+static void dma_complete_func(void *completion)
+{
+ complete(completion);
+}
+
+static int atmel_nand_dma_op(struct mtd_info *mtd, void *buf, int len,
+ int is_read)
+{
+ struct dma_device *dma_dev;
+ enum dma_ctrl_flags flags;
+ dma_addr_t dma_src_addr, dma_dst_addr, phys_addr;
+ struct dma_async_tx_descriptor *tx = NULL;
+ dma_cookie_t cookie;
+ struct nand_chip *chip = mtd->priv;
+ struct atmel_nand_host *host = chip->priv;
+ void *p = buf;
+ int err = -EIO;
+ enum dma_data_direction dir = is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+ if (buf >= high_memory) {
+ struct page *pg;
+
+ if (((size_t)buf & PAGE_MASK) !=
+ ((size_t)(buf + len - 1) & PAGE_MASK)) {
+ dev_warn(host->dev, "Buffer not fit in one page\n");
+ goto err_buf;
+ }
+
+ pg = vmalloc_to_page(buf);
+ if (pg == 0) {
+ dev_err(host->dev, "Failed to vmalloc_to_page\n");
+ goto err_buf;
+ }
+ p = page_address(pg) + ((size_t)buf & ~PAGE_MASK);
+ }
+
+ dma_dev = host->dma_chan->device;
+
+ flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP |
+ DMA_COMPL_SKIP_DEST_UNMAP;
+
+ phys_addr = dma_map_single(dma_dev->dev, p, len, dir);
+ if (dma_mapping_error(dma_dev->dev, phys_addr)) {
+ dev_err(host->dev, "Failed to dma_map_single\n");
+ goto err_buf;
+ }
+
+ if (is_read) {
+ dma_src_addr = host->io_phys;
+ dma_dst_addr = phys_addr;
+ } else {
+ dma_src_addr = phys_addr;
+ dma_dst_addr = host->io_phys;
+ }
+
+ tx = dma_dev->device_prep_dma_memcpy(host->dma_chan, dma_dst_addr,
+ dma_src_addr, len, flags);
+ if (!tx) {
+ dev_err(host->dev, "Failed to prepare DMA memcpy\n");
+ goto err_dma;
+ }
+
+ init_completion(&host->comp);
+ tx->callback = dma_complete_func;
+ tx->callback_param = &host->comp;
+
+ cookie = tx->tx_submit(tx);
+ if (dma_submit_error(cookie)) {
+ dev_err(host->dev, "Failed to do DMA tx_submit\n");
+ goto err_dma;
+ }
+
+ dma_async_issue_pending(host->dma_chan);
+ wait_for_completion(&host->comp);
+
+ err = 0;
+
+err_dma:
+ dma_unmap_single(dma_dev->dev, phys_addr, len, dir);
+err_buf:
+ if (err != 0)
+ dev_warn(host->dev, "Fall back to CPU I/O\n");
+ return err;
+}
+
+static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct atmel_nand_host *host = chip->priv;
+
+ if (use_dma && len >= mtd->oobsize)
+ if (atmel_nand_dma_op(mtd, buf, len, 1) == 0)
+ return;
+
+ if (host->board->bus_width_16)
+ atmel_read_buf16(mtd, buf, len);
+ else
+ atmel_read_buf8(mtd, buf, len);
+}
+
+static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct atmel_nand_host *host = chip->priv;
+
+ if (use_dma && len >= mtd->oobsize)
+ if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0)
+ return;
+
+ if (host->board->bus_width_16)
+ atmel_write_buf16(mtd, buf, len);
+ else
+ atmel_write_buf8(mtd, buf, len);
+}
+