diff options
Diffstat (limited to 'kernel/irq/irq_sim.c')
| -rw-r--r-- | kernel/irq/irq_sim.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c new file mode 100644 index 000000000000..24caabf1a0f7 --- /dev/null +++ b/kernel/irq/irq_sim.c @@ -0,0 +1,164 @@ +/* + * Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/irq_sim.h> +#include <linux/irq.h> + +struct irq_sim_devres { + struct irq_sim *sim; +}; + +static void irq_sim_irqmask(struct irq_data *data) +{ + struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); + + irq_ctx->enabled = false; +} + +static void irq_sim_irqunmask(struct irq_data *data) +{ + struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); + + irq_ctx->enabled = true; +} + +static struct irq_chip irq_sim_irqchip = { + .name = "irq_sim", + .irq_mask = irq_sim_irqmask, + .irq_unmask = irq_sim_irqunmask, +}; + +static void irq_sim_handle_irq(struct irq_work *work) +{ + struct irq_sim_work_ctx *work_ctx; + + work_ctx = container_of(work, struct irq_sim_work_ctx, work); + handle_simple_irq(irq_to_desc(work_ctx->irq)); +} + +/** + * irq_sim_init - Initialize the interrupt simulator: allocate a range of + * dummy interrupts. + * + * @sim: The interrupt simulator object to initialize. + * @num_irqs: Number of interrupts to allocate + * + * Returns 0 on success and a negative error number on failure. + */ +int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs) +{ + int i; + + sim->irqs = kmalloc_array(num_irqs, sizeof(*sim->irqs), GFP_KERNEL); + if (!sim->irqs) + return -ENOMEM; + + sim->irq_base = irq_alloc_descs(-1, 0, num_irqs, 0); + if (sim->irq_base < 0) { + kfree(sim->irqs); + return sim->irq_base; + } + + for (i = 0; i < num_irqs; i++) { + sim->irqs[i].irqnum = sim->irq_base + i; + sim->irqs[i].enabled = false; + irq_set_chip(sim->irq_base + i, &irq_sim_irqchip); + irq_set_chip_data(sim->irq_base + i, &sim->irqs[i]); + irq_set_handler(sim->irq_base + i, &handle_simple_irq); + irq_modify_status(sim->irq_base + i, + IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE); + } + + init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq); + sim->irq_count = num_irqs; + + return 0; +} +EXPORT_SYMBOL_GPL(irq_sim_init); + +/** + * irq_sim_fini - Deinitialize the interrupt simulator: free the interrupt + * descriptors and allocated memory. + * + * @sim: The interrupt simulator to tear down. + */ +void irq_sim_fini(struct irq_sim *sim) +{ + irq_work_sync(&sim->work_ctx.work); + irq_free_descs(sim->irq_base, sim->irq_count); + kfree(sim->irqs); +} +EXPORT_SYMBOL_GPL(irq_sim_fini); + +static void devm_irq_sim_release(struct device *dev, void *res) +{ + struct irq_sim_devres *this = res; + + irq_sim_fini(this->sim); +} + +/** + * irq_sim_init - Initialize the interrupt simulator for a managed device. + * + * @dev: Device to initialize the simulator object for. + * @sim: The interrupt simulator object to initialize. + * @num_irqs: Number of interrupts to allocate + * + * Returns 0 on success and a negative error number on failure. + */ +int devm_irq_sim_init(struct device *dev, struct irq_sim *sim, + unsigned int num_irqs) +{ + struct irq_sim_devres *dr; + int rv; + + dr = devres_alloc(devm_irq_sim_release, sizeof(*dr), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + rv = irq_sim_init(sim, num_irqs); + if (rv) { + devres_free(dr); + return rv; + } + + dr->sim = sim; + devres_add(dev, dr); + + return 0; +} +EXPORT_SYMBOL_GPL(devm_irq_sim_init); + +/** + * irq_sim_fire - Enqueue an interrupt. + * + * @sim: The interrupt simulator object. + * @offset: Offset of the simulated interrupt which should be fired. + */ +void irq_sim_fire(struct irq_sim *sim, unsigned int offset) +{ + if (sim->irqs[offset].enabled) { + sim->work_ctx.irq = irq_sim_irqnum(sim, offset); + irq_work_queue(&sim->work_ctx.work); + } +} +EXPORT_SYMBOL_GPL(irq_sim_fire); + +/** + * irq_sim_irqnum - Get the allocated number of a dummy interrupt. + * + * @sim: The interrupt simulator object. + * @offset: Offset of the simulated interrupt for which to retrieve + * the number. + */ +int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset) +{ + return sim->irqs[offset].irqnum; +} +EXPORT_SYMBOL_GPL(irq_sim_irqnum); |