| Message ID | 20170708224413.18281-4-grygorii.strashko@ti.com |
|---|---|
| State | New |
| Headers | show |
On Sun, Jul 9, 2017 at 12:44 AM, Grygorii Strashko <grygorii.strashko@ti.com> wrote: > Now IRQ mappings are always created for all (allowed) GPIOs in gpio irqchip in > gpiochip_irqchip_add_key() which goes against the idea of SPARSE_IRQ and, > as result, leads to: > - increasing of memory consumption because of allocated IRQ descriptors most > of which will never ever be used (especially on platform with a > high number of GPIOs) > - imposibility to use GPIO irqchip APIs by gpio drivers when HW implements > GPIO IRQ functionality as IRQ crossbar/multiplexer 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(). > > [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1435847.html > Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> This is obviously better and what I should have done from the beginning had I only been smart enough, so what better to do than to throw this in now for -next and see what happens :) Patch applied. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 9568708..ee6ba07 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1605,6 +1605,9 @@ 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 @@ -1671,7 +1674,9 @@ 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); } /** @@ -1747,9 +1752,6 @@ 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; @@ -1806,25 +1808,6 @@ 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; diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index af20369..a3e2e3e 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -165,7 +165,6 @@ struct gpio_chip { */ struct irq_chip *irqchip; struct irq_domain *irqdomain; - unsigned int irq_base; irq_flow_handler_t irq_handler; unsigned int irq_default_type; unsigned int irq_chained_parent;
Now IRQ mappings are always created for all (allowed) GPIOs in gpio irqchip in gpiochip_irqchip_add_key() which goes against the idea of SPARSE_IRQ and, as result, leads to: - increasing of memory consumption because of allocated IRQ descriptors most of which will never ever be used (especially on platform with a high number of GPIOs) - imposibility to use GPIO irqchip APIs by gpio drivers when HW implements GPIO IRQ functionality as IRQ crossbar/multiplexer 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(). [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1435847.html Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> --- drivers/gpio/gpiolib.c | 29 ++++++----------------------- include/linux/gpio/driver.h | 1 - 2 files changed, 6 insertions(+), 24 deletions(-)