From 95fa6dbe58f286a8f87cb37b7516232eb678de2d Mon Sep 17 00:00:00 2001 From: Sander Vanheule Date: Sat, 9 Apr 2022 21:55:48 +0200 Subject: [PATCH 3/6] gpio: realtek-otto: Support per-cpu interrupts On SoCs with multiple cores, it is possible that the GPIO interrupt controller supports assigning specific pins to one or more cores. IRQ balancing can be performed on a line-by-line basis if the parent interrupt is routed to all available cores, which is the default upon initialisation. Signed-off-by: Sander Vanheule Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-realtek-otto.c | 75 +++++++++++++++++++++++++++++++- 1 file changed, 74 insertions(+), 1 deletion(-) --- a/drivers/gpio/gpio-realtek-otto.c +++ b/drivers/gpio/gpio-realtek-otto.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only #include +#include #include #include #include @@ -55,6 +56,8 @@ struct realtek_gpio_ctrl { struct gpio_chip gc; void __iomem *base; + void __iomem *cpumask_base; + struct cpumask cpu_irq_maskable; raw_spinlock_t lock; u16 intr_mask[REALTEK_GPIO_PORTS_PER_BANK]; u16 intr_type[REALTEK_GPIO_PORTS_PER_BANK]; @@ -76,6 +79,11 @@ enum realtek_gpio_flags { * fields, and [BA, DC] for 2-bit fields. */ GPIO_PORTS_REVERSED = BIT(1), + /* + * Interrupts can be enabled per cpu. This requires a secondary IO + * range, where the per-cpu enable masks are located. + */ + GPIO_INTERRUPTS_PER_CPU = BIT(2), }; static struct realtek_gpio_ctrl *irq_data_to_ctrl(struct irq_data *data) @@ -247,14 +255,61 @@ static void realtek_gpio_irq_handler(str chained_irq_exit(irq_chip, desc); } +static inline void __iomem *realtek_gpio_irq_cpu_mask(struct realtek_gpio_ctrl *ctrl, + unsigned int port, int cpu) +{ + return ctrl->cpumask_base + ctrl->port_offset_u8(port) + + REALTEK_GPIO_PORTS_PER_BANK * cpu; +} + +static int realtek_gpio_irq_set_affinity(struct irq_data *data, + const struct cpumask *dest, bool force) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + unsigned int port = line / 8; + unsigned int port_pin = line % 8; + void __iomem *irq_cpu_mask; + unsigned long flags; + int cpu; + u8 v; + + if (!ctrl->cpumask_base) + return -ENXIO; + + raw_spin_lock_irqsave(&ctrl->lock, flags); + + for_each_cpu(cpu, &ctrl->cpu_irq_maskable) { + irq_cpu_mask = realtek_gpio_irq_cpu_mask(ctrl, port, cpu); + v = ioread8(irq_cpu_mask); + + if (cpumask_test_cpu(cpu, dest)) + v |= BIT(port_pin); + else + v &= ~BIT(port_pin); + + iowrite8(v, irq_cpu_mask); + } + + raw_spin_unlock_irqrestore(&ctrl->lock, flags); + + irq_data_update_effective_affinity(data, dest); + + return 0; +} + static int realtek_gpio_irq_init(struct gpio_chip *gc) { struct realtek_gpio_ctrl *ctrl = gpiochip_get_data(gc); unsigned int port; + int cpu; for (port = 0; (port * 8) < gc->ngpio; port++) { realtek_gpio_write_imr(ctrl, port, 0, 0); realtek_gpio_clear_isr(ctrl, port, GENMASK(7, 0)); + + for_each_cpu(cpu, &ctrl->cpu_irq_maskable) + iowrite8(GENMASK(7, 0), realtek_gpio_irq_cpu_mask(ctrl, port, cpu)); } return 0; @@ -266,6 +321,7 @@ static struct irq_chip realtek_gpio_irq_ .irq_mask = realtek_gpio_irq_mask, .irq_unmask = realtek_gpio_irq_unmask, .irq_set_type = realtek_gpio_irq_set_type, + .irq_set_affinity = realtek_gpio_irq_set_affinity, }; static const struct of_device_id realtek_gpio_of_match[] = { @@ -290,8 +346,10 @@ static int realtek_gpio_probe(struct pla unsigned int dev_flags; struct gpio_irq_chip *girq; struct realtek_gpio_ctrl *ctrl; + struct resource *res; u32 ngpios; - int err, irq; + unsigned int nr_cpus; + int cpu, err, irq; ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL); if (!ctrl) @@ -352,6 +410,21 @@ static int realtek_gpio_probe(struct pla girq->init_hw = realtek_gpio_irq_init; } + cpumask_clear(&ctrl->cpu_irq_maskable); + + if ((dev_flags & GPIO_INTERRUPTS_PER_CPU) && irq > 0) { + ctrl->cpumask_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res); + if (IS_ERR(ctrl->cpumask_base)) + return dev_err_probe(dev, PTR_ERR(ctrl->cpumask_base), + "missing CPU IRQ mask registers"); + + nr_cpus = resource_size(res) / REALTEK_GPIO_PORTS_PER_BANK; + nr_cpus = min(nr_cpus, num_present_cpus()); + + for (cpu = 0; cpu < nr_cpus; cpu++) + cpumask_set_cpu(cpu, &ctrl->cpu_irq_maskable); + } + return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl); }