Pass the device type specific needs_bounce function in at dmabounce
register time, avoiding the need for a platform specific global
function to do this.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
DMA addresses should not be casted to void * for printing. Fix
that to be consistent with the rest of the file.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the decision whether to bounce into __dma_map_page(), before
the check for high pages. This avoids triggering the high page
check for devices which aren't using dmabounce. Fix the unmap path
to cope too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the decision to perform DMA bouncing out of map_single() into its
own stand-alone function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use dma_map_page()/dma_unmap_page() internals to handle dma_map_single()
and dma_unmap_single().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When map_single() is unable to obtain a safe buffer, we must return
the dma_addr_t error value, which is ~0 rather than 0.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add ARM support for the DMA debug infrastructure, which allows the
DMA API usage to be debugged.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The DMA API has the notion of buffer ownership; make it explicit in the
ARM implementation of this API. This gives us a set of hooks to allow
us to deal with CPU cache issues arising from non-cache coherent DMA.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-By: Jamie Iles <jamie@jamieiles.com>
Commit f74f7e57ae (ARM: use
flush_kernel_dcache_area() for dmabounce) has broken dmabounce build:
CC arch/arm/common/dmabounce.o
arch/arm/common/dmabounce.c: In function 'unmap_single':
arch/arm/common/dmabounce.c:315: error: implicit declaration of function '__cpuc_flush_kernel_dcache_area'
make[2]: *** [arch/arm/common/dmabounce.o] Error 1
Fix it.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
After copying data from the bounce buffer to the real buffer, use
flush_kernel_dcache_page() to ensure that data is written back in
manner coherent with future userspace mappings.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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: Nicolas Pitre <nico@marvell.com>
Validate the direction argument like x86 does. In addition,
validate the dma_unmap_* parameters against those passed to
dma_map_* when using the DMA bounce code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The dmabounce dma_sync_xxx() implementation have been broken for
quite some time; they all copy data between the DMA buffer and
the CPU visible buffer no irrespective of the change of ownership.
(IOW, a DMA_FROM_DEVICE mapping copies data from the DMA buffer
to the CPU buffer during a call to dma_sync_single_for_device().)
Fix it by getting rid of sync_single(), moving the contents into
the recently created dmabounce_sync_for_xxx() functions and adjusting
appropriately.
This also makes it possible to properly support the DMA range sync
functions.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We can translate a struct page directly to a DMA address using
page_to_dma(). No need to use page_address() followed by
virt_to_dma().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Convert the existing dma_sync_single_for_* APIs to the new range based
APIs, and make the dma_sync_single_for_* API a superset of it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King
Mike Rapoport
Nicolas Pitre
Russell King