Messages in this thread Patch in this message | | | From | Masahiro Yamada <> | Subject | [PATCH v2 1/3] mtd: nand: cafe: remove use of NAND_OWN_BUFFERS | Date | Tue, 5 Dec 2017 17:47:14 +0900 |
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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: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> ---
Changes in v2: - Newly added
drivers/mtd/nand/cafe_nand.c | 24 ++++-------------------- 1 file changed, 4 insertions(+), 20 deletions(-)
diff --git a/drivers/mtd/nand/cafe_nand.c b/drivers/mtd/nand/cafe_nand.c index bc558c4..add4613 100644 --- a/drivers/mtd/nand/cafe_nand.c +++ b/drivers/mtd/nand/cafe_nand.c @@ -613,7 +613,6 @@ 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... */ @@ -661,7 +660,6 @@ 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; @@ -731,15 +729,12 @@ 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->dmaaddr, GFP_KERNEL); + 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); @@ -752,11 +747,6 @@ 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; @@ -801,10 +791,7 @@ 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); @@ -829,10 +816,7 @@ 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); } -- 2.7.4
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