Re: [PATCH v2 1/5] pinctrl: mediatek: Check gpio pin number and use binary search in mtk_hw_pin_field_lookup()

From: Light Hsieh
Date: Thu Sep 05 2019 - 02:00:23 EST


Dear reviewers,

v2 is the same as v1 except that commit message is corrected according
to Linus' comment for v1:

1. remove Change-Id lines
2. correct sysfs as debugfs

On Thu, 2019-09-05 at 13:53 +0800, Light Hsieh wrote:
> From: Light Hsieh <light.hsieh@xxxxxxxxxxxx>
>
> 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. Use binary search in mtk_hw_pin_field_lookup()
> Modify mtk_hw_pin_field_lookup() to use binary search for accelerating
> search.
>
> ---
> drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 24 +++++++++++++++++++-----
> drivers/pinctrl/mediatek/pinctrl-paris.c | 19 +++++++++++++++++++
> 2 files changed, 38 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> index 20e1c89..4687f63 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> @@ -68,7 +68,7 @@ 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;
> - u32 bits;
> + u32 bits, start = 0, end, found = 0, check;
>
> if (hw->soc->reg_cal && hw->soc->reg_cal[field].range) {
> rc = &hw->soc->reg_cal[field];
> @@ -79,21 +79,32 @@ static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
> 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 = 1;
> break;
> - c++;
> + } else if (start == end)
> + break;
> + 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 +193,9 @@ 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..28b4951 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-paris.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
> @@ -693,6 +693,9 @@ 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 +711,9 @@ 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 +728,9 @@ 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 +738,22 @@ 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);