Merge branch 'irq/for-gpio' into irq/core

Merge the irq simulator which is in a separate branch so it can be consumed
by the gpio folks.

Documentation/driver-model/devres.txt

@@ -312,6 +312,7 @@ IRQ
   devm_irq_alloc_descs_from()
   devm_irq_alloc_generic_chip()
   devm_irq_setup_generic_chip()
+  devm_irq_sim_init()
 
 LED
   devm_led_classdev_register()

include/linux/irq_sim.h

@@ -0,0 +1,44 @@
+#ifndef _LINUX_IRQ_SIM_H
+#define _LINUX_IRQ_SIM_H
+/*
+ * 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_work.h>
+#include <linux/device.h>
+
+/*
+ * Provides a framework for allocating simulated interrupts which can be
+ * requested like normal irqs and enqueued from process context.
+ */
+
+struct irq_sim_work_ctx {
+	struct irq_work		work;
+	int			irq;
+};
+
+struct irq_sim_irq_ctx {
+	int			irqnum;
+	bool			enabled;
+};
+
+struct irq_sim {
+	struct irq_sim_work_ctx	work_ctx;
+	int			irq_base;
+	unsigned int		irq_count;
+	struct irq_sim_irq_ctx	*irqs;
+};
+
+int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs);
+int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
+		      unsigned int num_irqs);
+void irq_sim_fini(struct irq_sim *sim);
+void irq_sim_fire(struct irq_sim *sim, unsigned int offset);
+int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset);
+
+#endif /* _LINUX_IRQ_SIM_H */

kernel/irq/Kconfig

@@ -63,6 +63,11 @@ config GENERIC_IRQ_CHIP
 config IRQ_DOMAIN
 	bool
 
+# Support for simulated interrupts
+config IRQ_SIM
+	bool
+	select IRQ_WORK
+
 # Support for hierarchical irq domains
 config IRQ_DOMAIN_HIERARCHY
 	bool

kernel/irq/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_IRQ_TIMINGS) += timings.o
 obj-$(CONFIG_GENERIC_IRQ_CHIP) += generic-chip.o
 obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
 obj-$(CONFIG_IRQ_DOMAIN) += irqdomain.o
+obj-$(CONFIG_IRQ_SIM) += irq_sim.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
 obj-$(CONFIG_GENERIC_IRQ_MIGRATION) += cpuhotplug.o

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);