asm/io: remove unnecessary xlate_dev_mem_ptr() and unxlate_dev_mem_ptr()

The asm-generic/io.h already has default definition, remove unnecessary
arch's defination.

Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@quicinc.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: mm: Make virt_to_pfn() a static inline

Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explicit and exposes any misuse of the
macro virt_to_pfn() acting polymorphic and accepting many types
such as (void *), (unitptr_t) or (unsigned long) as arguments
without warnings.

Doing this is a bit intrusive: virt_to_pfn() requires
PHYS_PFN_OFFSET and PAGE_SHIFT to be defined, and this is defined in
<asm/page.h>, so this must be included *before* <asm/memory.h>.

The use of macros were obscuring the unclear inclusion order here,
as the macros would eventually be resolved, but a static inline
like this cannot be compiled with unresolved macros.

The naive solution to include <asm/page.h> at the top of
<asm/memory.h> does not work, because <asm/memory.h> sometimes
includes <asm/page.h> at the end of itself, which would create a
confusing inclusion loop. So instead, take the approach to always
unconditionally include <asm/page.h> at the end of <asm/memory.h>

arch/arm uses <asm/memory.h> explicitly in a lot of places,
however it turns out that if we just unconditionally include
<asm/memory.h> into <asm/page.h> and switch all inclusions of
<asm/memory.h> to <asm/page.h> instead, we enforce the right
order and <asm/memory.h> will always have access to the
definitions.

Put an inclusion guard in place making it impossible to include
<asm/memory.h> explicitly.

Link: https://lore.kernel.org/linux-mm/20220701160004.2ffff4e5ab59a55499f4c736@linux-foundation.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

ARM: mm: kill unused runtime hook arch_iounmap()

Since the following commits,

v5.4
commit 59d3ae9a5bf6 ("ARM: remove Intel iop33x and iop13xx support")
v5.11
commit 3e3f354bc383 ("ARM: remove ebsa110 platform")

The runtime hook arch_iounmap() on ARM is useless, kill arch_iounmap()
and __iounmap().

Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20220607125027.44946-2-wangkefeng.wang@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

ARM: pxa/sa1100: move I/O space to PCI_IOBASE

PXA and StrongARM1100 traditionally map their I/O space 1:1 into virtual
memory, using a per-bus io_offset that matches the base address of the
ioremap mapping.

In order for PXA to work in a multiplatform config, this needs to
change so I/O space starts at PCI_IOBASE (0xfee00000). Since the pcmcia
soc_common support is shared with StrongARM1100, both have to change at
the same time. The affected machines are:

- Anything with a PCMCIA slot now uses pci_remap_iospace, which
is made available to PCMCIA configurations as well, rather than
just PCI. The first PCMCIA slot now starts at port number 0x10000.

- The Zeus and Viper platforms have PC/104-style ISA buses,
which have a static mapping for both I/O and memory space at
0xf1000000, which can no longer work. It does not appear to have
any in-tree users, so moving it to port number 0 makes them
behave like a traditional PC.

- SA1100 does support ISA slots in theory, but all machines that
originally enabled this appear to have been removed from the tree
ages ago, and the I/O space is never mapped anywhere.

- The Nanoengine machine has support for PCI slots, but looks
like this never included I/O space, the resources only define the
location for memory and config space.

With this, the definitions of __io() and IO_SPACE_LIMIT can be simplified,
as the only remaining cases are the generic PCI_IOBASE and the custom
inb()/outb() macros on RiscPC. S3C24xx still has a custom inb()/outb()
in this here, but this is already removed in another branch.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map

The semantics of pfn_valid() is to check presence of the memory map for a
PFN and not whether a PFN is covered by the linear map. The memory map
may be present for NOMAP memory regions, but they won't be mapped in the
linear mapping. Accessing such regions via __va() when they are
memremap()'ed will cause a crash.

