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-rw-r--r--kernel/irq/irq_sim.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
new file mode 100644
index 000000000..48006608b
--- /dev/null
+++ b/kernel/irq/irq_sim.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl>
+ * Copyright (C) 2020 Bartosz Golaszewski <bgolaszewski@baylibre.com>
+ */
+
+#include <linux/irq.h>
+#include <linux/irq_sim.h>
+#include <linux/irq_work.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+struct irq_sim_work_ctx {
+ struct irq_work work;
+ int irq_base;
+ unsigned int irq_count;
+ unsigned long *pending;
+ struct irq_domain *domain;
+};
+
+struct irq_sim_irq_ctx {
+ int irqnum;
+ bool enabled;
+ struct irq_sim_work_ctx *work_ctx;
+};
+
+struct irq_sim_devres {
+ struct irq_domain *domain;
+};
+
+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 int irq_sim_set_type(struct irq_data *data, unsigned int type)
+{
+ /* We only support rising and falling edge trigger types. */
+ if (type & ~IRQ_TYPE_EDGE_BOTH)
+ return -EINVAL;
+
+ irqd_set_trigger_type(data, type);
+
+ return 0;
+}
+
+static int irq_sim_get_irqchip_state(struct irq_data *data,
+ enum irqchip_irq_state which, bool *state)
+{
+ struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+ switch (which) {
+ case IRQCHIP_STATE_PENDING:
+ if (irq_ctx->enabled)
+ *state = test_bit(hwirq, irq_ctx->work_ctx->pending);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int irq_sim_set_irqchip_state(struct irq_data *data,
+ enum irqchip_irq_state which, bool state)
+{
+ struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+ switch (which) {
+ case IRQCHIP_STATE_PENDING:
+ if (irq_ctx->enabled) {
+ assign_bit(hwirq, irq_ctx->work_ctx->pending, state);
+ if (state)
+ irq_work_queue(&irq_ctx->work_ctx->work);
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static struct irq_chip irq_sim_irqchip = {
+ .name = "irq_sim",
+ .irq_mask = irq_sim_irqmask,
+ .irq_unmask = irq_sim_irqunmask,
+ .irq_set_type = irq_sim_set_type,
+ .irq_get_irqchip_state = irq_sim_get_irqchip_state,
+ .irq_set_irqchip_state = irq_sim_set_irqchip_state,
+};
+
+static void irq_sim_handle_irq(struct irq_work *work)
+{
+ struct irq_sim_work_ctx *work_ctx;
+ unsigned int offset = 0;
+ int irqnum;
+
+ work_ctx = container_of(work, struct irq_sim_work_ctx, work);
+
+ while (!bitmap_empty(work_ctx->pending, work_ctx->irq_count)) {
+ offset = find_next_bit(work_ctx->pending,
+ work_ctx->irq_count, offset);
+ clear_bit(offset, work_ctx->pending);
+ irqnum = irq_find_mapping(work_ctx->domain, offset);
+ handle_simple_irq(irq_to_desc(irqnum));
+ }
+}
+
+static int irq_sim_domain_map(struct irq_domain *domain,
+ unsigned int virq, irq_hw_number_t hw)
+{
+ struct irq_sim_work_ctx *work_ctx = domain->host_data;
+ struct irq_sim_irq_ctx *irq_ctx;
+
+ irq_ctx = kzalloc(sizeof(*irq_ctx), GFP_KERNEL);
+ if (!irq_ctx)
+ return -ENOMEM;
+
+ irq_set_chip(virq, &irq_sim_irqchip);
+ irq_set_chip_data(virq, irq_ctx);
+ irq_set_handler(virq, handle_simple_irq);
+ irq_modify_status(virq, IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
+ irq_ctx->work_ctx = work_ctx;
+
+ return 0;
+}
+
+static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq)
+{
+ struct irq_sim_irq_ctx *irq_ctx;
+ struct irq_data *irqd;
+
+ irqd = irq_domain_get_irq_data(domain, virq);
+ irq_ctx = irq_data_get_irq_chip_data(irqd);
+
+ irq_set_handler(virq, NULL);
+ irq_domain_reset_irq_data(irqd);
+ kfree(irq_ctx);
+}
+
+static const struct irq_domain_ops irq_sim_domain_ops = {
+ .map = irq_sim_domain_map,
+ .unmap = irq_sim_domain_unmap,
+};
+
+/**
+ * irq_domain_create_sim - Create a new interrupt simulator irq_domain and
+ * allocate a range of dummy interrupts.
+ *
+ * @fnode: struct fwnode_handle to be associated with this domain.
+ * @num_irqs: Number of interrupts to allocate.
+ *
+ * On success: return a new irq_domain object.
+ * On failure: a negative errno wrapped with ERR_PTR().
+ */
+struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
+ unsigned int num_irqs)
+{
+ struct irq_sim_work_ctx *work_ctx;
+
+ work_ctx = kmalloc(sizeof(*work_ctx), GFP_KERNEL);
+ if (!work_ctx)
+ goto err_out;
+
+ work_ctx->pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
+ if (!work_ctx->pending)
+ goto err_free_work_ctx;
+
+ work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs,
+ &irq_sim_domain_ops,
+ work_ctx);
+ if (!work_ctx->domain)
+ goto err_free_bitmap;
+
+ work_ctx->irq_count = num_irqs;
+ init_irq_work(&work_ctx->work, irq_sim_handle_irq);
+
+ return work_ctx->domain;
+
+err_free_bitmap:
+ bitmap_free(work_ctx->pending);
+err_free_work_ctx:
+ kfree(work_ctx);
+err_out:
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(irq_domain_create_sim);
+
+/**
+ * irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free
+ * the interrupt descriptors and allocated memory.
+ *
+ * @domain: The interrupt simulator domain to tear down.
+ */
+void irq_domain_remove_sim(struct irq_domain *domain)
+{
+ struct irq_sim_work_ctx *work_ctx = domain->host_data;
+
+ irq_work_sync(&work_ctx->work);
+ bitmap_free(work_ctx->pending);
+ kfree(work_ctx);
+
+ irq_domain_remove(domain);
+}
+EXPORT_SYMBOL_GPL(irq_domain_remove_sim);
+
+static void devm_irq_domain_release_sim(struct device *dev, void *res)
+{
+ struct irq_sim_devres *this = res;
+
+ irq_domain_remove_sim(this->domain);
+}
+
+/**
+ * devm_irq_domain_create_sim - Create a new interrupt simulator for
+ * a managed device.
+ *
+ * @dev: Device to initialize the simulator object for.
+ * @fnode: struct fwnode_handle to be associated with this domain.
+ * @num_irqs: Number of interrupts to allocate
+ *
+ * On success: return a new irq_domain object.
+ * On failure: a negative errno wrapped with ERR_PTR().
+ */
+struct irq_domain *devm_irq_domain_create_sim(struct device *dev,
+ struct fwnode_handle *fwnode,
+ unsigned int num_irqs)
+{
+ struct irq_sim_devres *dr;
+
+ dr = devres_alloc(devm_irq_domain_release_sim,
+ sizeof(*dr), GFP_KERNEL);
+ if (!dr)
+ return ERR_PTR(-ENOMEM);
+
+ dr->domain = irq_domain_create_sim(fwnode, num_irqs);
+ if (IS_ERR(dr->domain)) {
+ devres_free(dr);
+ return dr->domain;
+ }
+
+ devres_add(dev, dr);
+ return dr->domain;
+}
+EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);