LXR linux/kernel/irq/irq

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl>
   4 */
   5
   6#include <linux/slab.h>
   7#include <linux/irq_sim.h>
   8#include <linux/irq.h>
   9
  10struct irq_sim_devres {
  11        struct irq_sim          *sim;
  12};
  13
  14static void irq_sim_irqmask(struct irq_data *data)
  15{
  16        struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
  17
  18        irq_ctx->enabled = false;
  19}
  20
  21static void irq_sim_irqunmask(struct irq_data *data)
  22{
  23        struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
  24
  25        irq_ctx->enabled = true;
  26}
  27
  28static struct irq_chip irq_sim_irqchip = {
  29        .name           = "irq_sim",
  30        .irq_mask       = irq_sim_irqmask,
  31        .irq_unmask     = irq_sim_irqunmask,
  32};
  33
  34static void irq_sim_handle_irq(struct irq_work *work)
  35{
  36        struct irq_sim_work_ctx *work_ctx;
  37
  38        work_ctx = container_of(work, struct irq_sim_work_ctx, work);
  39        handle_simple_irq(irq_to_desc(work_ctx->irq));
  40}
  41
  42/**
  43 * irq_sim_init - Initialize the interrupt simulator: allocate a range of
  44 *                dummy interrupts.
  45 *
  46 * @sim:        The interrupt simulator object to initialize.
  47 * @num_irqs:   Number of interrupts to allocate
  48 *
  49 * On success: return the base of the allocated interrupt range.
  50 * On failure: a negative errno.
  51 */
  52int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs)
  53{
  54        int i;
  55
  56        sim->irqs = kmalloc_array(num_irqs, sizeof(*sim->irqs), GFP_KERNEL);
  57        if (!sim->irqs)
  58                return -ENOMEM;
  59
  60        sim->irq_base = irq_alloc_descs(-1, 0, num_irqs, 0);
  61        if (sim->irq_base < 0) {
  62                kfree(sim->irqs);
  63                return sim->irq_base;
  64        }
  65
  66        for (i = 0; i < num_irqs; i++) {
  67                sim->irqs[i].irqnum = sim->irq_base + i;
  68                sim->irqs[i].enabled = false;
  69                irq_set_chip(sim->irq_base + i, &irq_sim_irqchip);
  70                irq_set_chip_data(sim->irq_base + i, &sim->irqs[i]);
  71                irq_set_handler(sim->irq_base + i, &handle_simple_irq);
  72                irq_modify_status(sim->irq_base + i,
  73                                  IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
  74        }
  75
  76        init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq);
  77        sim->irq_count = num_irqs;
  78
  79        return sim->irq_base;
  80}
  81EXPORT_SYMBOL_GPL(irq_sim_init);
  82
  83/**
  84 * irq_sim_fini - Deinitialize the interrupt simulator: free the interrupt
  85 *                descriptors and allocated memory.
  86 *
  87 * @sim:        The interrupt simulator to tear down.
  88 */
  89void irq_sim_fini(struct irq_sim *sim)
  90{
  91        irq_work_sync(&sim->work_ctx.work);
  92        irq_free_descs(sim->irq_base, sim->irq_count);
  93        kfree(sim->irqs);
  94}
  95EXPORT_SYMBOL_GPL(irq_sim_fini);
  96
  97static void devm_irq_sim_release(struct device *dev, void *res)
  98{
  99        struct irq_sim_devres *this = res;
 100
 101        irq_sim_fini(this->sim);
 102}
 103
 104/**
 105 * irq_sim_init - Initialize the interrupt simulator for a managed device.
 106 *
 107 * @dev:        Device to initialize the simulator object for.
 108 * @sim:        The interrupt simulator object to initialize.
 109 * @num_irqs:   Number of interrupts to allocate
 110 *
 111 * On success: return the base of the allocated interrupt range.
 112 * On failure: a negative errno.
 113 */
 114int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
 115                      unsigned int num_irqs)
 116{
 117        struct irq_sim_devres *dr;
 118        int rv;
 119
 120        dr = devres_alloc(devm_irq_sim_release, sizeof(*dr), GFP_KERNEL);
 121        if (!dr)
 122                return -ENOMEM;
 123
 124        rv = irq_sim_init(sim, num_irqs);
 125        if (rv < 0) {
 126                devres_free(dr);
 127                return rv;
 128        }
 129
 130        dr->sim = sim;
 131        devres_add(dev, dr);
 132
 133        return rv;
 134}
 135EXPORT_SYMBOL_GPL(devm_irq_sim_init);
 136
 137/**
 138 * irq_sim_fire - Enqueue an interrupt.
 139 *
 140 * @sim:        The interrupt simulator object.
 141 * @offset:     Offset of the simulated interrupt which should be fired.
 142 */
 143void irq_sim_fire(struct irq_sim *sim, unsigned int offset)
 144{
 145        if (sim->irqs[offset].enabled) {
 146                sim->work_ctx.irq = irq_sim_irqnum(sim, offset);
 147                irq_work_queue(&sim->work_ctx.work);
 148        }
 149}
 150EXPORT_SYMBOL_GPL(irq_sim_fire);
 151
 152/**
 153 * irq_sim_irqnum - Get the allocated number of a dummy interrupt.
 154 *
 155 * @sim:        The interrupt simulator object.
 156 * @offset:     Offset of the simulated interrupt for which to retrieve
 157 *              the number.
 158 */
 159int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset)
 160{
 161        return sim->irqs[offset].irqnum;
 162}
 163EXPORT_SYMBOL_GPL(irq_sim_irqnum);
 164