On v5.4.y the crash happens on qemu-arm with UEFI [1]:

<1>[ 0.084476] 8<--- cut here ---
<1>[ 0.084595] Unable to handle kernel paging request at virtual address dfb76000
<1>[ 0.084938] pgd = (ptrval)
<1>[ 0.085038] [dfb76000] *pgd=5f7fe801, *pte=00000000, *ppte=00000000

...

<4>[ 0.093923] [<c0ed6ce8>] (memcpy) from [<c16a06f8>] (dmi_setup+0x60/0x418)
<4>[ 0.094204] [<c16a06f8>] (dmi_setup) from [<c16a38d4>] (arm_dmi_init+0x8/0x10)
<4>[ 0.094408] [<c16a38d4>] (arm_dmi_init) from [<c0302e9c>] (do_one_initcall+0x50/0x228)
<4>[ 0.094619] [<c0302e9c>] (do_one_initcall) from [<c16011e4>] (kernel_init_freeable+0x15c/0x1f8)
<4>[ 0.094841] [<c16011e4>] (kernel_init_freeable) from [<c0f028cc>] (kernel_init+0x8/0x10c)
<4>[ 0.095057] [<c0f028cc>] (kernel_init) from [<c03010e8>] (ret_from_fork+0x14/0x2c)

On kernels v5.10.y and newer the same crash won't reproduce on ARM because
commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with
for_each_mem_range()") changed the way memory regions are registered in
the resource tree, but that merely covers up the problem.

On ARM64 memory resources registered in yet another way and there the
issue of wrong usage of pfn_valid() to ensure availability of the linear
map is also covered.

Implement arch_memremap_can_ram_remap() on ARM and ARM64 to prevent access
to NOMAP regions via the linear mapping in memremap().

Link: https://lore.kernel.org/all/Yl65zxGgFzF1Okac@sirena.org.uk
Link: https://lkml.kernel.org/r/20220426060107.7618-1-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org> [5.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arm: ioremap: Remove unused ARM-specific function pci_ioremap_io()

This function is not used by any driver anymore. So completely remove it.

Link: https://lore.kernel.org/r/20211124154116.916-6-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

arm: ioremap: Implement standard PCI function pci_remap_iospace()

pci_remap_iospace() is standard PCI core function. Architecture code can
reimplement default core implementation if needs custom arch specific
functionality.

ARM needs custom implementation due to pci_ioremap_set_mem_type() hook
which allows ARM platforms to change mem type for iospace.

Implement this pci_remap_iospace() function for ARM architecture to
correctly handle pci_ioremap_set_mem_type() hook, which allows usage of
this standard PCI core function also for platforms which needs different
mem type (e.g. Marvell Armada 375, 38x and 39x).

Link: https://lore.kernel.org/r/20211124154116.916-2-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

ARM: add __arm_iomem_set_ro() to write-protect ioremapped area

__arm_iomem_set_ro() marks an ioremapped area read-only. This is
intended for use with __arm_ioremap_exec() to allow the kernel to
write some code into e.g. SRAM and then write-protect it so the
kernel doesn't complain about W+X mappings.

Tested-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

mm: remove xlate_dev_kmem_ptr()

Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr()
leftovers.

Link: https://lkml.kernel.org/r/20210324102351.6932-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm: Use the generic devmem_is_allowed()

This is exactly the same as the arm64 version, which I recently copied
into lib/ for use by the RISC-V port.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

remove ioremap_nocache and devm_ioremap_nocache

ioremap has provided non-cached semantics by default since the Linux 2.6
days, so remove the additional ioremap_nocache interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>

arch: rely on asm-generic/io.h for default ioremap_* definitions

Various architectures that use asm-generic/io.h still defined their
own default versions of ioremap_nocache, ioremap_wt and ioremap_wc
that point back to plain ioremap directly or indirectly. Remove these
definitions and rely on asm-generic/io.h instead. For this to work
the backup ioremap_* defintions needs to be changed to purely cpp
macros instea of inlines to cover for architectures like openrisc
that only define ioremap after including <asm-generic/io.h>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Palmer Dabbelt <palmer@dabbelt.com>

arm: remove ioremap_cached

No users of ioremap_cached are left, remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

arch/*: remove unused isa_page_to_bus()

isa_page_to_bus() is deprecated and is no longer used anywhere. Remove
it entirely.

