The implementation of dma_map_single() and dma_unmap_single() is
exactly the same for all the architectures that support them.
Factor them out to <linux/dma-mapping.h>, and make all drivers to
include <linux/dma-mapping.h> instead of <asm/dma-mapping.h>.
If we need to differentiate them for some architectures, we can
move the generic definitions to <asm-generic/dma-mapping.h>.
Add some comments to the helpers. The concept is quite similar to
the DMA-API of Linux kernel. Drivers are agnostic about what is
going on behind the scene. Just call dma_map_single() before the
DMA, and dma_unmap_single() after it.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Subsystems such as USB expect dma_map_single() and dma_unmap_single() to
do dcache flush/invalidate operations as required. For example, see
see drivers/usb/gadget/udc/udc-core.c::usb_gadget_map_request().
Currently drivers do this locally, (see drivers/usb/dwc3/ep0.c,
drivers/mtd/nand/raw/denali.c etc..)
Update arch specific dma_map_single() and dma_unmap_single() APIs to do
cache flush/invalidate operations, so that drivers need not implement
them locally.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Rick Chen <rick@andestech.com>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.com>
Import include/linux/dma-direction.h from Linux 4.13-rc7 and delete
duplicated definitions of enum dma_data_direction.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Some cross-platform drivers rely on this header present.
Make it so for x86.
It's just a copy'n'paste of arch/arm/include/asm/dma-mapping.h.
Suggested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
