Commit f880b07b authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Boris Brezillon
Browse files

mtd: nand: cafe: remove use of NAND_OWN_BUFFERS 



This driver is the last/only user of NAND_OWN_BUFFERS.  Boris suggested
to remove this flag.

Taking a closer look at this driver, it calls dma_alloc_coherent() for
the concatenated area for the DMA bounce buffer + struct nand_buffers,
but the latter does not need to be DMA-coherent; cafe_{write,read}_buf
simply do memcpy() between buffers when usedma==1.

Let's do dma_alloc_coherent() for the DMA bounce buffer in the front,
and leave the nand_buffers allocation to nand_scan_tail(), then rip off
NAND_OWN_BUFFERS.

The magic number, 2112, is still mysterious (hard-coded writesize +
oobsize ?), but this is not our main interest.  I am keeping it.

Suggested-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
parent 17fa8044

drivers/mtd/nand/cafe_nand.c

+4 −20
Original line number Diff line number Diff line
@@ -605,7 +605,6 @@ static int cafe_nand_probe(struct pci_dev *pdev, 
	uint32_t ctrl;

	int err = 0;

	int old_dma;

	struct nand_buffers *nbuf;



	/* Very old versions shared the same PCI ident for all three

	   functions on the chip. Verify the class too... */
@@ -653,7 +652,6 @@ static int cafe_nand_probe(struct pci_dev *pdev, 


	/* Enable the following for a flash based bad block table */

	cafe->nand.bbt_options = NAND_BBT_USE_FLASH;

	cafe->nand.options = NAND_OWN_BUFFERS;



	if (skipbbt) {

		cafe->nand.options |= NAND_SKIP_BBTSCAN;
@@ -723,15 +721,12 @@ static int cafe_nand_probe(struct pci_dev *pdev, 
	if (err)

		goto out_irq;



	cafe->dmabuf = dma_alloc_coherent(&cafe->pdev->dev,

				2112 + sizeof(struct nand_buffers) +

				mtd->writesize + mtd->oobsize,

	cafe->dmabuf = dma_alloc_coherent(&cafe->pdev->dev, 2112,

					  &cafe->dmaaddr, GFP_KERNEL);

	if (!cafe->dmabuf) {

		err = -ENOMEM;

		goto out_irq;

	}

	cafe->nand.buffers = nbuf = (void *)cafe->dmabuf + 2112;



	/* Set up DMA address */

	cafe_writel(cafe, cafe->dmaaddr & 0xffffffff, NAND_DMA_ADDR0);
@@ -744,11 +739,6 @@ static int cafe_nand_probe(struct pci_dev *pdev, 
	cafe_dev_dbg(&cafe->pdev->dev, "Set DMA address to %x (virt %p)\n",

		cafe_readl(cafe, NAND_DMA_ADDR0), cafe->dmabuf);



	/* this driver does not need the @ecccalc and @ecccode */

	nbuf->ecccalc = NULL;

	nbuf->ecccode = NULL;

	nbuf->databuf = (uint8_t *)(nbuf + 1);



	/* Restore the DMA flag */

	usedma = old_dma;
@@ -793,10 +783,7 @@ static int cafe_nand_probe(struct pci_dev *pdev, 
	goto out;



 out_free_dma:

	dma_free_coherent(&cafe->pdev->dev,

			2112 + sizeof(struct nand_buffers) +

			mtd->writesize + mtd->oobsize,

			cafe->dmabuf, cafe->dmaaddr);

	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);

 out_irq:

	/* Disable NAND IRQ in global IRQ mask register */

	cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
@@ -821,10 +808,7 @@ static void cafe_nand_remove(struct pci_dev *pdev) 
	nand_release(mtd);

	free_rs(cafe->rs);

	pci_iounmap(pdev, cafe->mmio);

	dma_free_coherent(&cafe->pdev->dev,

			2112 + sizeof(struct nand_buffers) +

			mtd->writesize + mtd->oobsize,

			cafe->dmabuf, cafe->dmaaddr);

	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);

	kfree(cafe);

}

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