Subject: [PATCH V3 1/3] arm: dma mapping: Export dma ops functions

From: [email-masked] (Marek Szyprowski)
Date: Wed, 21 Nov 2012 08:06:01 +0100

Hello,

On 11/20/2012 10:56 PM, Gregory CLEMENT wrote:
> Expose the DMA operations functions. Until now only the dma_ops
> structs in a whole or some dma operation were exposed. This patch
> exposes all the dma coherents operations. They can be reused when an
> architecture or a driver need to create its own set of dma_operation.
>
> Signed-off-by: Gregory CLEMENT <[email-masked]>

Besides arm_dma_set_mask() function I see no reason to export the other
arm dma related functions.

> ---
>   arch/arm/include/asm/dma-mapping.h |   48 ++++++++++++++++++++++++++++++++++++
>   arch/arm/mm/dma-mapping.c          |   25 ++++---------------
>   2 files changed, 53 insertions(+), 20 deletions(-)
>
> diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> index 2300484..b12d7c0 100644
> --- a/arch/arm/include/asm/dma-mapping.h
> +++ b/arch/arm/include/asm/dma-mapping.h
> @@ -112,6 +112,54 @@ static inline void dma_free_noncoherent(struct device *dev, size_t size,
>   extern int dma_supported(struct device *dev, u64 mask);
>   
>   /**
> + * arm_dma_map_page - map a portion of a page for streaming DMA
> + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
> + * @page: page that buffer resides in
> + * @offset: offset into page for start of buffer
> + * @size: size of buffer to map
> + * @dir: DMA transfer direction
> + *
> + * Ensure that any data held in the cache is appropriately discarded
> + * or written back.
> + *
> + * The device owns this memory once this call has completed.  The CPU
> + * can regain ownership by calling dma_unmap_page().
> + */
> +extern dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
> +				    unsigned long offset, size_t size,
> +				    enum dma_data_direction dir,
> +				    struct dma_attrs *attrs);
> +
> +/**
> + * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
> + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
> + * @handle: DMA address of buffer
> + * @size: size of buffer (same as passed to dma_map_page)
> + * @dir: DMA transfer direction (same as passed to dma_map_page)
> + *
> + * Unmap a page streaming mode DMA translation.  The handle and size
> + * must match what was provided in the previous dma_map_page() call.
> + * All other usages are undefined.
> + *
> + * After this call, reads by the CPU to the buffer are guaranteed to see
> + * whatever the device wrote there.
> + */
> +extern void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
> +				size_t size, enum dma_data_direction dir,
> +				struct dma_attrs *attrs);
> +
> +extern void arm_dma_sync_single_for_cpu(struct device *dev,
> +					dma_addr_t handle, size_t size,
> +					enum dma_data_direction dir);
> +
> +extern void arm_dma_sync_single_for_device(struct device *dev,
> +					dma_addr_t handle, size_t size,
> +					enum dma_data_direction dir);
> +
> +extern int arm_dma_set_mask(struct device *dev, u64 dma_mask);
> +
> +
> +/**
>    * arm_dma_alloc - allocate consistent memory for DMA
>    * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
>    * @size: required memory size
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 58bc3e4..dbb67ce 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -56,20 +56,13 @@ static void __dma_page_dev_to_cpu(struct page *, unsigned long,
>   		size_t, enum dma_data_direction);
>   
>   /**
> - * arm_dma_map_page - map a portion of a page for streaming DMA
> - * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
> - * @page: page that buffer resides in
> - * @offset: offset into page for start of buffer
> - * @size: size of buffer to map
> - * @dir: DMA transfer direction
> - *
>    * Ensure that any data held in the cache is appropriately discarded
>    * or written back.
>    *
>    * The device owns this memory once this call has completed.  The CPU
>    * can regain ownership by calling dma_unmap_page().
>    */
> -static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
> +dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
>   	     unsigned long offset, size_t size, enum dma_data_direction dir,
>   	     struct dma_attrs *attrs)
>   {
> @@ -86,12 +79,6 @@ static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *pag
>   }
>   
>   /**
> - * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
> - * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
> - * @handle: DMA address of buffer
> - * @size: size of buffer (same as passed to dma_map_page)
> - * @dir: DMA transfer direction (same as passed to dma_map_page)
> - *
>    * Unmap a page streaming mode DMA translation.  The handle and size
>    * must match what was provided in the previous dma_map_page() call.
>    * All other usages are undefined.
> @@ -99,7 +86,7 @@ static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *pag
>    * After this call, reads by the CPU to the buffer are guaranteed to see
>    * whatever the device wrote there.
>    */
> -static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
> +void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
>   		size_t size, enum dma_data_direction dir,
>   		struct dma_attrs *attrs)
>   {
> @@ -108,7 +95,7 @@ static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
>   				      handle & ~PAGE_MASK, size, dir);
>   }
>   
> -static void arm_dma_sync_single_for_cpu(struct device *dev,
> +void arm_dma_sync_single_for_cpu(struct device *dev,
>   		dma_addr_t handle, size_t size, enum dma_data_direction dir)
>   {
>   	unsigned int offset = handle & (PAGE_SIZE - 1);
> @@ -116,7 +103,7 @@ static void arm_dma_sync_single_for_cpu(struct device *dev,
>   	__dma_page_dev_to_cpu(page, offset, size, dir);
>   }
>   
> -static void arm_dma_sync_single_for_device(struct device *dev,
> +void arm_dma_sync_single_for_device(struct device *dev,
>   		dma_addr_t handle, size_t size, enum dma_data_direction dir)
>   {
>   	unsigned int offset = handle & (PAGE_SIZE - 1);
> @@ -124,8 +111,6 @@ static void arm_dma_sync_single_for_device(struct device *dev,
>   	__dma_page_cpu_to_dev(page, offset, size, dir);
>   }
>   
> -static int arm_dma_set_mask(struct device *dev, u64 dma_mask);
> -
>   struct dma_map_ops arm_dma_ops = {
>   	.alloc			= arm_dma_alloc,
>   	.free			= arm_dma_free,
> @@ -971,7 +956,7 @@ int dma_supported(struct device *dev, u64 mask)
>   }
>   EXPORT_SYMBOL(dma_supported);
>   
> -static int arm_dma_set_mask(struct device *dev, u64 dma_mask)
> +int arm_dma_set_mask(struct device *dev, u64 dma_mask)
>   {
>   	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
>   		return -EIO;

Best regards
-- 
Marek Szyprowski
Samsung Poland R&D Center