On Fri, Dec 29, 2017 at 9:18 AM, Christoph Hellwig <hch@xxxxxx> wrote:
The current PCI_DMA_BUS_IS_PHYS decided if a dma implementation is bound
by the dma mask in the device because it directly maps to a physical
address range (modulo an offset in the device), or if it is virtualized
by an iommu and can map any address (that includes virtual iommus like
swiotlb). The problem with this scheme is that it is per-architecture and
not per dma_ops instance, and we are growing more and more setups that
have multiple different dma operations in use on a single system, for
which this scheme can't provide a correct answer. Depending on the
architecture that means we either get a false positive or false negative
at the moment.
This patch instead extents the is_phys flag in struct dma_map_ops that
is currently only used by a few architectures to be used tree wide.
Note that this means that we now need a struct device parent in the
Scsi_Host or netdevice. Every modern driver has these, but there might
still be a few outdated legacy drivers out there, which now won't make
an intelligent decision.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
For m68k:
Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
--
To unsubscribe from this list: send the line "unsubscribe linux-m68k" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
