The values of ISA_DMA_THRESHOLD and MAX_DMA_ADDRESS are related; one is
the physical/bus address, the other is the virtual address.  Both need
to be kept in step, so rather than having platforms define both, allow
them to define a single macro which sets both of these macros
appropraitely.
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The unsigned long datatype is not sufficient for mapping physical addresses
>= 4GB.

This patch ensures that the address conversion code in asm/memory.h casts
to the correct type when handling physical addresses. The internal v2p
macros only deal with lowmem addresses, so these do not need to be modified.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

MSM's memory is aligned to 2MB, which is more than we can do with our
existing method as we're limited to the upper 8 bits.  Extend this by
using two instructions to 16 bits, automatically selected when MSM is
enabled.
Acked-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This idea came from Nicolas, Eric Miao produced an initial version,
which was then rewritten into this.

Patch the physical to virtual translations at runtime.  As we modify
the code, this makes it incompatible with XIP kernels, but allows us
to achieve this with minimal loss of performance.

As many translations are of the form:

	physical = virtual + (PHYS_OFFSET - PAGE_OFFSET)
	virtual = physical - (PHYS_OFFSET - PAGE_OFFSET)

we generate an 'add' instruction for __virt_to_phys(), and a 'sub'
instruction for __phys_to_virt().  We calculate at run time (PHYS_OFFSET
- PAGE_OFFSET) by comparing the address prior to MMU initialization with
where it should be once the MMU has been initialized, and place this
constant into the above add/sub instructions.

Once we have (PHYS_OFFSET - PAGE_OFFSET), we can calculate the real
PHYS_OFFSET as PAGE_OFFSET is a build-time constant, and save this for
the C-mode PHYS_OFFSET variable definition to use.

At present, we are unable to support Realview with Sparsemem enabled
as this uses a complex mapping function, and MSM as this requires a
constant which will not fit in our math instruction.

Add a module version magic string for this feature to prevent
incompatible modules being loaded.
Tested-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This uncouple PHYS_OFFSET from the platform definitions, thereby
facilitating run-time computation of the physical memory offset.
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@st.com>
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: NMagnus Damm <damm@opensource.se>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: NWan ZongShun <mcuos.com@gmail.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Acked-by: NEric Miao <eric.y.miao@gmail.com>
Acked-by: NJiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Changing the virt_to_phys() argument to "const volatile void *" avoids
compiler warnings in some situations where this function is used.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This changes the TCM handling so that a fixed area is reserved at
0xfffe0000-0xfffeffff for TCM. This areas is used by XScale but
XScale does not have TCM so the mechanisms are mutually exclusive.

This change is needed to make TCM detection more dynamic while
still being able to compile code into it, and is a must for the
unified ARM goals: the current TCM allocation at different places
in memory for each machine would be a nightmare if you want to
compile a single image for more than one machine with TCM so it
has to be nailed down in one place.
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Since we no longer support discontigmem, node is always zero, so
remove this argument.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Everything should now be using sparsemem rather than discontigmem, so
remove the code supporting discontigmem from ARM.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Makes it consistent with VMALLOC_START
Tested-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NAndreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Adds DMA area to 'virtual memory map' startup message
Tested-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NAndreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The non-highmem() and the __pfn_to_bus() based page_to_dma() both
compile to the same code, so its pointless having these two different
approaches.  Use the __pfn_to_bus() based version.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Tested-By: NJamie Iles <jamie@jamieiles.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Tested-By: NJamie Iles <jamie@jamieiles.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>

This reverts commit 75f4aa15.

We have a couple of platforms which require non-linear P:V mappings,
so we need these to be overridable.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

On OMAP platforms, some people want to declare to segment up the memory
between the kernel and a separate application such that there is a hole
in the middle of the memory as far as Linux is concerned.  However,
they want to be able to mmap() the hole.

This currently causes problems, because update_mmu_cache() thinks that
there are valid struct pages for the "hole".  Fix this by making
pfn_valid() slightly more expensive, by checking whether the PFN is
contained within the meminfo array.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Tested-by: NKhasim Syed Mohammed <khasim@ti.com>

Modules compiled to Thumb-2 have two additional relocations needing to
be resolved at load time, R_ARM_THM_CALL and R_ARM_THM_JUMP24, for BL
and B.W instructions. The maximum Thumb-2 addressing range is +/-2^24
(+/-16MB) therefore the MODULES_VADDR macro in asm/memory.h is set to
(MODULES_END - 8MB) for the Thumb-2 compiled kernel.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

If a machine class has a custom __virt_to_bus() implementation then it
must provide a __arch_page_to_dma() implementation as well which is
_not_ based on page_address() to support highmem.

