Re: [PATCH v7 1/6] Check gpio pin number and use binary search in mtk_hw_pin_field_lookup()

[Sean Wang <sean.wang@kernel.org>]

On Tue, Dec 31, 2019 at 5:42 AM Light Hsieh <light.hsieh@mediatek.com> wrote:
>
> 1. Check if gpio pin number is in valid range to prevent from get invalid
>    pointer 'desc' in the following code:
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
>
> 2. Improve  mtk_hw_pin_field_lookup()
> 2.1 Modify mtk_hw_pin_field_lookup() to use binary search for accelerating
>      search.
> 2.2 Correct message after the following check fail:
>     if (hw->soc->reg_cal && hw->soc->reg_cal[field].range) {
>                 rc = &hw->soc->reg_cal[field];
>     The original message is:
>         "Not support field %d for pin %d (%s)\n"
>     However, the check is on soc chip level, not on pin level yet.
>     So the message is corrected as:
>         "Not support field %d for this soc\n"
>
> Change-Id: I498a18df73e6a693e0e35635d5b92b8dc9c063ac

If removing the change-ids, add a prefix "pinctrl: mediatek:" to the
subject, and proper signed-off-by tags,
and then the overall looks good to me.

> ---
>  drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 27 ++++++++++++++++++------
>  drivers/pinctrl/mediatek/pinctrl-paris.c         | 25 ++++++++++++++++++++++
>  2 files changed, 46 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> index 20e1c89..d63e05e 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> @@ -68,32 +68,44 @@ static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
>  {
>         const struct mtk_pin_field_calc *c, *e;
>         const struct mtk_pin_reg_calc *rc;
> +       int start = 0, end, check;
> +       bool found = false;
>         u32 bits;
>
>         if (hw->soc->reg_cal && hw->soc->reg_cal[field].range) {
>                 rc = &hw->soc->reg_cal[field];
>         } else {
>                 dev_dbg(hw->dev,
> -                       "Not support field %d for pin %d (%s)\n",
> -                       field, desc->number, desc->name);
> +                       "Not support field %d for this soc\n", field);
>                 return -ENOTSUPP;
>         }
>
> +       end = rc->nranges - 1;
>         c = rc->range;
>         e = c + rc->nranges;
>
> -       while (c < e) {
> -               if (desc->number >= c->s_pin && desc->number <= c->e_pin)
> +       while (start <= end) {
> +               check = (start + end) >> 1;
> +               if (desc->number >= rc->range[check].s_pin
> +                && desc->number <= rc->range[check].e_pin) {
> +                       found = true;
> +                       break;
> +               } else if (start == end)
>                         break;
> -               c++;
> +               else if (desc->number < rc->range[check].s_pin)
> +                       end = check - 1;
> +               else
> +                       start = check + 1;
>         }
>
> -       if (c >= e) {
> +       if (!found) {
>                 dev_dbg(hw->dev, "Not support field %d for pin = %d (%s)\n",
>                         field, desc->number, desc->name);
>                 return -ENOTSUPP;
>         }
>
> +       c = rc->range + check;
> +
>         if (c->i_base > hw->nbase - 1) {
>                 dev_err(hw->dev,
>                         "Invalid base for field %d for pin = %d (%s)\n",
> @@ -182,6 +194,9 @@ int mtk_hw_set_value(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
>         if (err)
>                 return err;
>
> +       if (value < 0 || value > pf.mask)
> +               return -EINVAL;
> +
>         if (!pf.next)
>                 mtk_rmw(hw, pf.index, pf.offset, pf.mask << pf.bitpos,
>                         (value & pf.mask) << pf.bitpos);
> diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
> index 923264d..3e13ae7 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-paris.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
> @@ -81,6 +81,8 @@ static int mtk_pinconf_get(struct pinctrl_dev *pctldev,
>         int val, val2, err, reg, ret = 1;
>         const struct mtk_pin_desc *desc;
>
> +       if (pin >= hw->soc->npins)
> +               return -EINVAL;
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[pin];
>
>         switch (param) {
> @@ -206,6 +208,10 @@ static int mtk_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
>         int err = 0;
>         u32 reg;
>
> +       if (pin >= hw->soc->npins) {
> +               err = -EINVAL;
> +               goto err;
> +       }
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[pin];
>
>         switch ((u32)param) {
> @@ -693,6 +699,9 @@ static int mtk_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
>         const struct mtk_pin_desc *desc;
>         int value, err;
>
> +       if (gpio > hw->soc->npins)
> +               return -EINVAL;
> +
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
>
>         err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DIR, &value);
> @@ -708,6 +717,9 @@ static int mtk_gpio_get(struct gpio_chip *chip, unsigned int gpio)
>         const struct mtk_pin_desc *desc;
>         int value, err;
>
> +       if (gpio > hw->soc->npins)
> +               return -EINVAL;
> +
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
>
>         err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DI, &value);
> @@ -722,6 +734,9 @@ static void mtk_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
>         struct mtk_pinctrl *hw = gpiochip_get_data(chip);
>         const struct mtk_pin_desc *desc;
>
> +       if (gpio > hw->soc->npins)
> +               return;
> +
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
>
>         mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DO, !!value);
> @@ -729,12 +744,22 @@ static void mtk_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
>
>  static int mtk_gpio_direction_input(struct gpio_chip *chip, unsigned int gpio)
>  {
> +       struct mtk_pinctrl *hw = gpiochip_get_data(chip);
> +
> +       if (gpio > hw->soc->npins)
> +               return -EINVAL;
> +
>         return pinctrl_gpio_direction_input(chip->base + gpio);
>  }
>
>  static int mtk_gpio_direction_output(struct gpio_chip *chip, unsigned int gpio,
>                                      int value)
>  {
> +       struct mtk_pinctrl *hw = gpiochip_get_data(chip);
> +
> +       if (gpio > hw->soc->npins)
> +               return -EINVAL;
> +
>         mtk_gpio_set(chip, gpio, value);
>
>         return pinctrl_gpio_direction_output(chip->base + gpio);
> --
> 1.8.1.1.dirty