diff options
author | Grygorii Strashko <grygorii.strashko@ti.com> | 2017-07-21 11:49:00 -0500 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2017-08-14 15:01:12 +0200 |
commit | dc749a09ea5e413564115dee742c3bc958248707 (patch) | |
tree | ee3b196175cbd710dd6827307ededaab7786cb9e | |
parent | 108d23e322a247d9f89ba2e2742520ead0944cc9 (diff) |
gpiolib: allow gpio irqchip to map irqs dynamically
Now IRQ mappings are always created for all (allowed) GPIOs in gpiochip in
gpiochip_irqchip_add_key() which goes against the idea of SPARSE_IRQ and,
as result, leads to:
- increasing of memory consumption for IRQ descriptors most of which will
never ever be used (espessially on platform with a high number of GPIOs).
(sizeof(struct irq_desc) == 256 on my tested platforms)
- imposibility to use GPIO irqchip APIs by gpio drivers when HW implements
GPIO IRQ functionality as IRQ crossbar/router which has only limited
number of IRQ outputs (example from [1], all GPIOs can be mapped on only 8
IRQs).
Hence, remove static IRQ mapping code from gpiochip_irqchip_add_key() and
instead replace irq_find_mapping() with irq_create_mapping() in
gpiochip_to_irq(). Also add additional gpiochip_irqchip_irq_valid() calls
in gpiochip_to_irq() and gpiochip_irq_map().
After this change gpio2irq mapping will happen the following way when GPIO
irqchip APIs are used by gpio driver:
- IRQ mappings will be created statically if driver passes first_irq>0
vlaue in gpiochip_irqchip_add_key().
- IRQ mappings will be created dynamically from gpio_to_irq() or
of_irq_get().
Tested on am335x-evm and dra72-evm-revc.
- dra72-evm-revc: number of created irq mappings decreased from 402 -> 135
Mem savings 267*256 = 68352 (66kB)
- am335x-evm: number of created irq mappings decreased from 188 -> 63
Mem savings 125*256 = 32000 (31kB)
[1] https://lkml.org/lkml/2017/6/15/428
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r-- | drivers/gpio/gpiolib.c | 29 |
1 files changed, 6 insertions, 23 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index bd90737dce77..92a5503f739d 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1615,6 +1615,9 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, { struct gpio_chip *chip = d->host_data; + if (!gpiochip_irqchip_irq_valid(chip, hwirq)) + return -ENXIO; + irq_set_chip_data(irq, chip); /* * This lock class tells lockdep that GPIO irqs are in a different @@ -1681,7 +1684,9 @@ static void gpiochip_irq_relres(struct irq_data *d) static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) { - return irq_find_mapping(chip->irqdomain, offset); + if (!gpiochip_irqchip_irq_valid(chip, offset)) + return -ENXIO; + return irq_create_mapping(chip->irqdomain, offset); } /** @@ -1757,9 +1762,6 @@ int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip, struct lock_class_key *lock_key) { struct device_node *of_node; - bool irq_base_set = false; - unsigned int offset; - unsigned irq_base = 0; if (!gpiochip || !irqchip) return -EINVAL; @@ -1816,25 +1818,6 @@ int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip, irqchip->irq_release_resources = gpiochip_irq_relres; } - /* - * Prepare the mapping since the irqchip shall be orthogonal to - * any gpiochip calls. If the first_irq was zero, this is - * necessary to allocate descriptors for all IRQs. - */ - for (offset = 0; offset < gpiochip->ngpio; offset++) { - if (!gpiochip_irqchip_irq_valid(gpiochip, offset)) - continue; - irq_base = irq_create_mapping(gpiochip->irqdomain, offset); - if (!irq_base_set) { - /* - * Store the base into the gpiochip to be used when - * unmapping the irqs. - */ - gpiochip->irq_base = irq_base; - irq_base_set = true; - } - } - acpi_gpiochip_request_interrupts(gpiochip); return 0; |