Commit Graph

36 Commits

Author SHA1 Message Date
Marek Szyprowski
722ec35f7f arm64: dma-mapping: fix handling of devices registered before arch_initcall
This patch ensures that devices, which got registered before arch_initcall
will be handled correctly by IOMMU-based DMA-mapping code.

Cc: <stable@vger.kernel.org>
Fixes: 13b8629f65 ("arm64: Add IOMMU dma_ops")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-17 11:48:01 +00:00
Jisheng Zhang
a7c61a3452 arm64: add __init/__initdata section marker to some functions/variables
These functions/variables are not needed after booting, so mark them
as __init or __initdata.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-02 12:17:11 +00:00
Arnd Bergmann
1dccb598df arm64: simplify dma_get_ops
Including linux/acpi.h from asm/dma-mapping.h causes tons of compile-time
warnings, e.g.

 drivers/isdn/mISDN/dsp_ecdis.h:43:0: warning: "FALSE" redefined
 drivers/isdn/mISDN/dsp_ecdis.h:44:0: warning: "TRUE" redefined
 drivers/net/fddi/skfp/h/targetos.h:62:0: warning: "TRUE" redefined
 drivers/net/fddi/skfp/h/targetos.h:63:0: warning: "FALSE" redefined

However, it looks like the dependency should not even there as
I do not see why __generic_dma_ops() cares about whether we have
an ACPI based system or not.

The current behavior is to fall back to the global dma_ops when
a device has not set its own dma_ops, but only for DT based systems.
This seems dangerous, as a random device might have different
requirements regarding IOMMU or coherency, so we should really
never have that fallback and just forbid DMA when we have not
initialized DMA for a device.

This removes the global dma_ops variable and the special-casing
for ACPI, and just returns the dma ops that got set for the
device, or the dummy_dma_ops if none were present.

The original code has apparently been copied from arm32 where we
rely on it for ISA devices things like the floppy controller, but
we should have no such devices on ARM64.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[catalin.marinas@arm.com: removed acpi_disabled check in arch_setup_dma_ops()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-17 12:05:18 +00:00
Robin Murphy
bd1c6ff74c arm64/dma-mapping: Fix sizes in __iommu_{alloc,free}_attrs
The iommu-dma layer does its own size-alignment for coherent DMA
allocations based on IOMMU page sizes, but we still need to consider
CPU page sizes for the cases where a non-cacheable CPU mapping is
created. Whilst everything on the alloc/map path seems to implicitly
align things enough to make it work, some functions used by the
corresponding unmap/free path do not, which leads to problems freeing
odd-sized allocations. Either way it's something we really should be
handling explicitly, so do that to make both paths suitably robust.

Reported-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-16 10:05:35 +00:00
Andrew Morton
ce5c2d2c25 arm64: fixup for mm renames
__GFP_WAIT was renamed for __GFP_RECLAIM and the gfpflags_allow_blocking()
helper was added.

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-07 16:45:51 -08:00
Mel Gorman
d0164adc89 mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Robin Murphy
876945dbf6 arm64: Hook up IOMMU dma_ops
With iommu_dma_ops in place, hook them up to the configuration code, so
IOMMU-fronted devices will get them automatically.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-10-15 16:41:47 +02:00
Robin Murphy
13b8629f65 arm64: Add IOMMU dma_ops
Taking some inspiration from the arch/arm code, implement the
arch-specific side of the DMA mapping ops using the new IOMMU-DMA layer.

Since there is still work to do elsewhere to make DMA configuration happen
in a more appropriate order and properly support platform devices in the
IOMMU core, the device setup code unfortunately starts out carrying some
workarounds to ensure it works correctly in the current state of things.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-10-15 16:41:37 +02:00
Jisheng Zhang
ba9cc453c4 arm64: dma-mapping: check whether cma area is initialized or not
If CMA is turned on and CMA size is set to zero, kernel should
behave as if CMA was not enabled at compile time.
Every dma allocation should check existence of cma area
before requesting memory.

