Em Fri, 28 Dec 2012 20:23:34 +0100
Geert Uytterhoeven <ge...@linux-m68k.org> escreveu:
> 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’
>
> To fix this
> - Move the forward declarations and inline definitions to
> <linux/dma-mapping.h>, so all CONFIG_HAS_DMA=y architectures can use
> them,
> - Replace the hard "BUG_ON(!ops)" checks for dma_map_ops by soft checks,
> so architectures can fall back to the common code by returning NULL
> from their get_dma_ops(). Note that there are no "BUG_ON(!ops)" checks
> in other functions in <asm-generic/dma-mapping-common.h>,
> - Make "struct dma_map_ops *ops" const while we're at it.
>
> Signed-off-by: Geert Uytterhoeven <ge...@linux-m68k.org>
>From my side:
Acked-by: Mauro Carvalho Chehab <mche...@redhat.com>
> ---
> include/asm-generic/dma-mapping-common.h | 55
> ------------------------------
> include/linux/dma-mapping.h | 54 +++++++++++++++++++++++++++++
> 2 files changed, 54 insertions(+), 55 deletions(-)
>
> diff --git a/include/asm-generic/dma-mapping-common.h
> b/include/asm-generic/dma-mapping-common.h
> index de8bf89..2e248d8 100644
> --- a/include/asm-generic/dma-mapping-common.h
> +++ b/include/asm-generic/dma-mapping-common.h
> @@ -176,59 +176,4 @@ dma_sync_sg_for_device(struct device *dev, struct
> scatterlist *sg,
> #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, NULL)
> #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, NULL)
>
> -extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
> - void *cpu_addr, dma_addr_t dma_addr, size_t size);
> -
> -/**
> - * dma_mmap_attrs - map a coherent DMA allocation into user space
> - * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
> - * @vma: vm_area_struct describing requested user mapping
> - * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
> - * @handle: device-view address returned from dma_alloc_attrs
> - * @size: size of memory originally requested in dma_alloc_attrs
> - * @attrs: attributes of mapping properties requested in dma_alloc_attrs
> - *
> - * Map a coherent DMA buffer previously allocated by dma_alloc_attrs
> - * into user space. The coherent DMA buffer must not be freed by the
> - * driver until the user space mapping has been released.
> - */
> -static inline int
> -dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void
> *cpu_addr,
> - dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
> -{
> - struct dma_map_ops *ops = get_dma_ops(dev);
> - BUG_ON(!ops);
> - if (ops->mmap)
> - return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
> - return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
> -}
> -
> -#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL)
> -
> -static inline int dma_mmap_writecombine(struct device *dev, struct
> vm_area_struct *vma,
> - void *cpu_addr, dma_addr_t dma_addr, size_t size)
> -{
> - DEFINE_DMA_ATTRS(attrs);
> - dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> - return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
> -}
> -
> -int
> -dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
> - void *cpu_addr, dma_addr_t dma_addr, size_t size);
> -
> -static inline int
> -dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void
> *cpu_addr,
> - dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
> -{
> - struct dma_map_ops *ops = get_dma_ops(dev);
> - BUG_ON(!ops);
> - if (ops->get_sgtable)
> - return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
> - attrs);
> - return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size);
> -}
> -
> -#define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s,
> NULL)
> -
> #endif
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index 94af418..4b47150 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -74,6 +74,60 @@ static inline int is_device_dma_capable(struct device *dev)
>
> #ifdef CONFIG_HAS_DMA
> #include <asm/dma-mapping.h>
> +
> +extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
> + void *cpu_addr, dma_addr_t dma_addr, size_t size);
> +
> +/**
> + * dma_mmap_attrs - map a coherent DMA allocation into user space
> + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
> + * @vma: vm_area_struct describing requested user mapping
> + * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
> + * @handle: device-view address returned from dma_alloc_attrs
> + * @size: size of memory originally requested in dma_alloc_attrs
> + * @attrs: attributes of mapping properties requested in dma_alloc_attrs
> + *
> + * Map a coherent DMA buffer previously allocated by dma_alloc_attrs
> + * into user space. The coherent DMA buffer must not be freed by the
> + * driver until the user space mapping has been released.
> + */
> +static inline int
> +dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void
> *cpu_addr,
> + dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
> +{
> + const struct dma_map_ops *ops = get_dma_ops(dev);
> + if (ops && ops->mmap)
> + return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
> + return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
> +}
> +
> +#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL)
> +
> +static inline int dma_mmap_writecombine(struct device *dev, struct
> vm_area_struct *vma,
> + void *cpu_addr, dma_addr_t dma_addr, size_t size)
> +{
> + DEFINE_DMA_ATTRS(attrs);
> + dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> + return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
> +}
> +
> +int
> +dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
> + void *cpu_addr, dma_addr_t dma_addr, size_t size);
> +
> +static inline int
> +dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void
> *cpu_addr,
> + dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
> +{
> + const struct dma_map_ops *ops = get_dma_ops(dev);
> + if (ops && ops->get_sgtable)
> + return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
> + attrs);
> + return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size);
> +}
> +
> +#define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s,
> NULL)
> +
> #else
> #include <asm-generic/dma-mapping-broken.h>
> #endif
--
Cheers,
Mauro
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