2018-05-02 10:42:43

by Ladislav Michl

[permalink] [raw]
Subject: [PATCH v3] 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 <[email protected]>
Reported-by: "H. Nikolaus Schaller" <[email protected]>
Tested-by: "H. Nikolaus Schaller" <[email protected]>
---
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);
--
2.17.0



2018-05-02 10:48:41

by Peter Ujfalusi

[permalink] [raw]
Subject: Re: [PATCH v3] mtd: onenand: omap2: Disable DMA for HIGHMEM buffers



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 <[email protected]>

> Signed-off-by: Ladislav Michl <[email protected]>
> Reported-by: "H. Nikolaus Schaller" <[email protected]>
> Tested-by: "H. Nikolaus Schaller" <[email protected]>
> ---
> 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

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

2018-05-03 08:20:45

by Boris Brezillon

[permalink] [raw]
Subject: Re: [PATCH v3] mtd: onenand: omap2: Disable DMA for HIGHMEM buffers

On Wed, 2 May 2018 12:41:32 +0200
Ladislav Michl <[email protected]> wrote:

> dma_map_single does not work for vmalloc-ed buffers,
> so disable DMA in this case.
>
> Signed-off-by: Ladislav Michl <[email protected]>
> Reported-by: "H. Nikolaus Schaller" <[email protected]>
> Tested-by: "H. Nikolaus Schaller" <[email protected]>

Applied to mtd/master. Will be part of the next fixes PR I'll send
later this week.

Thanks,

Boris

> ---
> 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);