Arm has done this by commit e464ef16c4 ("arm: dma-mapping: add
checking cma area initialized"), also do this for arm64.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-09-14 12:28:30 +01:00
Robin Murphy
97942c2862 arm64: dma-mapping: Simplify pgprot handling
Since __get_dma_pgprot() does The Right Thing(TM) in the non-coherent
case, and the non-cacheable alias for DMA buffers is private to the
kernel anyway, we can simplify things slightly and make the code more
readable by just using PAGE_KERNEL as the base pgprot.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-08-03 13:17:38 +01:00
Robin Murphy
1d1ddf67dc arm64: dma-mapping: implement dma_get_sgtable()
The default dma_common_get_sgtable() implementation relies on the CPU
address of the buffer being a regular lowmem address. This is not always
the case on arm64, since allocations from the various DMA pools may have
remapped vmalloc addresses, rendering the use of virt_to_page() invalid.

Fix this by providing our own implementation based on the fact that we
can safely derive a physical address from the DMA address in both cases.

CC: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: made static]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:40 +01:00
Robin Murphy
aaf6f2f098 arm64: consolidate __swiotlb_mmap
Since commit 9d3bfbb4df ("arm64: Combine coherent and non-coherent
swiotlb dma_ops"), __dma_common_mmap is no longer shared between two
callers, so roll it into the remaining one.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:39 +01:00
Suthikulpanit, Suravee
b6197b93fa arm64 : Introduce support for ACPI _CCA object
section 6.2.17 _CCA states that ARM platforms require ACPI _CCA
object to be specified for DMA-cabpable devices. Therefore, this patch
specifies ACPI_CCA_REQUIRED in arm64 Kconfig.

In addition, to handle the case when _CCA is missing, arm64 would assign
dummy_dma_ops to disable DMA capability of the device.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-15 14:40:49 +02:00
Dean Nelson
2cff98b99c arm64: add missing PAGE_ALIGN() to __dma_free()
__dma_alloc() does a PAGE_ALIGN() on the passed in size argument before
doing anything else. __dma_free() does not. And because it doesn't, it is
possible to leak memory should size not be an integer multiple of PAGE_SIZE.

The solution is to add a PAGE_ALIGN() to __dma_free() like is done in
__dma_alloc().

Additionally, this patch removes a redundant PAGE_ALIGN() from
__dma_alloc_coherent(), since __dma_alloc_coherent() can only be called
from __dma_alloc(), which already does a PAGE_ALIGN() before the call.

Cc: stable@vger.kernel.org
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-04-29 17:39:39 +01:00
Marek Szyprowski
6829e274a6 arm64: dma-mapping: always clear allocated buffers
Buffers allocated by dma_alloc_coherent() are always zeroed on Alpha,
ARM (32bit), MIPS, PowerPC, x86/x86_64 and probably other architectures.
It turned out that some drivers rely on this 'feature'. Allocated buffer
might be also exposed to userspace with dma_mmap() call, so clearing it
is desired from security point of view to avoid exposing random memory
to userspace. This patch unifies dma_alloc_coherent() behavior on ARM64
architecture with other implementations by unconditionally zeroing
allocated buffer.

Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-04-27 11:39:50 +01:00
Suzuki K. Poulose
7132813c38 arm64: Honor __GFP_ZERO in dma allocations
Current implementation doesn't zero out the pages allocated.
Honor the __GFP_ZERO flag and zero out if set.

Cc: <stable@vger.kernel.org> # v3.14+
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-03-20 18:18:54 +00:00
Catalin Marinas
a1e50a8225 arm64: Increase the swiotlb buffer size 64MB
With commit 3690951fc6 (arm64: Use swiotlb late initialisation), the
swiotlb buffer size is limited to MAX_ORDER_NR_PAGES. However, there are
platforms with 32-bit only devices that require bounce buffering via
swiotlb. This patch changes the swiotlb initialisation to an early 64MB
memblock allocation. In order to get the swiotlb buffer correctly
allocated (via memblock_virt_alloc_low_nopanic), this patch also defines
ARCH_LOW_ADDRESS_LIMIT to the maximum physical address capable of 32-bit
DMA.

Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-02-27 18:05:55 +00:00
Catalin Marinas
9d3bfbb4df arm64: Combine coherent and non-coherent swiotlb dma_ops
Since dev_archdata now has a dma_coherent state, combine the two
coherent and non-coherent operations and remove their declaration,
together with set_dma_ops, from the arch dma-mapping.h file.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-23 16:43:55 +00:00
Laura Abbott
d4932f9e81 arm64: add atomic pool for non-coherent and CMA allocations
Neither CMA nor noncoherent allocations support atomic allocations.
Add a dedicated atomic pool to support this.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Riley <davidriley@chromium.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Ritesh Harjain <ritesh.harjani@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:52 -04:00
Sean Paul
a52ce12191 arm64: Use DMA_ERROR_CODE to denote failed allocation
This patch replaces the static assignment of ~0 to dma_handle with
DMA_ERROR_CODE to be consistent with other platforms.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-10-02 11:57:08 +01:00
Catalin Marinas
2189064795 arm64: Implement set_arch_dma_coherent_ops() to replace bus notifiers
Commit 6ecba8eb51 (arm64: Use bus notifiers to set per-device coherent
DMA ops) introduced bus notifiers to set the coherent dma ops based on
the 'dma-coherent' DT property. Since the generic of_dma_configure()
handles this property for platform and AMBA devices, replace the
notifiers with set_arch_dma_coherent_ops().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-09-22 11:48:31 +01:00
Catalin Marinas
a501e32430 arm64: Clean up the default pgprot setting
The primary aim of this patchset is to remove the pgprot_default and
prot_sect_default global variables and rely strictly on predefined
values. The original goal was to be able to run SMP kernels on UP
hardware by not setting the Shareability bit. However, it is unlikely to
see UP ARMv8 hardware and even if we do, the Shareability bit is no
longer assumed to disable cacheable accesses.

A side effect is that the device mappings now have the Shareability
attribute set. The hardware, however, should ignore it since Device
accesses are always Outer Shareable.

Following the removal of the two global variables, there is some PROT_*
macro reshuffling and cleanup, including the __PAGE_* macros (replaced
by PAGE_*).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
2014-05-09 15:53:37 +01:00
Catalin Marinas
6ecba8eb51 arm64: Use bus notifiers to set per-device coherent DMA ops
Recently, the default DMA ops have been changed to non-coherent for
alignment with 32-bit ARM platforms (and DT files). This patch adds bus
notifiers to be able to set the coherent DMA ops (with no cache
maintenance) for devices explicitly marked as coherent via the
"dma-coherent" DT property.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-03 22:20:34 +01:00
Ritesh Harjani
c7a4a7658d arm64: Make default dma_ops to be noncoherent
Currently arm64 dma_ops is by default made coherent which makes it
opposite in default policy from arm.

Make default dma_ops to be noncoherent (same as arm), as currently there
aren't any dma-capable drivers which assumes coherent ops

Signed-off-by: Ritesh Harjani <ritesh.harjani@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-03 22:20:33 +01:00
Catalin Marinas
196adf2f30 arm64: Remove pgprot_dmacoherent()
Since this macro is identical to pgprot_writecombine() and is only used
in a single place, remove it completely to avoid confusion. On ARMv7+
processors, the coherent DMA mapping must be Normal NonCacheable (a.k.a.
writecombine) to avoid mismatched hardware attribute aliases (with the
kernel linear mapping as Normal Cacheable).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-24 10:35:35 +00:00
Laura Abbott
214fdbe74a arm64: Support DMA_ATTR_WRITE_COMBINE
DMA_ATTR_WRITE_COMBINE is currently ignored. Set the pgprot
appropriately for non coherent opperations.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-24 10:26:10 +00:00
Laura Abbott
6e8d7968e9 arm64: Implement custom mmap functions for dma mapping
The current dma_ops do not specify an mmap function so maping
falls back to the default implementation. There are at least
two issues with using the default implementation:

1) The pgprot is always pgprot_noncached (strongly ordered)
memory even with coherent operations
2) dma_common_mmap calls virt_to_page on the remapped non-coherent
address which leads to invalid memory being mapped.

