addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); else addr = ops->map_page(dev, page, offset, size, dir, attrs); debug_dma_map_page(dev, page, offset, size, dir, addr); return addr; } static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t ...
+ dma_direct_unmap_page(dev, sg->dma_address,//caq:除p2p之外的,则走正常unmap流程 + sg_dma_len(sg), dir, attrs); + } } #endif int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, enum dma_data_direction dir, unsigned long attrs) { - int i; + stru...
dma_direct_map_page()、dma_direct_unmap_page()在kernel\dma\direct.c中定义。 代码语言:javascript 复制 dma_addr_tdma_direct_map_page(struct device*dev,struct page*page,unsigned long offset,size_t size,enumdma_data_direction dir,unsigned long attrs){phys_addr_t phys=page_to_phys(page)+offse...
addr =dma_direct_map_page(dev, page, offset, size, dir, attrs);elseaddr = ops->map_page(dev, page, offset, size, dir, attrs);debug_dma_map_page(dev, page, offset, size, dir, addr);returnaddr; }staticinlinevoiddma_unmap_page_attrs(structdevice *dev,dma_addr_taddr,size_tsize,enu...
* 物理地址dma_address通过dma_direct_map_page映射得来。 *在mmc_blk_data_prep中已经对每个sg设置了sg->page_link指向了BIO的page结构指针sg_set_page(*sg, page, len, offset); * 此处通过sg_page(sg)获得page结构指针做映射,见dma_direct_map_page ...
您应该调用 dma_mapping_error(),因为 dma_map_single() 可能会失败并返回错误。 这样做将确保映射代码在所有 DMA 实现上正确工作,而不依赖于底层实现的细节。 在不检查错误的情况下使用返回的地址可能会导致各种失败,从恐慌到静默数据损坏。 这同样适用于 dma_map_page() ...
This field can be used to force more restrictive alignment than implicitly specified by other DMA attributes, such as alignment on a page boundary. dam_attr_burstsizes Specifies the burst sizes that the device supports. (A burst size is the amount of data the device can transfer before ...
!dma 延伸模組會顯示 Direct Memory Access (DMA) 子系統的相關信息,以及驅動程式驗證器的 DMA 驗證器選項。
Searching to see if your driver is already open source and looking through it, a good starting point is this Wikipedia page that lists open-source/reverse-engineered wireless drivers that you could take values from for your firmware [Hard] Using a reverse-engineering program of your choice to ...
If the quirk-mmap-page property is specified, quirk-mmap. is used in quirk-mmap-page mode. In quirk-mmap-page mode, there is no error when u-dma-buf is subject to O_DIRECT. This mode is currently under development. Please use with caution....