Re: [PATCH v1 4/5] gpio: xilinx: Replace bitmap_bitremap() calls

From: Kent Gibson <warthog618@gmail.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Linus Walleij" <linus.walleij@linaro.org>,
	"Bartosz Golaszewski" <bartosz.golaszewski@linaro.org>,
	"Yury Norov" <yury.norov@gmail.com>,
	linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	"Shubhrajyoti Datta" <shubhrajyoti.datta@amd.com>,
	"Srinivas Neeli" <srinivas.neeli@amd.com>,
	"Michal Simek" <michal.simek@amd.com>,
	"Bartosz Golaszewski" <brgl@bgdev.pl>,
	"Andy Shevchenko" <andy@kernel.org>,
	"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
	"Marek Behún" <kabel@kernel.org>
Subject: Re: [PATCH v1 4/5] gpio: xilinx: Replace bitmap_bitremap() calls
Date: Tue, 26 Sep 2023 18:41:00 +0800	[thread overview]
Message-ID: <ZRK1PA2vZBdfAozG@sol> (raw)
In-Reply-To: <20230926052007.3917389-5-andriy.shevchenko@linux.intel.com>

On Tue, Sep 26, 2023 at 08:20:06AM +0300, Andy Shevchenko wrote:
> We have sparse and dence masks of the line mappings based on

dense

> the view point (Linux numbering or hardware numbering). Since
> the Linux side uses sequential bits for the mask, we can simply
> convert a Linux number to the hardware one and vise versa by

vice

> counting set bits in the respective mask. Hence replace
> bitmap_bitremap() calls by simpler equivalents.
> 
> With this done the dence mask is not needed and thus dropped.
> 

And dense again.

Cheers,
Kent.

> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/gpio/gpio-xilinx.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
> index f103c30cc74f..14ca3097563a 100644
> --- a/drivers/gpio/gpio-xilinx.c
> +++ b/drivers/gpio/gpio-xilinx.c
> @@ -46,7 +46,6 @@
>   * @gc: GPIO chip
>   * @regs: register block
>   * @hw_map: GPIO pin mapping on hardware side
> - * @sw_map: GPIO pin mapping on software side
>   * @state: GPIO write state shadow register
>   * @last_irq_read: GPIO read state register from last interrupt
>   * @dir: GPIO direction shadow register
> @@ -62,7 +61,6 @@ struct xgpio_instance {
>  	struct gpio_chip gc;
>  	void __iomem *regs;
>  	DECLARE_BITMAP(hw_map, 64);
> -	DECLARE_BITMAP(sw_map, 64);
>  	DECLARE_BITMAP(state, 64);
>  	DECLARE_BITMAP(last_irq_read, 64);
>  	DECLARE_BITMAP(dir, 64);
> @@ -76,12 +74,12 @@ struct xgpio_instance {
>  
>  static inline int xgpio_from_bit(struct xgpio_instance *chip, int bit)
>  {
> -	return bitmap_bitremap(bit, chip->hw_map, chip->sw_map, 64);
> +	return bitmap_weight(chip->hw_map, bit + 1);
>  }
>  
>  static inline int xgpio_to_bit(struct xgpio_instance *chip, int gpio)
>  {
> -	return bitmap_bitremap(gpio, chip->sw_map, chip->hw_map, 64);
> +	return find_nth_bit(chip->hw_map, 64, gpio);
>  }
>  
>  static inline u32 xgpio_get_value32(const unsigned long *map, int bit)
> @@ -619,9 +617,6 @@ static int xgpio_probe(struct platform_device *pdev)
>  	if (width[1] > 32)
>  		return -EINVAL;
>  
> -	/* Setup software pin mapping */
> -	bitmap_set(chip->sw_map, 0, width[0] + width[1]);
> -
>  	/* Setup hardware pin mapping */
>  	bitmap_set(chip->hw_map,  0, width[0]);
>  	bitmap_set(chip->hw_map, 32, width[1]);
> -- 
> 2.40.0.1.gaa8946217a0b
> 