Loongson doesn't support DMA address above 4GB traditionally. If memory
is more than 4GB, CONFIG_SWIOTLB and ZONE_DMA32 should be selected. In
this way, DMA pages are allocated below 4GB preferably. However, if low
memory is not enough, high pages are allocated and swiotlb is used for
bouncing.
Moreover, we provide a platform-specific dma_map_ops::set_dma_mask() to
set a device's dma_mask and coherent_dma_mask. We use these masks to
distinguishes an allocated page can be used for DMA directly, or need
swiotlb to bounce.
Recently, we found that 32-bit DMA isn't a hardware bug, but a hardware
configuration issue. So, latest firmware has enable the DMA support as
high as 40-bit. To support all-memory DMA for all devices (besides the
Loongson platform limit, there are still some devices have their own
DMA32 limit), and also to be compatible with old firmware, we keep use
swiotlb.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Signed-off-by: Hua Yan <yanh@lemote.com>
Tested-by: Alex Smith <alex.smith@imgtec.com>
Reviewed-by: Alex Smith <alex.smith@imgtec.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6636
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some MIPS controllers have hardware I/O coherency. This patch
detects those and turns off software coherency. A new kernel
command line option also allows the user to manually turn
software coherency on or off.
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
to check dma mapping errors on addresses returned by dma_map_single() and
dma_map_page() interfaces.
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Use asm-generic/dma-mapping-common.h to handle all DMA mapping operations
and establish a default get_dma_ops() that forwards all operations to the
existing code.
Augment dev_archdata to carry a pointer to the struct dma_map_ops, allowing
DMA operations to be overridden on a per device basis. Currently this is
never filled in, so the default dma_map_ops are used. A follow-on patch
sets this for Octeon PCI devices.
Also initialize the dma_debug system as it is now used if it is configured.
Includes fixes by Kevin Cernekee <cernekee@gmail.com>.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/1637/
Patchwork: http://patchwork.linux-mips.org/patch/1678/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Architectures implement dma_is_consistent() in different ways (some
misinterpret the definition of API in DMA-API.txt). So it hasn't been so
useful for drivers. We have only one user of the API in tree. Unlikely
out-of-tree drivers use the API.
Even if we fix dma_is_consistent() in some architectures, it doesn't look
useful at all. It was invented long ago for some old systems that can't
allocate coherent memory at all. It's better to export only APIs that are
definitely necessary for drivers.
Let's remove this API.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma_get_cache_alignment returns the minimum DMA alignment. Architectures
defines it as ARCH_DMA_MINALIGN (formally ARCH_KMALLOC_MINALIGN). So we
can unify dma_get_cache_alignment implementations.
Note that some architectures implement dma_get_cache_alignment wrongly.
dma_get_cache_alignment() should return the minimum DMA alignment. So
fully-coherent architectures should return 1. This patch also fixes this
issue.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ohci-sm501 driver requires dma_declare_coherent_memory(). It is used
by the driver's local memory allocation with dma_alloc_coherent().
Tested on TANBAC TB0287(VR4131 + SM501).
[Ralf: Fixed reject in dma-default.c and removed the entire #if 0'ed block
in dma-mapping.h instead of just the #if 0.]
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Synchronize dma_map_page/dma_unmap_page and dma_map_single/dma_unmap_single.
This will reduce unnecessary writebacks and invalidates.
[Ralf: make dma_unmap_page an inline function.]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Huacai Chen