[linux-block.git] / kernel / irq / irq_sim.c

// 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;
};

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.
 *
 * @fwnode:     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;
	work_ctx->work = IRQ_WORK_INIT_HARD(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_remove_sim(void *data)
{
	struct irq_domain *domain = data;

	irq_domain_remove_sim(domain);
}

/**
 * devm_irq_domain_create_sim - Create a new interrupt simulator for
 *                              a managed device.
 *
 * @dev:        Device to initialize the simulator object for.
 * @fwnode:     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_domain *domain;
	int ret;

	domain = irq_domain_create_sim(fwnode, num_irqs);
	if (IS_ERR(domain))
		return domain;

	ret = devm_add_action_or_reset(dev, devm_irq_domain_remove_sim, domain);
	if (ret)
		return ERR_PTR(ret);

	return domain;
}
EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);
Commit	Line	Data
52a65ff5	1	// SPDX-License-Identifier: GPL-2.0+
b19af510	2	/*
275220ca	3	* Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl>
337cbeb2	4	* Copyright (C) 2020 Bartosz Golaszewski <bgolaszewski@baylibre.com>
b19af510 BG	5	*/
b19af510 BG	6
b19af510	7	#include <linux/irq.h>
337cbeb2 BG	8	#include <linux/irq_sim.h>
	9	#include <linux/irq_work.h>
	10	#include <linux/interrupt.h>
	11	#include <linux/slab.h>
	12
	13	struct irq_sim_work_ctx {
	14	struct irq_work work;
	15	int irq_base;
	16	unsigned int irq_count;
	17	unsigned long *pending;
	18	struct irq_domain *domain;
	19	};
	20
	21	struct irq_sim_irq_ctx {
	22	int irqnum;
	23	bool enabled;
	24	struct irq_sim_work_ctx *work_ctx;
	25	};
b19af510 BG	26
	27	static void irq_sim_irqmask(struct irq_data *data)
	28	{
	29	struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
	30
	31	irq_ctx->enabled = false;
	32	}
	33
	34	static void irq_sim_irqunmask(struct irq_data *data)
	35	{
	36	struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
	37
	38	irq_ctx->enabled = true;
	39	}
	40
8d91ecc8 BG	41	static int irq_sim_set_type(struct irq_data *data, unsigned int type)
	42	{
	43	/* We only support rising and falling edge trigger types. */
	44	if (type & ~IRQ_TYPE_EDGE_BOTH)
	45	return -EINVAL;
	46
	47	irqd_set_trigger_type(data, type);
	48
	49	return 0;
	50	}
	51
337cbeb2 BG	52	static int irq_sim_get_irqchip_state(struct irq_data *data,
	53	enum irqchip_irq_state which, bool *state)
	54	{
	55	struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
	56	irq_hw_number_t hwirq = irqd_to_hwirq(data);
	57
	58	switch (which) {
	59	case IRQCHIP_STATE_PENDING:
	60	if (irq_ctx->enabled)
	61	*state = test_bit(hwirq, irq_ctx->work_ctx->pending);
	62	break;
	63	default:
	64	return -EINVAL;
	65	}
	66
	67	return 0;
	68	}
	69
	70	static int irq_sim_set_irqchip_state(struct irq_data *data,
	71	enum irqchip_irq_state which, bool state)
	72	{
	73	struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
	74	irq_hw_number_t hwirq = irqd_to_hwirq(data);
	75
	76	switch (which) {
	77	case IRQCHIP_STATE_PENDING:
	78	if (irq_ctx->enabled) {
	79	assign_bit(hwirq, irq_ctx->work_ctx->pending, state);
	80	if (state)
	81	irq_work_queue(&irq_ctx->work_ctx->work);
	82	}
	83	break;
	84	default:
	85	return -EINVAL;
	86	}
	87
	88	return 0;
	89	}
	90
b19af510	91	static struct irq_chip irq_sim_irqchip = {
337cbeb2 BG	92	.name = "irq_sim",
	93	.irq_mask = irq_sim_irqmask,
	94	.irq_unmask = irq_sim_irqunmask,
	95	.irq_set_type = irq_sim_set_type,
	96	.irq_get_irqchip_state = irq_sim_get_irqchip_state,
	97	.irq_set_irqchip_state = irq_sim_set_irqchip_state,
b19af510 BG	98	};
	99
	100	static void irq_sim_handle_irq(struct irq_work *work)
	101	{
	102	struct irq_sim_work_ctx *work_ctx;
06459901	103	unsigned int offset = 0;
06459901	104	int irqnum;
b19af510 BG	105
b19af510 BG	106	work_ctx = container_of(work, struct irq_sim_work_ctx, work);
06459901	107
337cbeb2	108	while (!bitmap_empty(work_ctx->pending, work_ctx->irq_count)) {
06459901	109	offset = find_next_bit(work_ctx->pending,
337cbeb2	110	work_ctx->irq_count, offset);
06459901	111	clear_bit(offset, work_ctx->pending);
337cbeb2	112	irqnum = irq_find_mapping(work_ctx->domain, offset);
06459901 BG	113	handle_simple_irq(irq_to_desc(irqnum));
06459901 BG	114	}
b19af510 BG	115	}
b19af510 BG	116
337cbeb2 BG	117	static int irq_sim_domain_map(struct irq_domain *domain,
	118	unsigned int virq, irq_hw_number_t hw)
	119	{
	120	struct irq_sim_work_ctx *work_ctx = domain->host_data;
