diff mbox

[1/1] mtd: spi-nor: fsl-qspi: dynamically map memory space for AHB read

Message ID 1437425294-32090-1-git-send-email-Frank.Li@freescale.com
State Changes Requested
Headers show

Commit Message

Frank Li July 20, 2015, 8:48 p.m. UTC 
From: Allen Xu <b45815@freescale.com>

QSPI may failed to map enough memory (256MB) for AHB read in
previous implementation, especially in 3G/1G memory layout kernel.
Dynamically map memory to avoid such issue.

This implementation generally map 4MB memory for AHB read, it should
be enough for common scenarios, and the side effect (0.6% performance
drop) is minor.

Previous implementation

root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=1K count=32K
32768+0 records in
32768+0 records out
33554432 bytes (34 MB) copied, 2.16006 s, 15.5 MB/s

root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=32M count=1
1+0 records in
1+0 records out
33554432 bytes (34 MB) copied, 1.43149 s, 23.4 MB/s

After applied the patch

root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=1K count=32K
32768+0 records in
32768+0 records out
33554432 bytes (34 MB) copied, 2.1743 s, 15.4 MB/s

root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=32M count=1
1+0 records in
1+0 records out
33554432 bytes (34 MB) copied, 1.43158 s, 23.4 MB/s

Signed-off-by: Allen Xu <b45815@freescale.com>
Signed-off-by: Frank Li <Frank.Li@freescale.com>
---
 drivers/mtd/spi-nor/fsl-quadspi.c | 48 ++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 8 deletions(-)

Comments

Han Xu July 23, 2015, 10 p.m. UTC | #1 
Please resend based on the latest l2-mtd repo.

On Mon, Jul 20, 2015 at 3:48 PM,  <Frank.Li@freescale.com> wrote:
> From: Allen Xu <b45815@freescale.com>
>
> QSPI may failed to map enough memory (256MB) for AHB read in
> previous implementation, especially in 3G/1G memory layout kernel.
> Dynamically map memory to avoid such issue.
>
> This implementation generally map 4MB memory for AHB read, it should
> be enough for common scenarios, and the side effect (0.6% performance
> drop) is minor.
>
> Previous implementation
>
> root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=1K count=32K
> 32768+0 records in
> 32768+0 records out
> 33554432 bytes (34 MB) copied, 2.16006 s, 15.5 MB/s
>
> root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=32M count=1
> 1+0 records in
> 1+0 records out
> 33554432 bytes (34 MB) copied, 1.43149 s, 23.4 MB/s
>
> After applied the patch
>
> root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=1K count=32K
> 32768+0 records in
> 32768+0 records out
> 33554432 bytes (34 MB) copied, 2.1743 s, 15.4 MB/s
>
> root@imx6qdlsolo:~# dd if=/dev/mtd0 of=/dev/null bs=32M count=1
> 1+0 records in
> 1+0 records out
> 33554432 bytes (34 MB) copied, 1.43158 s, 23.4 MB/s
>
> Signed-off-by: Allen Xu <b45815@freescale.com>
> Signed-off-by: Frank Li <Frank.Li@freescale.com>
> ---
>  drivers/mtd/spi-nor/fsl-quadspi.c | 48 ++++++++++++++++++++++++++++++++-------
>  1 file changed, 40 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> index 52a872f..69b95e8 100644
> --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> @@ -222,8 +222,10 @@ struct fsl_qspi {
>         struct mtd_info mtd[FSL_QSPI_MAX_CHIP];
>         struct spi_nor nor[FSL_QSPI_MAX_CHIP];
>         void __iomem *iobase;
> -       void __iomem *ahb_base; /* Used when read from AHB bus */
> +       void __iomem *ahb_addr;
>         u32 memmap_phy;
> +       u32 memmap_offs;
> +       u32 memmap_len;
>         struct clk *clk, *clk_en;
>         struct device *dev;
>         struct completion c;
> @@ -730,11 +732,41 @@ static int fsl_qspi_read(struct spi_nor *nor, loff_t from,
>         struct fsl_qspi *q = nor->priv;
>         u8 cmd = nor->read_opcode;
>
> -       dev_dbg(q->dev, "cmd [%x],read from (0x%p, 0x%.8x, 0x%.8x),len:%d\n",
> -               cmd, q->ahb_base, q->chip_base_addr, (unsigned int)from, len);
> +       /* if necessary,ioremap buffer before AHB read, */
> +       /* generally 4MB should be large enough */
> +       if (!q->ahb_addr) {
> +               q->ahb_addr = ioremap_nocache(
> +                               q->memmap_phy + q->chip_base_addr + from,
> +                               len > SZ_4M ? len : SZ_4M);
> +               if (!q->ahb_addr) {
> +                       dev_err(q->dev, "ioremap failed\n");
> +                       return -ENOMEM;
> +               }
> +               q->memmap_offs = q->chip_base_addr + from;
> +               q->memmap_len = len > SZ_4M ? len : SZ_4M;
> +       /* ioremap if the data requested is out of range */
> +       } else if (q->chip_base_addr + from < q->memmap_offs
> +                       || q->chip_base_addr + from + len >
> +                       q->memmap_offs + q->memmap_len) {
> +               iounmap(q->ahb_addr);
> +               q->ahb_addr = ioremap_nocache(
> +                               q->memmap_phy + q->chip_base_addr + from,
> +                               len > SZ_4M ? len : SZ_4M);
> +               if (!q->ahb_addr) {
> +                       dev_err(q->dev, "ioremap failed\n");
> +                       return -ENOMEM;
> +               }
> +               q->memmap_offs = q->chip_base_addr + from;
> +               q->memmap_len = len > SZ_4M ? len : SZ_4M;
> +       }
> +
> +       dev_dbg(q->dev, "cmd [%x],read from 0x%p, len:%d\n",
> +               cmd, q->ahb_addr + q->chip_base_addr + from - q->memmap_offs,
> +               len);
>
>         /* Read out the data directly from the AHB buffer.*/
> -       memcpy(buf, q->ahb_base + q->chip_base_addr + from, len);
> +       memcpy(buf, q->ahb_addr + q->chip_base_addr + from - q->memmap_offs,
> +               len);
>
>         *retlen += len;
>         return 0;
> @@ -812,10 +844,6 @@ static int fsl_qspi_probe(struct platform_device *pdev)
>
>         res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>                                         "QuadSPI-memory");
> -       q->ahb_base = devm_ioremap_resource(dev, res);
> -       if (IS_ERR(q->ahb_base))
> -               return PTR_ERR(q->ahb_base);
> -
>         q->memmap_phy = res->start;
>
>         /* find the clocks */
> @@ -975,6 +1003,10 @@ static int fsl_qspi_remove(struct platform_device *pdev)
>
>         clk_unprepare(q->clk);
>         clk_unprepare(q->clk_en);
> +
> +       if (q->ahb_addr)
> +               iounmap(q->ahb_addr);
> +
>         return 0;
>  }
>
> --
> 1.9.1
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
diff mbox