Link: http://lkml.kernel.org/r/20190613161155.16946-1-steve@sk2.org
Signed-off-by: Stephen Kitt <steve@sk2.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM/io: Remove useless definition of mmiowb()

ARM includes asm-generic/io.h, which provides a dummy definition of
mmiowb() if one isn't already provided by the architecture.

Remove the useless definition.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

xen: don't include <xen/xen.h> from <asm/io.h> and <asm/dma-mapping.h>

Nothing Xen specific in these headers, which get included from a lot
of code in the kernel. So prune the includes and move them to the
Xen-specific files that actually use them instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove ARCH_BIOVEC_PHYS_MERGEABLE

Take the Xen check into the core code instead of delegating it to
the architectures.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

xen: provide a prototype for xen_biovec_phys_mergeable in xen.h

Having multiple externs in arch headers is not a good way to provide
a common interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

arm: remove the unused BIOVEC_MERGEABLE define

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: simplify BIOVEC_PHYS_MERGEABLE

Turn the macro into an inline, move it to blk.h and simplify the
arch hooks a bit.

Also rename the function to biovec_phys_mergeable as there is no need
to shout.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ARM: Implement pci_remap_cfgspace() interface

The PCI bus specification (rev 3.0, 3.2.5 "Transaction Ordering and
Posting") defines rules for PCI configuration space transactions ordering
and posting, that state that configuration writes have to be non-posted
transactions.

Current ioremap interface on ARM provides mapping functions that provide
"bufferable" writes transactions (ie ioremap uses MT_DEVICE memory type)
aka posted writes, so PCI host controller drivers have no arch interface to
remap PCI configuration space with memory attributes that comply with the
PCI specifications for configuration space.

Implement an ARM specific pci_remap_cfgspace() interface that allows to map
PCI config memory regions with MT_UNCACHED memory type (ie strongly ordered
- non-posted writes), providing a remap function that complies with PCI
specifications for config space transactions.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>

arm, arm64: don't include blk_types.h in <asm/io.h>

No need for it - we only use struct bio_vec in prototypes and already have
forward declarations for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

ARM: io: fix comment grammar

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

ARM: memremap: implement arch_memremap_wb()

The generic memremap() falls back to using ioremap_cache() to create
MEMREMAP_WB mappings if the requested region is not already covered
by the linear mapping, unless the architecture provides an implementation
of arch_memremap_wb().

Since ioremap_cache() is not appropriate on ARM to map memory with the
same attributes used for the linear mapping, implement arch_memremap_wb()
which does exactly that. Also, relax the WARN() check to allow MT_MEMORY_RW
mappings of pfn_valid() pages.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

ARM: reintroduce ioremap_cached() for creating cached I/O mappings

The original ARM-only ioremap flavor 'ioremap_cached' has been renamed
to 'ioremap_cache' to align with other architectures, and subsequently
abused in generic code to map things like firmware tables in memory.
For that reason, there is currently an effort underway to deprecate
ioremap_cache, whose semantics are poorly defined, and which is typed
with an __iomem annotation that is inappropriate for mappings of ordinary
memory.

However, original users of ioremap_cached() used it in a context where
the I/O connotation is appropriate, and replacing those instances with
memremap() does not make sense. So let's revive ioremap_cached(), so
that we can change back those original users before we drop ioremap_cache
entirely in favor of memremap.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

ARM: avoid unwanted GCC memset()/memcpy() optimisations for IO variants

We don't want GCC optimising our memset_io(), memcpy_fromio() or
memcpy_toio() variants, so we must not call one of the standard
functions. Provide a separate name for our assembly memcpy() and
memset() functions, and use that instead, thereby bypassing GCC's
ability to optimise these operations.

