• Krzysztof Kozlowski's avatar
    dma-mapping: use unsigned long for dma_attrs · 00085f1e
    Krzysztof Kozlowski authored
    The dma-mapping core and the implementations do not change the DMA
    attributes passed by pointer.  Thus the pointer can point to const data.
    However the attributes do not have to be a bitfield.  Instead unsigned
    long will do fine:
    
    1. This is just simpler.  Both in terms of reading the code and setting
       attributes.  Instead of initializing local attributes on the stack
       and passing pointer to it to dma_set_attr(), just set the bits.
    
    2. It brings safeness and checking for const correctness because the
       attributes are passed by value.
    
    Semantic patches for this change (at least most of them):
    
        virtual patch
        virtual context
    
        @r@
        identifier f, attrs;
    
        @@
        f(...,
        - struct dma_attrs *attrs
        + unsigned long attrs
        , ...)
        {
        ...
        }
    
        @@
        identifier r.f;
        @@
        f(...,
        - NULL
        + 0
         )
    
    and
    
        // Options: --all-includes
        virtual patch
        virtual context
    
        @r@
        identifier f, attrs;
        type t;
    
        @@
        t f(..., struct dma_attrs *attrs);
    
        @@
        identifier r.f;
        @@
        f(...,
        - NULL
        + 0
         )
    
    Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.comSigned-off-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
    Acked-by: default avatarVineet Gupta <vgupta@synopsys.com>
    Acked-by: default avatarRobin Murphy <robin.murphy@arm.com>
    Acked-by: default avatarHans-Christian Noren Egtvedt <egtvedt@samfundet.no>
    Acked-by: Mark Salter <msalter@redhat.com> [c6x]
    Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
    Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
    Reviewed-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
    Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
    Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
    Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
    Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
    Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
    Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
    Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
    Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
    Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
    Acked-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
    Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
    Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
    Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    00085f1e
dma-noop.c 1.65 KB