Fix both these issue by implementing a custom mmap function which
correctly accounts for remapped addresses and sets vm_pg_prot
appropriately.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[catalin.marinas@arm.com: replaced "arm64_" with "__" prefix for consistency]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-24 10:01:17 +00:00
Catalin Marinas
7363590d2c arm64: Implement coherent DMA API based on swiotlb
This patch adds support for DMA API cache maintenance on SoCs without
hardware device cache coherency.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-27 17:16:59 +00:00
Catalin Marinas
3690951fc6 arm64: Use swiotlb late initialisation
Since arm64 does not support ISA, there is no need for early swiotlb
initialisation. This patch switches the DMA mapping code to
swiotlb_tlb_late_init_with_default_size(). A side effect of this is that
GFP_DMA is used for the swiotlb buffer and devices with a 32-bit
coherent mask are correctly supported.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-27 14:11:53 +00:00
Catalin Marinas
19e7640d1f arm64: Replace ZONE_DMA32 with ZONE_DMA
On arm64 we do not have two DMA zones, so it does not make sense to
implement ZONE_DMA32. This patch changes ZONE_DMA32 with ZONE_DMA, the
latter covering 32-bit dma address space to honour GFP_DMA allocations.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-27 12:09:22 +00:00
Ritesh Harjani
bb10eb7b4d arm64: Change misleading function names in dma-mapping
arm64_swiotlb_alloc/free_coherent name can be misleading
somtimes with CMA support being enabled after this
patch (c2104debc235b745265b64d610237a6833fd53)

Change this name to be more generic:
__dma_alloc/free_coherent

Signed-off-by: Ritesh Harjani <ritesh.harjani@gmail.com>
[catalin.marinas@arm.com: renamed arm64_swiotlb_dma_ops to coherent_swiotlb_dma_ops]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26 11:16:28 +00:00
Laura Abbott
ccc9e244eb arm64: Align CMA sizes to PAGE_SIZE
dma_alloc_from_contiguous takes number of pages for a size.
Align up the dma size passed in to page size to avoid truncation
and allocation failures on sizes less than PAGE_SIZE.

Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05 10:28:27 +00:00
Laura Abbott
6ac2104deb arm64: Enable CMA
arm64 bit targets need the features CMA provides. Add the appropriate
hooks, header files, and Kconfig to allow this to happen.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19 17:44:09 +00:00
Laura Abbott
c666e8d5ca arm64: Warn on NULL device structure for dma APIs
Although parts of the DMA apis may properly check for NULL devices,
there may be some places that don't. Rather than fix up all the
possible locations, just require a non-NULL device structure to be
used for allocating/freeing.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[catalin.marinas@arm.com: s/WARN/WARN_ONCE/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19 17:44:08 +00:00
Catalin Marinas
27222a3d2b arm64: Call swiotlb_init() instead of swiotlb_init_with_default_size()
Following commit 74838b7 (swiotlb: add the late swiotlb initialization
function with iotlb memory) the swiotlb_init_with_default_size() is a
static function. This patch changes the arm64 code to call
swiotlb_init() instead and use the default size of 64MB. It is assumed
that AArch64 platforms have enough RAM to afford the pre-allocated
swiotlb memory. It also removes the #ifdef around this call since
CONFIG_SWIOTLB is always enabled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-10-08 16:02:09 +01:00
Catalin Marinas
09b5541246 arm64: DMA mapping API
This patch adds support for the DMA mapping API. It uses dma_map_ops for
flexibility and it currently supports swiotlb. This patch could be
simplified further if the DMA accesses are coherent (not mandated by the
architecture) or if corresponding hooks are placed in the generic
swiotlb code to deal with cache maintenance.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-17 13:42:05 +01:00