GCCs optimisation may introduce unaligned accesses which are invalid
for device mappings.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: io: convert ioremap*() to functions

Convert the ioremap*() preprocessor macros to real functions, moving
them out of line. This allows us to kill off __arm_ioremap(), and
__arm_iounmap() helpers, and remove __arm_ioremap_pfn_caller() from
global view.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: io: fix ioremap_wt() implementation

ioremap_wt() was added by aliasing it to ioremap_nocache(), which is a
device mapping. Device mappings do not allow unaligned accesses, but
it appears that GCC is able to inline its own memcpy() implementation
which may use such accesses. The only user of this is pmem, which
uses memcpy() on the region.

Therefore, this is unsafe. We must implement ioremap_wt() correctly
for ARM, or not at all.

This patch adds a more correct implementation by re-using ioremap_wc()
to provide a normal-memory non-cacheable mapping.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: io: document ARM specific behaviour of ioremap*() implementations

Add documentation of the ARM specific behaviour of the mappings setup by
the ioremap() series of macros.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/*/io.h: Add ioremap_wt() to all architectures

Add ioremap_wt() to all arch-specific asm/io.h headers which
define ioremap_wc() locally. These headers do not include
<asm-generic/iomap.h>. Some of them include <asm-generic/io.h>,
but ioremap_wt() is defined for consistency since they define
all ioremap_xxx locally.

In all architectures without Write-Through support, ioremap_wt()
is defined indentical to ioremap_nocache().

frv and m68k already have ioremap_writethrough(). On those we
add ioremap_wt() indetical to ioremap_writethrough() and defines
ARCH_HAS_IOREMAP_WT in both architectures.

The ioremap_wt() interface is exported to drivers.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-9-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ARM: optimize memset_io()/memcpy_fromio()/memcpy_toio()

If we are building for a LE platform, and we haven't overriden the
MMIO ops, then we can optimize the mem*io operations using the
standard string functions.

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

ARM: 8341/1: io: Unpessimize relaxed io accessors

commit 195bbcac2e5c12f7fb ("ARM: 7500/1: io: avoid writeback addressing
modes for __raw_ accessors") disables writeback addressing modes for
raw i/o. However, the "+Q" output constraint forces the compiler to
disable load hoist optimizations (because the output constraint informs the
compiler of memory stores which the compiler assumes may alias other memory).

Since the relaxed accessors only guarantee ordering wrt i/o accesses to the
same device and not to main memory, there's never a possibility of an accessor
invalidating a hoisted load (because only non-i/o loads would have been hoisted).

The effect is especially noticable with complex address inputs in loops.
For example, the following code:

#include <linux/kernel.h>
#include <linux/io.h>

static const int *remap;

void wr_loop(void __iomem *base, int c, int val)
{
int i;

for (i = 0; i < c; i++)
writew_relaxed(val, base + remap[c >> 2]);
}

generates

current master | this patch
0: e3510000 cmp r1, #0 | 0: e3510000 cmp r1, #0
4: d12fff1e bxle lr | 4: d12fff1e bxle lr
8: e3003000 movw r3, #0 | 8: e3c1c003 bic ip, r1, #3
c: e3403000 movt r3, #0 | c: e6ff2072 uxth r2, r2
10: e92d4010 push {r4, lr} | 10: e3a03000 mov r3, #0
14: e6ff2072 uxth r2, r2 | 14: e59cc000 ldr ip, [ip]
18: e3c14003 bic r4, r1, #3 | 18: e080000c add r0, r0, ip
1c: e593e000 ldr lr, [r3] |
20: e3a03000 mov r3, #0 | 1c: e1c020b0 strh r2, [r0]
| 20: e2833001 add r3, r3, #1
24: e79ec004 ldr ip, [lr, r4] | 24: e1530001 cmp r3, r1
28: e080c00c add ip, r0, ip | 28: 1afffffb bne 1c
2c: e1cc20b0 strh r2, [ip] | 2c: e12fff1e bx lr
30: e2833001 add r3, r3, #1 |
34: e1530001 cmp r3, r1 |
38: 1afffff9 bne 24 |
|
3c: e8bd8010 pop {r4, pc} |

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

ARM: Use include/asm-generic/io.h

Include the generic I/O header file so that duplicate implementations
can be removed. This will also help to establish consistency across more
architectures regarding which accessors they support.

