mtd: onenand: omap2: Disable DMA for HIGHMEM buffers

dma_map_single does not work for vmalloc-ed buffers,
so disable DMA in this case.

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>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

diff --git a/drivers/mtd/nand/onenand/omap2.c b/drivers/mtd/nand/onenand/omap2.c
index 9c159f0..3211371 100644 (file)
--- 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);