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Commit 997cde2a authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Boris Brezillon
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mtd: nand: denali: skip driver internal bounce buffer when possible 



For ecc->read_page() and ecc->write_page(), it is possible to call
dma_map_single() against the given buffer.  This bypasses the driver
internal bounce buffer and save the memcpy().

Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
parent 57a4d8b5

drivers/mtd/nand/denali.c

+12 −26
Original line number Diff line number Diff line
@@ -600,12 +600,16 @@ static int denali_pio_xfer(struct denali_nand_info *denali, void *buf, 
static int denali_dma_xfer(struct denali_nand_info *denali, void *buf,

			   size_t size, int page, int raw, int write)

{

	dma_addr_t dma_addr = denali->dma_addr;

	dma_addr_t dma_addr;

	uint32_t irq_mask, irq_status, ecc_err_mask;

	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;

	int ret = 0;



	dma_sync_single_for_device(denali->dev, dma_addr, size, dir);

	dma_addr = dma_map_single(denali->dev, buf, size, dir);

	if (dma_mapping_error(denali->dev, dma_addr)) {

		dev_dbg(denali->dev, "Failed to DMA-map buffer. Trying PIO.\n");

		return denali_pio_xfer(denali, buf, size, page, raw, write);

	}



	if (write) {

		/*
@@ -636,7 +640,7 @@ static int denali_dma_xfer(struct denali_nand_info *denali, void *buf, 
		ret = -EBADMSG;



	denali_enable_dma(denali, false);

	dma_sync_single_for_cpu(denali->dev, dma_addr, size, dir);

	dma_unmap_single(denali->dev, dma_addr, size, dir);



	if (irq_status & INTR__ERASED_PAGE)

		memset(buf, 0xff, size);
@@ -822,12 +826,10 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip, 
	int stat = 0;

	int ret;



	ret = denali_data_xfer(denali, denali->buf, mtd->writesize, page, 0, 0);

	ret = denali_data_xfer(denali, buf, mtd->writesize, page, 0, 0);

	if (ret && ret != -EBADMSG)

		return ret;



	memcpy(buf, denali->buf, mtd->writesize);



	if (denali->caps & DENALI_CAP_HW_ECC_FIXUP)

		stat = denali_hw_ecc_fixup(mtd, denali, &uncor_ecc_flags);

	else if (ret == -EBADMSG)
@@ -931,10 +933,8 @@ static int denali_write_page(struct mtd_info *mtd, struct nand_chip *chip, 
{

	struct denali_nand_info *denali = mtd_to_denali(mtd);



	memcpy(denali->buf, buf, mtd->writesize);



	return denali_data_xfer(denali, denali->buf, mtd->writesize, page,

				0, 1);

	return denali_data_xfer(denali, (void *)buf, mtd->writesize,

				page, 0, 1);

}



static void denali_select_chip(struct mtd_info *mtd, int chip)
@@ -1374,14 +1374,8 @@ int denali_init(struct denali_nand_info *denali) 
	}



	if (denali->dma_avail) {

		denali->dma_addr = dma_map_single(denali->dev, denali->buf,

						  mtd->writesize + mtd->oobsize,

						  DMA_BIDIRECTIONAL);

		if (dma_mapping_error(denali->dev, denali->dma_addr)) {

			dev_info(denali->dev,

				 "Failed to map DMA buffer. Disabling DMA.\n");

			denali->dma_avail = 0;

		};

		chip->options |= NAND_USE_BOUNCE_BUFFER;

		chip->buf_align = 16;

	}



	/*
@@ -1471,16 +1465,8 @@ EXPORT_SYMBOL(denali_init); 
void denali_remove(struct denali_nand_info *denali)

{

	struct mtd_info *mtd = nand_to_mtd(&denali->nand);

	/*

	 * Pre-compute DMA buffer size to avoid any problems in case

	 * nand_release() ever changes in a way that mtd->writesize and

	 * mtd->oobsize are not reliable after this call.

	 */

	int bufsize = mtd->writesize + mtd->oobsize;



	nand_release(mtd);

	denali_disable_irq(denali);

	dma_unmap_single(denali->dev, denali->dma_addr, bufsize,

			 DMA_BIDIRECTIONAL);

}

EXPORT_SYMBOL(denali_remove);