Signed-off-by: Thierry Reding <treding@nvidia.com>

ARM: Define PCI_IOBASE as the base of virtual PCI IO space

This is needed for calls into OF code that parses PCI ranges. It signals
support for memory mapped PCI I/O accesses that are described by device
trees.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
CC: Russell King <linux@arm.linux.org.uk>
CC: Rob Herring <robh+dt@kernel.org>

ARM: 8060/1: mm: allow sub-architectures to override PCI I/O memory type

Due to a design incompatibility between the PCIe Marvell controller
and the Cortex-A9, stressing PCIe devices with a lot of traffic
quickly causes a deadlock.

One part of the workaround for this is to have all PCIe regions mapped
as strongly-ordered (MT_UNCACHED) instead of the default
MT_DEVICE. While the arch_ioremap_caller() mechanism allows
sub-architecture code to override ioremap(), used to map PCIe memory
regions, there isn't such a mechanism to override the behavior of
pci_ioremap_io().

This commit adds the arch_pci_ioremap_mem_type variable, initialized
to MT_DEVICE by default, and that sub-architecture code can
override. We have chosen to expose a single variable rather than
offering the possibility of overriding the entire pci_ioremap_io(),
because implementing pci_ioremap_io() requires calling functions
(get_mem_type()) that are private to the arch/arm/mm/ code.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7930/1: Introduce atomic MMIO modify

Some SoC have MMIO regions that are shared across orthogonal
subsystems. This commit implements a possible solution for the
thread-safe access of such regions through a spinlock-protected API.

Concurrent access is protected with a single spinlock for the
entire MMIO address space. While this protects shared-registers,
it also serializes access to unrelated/unshared registers.

We add relaxed and non-relaxed variants, by using writel_relaxed and writel,
respectively. The rationale for this is that some users may not require
register write completion but only thread-safe access to a register.

Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7933/1: rename ioremap_cached to ioremap_cache

ioremap_cache is more aligned with other architectures.
There are only 2 users of this in the kernel: pxa2xx-flash and Xen.

This fixes Xen build failures on arm64:

drivers/tty/hvc/hvc_xen.c:233:2: error: implicit declaration of function 'ioremap_cached' [-Werror=implicit-function-declaration]
drivers/xen/grant-table.c:1174:3: error: implicit declaration of function 'ioremap_cached' [-Werror=implicit-function-declaration]
drivers/xen/xenbus/xenbus_probe.c:778:4: error: implicit declaration of function 'ioremap_cached' [-Werror=implicit-function-declaration]

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7896/1: rename ioremap_cached to ioremap_cache

ioremap_cache is more aligned with other architectures. There are only
2 users of this in the kernel: pxa2xx-flash and Xen.

This fixes Xen build failures on arm64 caused by commit c04e8e2fe5 (arm64:
allow ioremap_cache() to use existing RAM mappings)

drivers/tty/hvc/hvc_xen.c:233:2: error: implicit declaration of function 'ioremap_cached' [-Werror=implicit-function-declaration]
drivers/xen/grant-table.c:1174:3: error: implicit declaration of function 'ioremap_cached' [-Werror=implicit-function-declaration]
drivers/xen/xenbus/xenbus_probe.c:778:4: error: implicit declaration of function 'ioremap_cached' [-Werror=implicit-function-declaration]

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arm,arm64/include/asm/io.h: define struct bio_vec

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arm,arm64: do not always merge biovec if we are running on Xen

This is similar to what it is done on X86: biovecs are prevented from merging
otherwise every dma requests would be forced to bounce on the swiotlb buffer.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>


Changes in v7:
- remove the extra autotranslate check in biomerge.c.

