参照元

説明

引数

返り値

参考

実装

/**
 * 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,
             unsigned long offset, size_t size, enum dma_data_direction dir,
             struct dma_attrs *attrs)
{
        if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
                __dma_page_cpu_to_dev(page, offset, size, dir);
        return pfn_to_dma(dev, page_to_pfn(page)) + offset;
}

コメント


トップ   編集 凍結 差分 履歴 添付 複製 名前変更 リロード   新規 一覧 検索 最終更新   ヘルプ   最終更新のRSS
Last-modified: 2016-02-22 (月) 16:52:17