On Thu, 19 Jul 2018 01:57:06 +0200
Janusz Krzysztofik <jmkrzy...@gmail.com> wrote:

> Further optimize processing speed of read/write callback functions by
> resolving private structure pointer only once per callback and passing
> it to all subfunctions instead of mtd_info.

Not sure this has a real impact on perfs, but I also prefer not using
mtd_info objects within NAND drivers, so I'm good with the change
itself (its probably worth changing the commit message though)

> 
> Signed-off-by: Janusz Krzysztofik <jmkrzy...@gmail.com>
> ---
>  drivers/mtd/nand/raw/ams-delta.c | 44 
> +++++++++++++++++++++++-----------------
>  1 file changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/ams-delta.c 
> b/drivers/mtd/nand/raw/ams-delta.c
> index dfefcd79b420..d7e4c9dbef67 100644
> --- a/drivers/mtd/nand/raw/ams-delta.c
> +++ b/drivers/mtd/nand/raw/ams-delta.c
> @@ -72,10 +72,9 @@ static const struct mtd_partition partition_info[] = {
>         .size         =  3 * SZ_256K },
>  };
>  
> -static void ams_delta_write_next_byte(struct mtd_info *mtd, u_char byte)
> +static void ams_delta_write_next_byte(struct ams_delta_nand *priv, u_char 
> byte)
>  {
> -     struct nand_chip *this = mtd_to_nand(mtd);
> -     struct ams_delta_nand *priv = nand_get_controller_data(this);
> +     struct nand_chip *this = &priv->nand_chip;
>  
>       writew(byte, this->IO_ADDR_W);
>       gpiod_set_value(priv->gpiod_nwe, 0);
> @@ -83,21 +82,18 @@ static void ams_delta_write_next_byte(struct mtd_info 
> *mtd, u_char byte)
>       gpiod_set_value(priv->gpiod_nwe, 1);
>  }
>  
> -static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
> +static void ams_delta_write_first_byte(struct ams_delta_nand *priv, u_char 
> byte)
>  {
> -     struct nand_chip *this = mtd_to_nand(mtd);
> -     struct ams_delta_nand *priv = nand_get_controller_data(this);
>       void __iomem *io_base = priv->io_base;
>  
>       writew(0, io_base + OMAP_MPUIO_IO_CNTL);
>  
> -     ams_delta_write_next_byte(mtd, byte);
> +     ams_delta_write_next_byte(priv, byte);
>  }
>  
> -static u_char ams_delta_read_next_byte(struct mtd_info *mtd)
> +static u_char ams_delta_read_next_byte(struct ams_delta_nand *priv)
>  {
> -     struct nand_chip *this = mtd_to_nand(mtd);
> -     struct ams_delta_nand *priv = nand_get_controller_data(this);
> +     struct nand_chip *this = &priv->nand_chip;
>       u_char res;
>  
>       gpiod_set_value(priv->gpiod_nre, 0);
> @@ -108,36 +104,46 @@ static u_char ams_delta_read_next_byte(struct mtd_info 
> *mtd)
>       return res;
>  }
>  
> -static u_char ams_delta_read_byte(struct mtd_info *mtd)
> +static u_char ams_delta_read_first_byte(struct ams_delta_nand *priv)
>  {
> -     struct nand_chip *this = mtd_to_nand(mtd);
> -     struct ams_delta_nand *priv = nand_get_controller_data(this);
>       void __iomem *io_base = priv->io_base;
>  
>       writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
>  
> -     return ams_delta_read_next_byte(mtd);
> +     return ams_delta_read_next_byte(priv);
> +}
> +
> +static u_char ams_delta_read_byte(struct mtd_info *mtd)
> +{
> +     struct nand_chip *this = mtd_to_nand(mtd);
> +     struct ams_delta_nand *priv = nand_get_controller_data(this);
> +
> +     return ams_delta_read_first_byte(priv);
>  }
>  
>  static void ams_delta_write_buf(struct mtd_info *mtd, const u_char *buf,
>                               int len)
>  {
> +     struct nand_chip *this = mtd_to_nand(mtd);
> +     struct ams_delta_nand *priv = nand_get_controller_data(this);
>       int i;
>  
>       if (len > 0)
> -             ams_delta_write_byte(mtd, buf[0]);
> +             ams_delta_write_first_byte(priv, buf[0]);
>       for (i = 1; i < len; i++)
> -             ams_delta_write_next_byte(mtd, buf[i]);
> +             ams_delta_write_next_byte(priv, buf[i]);
>  }
>  
>  static void ams_delta_read_buf(struct mtd_info *mtd, u_char *buf, int len)
>  {
> +     struct nand_chip *this = mtd_to_nand(mtd);
> +     struct ams_delta_nand *priv = nand_get_controller_data(this);
>       int i;
>  
>       if (len > 0)
> -             buf[0] = ams_delta_read_byte(mtd);
> +             buf[0] = ams_delta_read_first_byte(priv);
>       for (i = 1; i < len; i++)
> -             buf[i] = ams_delta_read_next_byte(mtd);
> +             buf[i] = ams_delta_read_next_byte(priv);
>  }
>  
>  /*
> @@ -161,7 +167,7 @@ static void ams_delta_hwcontrol(struct mtd_info *mtd, int 
> cmd,
>       }
>  
>       if (cmd != NAND_CMD_NONE)
> -             ams_delta_write_byte(mtd, cmd);
> +             ams_delta_write_first_byte(priv, cmd);
>  }
>  
>  static int ams_delta_nand_ready(struct mtd_info *mtd)

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