ARM: 7728/1: mm: Use phys_addr_t properly for ioremap functions

Several of the ioremap functions use unsigned long in places
resulting in truncation if physical addresses greater than
4G are passed in. Change the types of the functions and the
callers accordingly.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7567/1: io: avoid GCC's offsettable addressing modes for halfword accesses

Using the 'o' memory constraint in inline assembly can result in GCC
generating invalid immediate offsets for memory access instructions with
reduced addressing capabilities (i.e. smaller than 12-bit immediate
offsets):

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54983

As there is no constraint to specify the exact addressing mode we need,
fallback to using 'Q' exclusively for halfword I/O accesses. This may
emit an additional add instruction (using an extra register) in order
to construct the address but it will always be accepted by GAS.

Reported-by: Bastian Hecht <hechtb@googlemail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

/dev/mem: use phys_addr_t for physical addresses

This patch fixes the /dev/mem driver to use phys_addr_t for physical
addresses. This is required on PAE systems, especially those that run
entirely out of >4G physical memory space.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM: 7500/1: io: avoid writeback addressing modes for __raw_ accessors

Data aborts taken to hyp mode do not provide a valid instruction
syndrome field in the HSR if the faulting instruction is a memory
access using a writeback addressing mode.

For hypervisors emulating MMIO accesses to virtual peripherals, taking
such an exception requires disassembling the faulting instruction in
order to determine the behaviour of the access. Since this requires
manually walking the two stages of translation, the world must be
stopped to prevent races against page aging in the guest, where the
first-stage translation is invalidated after the hypervisor has
translated to an IPA and the physical page is reused for something else.

This patch avoids taking this heavy performance penalty when running
Linux as a guest by ensuring that our I/O accessors do not make use of
writeback addressing modes.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: Add fixed PCI i/o mapping

This adds a fixed virtual mapping for PCI i/o addresses. The mapping is
located at the last 2MB of vmalloc region (0xfee00000-0xff000000). 2MB
is used to align with PMD size, but IO_SPACE_LIMIT is 1MB. The space
is reserved after .map_io and can be mapped at any time later with
pci_ioremap_io. Platforms which need early i/o mapping (e.g. for vga
console) can call pci_map_io_early in their .map_io function.

This has changed completely from the 1st implementation which only
supported creating the static mapping at .map_io.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>

ARM: fix out[bwl]()

out[bwl]() had a side effect that gcc read-back from the register after
writing its value. This causes a problem for at least 3c589_cs, which
spits out lots of "adapter failure, FIFO diagnostic register 2011."

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: fix __io macro for PCMCIA

With commit c334bc1 (ARM: make mach/io.h include optional), PCMCIA was
broken. PCMCIA depends on __io() returning a valid i/o address, and most
ARM platforms require IO_SPACE_LIMIT be set to 0xffffffff for PCMCIA. This
needs a better fix with a fixed i/o address mapping, but for now we just
restore things to the previous behavior.

This fixes at91, omap1, pxa and sa11xx. pxa needs io.h if PCI is enabled,
but PCMCIA is not. sa11xx already has IO_SPACE_LIMIT set to 0xffffffff,
so it doesn't need an io.h.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Joachim Eastwood <joachim.eastwood@jotron.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Tested-by: Paul Parsons <lost.distance@yahoo.com> (pxa270)
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

Disintegrate asm/system.h for ARM

Disintegrate asm/system.h for ARM.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org

ARM: create a common IOMEM definition

Several platforms create IOMEM defines for casting to 'void __iomem *',
and other platforms are incorrectly using __io() macro for the same
purpose. This creates a common definition and removes all the platform
specific versions. Rather than try to make linux/io.h and asm/io.h
assembly safe, the assembly version of IOMEM is moved into
asm/assembler.h.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>

ARM: kill off __mem_pci

__mem_pci is only used to enable readl/writel and friends. Just condition
this on readl being defined and remove all the __mem_pci defines.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Stephen Warren <swarren@nvidia.com>

ARM: make mach/io.h include optional

Add a kconfig option NEED_MACH_IO_H to conditionally include mach/io.h.

