[PATCH v2 0/9] Provide dma_mmap_coherent() and dma_get_sgtable()

[Geert Uytterhoeven <geert@linux-m68k.org>]

dma_common_mmap() and dma_common_get_sgtable() are defined in
drivers/base/dma-mapping.c, and always compiled if CONFIG_HAS_DMA=y.

However, their forward declarations and the inline functions defined on top
of them (dma_mmap_attrs(), dma_mmap_coherent(), dma_mmap_writecombine(),
dma_get_sgtable_attrs()), dma_get_sgtable()) are in
<asm-generic/dma-mapping-common.h>, which is not included by all
architectures supporting CONFIG_HAS_DMA=y.  There exist no alternative
implementations.

Hence for e.g. m68k allmodconfig, I get:

drivers/media/v4l2-core/videobuf2-dma-contig.c: In function ‘vb2_dc_mmap’:
drivers/media/v4l2-core/videobuf2-dma-contig.c:204: error: implicit declaration of function ‘dma_mmap_coherent’
drivers/media/v4l2-core/videobuf2-dma-contig.c: In function ‘vb2_dc_get_base_sgt’:
drivers/media/v4l2-core/videobuf2-dma-contig.c:387: error: implicit declaration of function ‘dma_get_sgtable’

This series adds dma_mmap_coherent() and dma_get_sgtable() for all
architectures that set CONFIG_HAS_DMA=y, but don't use dma_map_ops.

  - On architectures for which I received an ack (avr32, blackfin, cris,
    and m68k), the patches are unchanged compared to v1: dma_mmap_coherent()
    and dma_get_sgtable() are implement as inline stubs using
    dma_common_mmap() and dma_common_get_sgtable().

  - On architectures where the current API cannot be implemented (parisc),
    dma_mmap_coherent() and dma_get_sgtable() are dummy implementations that
    just return -EINVAL, until the API has been finalized.

  - On architectures for which I did not receive an ack (c6x, frv, mn10300,
    and xtensa), dma_mmap_coherent() and dma_get_sgtable() are dummy
    implementations that just return -EINVAL, too.

I'll add this to the m68k for-next branch, so hopefully we can get an
unbroken build in 3.8.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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