From b17566a6b08be18ded5472a2e4bbc066593b3662 Mon Sep 17 00:00:00 2001 From: Janusz Krzysztofik Date: Wed, 5 Sep 2018 23:50:08 +0200 Subject: gpiolib: Implement fast processing path in get/set array Certain GPIO descriptor arrays returned by gpio_get_array() may contain information on direct mapping of array members to pins of a single GPIO chip in hardware order. In such cases, bitmaps of values can be passed directly from/to the chip's .get/set_multiple() callbacks without wasting time on iterations. Add respective code to gpiod_get/set_array_bitmap_complex() functions. Pins not applicable for fast path are processed as before, skipping over the 'fast' ones. Cc: Jonathan Corbet Signed-off-by: Janusz Krzysztofik Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 82 insertions(+), 5 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index cd7c1deed132..d7532aa6c0bc 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2789,7 +2789,36 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, struct gpio_array *array_info, unsigned long *value_bitmap) { - int i = 0; + int err, i = 0; + + /* + * Validate array_info against desc_array and its size. + * It should immediately follow desc_array if both + * have been obtained from the same gpiod_get_array() call. + */ + if (array_info && array_info->desc == desc_array && + array_size <= array_info->size && + (void *)array_info == desc_array + array_info->size) { + if (!can_sleep) + WARN_ON(array_info->chip->can_sleep); + + err = gpio_chip_get_multiple(array_info->chip, + array_info->get_mask, + value_bitmap); + if (err) + return err; + + if (!raw && !bitmap_empty(array_info->invert_mask, array_size)) + bitmap_xor(value_bitmap, value_bitmap, + array_info->invert_mask, array_size); + + if (bitmap_full(array_info->get_mask, array_size)) + return 0; + + i = find_first_zero_bit(array_info->get_mask, array_size); + } else { + array_info = NULL; + } while (i < array_size) { struct gpio_chip *chip = desc_array[i]->gdev->chip; @@ -2820,7 +2849,12 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, int hwgpio = gpio_chip_hwgpio(desc); __set_bit(hwgpio, mask); - i++; + + if (array_info) + find_next_zero_bit(array_info->get_mask, + array_size, i); + else + i++; } while ((i < array_size) && (desc_array[i]->gdev->chip == chip)); @@ -2831,7 +2865,7 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, return ret; } - for (j = first; j < i; j++) { + for (j = first; j < i; ) { const struct gpio_desc *desc = desc_array[j]; int hwgpio = gpio_chip_hwgpio(desc); int value = test_bit(hwgpio, bits); @@ -2840,6 +2874,11 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, value = !value; __assign_bit(j, value_bitmap, value); trace_gpio_value(desc_to_gpio(desc), 1, value); + + if (array_info) + find_next_zero_bit(array_info->get_mask, i, j); + else + j++; } if (mask != fastpath) @@ -3043,6 +3082,32 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, { int i = 0; + /* + * Validate array_info against desc_array and its size. + * It should immediately follow desc_array if both + * have been obtained from the same gpiod_get_array() call. + */ + if (array_info && array_info->desc == desc_array && + array_size <= array_info->size && + (void *)array_info == desc_array + array_info->size) { + if (!can_sleep) + WARN_ON(array_info->chip->can_sleep); + + if (!raw && !bitmap_empty(array_info->invert_mask, array_size)) + bitmap_xor(value_bitmap, value_bitmap, + array_info->invert_mask, array_size); + + gpio_chip_set_multiple(array_info->chip, array_info->set_mask, + value_bitmap); + + if (bitmap_full(array_info->set_mask, array_size)) + return 0; + + i = find_first_zero_bit(array_info->set_mask, array_size); + } else { + array_info = NULL; + } + while (i < array_size) { struct gpio_chip *chip = desc_array[i]->gdev->chip; unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)]; @@ -3070,7 +3135,14 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, int hwgpio = gpio_chip_hwgpio(desc); int value = test_bit(i, value_bitmap); - if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + /* + * Pins applicable for fast input but not for + * fast output processing may have been already + * inverted inside the fast path, skip them. + */ + if (!raw && !(array_info && + test_bit(i, array_info->invert_mask)) && + test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; trace_gpio_value(desc_to_gpio(desc), 0, value); /* @@ -3089,7 +3161,12 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, __clear_bit(hwgpio, bits); count++; } - i++; + + if (array_info) + find_next_zero_bit(array_info->set_mask, + array_size, i); + else + i++; } while ((i < array_size) && (desc_array[i]->gdev->chip == chip)); /* push collected bits to outputs */ -- cgit v1.2.3-59-g8ed1b