This patch fixes existing __arch_page_to_dma() and provide a default
implementation otherwise.  The default implementation for highmem is
based on __pfn_to_bus() which is defined only when no custom
__virt_to_bus() is provided by the machine class.

That leaves only ebsa110 and footbridge which cannot support highmem
until they provide their own __arch_page_to_dma() implementation.
But highmem support on those legacy platforms with limited memory is
certainly not a priority.
Signed-off-by: NNicolas Pitre <nico@marvell.com>

The kmap virtual area borrows a 2MB range at the top of the 16MB area
below PAGE_OFFSET currently reserved for kernel modules and/or the
XIP kernel.  This 2MB corresponds to the range covered by 2 consecutive
second-level page tables, or a single pmd entry as seen by the Linux
page table abstraction.  Because XIP kernels are unlikely to be seen
on systems needing highmem support, there shouldn't be any shortage of
VM space for modules (14 MB for modules is still way more than twice the
typical usage).

Because the virtual mapping of highmem pages can go away at any moment
after kunmap() is called on them, we need to bypass the delayed cache
flushing provided by flush_dcache_page() in that case.

The atomic kmap versions are based on fixmaps, and
__cpuc_flush_dcache_page() is used directly in that case.
Signed-off-by: NNicolas Pitre <nico@marvell.com>

Let's provide an overridable default instead of having every machine
class define __virt_to_bus and __bus_to_virt to the same thing.  What
most platforms are using is bus_addr == phys_addr so such is the default.

One exception is ebsa110 which has no DMA what so ever, so the actual
definition is not important except only for proper compilation.  Also
added a comment about the special footbridge bus translation.

Let's also remove comments alluding to set_dma_addr which is not
(and should not) be commonly used.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There is no machine class overriding this.  If non linear translations
are implemented again for some machines then this could be restored at
that time.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

As of 73bdf0a6, the kernel needs
to know where modules are located in the virtual address space.
On ARM, we located this region between MODULE_START and MODULE_END.
Unfortunately, everyone else calls it MODULES_VADDR and MODULES_END.
Update ARM to use the same naming, so is_vmalloc_or_module_addr()
can work properly.  Also update the comment on mm/vmalloc.c to
reflect that ARM also places modules in a separate region from the
vmalloc space.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Most ARM machines don't need a special "DMA" memory zone, and
when configured out, the kernel becomes a bit smaller:

|   text    data     bss     dec     hex filename
|3826182  102384  111700 4040266  3da64a vmlinux
|3823593  101616  111700 4036909  3d992d vmlinux.nodmazone

This is because the system now has only one zone total which effect is
to optimize away many conditionals in page allocation paths.

So let's configure this zone only on machines that need split zones.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There's no point scattering this around the tree, the parsing
of the parameter might as well live beside the code which uses
it.  That also means we can make vmalloc_reserve a static
variable.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds a config option (CONFIG_VMSPLIT_*) to allow choosing
between 3:1, 2:2 and 1:3 user:kernel memory splits.
Tested-by: NRiku Voipio <riku.voipio@iki.fi>
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

OMAP at least gets the return type(s) for the DMA translation functions
wrong, which can lead to subtle errors.  Avoid this by moving the DMA
translation functions to asm/dma-mapping.h, and converting them to
inline functions.

Fix the OMAP DMA translation macros to use the correct argument and
result types.

Also, remove the unnecessary casts in dmabounce.c.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch will truncate and/or ignore memory banks if their kernel
direct mappings would (partially) overlap with the vmalloc area or
the mappings between the vmalloc area and the address space top, to
prevent crashing during early boot if there happens to be more RAM
installed than we are expecting.

Since the start of the vmalloc area is not at a fixed address (but
the vmalloc end address is, via the per-platform VMALLOC_END define),
a default area of 128M is reserved for vmalloc mappings, which can
be shrunk or enlarged by passing an appropriate vmalloc= command line
option as it is done on x86.