Basing this on CONFIG_PCI and CONFIG_ISA doesn't quite work. Most ISA
platforms don't need mach/io.h, but ebsa110 does. Most PCI platforms need
mach/io.h for now, but ks8695 doesn't which means i/o accesses are broken.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Nicolas Pitre <nico@linaro.org>

ARM: remove compile time __arch_ioremap/__arch_iounmap

Now that all custom ioremap/iounmap users are converted to runtime hook,
remove the compile time defines.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>

ARM: provide runtime hook for ioremap/iounmap

We have compile time over-ride of ioremap and iounmap, but an run-time
override is needed for multi-platform builds. This adds an extra function
pointer check, but ioremap is not peformance critical. The option for
compile time selection remains.

The caller variant is used here to provide correct caller information as
ARM can only support level 0 for __builtin_return_address.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicolas Pitre <nico@linaro.org>

arm: switch to GENERIC_PCI_IOMAP

arm copied pci_iomap from generic code, probably to avoid
pulling the rest of iomap.c in. Since that's in
a separate file now, we can reuse the common implementation.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

ARM: 7129/1: Add __arm_ioremap_exec for mapping external memory as MT_MEMORY

This allows mapping external memory such as SRAM for use.

This is needed for some small chunks of code, such as reprogramming
SDRAM memory source clocks that can't be executed in SDRAM. Other
use cases include some PM related code.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7118/1: rename temp variable in read*_relaxed()

This resolves the following sparse warning from readl() and other macros,
which ends up embedding readl_relaxed() using the same variable.

arch/arm/mach-tegra/dma.c:169:8: warning: symbol '__v' shadows an earlier one
arch/arm/mach-tegra/dma.c:169:8: originally declared here

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: add io{read,write}{16,32}be functions

These functions are used in some PCI drivers with big-endian
MMIO space, and they are trivial to add here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

doc: fix broken references

There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

ARM: io: add a default IO_SPACE_LIMIT definition

Add a default IO_SPACE_LIMIT definition. Explain the chosen value and
suggest why platforms would want to make it larger.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: io: ensure inb/outb() et.al. are properly ordered on ARMv6+

Ensure that the ISA/PCI IO space accessors are properly ordered on
ARMv6+ architectures. These should always be ordered with respect to
all other accesses.

This also fixes __iormb() and __iowmb() not being visible to ioread/
iowrite if a platform defines its own MMIO accessors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: io: simplify ioremap* and iounmap definitions

We don't need to repeat the same definitions of the ioremap*(),
once in terms of __arch_ioremap() and again in terms of __arm_ioremap().
Instead, if the platform hasn't provided an __arch_ioremap, define
this to be __arm_ioremap, and only define the ioremap*() set using
__arch_ioremap.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: io: make iounmap() a simple macro

Defining iounmap() with arguments prevents it from being used as a
function pointer, causing platforms to work around this. Instead,
define it to be a simple macro.

Do the same for __arch_io(re|un)map too.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem

There are very few legitimate use cases, if any, for directly accessing
system RAM through /dev/mem. So let's mimic what they do on x86 and
forbid it when CONFIG_STRICT_DEVMEM is turned on.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>

ARM: Add barriers to io{read,write}{8,16,32} accessors as well

The ioread/iowrite accessors also need barriers as they're used in
place of readl/writel et.al. in portable drivers. Create __iormb()
and __iowmb() which are conditionally defined to be barriers dependent
on ARM_DMA_MEM_BUFFERABLE, and always use these macros in the accessors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 6273/1: Add barriers to the I/O accessors if ARM_DMA_MEM_BUFFERABLE

