// SPDX-License-Identifier: BSD-2-Clause
/*
 * Copyright (c) 2016-2019, Linaro Limited
 */

#include <kernel/dt.h>
#include <kernel/interrupt.h>
#include <kernel/panic.h>
#include <libfdt.h>
#include <mm/core_memprot.h>
#include <stdlib.h>
#include <trace.h>
#include <assert.h>

/*
 * NOTE!
 *
 * We're assuming that there's no concurrent use of this interface, except
 * delivery of interrupts in parallel. Synchronization will be needed when
 * we begin to modify settings after boot initialization.
 */

static struct itr_chip *itr_main_chip __nex_bss;

TEE_Result itr_chip_init(struct itr_chip *chip)
{
	if (!itr_chip_is_valid(chip))
		return TEE_ERROR_BAD_PARAMETERS;

	SLIST_INIT(&chip->handlers);

	return TEE_SUCCESS;
}

void interrupt_main_init(struct itr_chip *chip)
{
	if (itr_chip_init(chip))
		panic();

	itr_main_chip = chip;
}

struct itr_chip *interrupt_get_main_chip(void)
{
	assert(itr_main_chip);
	return itr_main_chip;
}

#ifdef CFG_DT
int dt_get_irq_type_prio(const void *fdt, int node, uint32_t *type,
			 uint32_t *prio)
{
	const uint32_t *prop = NULL;
	int count = 0;
	int it_num = DT_INFO_INVALID_INTERRUPT;

	if (!itr_main_chip || !itr_main_chip->dt_get_irq)
		return it_num;

	prop = fdt_getprop(fdt, node, "interrupts", &count);
	if (!prop)
		return it_num;

	return itr_main_chip->dt_get_irq(prop, count, type, prio);
}
#endif

void itr_handle(size_t it)
{
	interrupt_call_handlers(itr_main_chip, it);
}

struct itr_handler *itr_alloc_add_type_prio(size_t it, itr_handler_t handler,
					    uint32_t flags, void *data,
					    uint32_t type, uint32_t prio)
{
	struct itr_handler *hdl = calloc(1, sizeof(*hdl));

	if (hdl) {
		hdl->it = it;
		hdl->handler = handler;
		hdl->flags = flags;
		hdl->data = data;
		itr_add_type_prio(hdl, type, prio);
	}

	return hdl;
}

void itr_free(struct itr_handler *hdl)
{
	if (!hdl)
		return;

	itr_main_chip->ops->disable(itr_main_chip, hdl->it);

	SLIST_REMOVE(&itr_main_chip->handlers, hdl, itr_handler, link);
	free(hdl);
}

void itr_add_type_prio(struct itr_handler *h, uint32_t type, uint32_t prio)
{
	struct itr_handler __maybe_unused *hdl = NULL;

	SLIST_FOREACH(hdl, &itr_main_chip->handlers, link)
		if (hdl->it == h->it)
			assert((hdl->flags & ITRF_SHARED) &&
			       (h->flags & ITRF_SHARED));

	itr_main_chip->ops->add(itr_main_chip, h->it, type, prio);
	SLIST_INSERT_HEAD(&itr_main_chip->handlers, h, link);
}

void itr_enable(size_t it)
{
	itr_main_chip->ops->enable(itr_main_chip, it);
}

void itr_disable(size_t it)
{
	itr_main_chip->ops->disable(itr_main_chip, it);
}

void itr_raise_pi(size_t it)
{
	itr_main_chip->ops->raise_pi(itr_main_chip, it);
}

void itr_raise_sgi(size_t it, uint8_t cpu_mask)
{
	itr_main_chip->ops->raise_sgi(itr_main_chip, it, cpu_mask);
}

void itr_set_affinity(size_t it, uint8_t cpu_mask)
{
	itr_main_chip->ops->set_affinity(itr_main_chip, it, cpu_mask);
}

/* This function is supposed to be overridden in platform specific code */
void __weak __noreturn interrupt_main_handler(void)
{
	panic("Secure interrupt handler not defined");
}

/*
 * Interrupt controller chip support
 */
void interrupt_call_handlers(struct itr_chip *chip, size_t itr_num)
{
	struct itr_handler *h = NULL;
	bool was_handled = false;

	assert(chip);

	SLIST_FOREACH(h, &chip->handlers, link) {
		if (h->it == itr_num) {
			if (h->handler(h) == ITRR_HANDLED)
				was_handled = true;
			else if (!(h->flags & ITRF_SHARED))
				break;
		}
	}

	if (!was_handled) {
		EMSG("Mask unhandled interrupt %s:%zu", chip->name, itr_num);
		interrupt_mask(chip, itr_num);
	}
}

TEE_Result interrupt_configure(struct itr_chip *chip, size_t itr_num,
			       uint32_t type, uint32_t prio)
{
	chip->ops->add(chip, itr_num, type, prio);

	return TEE_SUCCESS;
}

TEE_Result interrupt_add_configure_handler(struct itr_handler *hdl,
					   uint32_t type, uint32_t prio)
{
	struct itr_handler *h = NULL;

	assert(hdl && hdl->chip->ops && is_unpaged(hdl) &&
	       hdl->handler && is_unpaged(hdl->handler));

	SLIST_FOREACH(h, &hdl->chip->handlers, link) {
		if (h->it == hdl->it &&
		    (!(hdl->flags & ITRF_SHARED) ||
		     !(h->flags & ITRF_SHARED))) {
			EMSG("Shared and non-shared flags on interrupt %s#%zu",
			     hdl->chip->name, hdl->it);
			return TEE_ERROR_GENERIC;
		}
	}

	interrupt_configure(hdl->chip, hdl->it, type, prio);

	SLIST_INSERT_HEAD(&hdl->chip->handlers, hdl, link);

	return TEE_SUCCESS;
}

void interrupt_remove_handler(struct itr_handler *hdl)
{
	struct itr_handler *h = NULL;
	bool disable_itr = true;

	if (!hdl)
		return;

	SLIST_FOREACH(h, &hdl->chip->handlers, link)
		if (h == hdl)
			break;
	if (!h) {
		DMSG("Invalid %s:%zu", hdl->chip->name, hdl->it);
		assert(false);
		return;
	}

	if (hdl->flags & ITRF_SHARED) {
		SLIST_FOREACH(h, &hdl->chip->handlers, link) {
			if (h != hdl && h->it == hdl->it) {
				disable_itr = false;
				break;
			}
		}
	}

	if (disable_itr)
		interrupt_disable(hdl->chip, hdl->it);

	SLIST_REMOVE(&hdl->chip->handlers, hdl, itr_handler, link);
}

TEE_Result interrupt_alloc_add_handler(struct itr_chip *chip, size_t itr_num,
				       itr_handler_t handler, uint32_t flags,
				       void *data, struct itr_handler **out_hdl)
{
	TEE_Result res = TEE_ERROR_GENERIC;
	struct itr_handler *hdl = NULL;

	hdl = calloc(1, sizeof(*hdl));
	if (!hdl)
		return TEE_ERROR_OUT_OF_MEMORY;

	*hdl = ITR_HANDLER(chip, itr_num, flags, handler, data);

	res = interrupt_add_handler(hdl);
	if (res) {
		free(hdl);
		return res;
	}

	if (out_hdl)
		*out_hdl = hdl;

	return TEE_SUCCESS;
}

void interrupt_remove_free_handler(struct itr_handler *hdl)
{
	if (hdl) {
		interrupt_remove_handler(hdl);
		free(hdl);
	}
}