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>
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>
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>
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>
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>
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.
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>
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>
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>
Pull ARM updates from Russell King:
"This is the first chunk of ARM updates for this merge window.
Conflicts are expected in two files - asm/timex.h and
mach-integrator/integrator_cp.c. Nothing particularly stands out more
than anything else.
Most of the growth is down to the opcodes stuff from Dave Martin,
which is countered by Rob's patches to use more of the asm-generic
headers on ARM."
(A few more conflicts grew since then, but it all looked fairly trivial)
* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (44 commits)
ARM: 7548/1: include linux/sched.h in syscall.h
ARM: 7541/1: Add ARM ERRATA 775420 workaround
ARM: ensure vm_struct has its phys_addr member filled in
ARM: 7540/1: kexec: Check segment memory addresses
ARM: 7539/1: kexec: scan for dtb magic in segments
ARM: 7538/1: delay: add registration mechanism for delay timer sources
ARM: 7536/1: smp: Formalize an IPI for wakeup
ARM: 7525/1: ptrace: use updated syscall number for syscall auditing
ARM: 7524/1: support syscall tracing
ARM: 7519/1: integrator: convert platform devices to Device Tree
ARM: 7518/1: integrator: convert AMBA devices to device tree
ARM: 7517/1: integrator: initial device tree support
ARM: 7516/1: plat-versatile: add DT support to FPGA IRQ
ARM: 7515/1: integrator: check PL010 base address from resource
ARM: 7514/1: integrator: call common init function from machine
ARM: 7522/1: arch_timers: register a time/cycle counter
ARM: 7523/1: arch_timers: enable the use of the virtual timer
ARM: 7531/1: mark kernelmode mem{cpy,set} non-experimental
ARM: 7520/1: Build dtb files in all target
ARM: Fix build warning in arch/arm/mm/alignment.c
...
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>
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>
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>
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>
Rob Herring has done a sweeping change cleaning up all of the mach/io.h includes,
moving some of the oft-repeated macros to a common location and removing a bunch of
boiler plate. This is another step closer to a common zImage for multiple platforms.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=YIsn
-----END PGP SIGNATURE-----
Merge tag 'cleanup2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull "ARM: cleanups of io includes" from Olof Johansson:
"Rob Herring has done a sweeping change cleaning up all of the
mach/io.h includes, moving some of the oft-repeated macros to a common
location and removing a bunch of boiler plate. This is another step
closer to a common zImage for multiple platforms."
Fix up various fairly trivial conflicts (<mach/io.h> removal vs changes
around it, tegra localtimer.o is *still* gone, yadda-yadda).
* tag 'cleanup2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (29 commits)
ARM: tegra: Include assembler.h in sleep.S to fix build break
ARM: pxa: use common IOMEM definition
ARM: dma-mapping: convert ARCH_HAS_DMA_SET_COHERENT_MASK to kconfig symbol
ARM: __io abuse cleanup
ARM: create a common IOMEM definition
ARM: iop13xx: fix missing declaration of iop13xx_init_early
ARM: fix ioremap/iounmap for !CONFIG_MMU
ARM: kill off __mem_pci
ARM: remove bunch of now unused mach/io.h files
ARM: make mach/io.h include optional
ARM: clps711x: remove unneeded include of mach/io.h
ARM: dove: add explicit include of dove.h to addr-map.c
ARM: at91: add explicit include of hardware.h to uncompressor
ARM: ep93xx: clean-up mach/io.h
ARM: tegra: clean-up mach/io.h
ARM: orion5x: clean-up mach/io.h
ARM: davinci: remove unneeded mach/io.h include
[media] davinci: remove includes of mach/io.h
ARM: OMAP: Remove remaining includes for mach/io.h
ARM: msm: clean-up mach/io.h
...
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
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>
__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>
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>
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>
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 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>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (59 commits)
MAINTAINERS: linux-m32r is moderated for non-subscribers
linux@lists.openrisc.net is moderated for non-subscribers
Drop default from "DM365 codec select" choice
parisc: Kconfig: cleanup Kernel page size default
Kconfig: remove redundant CONFIG_ prefix on two symbols
cris: remove arch/cris/arch-v32/lib/nand_init.S
microblaze: add missing CONFIG_ prefixes
h8300: drop puzzling Kconfig dependencies
MAINTAINERS: microblaze-uclinux@itee.uq.edu.au is moderated for non-subscribers
tty: drop superfluous dependency in Kconfig
ARM: mxc: fix Kconfig typo 'i.MX51'
Fix file references in Kconfig files
aic7xxx: fix Kconfig references to READMEs
Fix file references in drivers/ide/
thinkpad_acpi: Fix printk typo 'bluestooth'
bcmring: drop commented out line in Kconfig
btmrvl_sdio: fix typo 'btmrvl_sdio_sd6888'
doc: raw1394: Trivial typo fix
CIFS: Don't free volume_info->UNC until we are entirely done with it.
treewide: Correct spelling of successfully in comments
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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=686153http://thread.gmane.org/gmane.linux.ide/46414http://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>
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>
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>
As Al did for Versatile in 2ad4f86b60,
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>
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>
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>
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>
