUINIT from assembly code. It also had two ".previous"
section statements that were paired off against __CPUINIT
(aka .section ".cpuinit.text") that also get removed here.

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

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

arm: mvebu: fix coherency_late_init() for multiplatform

As noticed by Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>, commit
865e0527d2d7 ('arm: mvebu: avoid hardcoded virtual address in
coherency code') added a postcore_initcall() to register the bus
notifier that the mvebu code needs to apply correct DMA operations on
its platform devices breaks the multiplatform boot on other platforms,
because the bus notifier registration is unconditional.

This commit fixes that by registering the bus notifier only if we have
the mvebu coherency unit described in the Device Tree. The conditional
used is exactly the same in which the bus_register_notifier() call was
originally enclosed before 865e0527d2d7 ('arm: mvebu: avoid hardcoded
virtual address in coherency code').

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reported-by: Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arm: mvebu: don't hardcode a physical address in headsmp.S

Now that the coherency_init() function is called a bit earlier, we can
actually read the physical address of the coherency unit registers
from the Device Tree, and communicate that to the headsmp.S code,
which avoids hardcoding a physical address.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arm: mvebu: avoid hardcoded virtual address in coherency code

Now that the coherency_get_cpu_count() function no longer requires a
very early mapping of the coherency unit registers, we can avoid the
hardcoded virtual address in coherency.c. However, the coherency
features are still used quite early, so we need to do the of_iomap()
early enough, at the ->init_timer() level, so we have the call of
coherency_init() at this point.

Unfortunately, at ->init_timer() time, it is not possible to register
a bus notifier, so we add a separate coherency_late_init() function
that gets called as as postcore_initcall(), when bus notifiers are
available.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arm: mvebu: remove dependency of SMP init on static I/O mapping

The ->smp_init_cpus() function is called very early during boot, at a
point where dynamic I/O mappings are not yet possible. However, in the
Armada 370/XP implementation of this function, we have to get the
number of CPUs. We used to do that by accessing a hardware register,
which requires relying on a static I/O mapping set up by
->map_io(). Not only this requires hardcoding a virtual address, but
it also prevents us from removing the static I/O mapping.

So this commit changes the way used to get the number of CPUs: we now
use the Device Tree, which is a representation of the hardware, and
provides us the number of available CPUs. This is also more accurate,
because it potentially allows to boot the Linux kernel on only a
number of CPUs given by the Device Tree, instead of unconditionally on
all CPUs.

As a consequence, the coherency_get_cpu_count() function becomes no
longer used, so we remove it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arm: mvebu: Add hardware I/O Coherency support

Armada 370 and XP come with an unit called coherency fabric. This unit
allows to use the Armada 370/XP as a nearly coherent architecture. The
coherency mechanism uses snoop filters to ensure the coherency between
caches, DRAM and devices. This mechanism needs a synchronization
barrier which guarantees that all the memory writes initiated by the
devices have reached their target and do not reside in intermediate
write buffers. That's why the architecture is not totally coherent and
we need to provide our own functions for some DMA operations.

Beside the use of the coherency fabric, the device units will have to
set the attribute flag of the decoding address window to select the
accurate coherency process for the memory transaction. This is done
each device driver programs the DRAM address windows. The value of the
attribute set by the driver is retrieved through the
orion_addr_map_cfg struct filled during the early initialization of
the platform.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Yehuda Yitschak <yehuday@marvell.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>

arm: mvebu: Add support for coherency fabric in mach-mvebu

The Armada 370 and Armada XP SOCs have a coherency fabric unit which
is responsible for ensuring hardware coherency between all CPUs and
between CPUs and I/O masters. This patch provides the basic support
needed for SMP.

Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>