When the coherent DMA buffers are mapped as Normal Non-cacheable
(ARM_DMA_MEM_BUFFERABLE enabled), buffer accesses are no longer ordered
with Device memory accesses causing failures in device drivers that do
not use the mandatory memory barriers before starting a DMA transfer.
LKML discussions led to the conclusion that such barriers have to be
added to the I/O accessors:

http://thread.gmane.org/gmane.linux.kernel/683509/focus=686153
http://thread.gmane.org/gmane.linux.ide/46414
http://thread.gmane.org/gmane.linux.kernel.cross-arch/5250

This patch introduces a wmb() barrier to the write*() I/O accessors to
handle the situations where Normal Non-cacheable writes are still in the
processor (or L2 cache controller) write buffer before a DMA transfer
command is issued. For the read*() accessors, a rmb() is introduced
after the I/O to avoid speculative loads where the driver polls for a
DMA transfer ready bit.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 6271/1: Introduce *_relaxed() I/O accessors

This patch introduces readl*_relaxed()/write*_relaxed() as the main I/O
accessors (when __mem_pci is defined). The standard read*()/write*()
macros are now based on the relaxed accessors.

This patch is in preparation for a subsequent patch which adds barriers
to the I/O accessors.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: Add caller information to ioremap

This allows the procfs vmallocinfo file to show who created the ioremap
regions. Note: __builtin_return_address(0) doesn't do what's expected
if its used in an inline function, so we leave __arm_ioremap callers
in such places alone.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] Add a common typesafe __io implementation

As Al did for Versatile in 2ad4f86b60b649fd7428265c08d73a3bd360c81b,
add a typesafe __io implementation for platforms to use. Convert
platforms to use this new simple typesafe implementation.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] Remove MT_DEVICE_IXP2000 and associated definitions

As of the previous commit, MT_DEVICE_IXP2000 encodes to the same
PTE bit encoding as MT_DEVICE, so it's now redundant. Convert
MT_DEVICE_IXP2000 to use MT_DEVICE instead, and remove its aliases.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] 5241/1: provide ioremap_wc()

This patch provides an ARM implementation of ioremap_wc().

We use different page table attributes depending on which CPU we
are running on:

- Non-XScale ARMv5 and earlier systems: The ARMv5 ARM documents four
possible mapping types (CB=00/01/10/11). We can't use any of the
cached memory types (CB=10/11), since that breaks coherency with
peripheral devices. Both CB=00 and CB=01 are suitable for _wc, and
CB=01 (Uncached/Buffered) allows the hardware more freedom than
CB=00, so we'll use that.

(The ARMv5 ARM seems to suggest that CB=01 is allowed to delay stores
but isn't allowed to merge them, but there is no other mapping type
we can use that allows the hardware to delay and merge stores, so
we'll go with CB=01.)

- XScale v1/v2 (ARMv5): same as the ARMv5 case above, with the slight
difference that on these platforms, CB=01 actually _does_ allow
merging stores. (If you want noncoalescing bufferable behavior
on Xscale v1/v2, you need to use XCB=101.)

- Xscale v3 (ARMv5) and ARMv6+: on these systems, we use TEXCB=00100
mappings (Inner/Outer Uncacheable in xsc3 parlance, Uncached Normal
in ARMv6 parlance).

The ARMv6 ARM explicitly says that any accesses to Normal memory can
be merged, which makes Normal memory more suitable for _wc mappings
than Device or Strongly Ordered memory, as the latter two mapping
types are guaranteed to maintain transaction number, size and order.
We use the Uncached variety of Normal mappings for the same reason
that we can't use C=1 mappings on ARMv5.

The xsc3 Architecture Specification documents TEXCB=00100 as being
Uncacheable and allowing coalescing of writes, which is also just
what we need.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach

This just leaves include/asm-arm/plat-* to deal with.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] move include/asm-arm to arch/arm/include/asm

Move platform independent header files to arch/arm/include/asm, leaving
those in asm/arch* and asm/plat* alone.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>