Patch

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 52a872f..69b95e8 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -222,8 +222,10 @@  struct fsl_qspi {
 	struct mtd_info mtd[FSL_QSPI_MAX_CHIP];
 	struct spi_nor nor[FSL_QSPI_MAX_CHIP];
 	void __iomem *iobase;
-	void __iomem *ahb_base; /* Used when read from AHB bus */
+	void __iomem *ahb_addr;
 	u32 memmap_phy;
+	u32 memmap_offs;
+	u32 memmap_len;
 	struct clk *clk, *clk_en;
 	struct device *dev;
 	struct completion c;
@@ -730,11 +732,41 @@  static int fsl_qspi_read(struct spi_nor *nor, loff_t from,
 	struct fsl_qspi *q = nor->priv;
 	u8 cmd = nor->read_opcode;
 
-	dev_dbg(q->dev, "cmd [%x],read from (0x%p, 0x%.8x, 0x%.8x),len:%d\n",
-		cmd, q->ahb_base, q->chip_base_addr, (unsigned int)from, len);
+	/* if necessary,ioremap buffer before AHB read, */
+	/* generally 4MB should be large enough */
+	if (!q->ahb_addr) {
+		q->ahb_addr = ioremap_nocache(
+				q->memmap_phy + q->chip_base_addr + from,
+				len > SZ_4M ? len : SZ_4M);
+		if (!q->ahb_addr) {
+			dev_err(q->dev, "ioremap failed\n");
+			return -ENOMEM;
+		}
+		q->memmap_offs = q->chip_base_addr + from;
+		q->memmap_len = len > SZ_4M ? len : SZ_4M;
+	/* ioremap if the data requested is out of range */
+	} else if (q->chip_base_addr + from < q->memmap_offs
+			|| q->chip_base_addr + from + len >
+			q->memmap_offs + q->memmap_len) {
+		iounmap(q->ahb_addr);
+		q->ahb_addr = ioremap_nocache(
+				q->memmap_phy + q->chip_base_addr + from,
+				len > SZ_4M ? len : SZ_4M);
+		if (!q->ahb_addr) {
+			dev_err(q->dev, "ioremap failed\n");
+			return -ENOMEM;
+		}
+		q->memmap_offs = q->chip_base_addr + from;
+		q->memmap_len = len > SZ_4M ? len : SZ_4M;
+	}
+
+	dev_dbg(q->dev, "cmd [%x],read from 0x%p, len:%d\n",
+		cmd, q->ahb_addr + q->chip_base_addr + from - q->memmap_offs,
+		len);
 
 	/* Read out the data directly from the AHB buffer.*/
-	memcpy(buf, q->ahb_base + q->chip_base_addr + from, len);
+	memcpy(buf, q->ahb_addr + q->chip_base_addr + from - q->memmap_offs,
+		len);
 
 	*retlen += len;
 	return 0;
@@ -812,10 +844,6 @@  static int fsl_qspi_probe(struct platform_device *pdev)
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 					"QuadSPI-memory");
-	q->ahb_base = devm_ioremap_resource(dev, res);
-	if (IS_ERR(q->ahb_base))
-		return PTR_ERR(q->ahb_base);
-
 	q->memmap_phy = res->start;
 
 	/* find the clocks */
@@ -975,6 +1003,10 @@  static int fsl_qspi_remove(struct platform_device *pdev)
 
 	clk_unprepare(q->clk);
 	clk_unprepare(q->clk_en);
+
+	if (q->ahb_addr)
+		iounmap(q->ahb_addr);
+
 	return 0;
 }