Re: [Linaro-mm-sig] [PATCH 6/7] common: dma-mapping: change alloc/free_coherent method to more generic alloc/free_attrs

Hello,

On Monday, September 05, 2011 12:44 PM Joerg Roedel wrote:

On Fri, Sep 02, 2011 at 03:53:18PM +0200, Marek Szyprowski wrote:

...

struct dma_map_ops {

• void* (*alloc_coherent)(struct device *dev, size_t size,

• 		dma_addr_t *dma_handle, gfp_t gfp);
  

• void (*free_coherent)(struct device *dev, size_t size,

• 	      void *vaddr, dma_addr_t dma_handle);
  

• void* (*alloc)(struct device *dev, size_t size,

• 		dma_addr_t *dma_handle, gfp_t gfp,
  

• 		struct dma_attrs *attrs);
  

• void (*free)(struct device *dev, size_t size,

• 	      void *vaddr, dma_addr_t dma_handle,
  

• 	      struct dma_attrs *attrs);
  

• int (*mmap)(struct device *, struct vm_area_struct *,

• 	  void *, dma_addr_t, size_t, struct dma_attrs *attrs);
  

• dma_addr_t (*map_page)(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir,

-- 1.7.1.569.g6f426

This needs conversion of all drivers implementing dma_map_ops or you will break a lot of architectures. A better approach is to keep *_coherent and implement alloc/free/mmap side-by-side until all drivers are converted. Also I miss some documentation about the new call-backs.

Right this patch will break all other architectures, however it was just a snapshot of my work-in-progress. Converting all other architectures from alloc_coherent to alloc with NULL attribute shouldn't be really hard and will be added in the final version - together with documentation.

Best regards