	121	struct irq_sim_irq_ctx *irq_ctx;
	122
	123	irq_ctx = kzalloc(sizeof(*irq_ctx), GFP_KERNEL);
	124	if (!irq_ctx)
	125	return -ENOMEM;
	126
	127	irq_set_chip(virq, &irq_sim_irqchip);
	128	irq_set_chip_data(virq, irq_ctx);
	129	irq_set_handler(virq, handle_simple_irq);
	130	irq_modify_status(virq, IRQ_NOREQUEST \| IRQ_NOAUTOEN, IRQ_NOPROBE);
	131	irq_ctx->work_ctx = work_ctx;
	132
	133	return 0;
	134	}
	135
	136	static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq)
	137	{
	138	struct irq_sim_irq_ctx *irq_ctx;
	139	struct irq_data *irqd;
	140
	141	irqd = irq_domain_get_irq_data(domain, virq);
	142	irq_ctx = irq_data_get_irq_chip_data(irqd);
	143
	144	irq_set_handler(virq, NULL);
	145	irq_domain_reset_irq_data(irqd);
	146	kfree(irq_ctx);
	147	}
	148
	149	static const struct irq_domain_ops irq_sim_domain_ops = {
	150	.map = irq_sim_domain_map,
	151	.unmap = irq_sim_domain_unmap,
	152	};
	153
b19af510	154	/**
337cbeb2 BG	155	* irq_domain_create_sim - Create a new interrupt simulator irq_domain and
337cbeb2 BG	156	* allocate a range of dummy interrupts.
b19af510	157	*
ef4cb70a	158	* @fwnode: struct fwnode_handle to be associated with this domain.
337cbeb2	159	* @num_irqs: Number of interrupts to allocate.
b19af510	160	*
337cbeb2 BG	161	* On success: return a new irq_domain object.
337cbeb2 BG	162	* On failure: a negative errno wrapped with ERR_PTR().
b19af510	163	*/
337cbeb2 BG	164	struct irq_domain irq_domain_create_sim(struct fwnode_handle fwnode,
337cbeb2 BG	165	unsigned int num_irqs)
b19af510	166	{
337cbeb2	167	struct irq_sim_work_ctx *work_ctx;
b19af510	168
337cbeb2 BG	169	work_ctx = kmalloc(sizeof(*work_ctx), GFP_KERNEL);
	170	if (!work_ctx)
	171	goto err_out;
b19af510	172
337cbeb2 BG	173	work_ctx->pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
	174	if (!work_ctx->pending)
	175	goto err_free_work_ctx;
b19af510	176
337cbeb2 BG	177	work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs,
	178	&irq_sim_domain_ops,
	179	work_ctx);
	180	if (!work_ctx->domain)
	181	goto err_free_bitmap;
06459901	182
337cbeb2	183	work_ctx->irq_count = num_irqs;
21673fcb	184	work_ctx->work = IRQ_WORK_INIT_HARD(irq_sim_handle_irq);
b19af510	185
337cbeb2	186	return work_ctx->domain;
b19af510	187
337cbeb2 BG	188	err_free_bitmap:
	189	bitmap_free(work_ctx->pending);
	190	err_free_work_ctx:
	191	kfree(work_ctx);
	192	err_out:
	193	return ERR_PTR(-ENOMEM);
b19af510	194	}
337cbeb2	195	EXPORT_SYMBOL_GPL(irq_domain_create_sim);
b19af510 BG	196
b19af510 BG	197	/**
337cbeb2 BG	198	* irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free
337cbeb2 BG	199	* the interrupt descriptors and allocated memory.
b19af510	200	*
337cbeb2	201	* @domain: The interrupt simulator domain to tear down.
b19af510	202	*/
337cbeb2	203	void irq_domain_remove_sim(struct irq_domain *domain)
b19af510	204	{
337cbeb2 BG	205	struct irq_sim_work_ctx *work_ctx = domain->host_data;
	206
	207	irq_work_sync(&work_ctx->work);
	208	bitmap_free(work_ctx->pending);
	209	kfree(work_ctx);
	210
	211	irq_domain_remove(domain);
b19af510	212	}
337cbeb2	213	EXPORT_SYMBOL_GPL(irq_domain_remove_sim);
b19af510	214
883ccef3	215	static void devm_irq_domain_remove_sim(void *data)
44e72c7e	216	{
883ccef3	217	struct irq_domain *domain = data;
44e72c7e	218
883ccef3	219	irq_domain_remove_sim(domain);
44e72c7e BG	220	}
	221
	222	/**
337cbeb2 BG	223	* devm_irq_domain_create_sim - Create a new interrupt simulator for
337cbeb2 BG	224	* a managed device.
44e72c7e BG	225	*
44e72c7e BG	226	* @dev: Device to initialize the simulator object for.
ef4cb70a	227	* @fwnode: struct fwnode_handle to be associated with this domain.
44e72c7e BG	228	* @num_irqs: Number of interrupts to allocate
44e72c7e BG	229	*
337cbeb2 BG	230	* On success: return a new irq_domain object.
337cbeb2 BG	231	* On failure: a negative errno wrapped with ERR_PTR().
44e72c7e	232	*/
337cbeb2 BG	233	struct irq_domain devm_irq_domain_create_sim(struct device dev,
	234	struct fwnode_handle *fwnode,
	235	unsigned int num_irqs)
44e72c7e	236	{
883ccef3 BG	237	struct irq_domain *domain;
883ccef3 BG	238	int ret;
44e72c7e	239
883ccef3 BG	240	domain = irq_domain_create_sim(fwnode, num_irqs);
	241	if (IS_ERR(domain))
	242	return domain;
44e72c7e	243
883ccef3 BG	244	ret = devm_add_action_or_reset(dev, devm_irq_domain_remove_sim, domain);
	245	if (ret)
	246	return ERR_PTR(ret);
44e72c7e	247
883ccef3	248	return domain;
b19af510	249	}
337cbeb2	250	EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);