Messages in this thread | | | Subject | Re: [PATCH v3] mtd: onenand: omap2: Disable DMA for HIGHMEM buffers | From | Peter Ujfalusi <> | Date | Wed, 2 May 2018 13:46:39 +0300 |
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On 2018-05-02 13:41, Ladislav Michl wrote: > dma_map_single does not work for vmalloc-ed buffers, > so disable DMA in this case.
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Signed-off-by: Ladislav Michl <ladis@linux-mips.org> > Reported-by: "H. Nikolaus Schaller" <hns@goldelico.com> > Tested-by: "H. Nikolaus Schaller" <hns@goldelico.com> > --- > Changes: > -v2: Added Tested-by tag, based on v4.17-rc1 (no change in patch itself) > -v3: Reworded commit log > > drivers/mtd/nand/onenand/omap2.c | 105 +++++++++++-------------------- > 1 file changed, 38 insertions(+), 67 deletions(-) > > diff --git a/drivers/mtd/nand/onenand/omap2.c b/drivers/mtd/nand/onenand/omap2.c > index 9c159f0dd9a6..321137158ff3 100644 > --- a/drivers/mtd/nand/onenand/omap2.c > +++ b/drivers/mtd/nand/onenand/omap2.c > @@ -375,56 +375,42 @@ static int omap2_onenand_read_bufferram(struct mtd_info *mtd, int area, > { > struct omap2_onenand *c = container_of(mtd, struct omap2_onenand, mtd); > struct onenand_chip *this = mtd->priv; > - dma_addr_t dma_src, dma_dst; > - int bram_offset; > + struct device *dev = &c->pdev->dev; > void *buf = (void *)buffer; > + dma_addr_t dma_src, dma_dst; > + int bram_offset, err; > size_t xtra; > - int ret; > > bram_offset = omap2_onenand_bufferram_offset(mtd, area) + area + offset; > - if (bram_offset & 3 || (size_t)buf & 3 || count < 384) > - goto out_copy; > - > - /* panic_write() may be in an interrupt context */ > - if (in_interrupt() || oops_in_progress) > + /* > + * If the buffer address is not DMA-able, len is not long enough to make > + * DMA transfers profitable or panic_write() may be in an interrupt > + * context fallback to PIO mode. > + */ > + if (!virt_addr_valid(buf) || bram_offset & 3 || (size_t)buf & 3 || > + count < 384 || in_interrupt() || oops_in_progress ) > goto out_copy; > > - if (buf >= high_memory) { > - struct page *p1; > - > - if (((size_t)buf & PAGE_MASK) != > - ((size_t)(buf + count - 1) & PAGE_MASK)) > - goto out_copy; > - p1 = vmalloc_to_page(buf); > - if (!p1) > - goto out_copy; > - buf = page_address(p1) + ((size_t)buf & ~PAGE_MASK); > - } > - > xtra = count & 3; > if (xtra) { > count -= xtra; > memcpy(buf + count, this->base + bram_offset + count, xtra); > } > > + dma_dst = dma_map_single(dev, buf, count, DMA_FROM_DEVICE); > dma_src = c->phys_base + bram_offset; > - dma_dst = dma_map_single(&c->pdev->dev, buf, count, DMA_FROM_DEVICE); > - if (dma_mapping_error(&c->pdev->dev, dma_dst)) { > - dev_err(&c->pdev->dev, > - "Couldn't DMA map a %d byte buffer\n", > - count); > - goto out_copy; > - } > > - ret = omap2_onenand_dma_transfer(c, dma_src, dma_dst, count); > - dma_unmap_single(&c->pdev->dev, dma_dst, count, DMA_FROM_DEVICE); > - > - if (ret) { > - dev_err(&c->pdev->dev, "timeout waiting for DMA\n"); > + if (dma_mapping_error(dev, dma_dst)) { > + dev_err(dev, "Couldn't DMA map a %d byte buffer\n", count); > goto out_copy; > } > > - return 0; > + err = omap2_onenand_dma_transfer(c, dma_src, dma_dst, count); > + dma_unmap_single(dev, dma_dst, count, DMA_FROM_DEVICE); > + if (!err) > + return 0; > + > + dev_err(dev, "timeout waiting for DMA\n"); > > out_copy: > memcpy(buf, this->base + bram_offset, count); > @@ -437,49 +423,34 @@ static int omap2_onenand_write_bufferram(struct mtd_info *mtd, int area, > { > struct omap2_onenand *c = container_of(mtd, struct omap2_onenand, mtd); > struct onenand_chip *this = mtd->priv; > - dma_addr_t dma_src, dma_dst; > - int bram_offset; > + struct device *dev = &c->pdev->dev; > void *buf = (void *)buffer; > - int ret; > + dma_addr_t dma_src, dma_dst; > + int bram_offset, err; > > bram_offset = omap2_onenand_bufferram_offset(mtd, area) + area + offset; > - if (bram_offset & 3 || (size_t)buf & 3 || count < 384) > - goto out_copy; > - > - /* panic_write() may be in an interrupt context */ > - if (in_interrupt() || oops_in_progress) > + /* > + * If the buffer address is not DMA-able, len is not long enough to make > + * DMA transfers profitable or panic_write() may be in an interrupt > + * context fallback to PIO mode. > + */ > + if (!virt_addr_valid(buf) || bram_offset & 3 || (size_t)buf & 3 || > + count < 384 || in_interrupt() || oops_in_progress ) > goto out_copy; > > - if (buf >= high_memory) { > - struct page *p1; > - > - if (((size_t)buf & PAGE_MASK) != > - ((size_t)(buf + count - 1) & PAGE_MASK)) > - goto out_copy; > - p1 = vmalloc_to_page(buf); > - if (!p1) > - goto out_copy; > - buf = page_address(p1) + ((size_t)buf & ~PAGE_MASK); > - } > - > - dma_src = dma_map_single(&c->pdev->dev, buf, count, DMA_TO_DEVICE); > + dma_src = dma_map_single(dev, buf, count, DMA_TO_DEVICE); > dma_dst = c->phys_base + bram_offset; > - if (dma_mapping_error(&c->pdev->dev, dma_src)) { > - dev_err(&c->pdev->dev, > - "Couldn't DMA map a %d byte buffer\n", > - count); > - return -1; > - } > - > - ret = omap2_onenand_dma_transfer(c, dma_src, dma_dst, count); > - dma_unmap_single(&c->pdev->dev, dma_src, count, DMA_TO_DEVICE); > - > - if (ret) { > - dev_err(&c->pdev->dev, "timeout waiting for DMA\n"); > + if (dma_mapping_error(dev, dma_src)) { > + dev_err(dev, "Couldn't DMA map a %d byte buffer\n", count); > goto out_copy; > } > > - return 0; > + err = omap2_onenand_dma_transfer(c, dma_src, dma_dst, count); > + dma_unmap_page(dev, dma_src, count, DMA_TO_DEVICE); > + if (!err) > + return 0; > + > + dev_err(dev, "timeout waiting for DMA\n"); > > out_copy: > memcpy(this->base + bram_offset, buf, count); >
- Péter
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