On a board with a 3:1 user:kernel split, VMALLOC_END at 0xfe000000,
two 512M RAM banks and vmalloc=128M (the default), this patch gives:

	Truncating RAM at 20000000-3fffffff to -35ffffff (vmalloc region overlap).
	Memory: 512MB 352MB = 864MB total

On a board with a 3:1 user:kernel split, VMALLOC_END at 0xfe800000,
two 256M RAM banks and vmalloc=768M, this patch gives:

	Truncating RAM at 00000000-0fffffff to -0e7fffff (vmalloc region overlap).
	Ignoring RAM at 10000000-1fffffff (vmalloc region overlap).
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Tested-by: NRiku Voipio <riku.voipio@iki.fi>

This just leaves include/asm-arm/plat-* to deal with.
Signed-off-by: NRussell 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: NRussell King <rmk+kernel@arm.linux.org.uk>

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

Most architectures have fairly simple discontiguous memory - a
simple set of successive regions each containing some memory.
These can be described simply as a log2 of their maximum size,
along with the base address of the first region and the number
of regions.

The base address is already described by PHYS_PFN_OFFSET, and
the number of regions via the MAX_NUMNODES and the number of
online nodes.

If we then supply the log2 of their maximum size, all the other
discontigmem macros can move into generic code.

There is one exception: lh7a40x seems to have a more complicated
setup; this is left alone.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Lennert Buytenhek

Analogous to the previous patch that allows ioremap() to use section
mappings, this patch allows ioremap() to use supersection mappings.
Original patch by Deepak Saxena.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Allow section mappings to be setup using ioremap() and torn down
with iounmap().  This requires additional support in the MM
context switch to ensure that mappings are properly synchronised
when mapped in.

Based an original implementation by Deepak Saxena, reworked and
ARMv6 support added by rmk.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Majorily based on Hyok Choi's patches, this fixes up the asm-arm
header files for mmuless systems.  Over and above Hyok's patches:

- nommu.h merged into mmu.h (it's only a structure)
- nommu_context.h is essentially the same as mmu_context.h, but
  without the MM switching code.

so there's no point having separate files.  Also, in memory.h,
there's no point #ifndef'ing PHYS_OFFSET and END_MEM - both
CONFIG_DRAM_BASE and CONFIG_DRAM_SIZE will always be set by the
configuration scripts.

Other files have minor formatting changes, but are essentially
the same.  Hyok's original patches were signed off thusly:
Signed-off-by: NHyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

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

This patch fixes arch_local_page_offset(pfn,nid) in arm.
This new one (added by unify_pfn_to_page patches) is obviously buggy.

This macro calculate page offset in a node.

Note: about LOCAL_MAP_NR()
comment in arm's sub-archs says...

 /*
  * Given a kaddr, LOCAL_MAP_NR finds the owning node of the memory
  * and returns the index corresponding to the appropriate page in the
  * node's mem_map.
  */

but LOCAL_MAP_NR() is designed to be able to take both paddr and kaddr.
In this case, paddr is better.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitu.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Lennert Buytenhek

This patch adds support for the I/O coherent cache available on the
xsc3.  The approach is to provide a simple API to determine whether the
chipset supports coherency by calling arch_is_coherent() and then
setting the appropriate system memory PTE and PMD bits.  In addition,
we call this API on dma_alloc_coherent() and dma_map_single() calls.
A generic version exists that will compile out all the coherency-related
code that is not needed on the majority of ARM systems.

Note that we do not check for coherency in the dma_alloc_writecombine()
function as that still requires a special PTE setting.  We also don't
touch dma_mmap_coherent() as that is a special ARM-only API that is by
definition only used on non-coherent system.
Signed-off-by: NDeepak Saxena <dsaxena@plexity.net>
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

ARM can use generic funcs.
PFN_TO_NID, LOCAL_MAP_NR are defined by sub-archs.
Signed-off-by: NKAMEZAWA Hirotuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Patch from Kevin Hilman

This patch increase available DMA-consistent memory allocated by dma_coherent_alloc(). The default remains at 2M (defined in asm/memory.h) and each platform has the ability to override in asm/arch-foo/memory.h.
Signed-off-by: NKevin Hilman <kevin@hilman.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Deepak Saxena

In working on adding 36-bit addressed supersection support to ioremap(),
I came to the conclusion that it would be far simpler to do so by just
splitting __ioremap() into a main external interface and adding an
__ioremap_pfn() function that takes a pfn + offset into the page that
__ioremap() can call. This way existing callers of __ioremap() won't have
to change their code and 36-bit systems will just call __ioremap_pfn()
and we will not have to deal with unsigned long long variables.

Note that __ioremap_pfn() should _NOT_ be called directly by drivers
but is reserved for use by arch_ioremap() implementations that map
32-bit resource regions into the real 36-bit address and then call
this new function.
Signed-off-by: NDeepak Saxena <dsaxena@plexity.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>