linux-stable.git/include/linux/dma-direct.h, branch v4.20.7

dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB

2018-11-21T17:47:52+00:00

With the overflow buffer removed, we no longer have a unique address
which is guaranteed not to be a valid DMA target to use as an error
token. The DIRECT_MAPPING_ERROR value of 0 tries to at least represent
an unlikely DMA target, but unfortunately there are already SWIOTLB
users with DMA-able memory at physical address 0 which now gets falsely
treated as a mapping failure and leads to all manner of misbehaviour.

The best we can do to mitigate that is flip DIRECT_MAPPING_ERROR to the
other commonly-used error value of all-bits-set, since the last single
byte of memory is by far the least-likely-valid DMA target.

Fixes: dff8d6c1ed58 ("swiotlb: remove the overflow buffer")
Reported-by: John Stultz 
Tested-by: John Stultz 
Acked-by: Konrad Rzeszutek Wilk 
Signed-off-by: Robin Murphy 
Signed-off-by: Christoph Hellwig

swiotlb: remove the overflow buffer

2018-10-19T06:43:46+00:00

Like all other dma mapping drivers just return an error code instead
of an actual memory buffer.  The reason for the overflow buffer was
that at the time swiotlb was invented there was no way to check for
dma mapping errors, but this has long been fixed.

Signed-off-by: Christoph Hellwig 
Acked-by: Catalin Marinas 
Reviewed-by: Robin Murphy 
Reviewed-by: Konrad Rzeszutek Wilk

dma-direct: implement complete bus_dma_mask handling

2018-10-01T14:28:03+00:00

Instead of rejecting devices with a too small bus_dma_mask we can handle
by taking the bus dma_mask into account for allocations and bounce
buffering decisions.

Signed-off-by: Christoph Hellwig

dma-direct: add an explicit dma_direct_get_required_mask

2018-10-01T14:27:15+00:00

This is somewhat modelled after the powerpc version, and differs from
the legacy fallback in use fls64 instead of pointlessly splitting up the
address into low and high dwords and in that it takes (__)phys_to_dma
into account.

Signed-off-by: Christoph Hellwig 
Acked-by: Benjamin Herrenschmidt 
Reviewed-by: Robin Murphy

dma-mapping: merge direct and noncoherent ops

2018-09-20T07:01:15+00:00

All the cache maintainance is already stubbed out when not enabled,
but merging the two allows us to nicely handle the case where
cache maintainance is required for some devices, but not others.

Signed-off-by: Christoph Hellwig 
Acked-by: Paul Burton  # MIPS parts

dma-mapping: provide a generic dma-noncoherent implementation

2018-05-19T06:46:12+00:00

Add a new dma_map_ops implementation that uses dma-direct for the
address mapping of streaming mappings, and which requires arch-specific
implemenations of coherent allocate/free.

Architectures have to provide flushing helpers to ownership trasnfers
to the device and/or CPU, and can provide optional implementations of
the coherent mmap functionality, and the cache_flush routines for
non-coherent long term allocations.

Signed-off-by: Christoph Hellwig 
Tested-by: Alexey Brodkin 
Acked-by: Vineet Gupta

dma/direct: Handle the memory encryption bit in common code

2018-03-20T09:01:59+00:00

Give the basic phys_to_dma() and dma_to_phys() helpers a __-prefix and add
the memory encryption mask to the non-prefixed versions.  Use the
__-prefixed versions directly instead of clearing the mask again in
various places.

Tested-by: Tom Lendacky 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Thomas Gleixner 
Cc: David Woodhouse 
Cc: Joerg Roedel 
Cc: Jon Mason 
Cc: Konrad Rzeszutek Wilk 
Cc: Linus Torvalds 
Cc: Muli Ben-Yehuda 
Cc: Peter Zijlstra 
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20180319103826.12853-13-hch@lst.de
Signed-off-by: Ingo Molnar

dma-direct: reject too small dma masks

2018-01-15T08:35:15+00:00

Signed-off-by: Christoph Hellwig 
Reviewed-by: Robin Murphy

dma-direct: make dma_direct_{alloc,free} available to other implementations

2018-01-15T08:35:14+00:00

So that they don't need to indirect through the operation vector.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Vladimir Murzin

dma-mapping: move dma_mark_clean to dma-direct.h

2018-01-10T15:41:12+00:00

And unlike the other helpers we don't require a  as
this helper is a special case for ia64 only, and this keeps it as
simple as possible.

Signed-off-by: Christoph Hellwig