On Sun, May 03, 2020 at 12:21:54AM +0530, Syed Nayyar Waris wrote: > This patch reimplements the xgpio_set_multiple function in > drivers/gpio/gpio-xilinx.c to use the new for_each_set_clump macro. > Instead of looping for each bit in xgpio_set_multiple > function, now we can check each channel at a time and save cycles. > > Cc: Linus Walleij <[email protected]> > Cc: Bartosz Golaszewski <[email protected]> > Cc: Michal Simek <[email protected]> > Signed-off-by: Syed Nayyar Waris <[email protected]> > Signed-off-by: William Breathitt Gray <[email protected]> > --- > Changes in v4: > - Minor change: Hardcode value for better code readability. > > Changes in v3: > - No change. > > Changes in v2: > - No change. > > drivers/gpio/gpio-xilinx.c | 64 ++++++++++++++++++++------------------ > 1 file changed, 34 insertions(+), 30 deletions(-) > > diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c > index 67f9f82e0db0..67c5eeaf1bb9 100644 > --- a/drivers/gpio/gpio-xilinx.c > +++ b/drivers/gpio/gpio-xilinx.c > @@ -136,39 +136,43 @@ static void xgpio_set(struct gpio_chip *gc, unsigned > int gpio, int val) > static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask, > unsigned long *bits) > { > - unsigned long flags; > + unsigned long flags[2]; > struct xgpio_instance *chip = gpiochip_get_data(gc); > - int index = xgpio_index(chip, 0); > - int offset, i; > - > - spin_lock_irqsave(&chip->gpio_lock[index], flags); > - > - /* Write to GPIO signals */ > - for (i = 0; i < gc->ngpio; i++) { > - if (*mask == 0) > - break; > - /* Once finished with an index write it out to the register */ > - if (index != xgpio_index(chip, i)) { > - xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET + > - index * XGPIO_CHANNEL_OFFSET, > - chip->gpio_state[index]); > - spin_unlock_irqrestore(&chip->gpio_lock[index], flags); > - index = xgpio_index(chip, i); > - spin_lock_irqsave(&chip->gpio_lock[index], flags); > - } > - if (__test_and_clear_bit(i, mask)) { > - offset = xgpio_offset(chip, i); > - if (test_bit(i, bits)) > - chip->gpio_state[index] |= BIT(offset); > - else > - chip->gpio_state[index] &= ~BIT(offset); > - } > + u32 *const state = chip->gpio_state; > + unsigned int *const width = chip->gpio_width; > + const unsigned long state_size = 32; > + const unsigned long total_state_bits = state_size * 2;
Hello Syed,
I don't think there's much need for these two variables either. You can
remove the state_size and total_state_bits variables, and instead inline
32 and 64 directly in your code below.
William Breathitt Gray
> + unsigned long offset, clump;
> + size_t index;
> +
> + DECLARE_BITMAP(old, 64);
> + DECLARE_BITMAP(new, 64);
> + DECLARE_BITMAP(changed, 64);
> +
> + spin_lock_irqsave(&chip->gpio_lock[0], flags[0]);
> + spin_lock_irqsave(&chip->gpio_lock[1], flags[1]);
> +
> + bitmap_set_value(old, state[0], 0, width[0]);
> + bitmap_set_value(old, state[1], width[0], width[1]);
> + bitmap_replace(new, old, bits, mask, gc->ngpio);
> +
> + bitmap_set_value(old, state[0], 0, state_size);
> + bitmap_set_value(old, state[1], state_size, state_size);
> + state[0] = bitmap_get_value(new, 0, width[0]);
> + state[1] = bitmap_get_value(new, width[0], width[1]);
> + bitmap_set_value(new, state[0], 0, state_size);
> + bitmap_set_value(new, state[1], state_size, state_size);
> + bitmap_xor(changed, old, new, total_state_bits);
> +
> + for_each_set_clump(offset, clump, changed, total_state_bits,
> state_size) {
> + index = offset / state_size;
> + xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> + index * XGPIO_CHANNEL_OFFSET,
> + state[index]);
> }
>
> - xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> - index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
> -
> - spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
> + spin_unlock_irqrestore(&chip->gpio_lock[1], flags[1]);
> + spin_unlock_irqrestore(&chip->gpio_lock[0], flags[0]);
> }
>
> /**
> --
> 2.26.2
>
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